Sustaining conservation values in selectively logged tropical forests: the attained and the attainable (original) (raw)
Carbon pools recover more quickly than plant biodiversity in tropical secondary forests
Proceedings of the Royal Society B: Biological Sciences, 2013
Carbon pools recover more quickly than plant biodiversity in Supplementary data tml Although increasing efforts are being made to restore tropical forests, little information is available regarding the time scales required for carbon and plant biodiversity to recover to the values associated with undisturbed forests. To address this knowledge gap, we carried out a meta-analysis comparing data from more than 600 secondary tropical forest sites with nearby undisturbed reference forests. Above-ground biomass approached equivalence to reference values within 80 years since last disturbance, whereas below-ground biomass took longer to recover. Soil carbon content showed little relationship with time since disturbance. Tree species richness recovered after about 50 years. By contrast, epiphyte richness did not reach equivalence to undisturbed forests. The proportion of undisturbed forest trees and epiphyte species found in secondary forests was low and changed little over time. Our results indicate that carbon pools and biodiversity show different recovery rates under passive, secondary succession and that colonization by undisturbed forest plant species is slow. Initiatives such as the Convention on Biological Diversity and REDDþ should therefore encourage active management to help to achieve their aims of restoring both carbon and biodiversity in tropical forests.
Two-Stage Recovery of Amphibian Assemblages Following Selective Logging of Tropical Forests
Conservation Biology, 2013
There is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating effects of logging on faunal communities. We conducted a large-scale replicated field study in 3 selectively logged moist semideciduous forests in West Africa at varying times after timber extraction to assess post logging effects on amphibian assemblages. Specifically, we assessed whether the diversity, abundance, and assemblage composition of amphibians changed over time for forest-dependent species and those tolerant of forest disturbance. In 2009, we sampled amphibians in 3 forests (total of 48 study plots, each 2 ha) in southwestern Ghana. In each forest, we established plots in undisturbed forest, recently logged forest, and forest logged 10 and 20 years previously. Logging intensity was constant across sites with 3 trees/ha removed. Recently logged forests supported substantially more species than unlogged forests. This was due to an influx of disturbance-tolerant species after logging. Simultaneously Simpson's index decreased, with increased in dominance of a few species. As time since logging increased richness of disturbance-tolerant species decreased until 10 years after logging when their composition was indistinguishable from unlogged forests. Simpson's index increased with time since logging and was indistinguishable from unlogged forest 20 years after logging. Forest specialists decreased after logging and recovered slowly. However, after 20 years amphibian assemblages had returned to a state indistinguishable from that of undisturbed forest in both abundance and composition. These results demonstrate that even with low-intensity logging (≤3 trees/ha) a minimum 20-year rotation of logging is required for effective conservation of amphibian assemblages in moist semideciduous forests. Furthermore, remnant patches of intact forests retained in the landscape and the presence of permanent brooks may aid in the effective recovery of amphibian assemblages.
PLoS ONE, 2012
The geographic distribution of Bornean orang-utans and its overlap with existing land-use categories (protected areas, logging and plantation concessions) is a necessary foundation to prioritize conservation planning. Based on an extensive orang-utan survey dataset and a number of environmental variables, we modelled an orang-utan distribution map. The modelled orang-utan distribution map covers 155,106 km 2 (21% of Borneo's landmass) and reveals four distinct distribution areas. The most important environmental predictors are annual rainfall and land cover. The overlap of the orang-utan distribution with land-use categories reveals that only 22% of the distribution lies in protected areas, but that 29% lies in natural forest concessions. A further 19% and 6% occurs in largely undeveloped oil palm and tree plantation concessions, respectively. The remaining 24% of the orang-utan distribution range occurs outside of protected areas and outside of concessions. An estimated 49% of the orang-utan distribution will be lost if all forest outside of protected areas and logging concessions is lost. To avoid this potential decline plantation development in orang-utan habitats must be halted because it infringes on national laws of species protection. Further growth of the plantation sector should be achieved through increasing yields in existing plantations and expansion of new plantations into areas that have already been deforested. To reach this goal a large scale island-wide land-use masterplan is needed that clarifies which possible land uses and managements are allowed in the landscape and provides new standardized strategic conservation policies. Such a process should make much better use of non-market values of ecosystem services of forests such as water provision, flood control, carbon sequestration, and sources of livelihood for rural communities. Presently land use planning is more driven by vested interests and direct and immediate economic gains, rather than by approaches that take into consideration social equity and environmental sustainability.
Acting Optimally for Biodiversity in a World Obsessed with REDD+
Conservation Letters
REDD+ presents novel options for conservation in the tropics, yet it is unclear how biodiversity-focused organizations or actors should react to these carbon-focused opportunities. Here, we critically assess for the first time the expected outcomes of five contrasting scenarios of engagement between a biodiversity actor and REDD+. We discover that in the Berau regency, Indonesia, it is usually beneficial for a biodiversity actor to react in some way to REDD+, but the preferred reaction depends on whether a REDD+ project is already developing in the region, and the scale and type of conservation objectives. In general, from a strict biodiversity perspective, the most cost efficient reaction to the presence of REDD+ is to use biodiversity funds to protect areas neglected by REDD+. Our results demonstrate that if biodiversity actors fail to adapt the way they pursue conservation in the tropics, REDD+ opportunities could go largely untapped.
Conservation Letters
This article describes the first application of systematic conservation planning for prioritizing REDD+ (reducing emissions from deforestation and forest degradation) strategies and agricultural expansion. For a REDD+ program in Indonesian Borneo, we find that the most cost-effective way to reduce forest-based emissions by 25% is to better manage protected areas and logging concessions. A more ambitious emissions reduction target would require constraining agricultural expansion and logging, which incurs opportunity costs. We discover, however, that these impacts can be mitigated by relocating oil palm (Elaeis guineensis) agricultural leases to areas that store, on average, 130 tons less carbon per hectare and are 8% more productive for oil palm. This reduces the costs of meeting REDD+ targets, avoids conflict with agriculture, and has the unanticipated effect of minimizing impacts on logging. Our approach presents a transparent and defensible method for prioritizing REDD+ locations...
Applied Vegetation Science, 2014
ABSTRACT While attention on logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arises from studies carried out in undisturbed tropical forests. This bias is problematic given that logged and disturbed tropical forests are now covering a larger area than the so-called primary forests. A new network of permanent sample plots in logged forests, the Tropical managed Forests Observatory (TmFO), aims to fill this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales. TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 490 permanent plots and 921 ha of forest inventories.
Global change biology, 2015
Tropical forests harbor a significant portion of global biodiversity and are a critical component of the climate system. Reducing deforestation and forest degradation contributes to global climate-change mitigation efforts, yet emissions and removals from forest dynamics are still poorly quantified. We reviewed the main challenges to estimate changes in carbon stocks and biodiversity due to degradation and recovery of tropical forests, focusing on three main areas: (1) the combination of field surveys and remote sensing; (2) evaluation of biodiversity and carbon values under a unified strategy; and (3) research efforts needed to understand and quantify forest degradation and recovery. The improvement of models and estimates of changes of forest carbon can foster process-oriented monitoring of forest dynamics, including different variables and using spatially explicit algorithms that account for regional and local differences, such as variation in climate, soil, nutrient content, top...
Reconciling Forest Conservation and Logging in Indonesian Borneo
PLoS ONE, 2013
Combining protected areas with natural forest timber concessions may sustain larger forest landscapes than is possible via protected areas alone. However, the role of timber concessions in maintaining natural forest remains poorly characterized. An estimated 57% (303,525 km 2 ) of Kalimantan's land area (532,100 km 2 ) was covered by natural forest in 2000. About 14,212 km 2 (4.7%) had been cleared by 2010. Forests in oil palm concessions had been reduced by 5,600 km 2 (14.1%), while the figures for timber concessions are 1,336 km 2 (1.5%), and for protected forests are 1,122 km 2 (1.2%). These deforestation rates explain little about the relative performance of the different land use categories under equivalent conversion risks due to the confounding effects of location. An estimated 25% of lands allocated for timber harvesting in 2000 had their status changed to industrial plantation concessions in 2010. Based on a sample of 3,391 forest plots (161 km; 100 ha), and matching statistical analyses, 2000-2010 deforestation was on average 17.6 ha lower (95% C.I.: 222.3 ha-212.9 ha) in timber concession plots than in oil palm concession plots. When location effects were accounted for, deforestation rates in timber concessions and protected areas were not significantly different (Mean difference: 0.35 ha; 95% C.I.: 20.002 ha-0.7 ha). Natural forest timber concessions in Kalimantan had similar ability as protected areas to maintain forest cover during 2000-2010, provided the former were not reclassified to industrial plantation concessions. Our study indicates the desirability of the Government of Indonesia designating its natural forest timber concessions as protected areas under the IUCN Protected Area Category VI to protect them from reclassification.
Harvest Regulation for Multi-Resource Management, Old and New Approaches (Old and New)
Forests, 2015
Current Mexican forest management is the product of a history that dates back to 1926. Earlier approaches were directly or indirectly aimed at attaining the normal forest model. Around 1980, multi-resource and environmental impact considerations were mandated for all private timber operations. Timber-oriented silviculture was deemed insufficient to take proper care of non-timber values in the forest. Concerns about water quality, biodiversity, and natural conservation were the motives for promoting voluntary best
Land, 2014
Various international bodies and non-governmental organizations (NGOs) have proposed guidelines for safeguarding biodiversity. Nevertheless, quantitative criteria for safeguarding biodiversity should first be established to measure the attainment of biodiversity conservation if biodiversity is to be safeguarded effectively. We conducted research on the impact of logging on biodiversity of dung beetles and small mammals in a production forest in Temengor Forest Reserve, Perak, Malaysia. This was done to develop such quantitative criteria for Malaysian production forests while paying special attention to the effects of road networks, such as skid trails, logging roads, and log yards, on biodiversity. Species assemblages of dung beetles as well as small mammals along and adjacent to road networks were significantly different from those in forest interiors. Therefore, minimizing the road network density will contribute to retaining biodiversity; this will allow us to use road network density as a quantitative criterion for safeguarding biodiversity in production forests. Additionally, road network density is easily measurable and verifiable by remote sensing, which enables us to check the implementation of the criteria.
Ecological Applications, 2014
Strong global demand for tropical timber and agricultural products has driven large-scale logging and subsequent conversion of tropical forests. Given that the majority of tropical landscapes have been or will likely be logged, the protection of biodiversity within tropical forests thus depends on whether species can persist in these economically exploited lands, and if species cannot persist, whether we can protect enough primary forest from logging and conversion. However, our knowledge of the impact of logging and conversion on biodiversity is limited to a few taxa, often sampled in different locations with complex land-use histories, hampering attempts to plan cost-effective conservation strategies and to draw conclusions across taxa. Spanning a land-use gradient of primary forest, once-and twice-logged forests, and oil palm plantations, we used traditional sampling and DNA metabarcoding to compile an extensive data set in Sabah, Malaysian Borneo for nine vertebrate and invertebrate taxa to quantify the biological impacts of logging and oil palm, develop cost-effective methods of protecting biodiversity, and examine whether there is congruence in response among taxa. Logged forests retained high species richness, including, on average, 70% of species found in primary forest. In contrast, conversion to oil palm dramatically reduces species richness, with significantly fewer primary-forest species than found on logged forest transects for seven taxa. Using a systematic conservation planning analysis, we show that efficient protection of primary-forest species is achieved with land portfolios that include a large proportion of logged-forest plots. Protecting logged forests is thus a cost-effective method of protecting an ecologically and taxonomically diverse range of species, particularly when conservation budgets are limited. Six indicator groups (birds, leaf-litter ants, beetles, aerial hymenopterans, flies, and true bugs) proved to be consistently good predictors of the response of the other taxa to logging and oil palm. Our results confidently establish the high conservation value of logged forests and the low value of oil palm. Cross-taxon congruence in responses to disturbance also suggests that the practice of focusing on key indicator taxa yields important information of general biodiversity in studies of logging and oil palm.
Airborne LiDAR Detects Selectively Logged Tropical Forest Even in an Advanced Stage of Recovery
Remote Sensing, 2015
Identifying historical forest disturbances is difficult, especially in selectively logged areas. LiDAR is able to measure fine-scale variations in forest structure over multiple kilometers. We use LiDAR data from ca. 16 km 2 of forest in Sierra Leone, West Africa, to discriminate areas of old-growth from areas recovering from selective logging for 23 years. We examined canopy height variation and gap size distributions. We found that though recovering blocks of forest differed little in height from old-growth forest (up to 3 m), they had a greater area of canopy gaps (average 10.2% gap fraction in logged areas, compared to 5.6% in unlogged area); and greater numbers of gaps penetrating to the forest floor (162 gaps at 2 m height in logged blocks, and 101 in an unlogged block). Comparison of LiDAR measurements with field data demonstrated that LiDAR delivered accurate results. We found that gap size distributions deviated from power-laws reported previously, with substantially fewer large gaps than predicted by power-law functions. Our
Social and Environmental Impacts of Forest Management Certification in Indonesia
PLOS ONE, 2015
In response to unsustainable timber production in tropical forest concessions, voluntary forest management certification programs such as the Forest Stewardship Council (FSC) have been introduced to improve environmental, social, and economic performance over existing management practices. However, despite the proliferation of forest certification over the past two decades, few studies have evaluated its effectiveness. Using temporally and spatially explicit village-level data on environmental and socio-economic indicators in Kalimantan (Indonesia), we evaluate the performance of the FSC-certified timber concessions compared to non-certified logging concessions. Employing triple difference matching estimators, we find that between 2000 and 2008 FSC reduced aggregate deforestation by 5 percentage points and the incidence of air pollution by 31%. It had no statistically significant impacts on fire incidence or core areas, but increased forest perforation by 4 km 2 on average. In addition, we find that FSC reduced firewood dependence (by 33%), respiratory infections (by 32%) and malnutrition (by 1 person) on average. By conducting a rigorous statistical evaluation of FSC certification in a biodiversity hotspot such as Indonesia, we provide a reference point and offer methodological and data lessons that could aid the design of ongoing and future evaluations of a potentially critical conservation policy.
Environmental Evidence, 2015
Background: Currently, about 400 million hectares of tropical moist forests worldwide are designated production forests, about a quarter of which are managed by rural communities and indigenous peoples. There has been a gradual impoverishment of forest resources inside selectively logged forests in which the volume of timber extracted over the first cutting cycle was mostly from large, old trees that matured over a century or more and grew in the absence of strong anthropological pressures. In forests now being logged for a second and third time, that volume has not been reconstituted due in part to the lack of implementation of post-logging silvicultural treatments. This depletion of timber stocks renders the degraded forests prone to conversion to other land uses. Although it is essential to preserve undisturbed primary forests through the creation of protected areas, these areas alone will not be able to ensure the conservation of all species on a pan-tropical scale, for social, economic and political reasons. The conservation of tropical forests of tomorrow will mostly take place within human-modified (logged, domesticated) forests. In this context, silvicultural interventions are considered by many tropical foresters and forest ecologists as tools capable of effectively conserving tropical forest biodiversity and ecosystem services while stimulating forest production. This systematic review aims to assess past and current evidence of the impact of silviculture on tropical forests and to identify silvicultural practices appropriate for the current conditions in the forests and forestry sectors of the Congo Basin, Amazonia and Southeast Asia. Methods: This systematic review will undertake an extensive search of literature to assess the relative effectiveness of different silvicultural interventions on timber production and the conservation value of forests, and to determine whether there is a relationship between sustainability of timber harvesting and the maintenance/conservation of other ecosystem services and biodiversity in production forests. Data will be extracted for meta-analysis of at least sub-sets of the review questions. Findings are expected to help inform policy and develop evidence-based practice guidelines on silvicultural practices in tropical forests.
Biodiversity and Conservation, 2014
Planted forests are increasingly contributing wood products and other ecosystem services at a global scale. These forests will be even more important as carbon markets develop and REDD-plus forest programs (forests used specifically to reduce atmospheric emissions of CO 2 through deforestation and forest degradation) become common. Restoring degraded and deforested areas with long-rotation planted forests can be accomplished in a manner that enhances carbon storage and other key ecosystem services. Knowledge from natural systems and understanding the functioning novel of Communicated by Karen E. Hodges.
Carbon emissions performance of commercial logging in East Kalimantan, Indonesia
Global Change Biology, 2014
Adoption of reduced-impact logging (RIL) methods could reduce CO 2 emissions by 30-50% across at least 20% of remaining tropical forests. We developed two cost effective and robust indices for comparing the climate benefits (reduced CO 2 emissions) due to RIL. The indices correct for variability in the volume of commercial timber among concessions. We determined that a correction for variability in terrain slope was not needed. We found that concessions certified by the Forest Stewardship Council (FSC, N = 3), when compared with noncertified concessions (N = 6), did not have lower overall CO 2 emissions from logging activity (felling, skidding, and hauling). On the other hand, FSC certified concessions did have lower emissions from one type of logging impact (skidding), and we found evidence of a range of improved practices using other field metrics. One explanation of these results may be that FSC criteria and indicators, and associated RIL practices, were not designed to achieve overall emissions reductions. Also, commonly used field metrics are not reliable proxies for overall logging emissions performance. Furthermore, the simple distinction between certified and noncertified concessions does not fully represent the complex history of investments in improved logging practices. To clarify the relationship between RIL and emissions reductions, we propose the more explicit term 'RIL-C' to refer to the subset of RIL practices that can be defined by quantified thresholds and that result in measurable emissions reductions. If tropical forest certification is to be linked with CO 2 emissions reductions, certification standards need to explicitly require RIL-C practices.
Futures of Tropical Forests ( sensu lato )
Biotropica, 2014
When net deforestation declines in the tropics, attention will be drawn to the composition and structure of the retained, restored, invaded, and created forests. At that point, the seemingly inexorable trends toward increased intensities of exploitation and management will be recognized as having taken their tolls of biodiversity and other forest values. Celebrations when a country passes this 'forest transition' will then be tempered by realization that what has been accepted as 'forest' spans the gamut from short-rotation mono-clonal stands of genetically engineered trees to fully protected old growth natural forest. With management intensification, climate change, species introductions, landscape fragmentation, fire, and shifts in economics and governance, forests will vary along gradients of biodiversity, novelty of composition, stature, permanence, and the relative roles of natural and anthropogenic forces. Management intensity will increase with the increased availability of financial capital associated with economic globalization, scarcity of wood and other forest products, demand for biofuels, improved governance (e.g., security of property rights), improved accessibility, and technological innovations that lead to new markets for forest products. In a few places, the trend toward land-use intensification will be counterbalanced by recognition of the many benefits of natural and semi-natural forests, especially where forest-fate determiners are compensated for revenues foregone from not intensifying management. Land-use practices informed by research designed and conducted by embedded scientists will help minimize the tradeoffs between the financial profits from forest management and the benefits of retention of biodiversity and the full range of environmental services.
Avian responses to selective logging shaped by species traits and logging practices
Proceedings. Biological sciences / The Royal Society, 2015
Selective logging is one of the most common forms of forest use in the tropics. Although the effects of selective logging on biodiversity have been widely studied, there is little agreement on the relationship between life-history traits and tolerance to logging. In this study, we assessed how species traits and logging practices combine to determine species responses to selective logging, based on over 4000 observations of the responses of nearly 1000 bird species to selective logging across the tropics. Our analysis shows that species traits, such as feeding group and body mass, and logging practices, such as time since logging and logging intensity, interact to influence a species' response to logging. Frugivores and insectivores were most adversely affected by logging and declined further with increasing logging intensity. Nectarivores and granivores responded positively to selective logging for the first two decades, after which their abundances decrease below pre-logging l...
The exceptional value of intact forest ecosystems
Nature ecology & evolution, 2018
As the terrestrial human footprint continues to expand, the amount of native forest that is free from significant damaging human activities is in precipitous decline. There is emerging evidence that the remaining intact forest supports an exceptional confluence of globally significant environmental values relative to degraded forests, including imperilled biodiversity, carbon sequestration and storage, water provision, indigenous culture and the maintenance of human health. Here we argue that maintaining and, where possible, restoring the integrity of dwindling intact forests is an urgent priority for current global efforts to halt the ongoing biodiversity crisis, slow rapid climate change and achieve sustainability goals. Retaining the integrity of intact forest ecosystems should be a central component of proactive global and national environmental strategies, alongside current efforts aimed at halting deforestation and promoting reforestation.
Opportunity costs of carbon sequestration in a forest concession in central Africa
Carbon Balance and Management, 2014
Background: A large proportion of the tropical rain forests of central Africa undergo periodic selective logging for timber harvesting. The REDD+ mechanism could promote less intensive logging if revenue from the additional carbon stored in the forest compensates financially for the reduced timber yield. Results: Carbon stocks, and timber yields, and their associated values, were predicted at the scale of a forest concession in Gabon over a project scenario of 40 yr with reduced logging intensity. Considering that the timber contribution margin (i.e. the selling price of timber minus its production costs) varies between 10 and US$40 m −3 , the minimum price of carbon that enables carbon revenues to compensate forgone timber benefits ranges between US$4.4 and US$25.9/tCO 2 depending on the management scenario implemented. Conclusions: Where multiple suppliers of emission reductions compete in a REDD+ carbon market, tropical timber companies are likely to change their management practices only if very favourable conditions are met, namely if the timber contribution margin remains low enough and if alternative management practices and associated incentives are appropriately chosen.
Brazil Nut (Bertholletia excelsa, Lecythidaceae) Regeneration in Logging Gaps in the Peruvian Amazon
International Journal of Forestry Research, 2014
Brazil nut (Bertholletia excelsaBonpl.) extraction serves as an important economic resource in the Madre de Dios region of Peru simultaneously promoting forest conservation, yet, under current management, it cannot compete with other land uses. This study investigated the effects of logging gaps on Brazil nut natural regeneration. A total of 48 paired logging gap-understory sites were visited in Brazil nut concessions in the Tambopata province of Madre de Dios, Peru. At each site, the number of Brazil nut recruits was counted and canopy openness and gap area were measured. Significantly higher levels of recruit density were found in logging gaps than in understory sites. Additionally, recruit density was positively correlated with canopy openness. Further, in experimental plantings in paired gap and understory sites, canopy openness, height, total leaf area, and number were recorded from August 2011 to February 2012. Height, total leaf area, and leaf number were significantly higher...
Intact Forest in Selective Logging Landscapes in the Tropics
Frontiers in Forests and Global Change
The selective logging that characterizes most timber extraction operations in the tropics leaves large patches of logging blocks (i. e., areas allocated for harvesting) intact, with no direct impacts of the harvest. For example, in the ∼10,000 ha we sampled in 48 forest management enterprises in Africa (Gabon, Republic of Congo, and the Democratic Republic of Congo), Indonesia, Suriname, and Mexico, an average of 57% (range 22-97%) of the area in logging blocks was not directly affected by timber harvests. The proportion of intact forest within logging blocks decreased very slightly with increases in harvest intensity in the accessed portion of the logging blocks (9-86 m 3 ha -1 ) but decreased strongly with harvest intensity in entire logging blocks (0.3-48.2 m 3 ha -1 ). More forest was left intact in areas farther from roads, on slopes >40%, and within 25 m of perennial streams, but the effect sizes of each of these variables was small (∼8%). It is less clear how much of the intact forest left after one harvest will remain intact through the next. Conservation benefits without reductions in timber yields will derive from better management planning so that sensitive and ecologically critical areas, such as steep slopes and riparian buffers, constitute permanent reserves of intact forest in selectively logged landscapes in the tropics.
Diversity
This article addresses a case study on the application of criteria for harvesting, aiming at restoration and profitability in a degraded tropical forest in the Amazon. The objective is to provide technical and economic information to promote a truly sustainable silvicultural management system in forests with this profile and turn them into a desirable financial asset for conservation and social development. In the forest census, 85.907 trees ha−1 (100.8566 m3 ha−1) were inventoried with diameter at breast height (dbh) ≥ 25 cm, belonging to 106 commercial species. When applying the harvest criteria, 19.923 trees ha−1 (29.99 m3 ha−1), referring to 53 species, were destined for harvest. Some trees were selected by more than one criterion, totalizing 17.985 trees ha−1 by density, 1.831 trees ha−1 by compromised health, 0.212 trees ha−1 by maximum dbh, 18.933 trees ha−1 by minimum dbh, 1.385 trees ha−1 by tree stem (quality 3), and 0.080 trees ha−1 by species conservation. In all scenari...
Dynamics of Tree Species Diversity in Unlogged and Selectively Logged Malaysian Forests
Scientific reports, 2018
Selective logging that is commonly conducted in tropical forests may change tree species diversity. In rarely disturbed tropical forests, locally rare species exhibit higher survival rates. If this non-random process occurs in a logged forest, the forest will rapidly recover its tree species diversity. Here we determined whether a forest in the Pasoh Forest Reserve, Malaysia, which was selectively logged 40 years ago, recovered its original species diversity (species richness and composition). To explore this, we compared the dynamics of secies diversity between unlogged forest plot (18.6 ha) and logged forest plot (5.4 ha). We found that 40 years are not sufficient to recover species diversity after logging. Unlike unlogged forests, tree deaths and recruitments did not contribute to increased diversity in the selectively logged forests. Our results predict that selectively logged forests require a longer time at least than our observing period (40 years) to regain their diversity.
IOP Conference Series: Earth and Environmental Science
Sikundur forest area is located at Gunung Leuser National Park (GLNP), in Aras Napal, Langkat, North Sumatra Province, representing mixture forest of lowland Dipterocarpaceae. Two 0.5 ha permanent plots of 50 x 100 m were established at twenty-two years old logged-over Sikundur Forest and located subjectively according to topography and river bank. This dryland forest was logged for the first cycle in 1978 by forest concession right. This study aimed to identify the species composition and to determine the diversity index of plants after 22 years logged over area. The results showed that significant tribes were Dipterocarpaceae, Euphorbiaceae, and Myrtaceae which are the richest family in two permanent plots. The horizontal structure of forest indicated that the diversity index of Dipterocarpaceae in two plots tended to be centered, showing the high value of diversity index of Dipterocarpaceae family. The present study suggested the periodic activities on natural regeneration, and the measurement of the dynamics stock plant are highly recommended.
The Effect of Logging and Strip Cutting on Forest Floor Light Condition and Following Change
Forests, 2017
We monitored changes in light conditions at a primary forest and two managed forest sites (one with line planting) after reduced-impact logging in Central Kalimantan, Indonesia. We also assessed the effect of the light conditions on seedlings in the planting lines. Hemispherical photographs were taken over a period of 31 months in three 50 × 50-m quadrats at each site and in three 100-m transects along the planting lines. The location of each photo was categorized according to the corresponding type of disturbance, including skid trails, logging gaps, and planting lines. Following logging, the level of canopy openness (CO) increased at both managed forest sites and did not differ significantly between the two. However, CO was greater in skid trails and logging gaps than in planting lines. After 31 months, the mean level of CO at each managed site had decreased significantly due to the establishment of new seedlings. Correlations between changes in CO and the growth of planted seedlings suggested that growth was inhibited by the invasion of the new species. However, the level of CO along the planting lines was greater than that at other disturbed locations. A high level of CO promoted invasion by new species that colonized the space. Line planting may influence forest dynamics and maintain a high level of CO.
The effects of restoring logged tropical forests on avian phylogenetic and functional diversity
Ecological Applications
Selective logging is the most prevalent land-use change in the tropics. Despite the resulting degradation of forest structure, selectively logged forests still harbour a substantial amount of biodiversity leading to suggestions that their protection is the next best alternative to conserving primary, old-growth forests. Restoring carbon stocks under Reducing Emissions from Deforestation and Forest Degradation (REDD+) schemes is a potential method for obtaining funding to protect logged forests, via enrichment planting and liberation cutting of vines. This study investigates the impacts of restoring logged forests in Borneo on avian phylogenetic diversity-the total evolutionary history shared across all species within a community-and on functional diversity, with important implications for the protection of Accepted Article This article is protected by copyright. All rights reserved. evolutionarily unique species and the provision of many ecosystem services. Overall and understorey avifaunal communities were studied using point count and mist-netting surveys, respectively. Restoration caused a significant loss in phylogenetic diversity and MPD (mean pairwise distance) leaving an overall bird community of less total evolutionary history and more closely related species compared to unlogged forests, while the understorey bird community had MNTD (mean nearest taxon distance) that returned towards the lower levels found in a primary forest, indicating more closely related species pairs. The overall bird community experienced a significant loss of functional strategies and species with more specialized traits in restored forests compared to that of unlogged forests, which led to functional clustering in the community. Restoration also led to a reduction in functional richness and thus niches occupied in the understorey bird community compared to unlogged forests. While there are additional benefits of restoration for forest regeneration, carbon sequestration, future timber harvests, and potentially reduced threat of forest conversion, this must be weighed against the apparent loss of phylogenetic and functional diversity from unlogged forest levels, making the biodiversity-friendliness of carbon sequestration schemes questionable under future REDD+ agreements. To reduce perverse biodiversity outcomes, it is important to focus restoration only on the most degraded areas or at reduced intensity where breaks between regimes are incorporated.
The impacts of tropical forest disturbance on species vital rates
Conservation biology : the journal of the Society for Conservation Biology, 2018
Tropical forests are experiencing enormous threats from deforestation and habitat degradation. Much of our knowledge on the impacts of these land-use changes on tropical species comes from studies examining patterns of richness and abundance. Demographic vital rates (survival, reproduction and movement) can also be impacted by land-use change in a way that increases species vulnerability to local extinction, but in many cases these impacts may not be manifested in short-term changes in abundance or species richness. We assessed current knowledge and research effort concerning how land-use change affects species vital rates in tropical forest vertebrates. We find a general paucity of empirical research on demography across taxa and regions, with some biases towards mammals and birds, and land-use transitions including fragmentation and agriculture. There is also considerable between-species variation in demographic responses to land-use change, which could reflect trait-based differe...
Exotic eucalypts: from demonized trees to allies of tropical forest restoration?
Journal of Applied Ecology
The income obtained from eucalypt wood production offset 44-75% of restoration implementation costs. 6. Synthesis and applications. Many of the negative effects attributed to eucalypts on the growth and natural regeneration of native trees depend on features of the production system, landscape structure, soil, and climate in which they are grown, rather than the effects of eucalypts per se. In Brazil's Atlantic Forest region, exotic eucalypts can become important allies of tropical forest restoration, and their use and investment opportunities should be considered within the portfolio of options supported by public and private funding and policies.
How persistent are the impacts of logging roads on Central African forest vegetation?
Journal of Applied Ecology, 2016
1. Logging roads can trigger tropical forest degradation by reducing the integrity of the ecosystem and providing access for encroachment. Therefore, road management is crucial in reconciling selective logging and biodiversity conservation. Most logging roads are abandoned after timber harvesting; however, little is known about their long-term impacts on forest vegetation and accessibility, especially in Central Africa. 2. In 11 logging concessions in the Congo Basin we field-sampled a chronosequence of roads that, judging from satellite images, had been abandoned between 1985 and 2015. We assessed recovery of timber resources, tree diversity and above-ground biomass in three zones: the road track, the road edge (where forest had been cleared during road construction) and the adjacent logged forest. 3. The density of commercial timber species < 15 cm DBH was almost three times higher in the road track (321 individuals ha-1) and edge (267) than in the logged adjacent forest (97). Over time, tree species diversity converged to a comparable level between roads and adjacent forests, along with an increase in canopy closure. 4. The average width of forest clearing for road construction was 20 m, covering a total 0.76% of the forest area inside concessions. After 15 years following abandonment, road tracks had recovered
Sustainability
The balance between the supply of multiple ecosystem services (ES) and the fulfillment of society demands is a challenge, especially in the tropics where different land use transition phases emerge. These phases are characterized by either a decline (from intact old-growth to logged forests) or a recovery of ES (successional forests, plantations, and agroforestry systems). This highlights the importance of ecosystem service multifunctionality (M) assessments across these land use transition phases as a basis for forest management and conservation. We analyzed synergies and trade-offs of ES to identify potential umbrella ES. We also evaluated the impact of logging activities in the decline of ES and M, and the influence of three recovery phases in the supply of ES and M. We installed 156 inventory plots (1600 m2) in the Ecuadorian Central Amazon and the Chocó. We estimated indicators for provisioning, regulating, supporting services and biodiversity. M indicator was estimated using t...
Diversity
Background: The impact of selective thinning on forest diversity has been extensively studied in temperate and boreal regions. However, in the tropics, knowledge is still poor regarding the impacts of this silvicultural treatment on functional diversity, especially in tropical mountain forests, which are considered to be highly biodiverse ecosystems and also endangered by human activities. By evaluating the changes on functional diversity by using different indicators, hypothesizing that selective thinning significantly affects (directly or indirectly) tropical mountain forests, this work promotes sustainable ecosystem use. Methods: A total of 52 permanent plots of 2500 m2 each were installed in a primary mountain forest in the San Francisco Biological Reserve to assess the impact of this silvicultural treatment. Selective thinning can be defined as a controlled process, in which trees that compete with ecologically and/or valuable timber species are progressively removed to stimula...
Tropical forest recovery from logging: a 24 year silvicultural experiment from Central Africa
Philosophical Transactions of the Royal Society B: Biological Sciences, 2013
Large areas of African moist forests are being logged in the context of supposedly sustainable management plans. It remains however controversial whether harvesting a few trees per hectare can be maintained in the long term while preserving other forest services as well. We used a unique 24 year silvicultural experiment, encompassing 10 4 ha plots established in the Central African Republic, to assess the effect of disturbance linked to logging (two to nine trees ha −1 greater than or equal to 80 cm DBH) and thinning (11–41 trees ha −1 greater than or equal to 50 cm DBH) on the structure and dynamics of the forest. Before silvicultural treatments, above-ground biomass (AGB) and timber stock (i.e. the volume of commercial trees greater than or equal to 80 cm DBH) in the plots amounted 374.5 ± 58.2 Mg ha −1 and 79.7 ± 45.9 m 3 ha −1 , respectively. We found that (i) natural control forest was increasing in AGB (2.58 ± 1.73 Mg dry mass ha −1 yr −1 ) and decreasing in timber stock (−0.3...
International Journal of Biodiversity Science, Ecosystem Services & Management, 2016
To test a pragmatic enrichment technique of degraded forests with high-value species Secondary objectives: 1. To compare species behavior in the early stage of plantation (<5yrs) in order to identify the best candidate species (growth/survival) 2. To search for relationships between traits and performance of the species 3. To estimate the cost of mixed-species plantations Objectives Objectives Methods Results Discussion How can managing for high value timbers promote biodiversity, and how can managing for biodiversity promote high value timbers? Methods Study site Context Objectives Methods Results Discussion How can managing for high value timbers promote biodiversity, and how can managing for biodiversity promote high value timbers? Enrichment technique Context Objectives Methods Results Discussion How can managing for high value timbers promote biodiversity, and how can managing for biodiversity promote high value timbers? Enrichment technique Context Objectives Methods Results Discussion How can managing for high value timbers promote biodiversity, and how can managing for biodiversity promote high value timbers? Enrichment technique Context Objectives Methods Results Discussion How can managing for high value timbers promote biodiversity, and how can managing for biodiversity promote high value timbers? Studied species Context Objectives Methods Results Discussion • High-value species : IUCN red list, e.g. CR Mukulungu Autranella congolensis How can managing for high value timbers promote biodiversity, and how can managing for biodiversity promote high value timbers? Studied species Context Objectives Methods Results Discussion • High-value species : CITES appendix, e.g. Assamela (kokrodua) Pericopsis elata How can managing for high value timbers promote biodiversity, and how can managing for biodiversity promote high value timbers? Studied species Context Objectives Methods Results Discussion • High-value species : NTFP, e.g. Moabi Baillonella toxisperma How can managing for high value timbers promote biodiversity, and how can managing for biodiversity promote high value timbers? Permanent plot design Context Objectives Methods Results Discussion
SDG 15: Life on Land – The Central Role of Forests in Sustainable Development
Sustainable Development Goals: Their Impacts on Forests and People, 2019
There will be trade-offs between SDG 15 and other SDGs resulting from competition for land, but there are also synergies and opportunities. • The principal opportunity of SDG 15 is that it will be recognised and integrated, along with the other SDGs, in all developments. • The main risk is that short-term priorities and a 'business as usual' approach will undermine this opportunity for integration and synergy and SDG 15 will often be overlooked. • The scale, and complexity, of challenges for conserving life on land, versus the limited resources available, pose many challenges. • Greater cross-sectoral integration, not just sectoral policy reform, is essential to advancing SDG 15. • We encourage conservation and development professionals to engage with those responsible for all the Agenda 2030 targets to ensure that SDG 15 is a priority in all SDG related processes.
A methodological framework to assess the carbon balance of tropical managed forests
Carbon Balance and Management, 2016
Background: Managed forests are a major component of tropical landscapes. Production forests as designated by national forest services cover up to 400 million ha, i.e. half of the forested area in the humid tropics. Forest management thus plays a major role in the global carbon budget, but with a lack of unified method to estimate carbon fluxes from tropical managed forests. In this study we propose a new time-and spatially-explicit methodology to estimate the above-ground carbon budget of selective logging at regional scale. Results: The yearly balance of a logging unit, i.e. the elementary management unit of a forest estate, is modelled by aggregating three sub-models encompassing (i) emissions from extracted wood, (ii) emissions from logging damage and deforested areas and (iii) carbon storage from post-logging recovery. Models are parametrised and uncertainties are propagated through a MCMC algorithm. As a case study, we used 38 years of National Forest Inventories in French Guiana, northeastern Amazonia, to estimate the above-ground carbon balance (i.e. the net carbon exchange with the atmosphere) of selectively logged forests. Over this period, the net carbon balance of selective logging in the French Guianan Permanent Forest Estate is estimated to be comprised between 0.12 and 1.33 Tg C, with a median value of 0.64 Tg C. Uncertainties over the model could be diminished by improving the accuracy of both logging damage and large woody necromass decay submodels. Conclusions: We propose an innovating carbon accounting framework relying upon basic logging statistics. This flexible tool allows carbon budget of tropical managed forests to be estimated in a wide range of tropical regions.
Multiple Patterns of Forest Disturbance and Logging Shape Forest Landscapes in Paragominas, Brazil
Forests, 2016
In the Brazilian Amazon, multiple logging activities are undergoing, involving different actors and interests. They shape a disturbance gradient bound to the intensity and frequency of logging, and forest management techniques. However, until now, few studies have been carried out at the landscape scale taking into account these multiple types of logging and this disturbance gradient. Here we address this issue of how to account for the multiple logging activities shaping the current forest landscape. We developed an inexpensive and efficient remote sensing methodology based on Landsat imagery to detect and track logging activity based on the monitoring of canopy openings. Then, we implemented a set of remote sensing indicators to follow the different trajectories of forest disturbance through time. Using these indicators, we emphasized five major spatial and temporal disturbance patterns occurring in the municipality of Paragominas (State of Pará, Brazilian Amazon), from well-managed forests to highly over-logged forests. Our disturbance indicators provide observable evidence for the difference between legal and illegal patterns, with some illegal areas having suffered more than three explorations in fifteen years. They also clearly underlined the efficiency of Reduced Impact Logging (RIL) techniques applied under Forest Stewardship Council (FSC) guidelines to reduce the logging impacts in terms of canopy openings. For these reasons, we argue the need to promote legal certified logging to conserve forests, as without them, many actors mine the forest resources without any concerns for future stocks. Finally, our remote tracking methodology, which produces easy to interpret disturbance indicators, could be a real boon to forest managers, including for conservationists working in protected areas and stakeholders dealing with international trade rules such as RBUE (Wood regulation of European Union) or FLEGT (Forest Law for Enforcement, Governance and Trade).
Forests
To illustrate the importance of theories-of-change (ToCs) for evaluation of conservation interventions, we consider the global ToC from the Forest Stewardship Council (FSC) and then develop a more explicit ToC focused on the sustained timber yield (STY) aspiration for natural forest management in Indonesia. We use these ToCs to consider certification implementation processes vis-à-vis indicators for STY extracted from FSC’s Indonesian Stewardship Standard that mentions STY explicitly in 45 and implicitly in 21 of 237 indicators. Analysis of 38 audit reports about 23 enterprises (2001–2017) revealed that only 77 of 504 major non-conformities assigned by auditors addressed STY. This apparent lack of attention to STY is surprising given the exhaustion of timber stocks in many production forests and the closure of many forest enterprises over the past two decades, but our ToC reveals numerous unsatisfied and unsatisfiable assumptions in certification that preclude detection of unsustain...
Journal of Forest Planning
The conservation of selectively logged tropical forests has received increasing attention, especially under the REDD+ scheme of the United Nations Framework Convention on Climate Change. However, knowledge of the structure of large-scale logged forests remains limited, especially in seasonally dry tropical regions, while there have been many studies on intact old-growth closed-canopy tropical forests. In this study, data from 327 plots were used in a large-scale forest inventory with systematic sampling covering 139,360 ha to reveal the condition of selectively logged mixed-deciduous forest managed traditionally under the Myanmar selection system (MSS). The overall averages (±SE) for the trees > 10 cm DBH were 140 ± 4.95 trees/ha for tree density, 6.18 ± 0.26 m 2 /ha for basal area and 66.2 ± 3.17 Mg/ha for aboveground biomass. These values are lower than or close to the lower end of the reported values in undisturbed or even disturbed tropical forests. There were very few harvestable large trees of commercial species. We conclude that there has been widespread large-scale forest degradation in the traditionally logged forest of our study site. The possible reasons for forest degradation include the shorter cutting-cycle than the MSS-standard of 30 years, more illegal logging for timber than legal logging, and local demand for charcoal. Restoration of the degraded forests should be prioritized, together with control of illegal logging.
Understanding the importance of primary tropical forest protection as a mitigation strategy
Mitigation and Adaptation Strategies for Global Change
Given the short time-frame to limit global warming, and the current emissions gap, it is critical to prioritise mitigation actions. To date, scant attention has been paid to the mitigation benefits of primary forest protection. We estimated tropical forest ecosystem carbon stocks and flows. The ecosystem carbon stock of primary tropical forests is estimated at 141–159 Pg C (billion tonnes of carbon) which is some 49–53% of all tropical forest carbon, the living biomass component of which alone is 91–103% of the remaining carbon budget to limit global warming to below 1.5 degrees above pre-industrial levels. Furthermore, tropical forests have ongoing sequestration rates 0.47–1.3 Pg C yr−1, equivalent to 8–13% of annual global anthropogenic CO2 (carbon dioxide) emissions. We examined three main forest-based strategies used in the land sector—halting deforestation, increasing forest restoration and improving the sustainable management of production forests. The mitigation benefits of p...
Degradation and forgone removals increase the carbon impact of intact forest loss by 626%
Science Advances
Intact tropical forests, free from substantial anthropogenic influence, store and sequester large amounts of atmospheric carbon but are currently neglected in international climate policy. We show that between 2000 and 2013, direct clearance of intact tropical forest areas accounted for 3.2% of gross carbon emissions from all deforestation across the pantropics. However, full carbon accounting requires the consideration of forgone carbon sequestration, selective logging, edge effects, and defaunation. When these factors were considered, the net carbon impact resulting from intact tropical forest loss between 2000 and 2013 increased by a factor of 6 (626%), from 0.34 (0.37 to 0.21) to 2.12 (2.85 to 1.00) petagrams of carbon (equivalent to approximately 2 years of global land use change emissions). The climate mitigation value of conserving the 549 million ha of tropical forest that remains intact is therefore significant but will soon dwindle if their rate of loss continues to accele...
Types and rates of forest disturbance in Brazilian Legal Amazon, 2000-2013
Science advances, 2017
Deforestation rates in primary humid tropical forests of the Brazilian Legal Amazon (BLA) have declined significantly since the early 2000s. Brazil's national forest monitoring system provides extensive information for the BLA but lacks independent validation and systematic coverage outside of primary forests. We use a sample-based approach to consistently quantify 2000-2013 tree cover loss in all forest types of the region and characterize the types of forest disturbance. Our results provide unbiased forest loss area estimates, which confirm the reduction of primary forest clearing (deforestation) documented by official maps. By the end of the study period, nonprimary forest clearing, together with primary forest degradation within the BLA, became comparable in area to deforestation, accounting for an estimated 53% of gross tree cover loss area and 26 to 35% of gross aboveground carbon loss. The main type of tree cover loss in all forest types was agroindustrial clearing for pa...
Historical Patterns of Natural Forest Management in Costa Rica: The Good, the Bad and the Ugly
Forests, 2014
We present an in-depth analysis of natural forest management practices in Costa Rica based on a new historical forestry GIS database encompassing five conservation regions in the country where selective logging has been prevalent for the last 18 years. Natural forest management refers to the selective logging practices for the production of timber in natural forest ecosystems. The study considers natural forest management plans developed following a standardized format, based on Forestry Law 7575, established in 1996. Our results show a positive aspect of forest management where a large percentage of the managed forest is still standing, contrary to other tropical countries where selective logging promotes land use change. The negative finding is that managed forest areas occur in the last remaining forest fragments outside of protected areas, which challenges the continuity of selective logging in the near and mid future due to the potential impoverishment of the isolated forest stands. The most negative aspect is the recent establishment, by law, of a very short return logging cycle (10-15 years-minimum cutting cycle) as it contradicts ecological studies showing that tropical forests require over 60 years for the forest structure and composition to return to a state similar to pre-logging states. Our results should inform decision makers and managers in conservation areas to review current policies and establish new benchmarks for sustainable forest management in the country.
Overcoming Key Barriers for Secondary Cloud Forest Management in Mexico
Land
Secondary cloud forests (SCFs), those that regenerate naturally following abandonment of human activities in previously deforested land, are of great value as refuges of high species diversity and for their critical role in hydrological regulation. This opinion paper analyzes the main environmental, socio-economic, and regulatory aspects that currently hamper the sustainable use and conservation of SCFs in Mexico for the provision of timber and ecosystem services. The main constraints identified include contradictory norms and policies and the marginalization of smallholders in timber production activities. Developing economic incentives for forest product harvesting and provision of ecosystem services derived from SCFs, while also addressing legal and normative aspects related to their sustainable use, is paramount. Given the high heterogeneity in floristic composition and stand structure of SCFs among localities, technical and social norms for sustainable use should be sufficientl...
Selection of dipterocarp species for enrichment planting in a secondary tropical rainforest
Forest Science and Technology
The selection of species for enrichment planting that involves native species in a secondary lowland dipterocarps forest as one of the tropical rainforest types should be conducted to maintain the sustainable management of tropical rainforests. The research of species trial of dipterocarp species was planted under a randomized complete block design with four replications. The following parameters were examined: survival rate, diameter breast height (DBH), pilodyn penetration (PP), and stress wave velocity (SWV). The survival rate (F ¼ 1.72; p ¼ 0.047), DBH (F ¼ 6.67, p < 0.0001), and pilodyn penetration (F ¼ 14.19; p < 0.001) significantly differed at 12.5 years after planting. The survival rate of Shorea leprosula was the highest (85%) of all the species, and the survival rate of other species, namely, S. macrophylla, S. ovalis, S. johorensis, S. scaberima, and S. parvifolia, was more than 70%. The best growth of DBH parameter was observed in S. platyclados. The DBH growth of S. platyclados 12.5 years after planting were 27.62 cm (mean annual diameter increment [MADI] ¼ 2.2 cm/year). The species whose growth in DBH was similar to those of S. platyclados were S. leprosula, S. parvivolia, and S. ovalis. However, stress wave velocity (SWV) was not significantly different among dipterocarp species (F ¼ 1.26; p ¼ 0.234). Pilodyn penetration (PP) was significantly correlated with DBH (Pearson's correlations ¼ 0.306; p < 0.001), whereas stress wave velocity was not significantly correlated with DBH and PP (p > 0.05), and their Pearson's correlations were 0.043 and À0.012, respectively. These results suggested that each dipterocarp species varied in terms of their growth and wood properties. Thus, choosing the species for enrichment planting in secondary tropical rainforests depends on the characteristics of each species and the desired final product of forest management.
Tropical Conservation Science, 2021
Much of the lowland tropical forests in the Solomon Islands have been heavily logged. However, little is known about the recovery status of these forests. We examined factors that influenced the recovery of forest structural attributes within 50 years after selective logging on Kolombangara Island in the western Solomon Islands. Twelve study sites—six logged and six unlogged—were identified across the Island, with two logged sites in each of three recovery-time classes: 10, 30, and 50 years after logging. Within each study site, 12 0.1-ha plots were randomly established, and a series of forest attributes measured in each plot. Our results revealed that local logging intensity and soil attributes have stronger influence on forest-structural recovery than do site attributes such as local topography or tree architecture. Furthermore, half a century of regeneration following logging is insufficient to permit full recovery of forest structure. We conclude that logged forests on Kolombang...
Remote. Sens., 2021
Selective logging in the tropics is a major driver of forest degradation by altering forest structure and function, including significant losses of aboveground carbon. In this study, we used a 30-year Landsat time series (1985–2015) to analyze forest degradation and carbon emissions due to selective logging in a Forest Reserve of the Venezuelan Amazon. Our work was conducted in two phases: the first, by means of a direct method we detected the infrastructure related to logging at the sub-pixel level, and for the second, we used an indirect approach using buffer areas applied to the results of the selective logging mapping. Pre- and post-logging forest inventory data, combined with the mapping analysis were used to quantify the effects of logging on aboveground carbon emissions for three different sources: hauling, skidding and tree felling. With an overall precision of 0.943, we demonstrate the potential of this method to efficiently map selective logging and forest degradation with...
Forests
Selective logging is one of the main natural forest harvesting approaches worldwide and contributes nearly 15% of global timber needs. However, there are increasing concerns that ongoing selective logging practices have led to decreased forest product supply, increased forest degradation, and contributed to forest based carbon emissions. Taking cases of natural forest harvesting practices from the Tarai region of Nepal and Queensland Australia, this study assesses forest product recovery and associated carbon emissions along the timber production chain. Field measurements and product flow analysis of 127 commercially harvested trees up to the exit gate of sawmills and interaction with sawmill owners and forest managers reveal that: (1) Queensland selective logging has less volume recovery (52.8%) compared to Nepal (94.5%) leaving significant utilizable volume in the forest, (2) Stump volume represents 5.5% of total timber volume in Nepal and 3.9% in Queensland with an average stump ...
Biotropica, 2016
Biodiversity in pristine forest biomes is increasingly disturbed by human activity. Drivers such as logging and climate extremes are thought to collectively erode diversity, but their interactions are not well understood. However, ignoring such complexities may result in poor conservation management decisions. Here, we present the first study dealing with the complexity arising from the effects of interactions of two increasingly important disturbance factors (selective logging and climatic extreme events) on beta diversity patterns at different scales. Specifically, we examined extensive amphibian assemblage datasets obtained within a quasi-experimental pre-/postharvesting scheme in the lowland rainforests of Central Guyana. Changes in small-scale patterns of beta diversity were not detectable at the higher landscape level, indicating that local-scale dynamics are more informative for evaluating disturbance impacts. The results also underscore the importance of including abundance data when investigating homogenization or heterogenization effects, which should be considered when designing post-logging impact assessments and selecting impact indicators. Moreover, logging should be regarded as a multifaceted driver that contributes to changes in biodiversity patterns in different ways, depending on 2 interactions with other drivers. The effects of extreme climate events were significantly more pronounced in unlogged forest, while logged forest assemblages appeared buffered due to the presence of novel habitats. Imprudent post-logging renaturation measures may thus counteract conservation targets. These findings highlight the fact that indicator bias and unaccounted interactions between multiple drivers can lead to misguided management strategies.
Sustainability Challenges in Sub-Saharan Africa I
Tree-dominated forests and grass-dominated savannas represent the two main tropical biomes covering the overwhelming majority of sub-Saharan Africa (SSA) (White 1983). Forests and savannas have a different, even antagonistic, ecological functioning (Staver et al. 2011a), but they both provide critical services to local populations (see Chaps. 7 and 10, Vol. 1; Chaps. 5 and 6, Vol. 2). Tropical forests are dominated by trees, forming closed canopies and complex vertical structures, and contain in their understory C3 grasses that are more adapted to humidity and shadow. Such forests are encountered in areas of high annual rainfall and limited seasonality (Malhi et al. 2009), and are very sensitive to disturbances. In contrast, trees and C4 grasses in tropical savannas coexist, are more adapted to aridity, are shade intolerant, and are found in areas that are drier and have higher seasonality (Ratnam et al. 2011). Savannas rely on frequent disturbances due to fires and/or mega-herbivores that maintain an open canopy and species diversity (Bond et al. 2005; Sankaran et al. 2005; Staver and Bond 2014). The occurrence of tropical forests and savannas is, however, not rigidly determined by climatic conditions. Recent analyses of remotely sensed tree cover at the global (Hirota et al. 2011; Staver et al. 2011b) and at the regional (Favier et al. 2012) scales, supported by theoretical work (Staver et al. 2011a; Staver and Levin 2012),
Scientific Reports
Despite increasing attention for relationships between species richness and ecosystem services, for tropical forests such relationships are still under discussion. Contradicting relationships have been reported concerning carbon stock, while little is known about relationships concerning timber stock and the abundance of non-timber forest product producing plant species (NTFP abundance). Using 151 1-ha plots, we related tree and arborescent palm species richness to carbon stock, timber stock and NTFP abundance across the Guiana Shield, and using 283 1-ha plots, to carbon stock across all of Amazonia. We analysed how environmental heterogeneity influenced these relationships, assessing differences across and within multiple forest types, biogeographic regions and subregions. Species richness showed significant relationships with all three ecosystem services, but relationships differed between forest types and among biogeographical strata. We found that species richness was positively...
Canopy Architecture After Selective Logging in a Secondary Atlantic Rainforest in Brazil
Floresta e Ambiente, 2019
Sustainable forest management promotes financial revenues while keeping the forest cover and environmental services. Nevertheless, the logging operation causes changes in the forest and canopy horizontal and vertical structure. Our objective is to evaluate the changes in the forest canopy and its consequences to the forest management, following logging in a secondary Atlantic Rainforest. We used hemispherical photography to determine the Canopy Openness (CO), Leaf Area Index (LAI) and the radiation absorption (fAPAR) in nine experimental plots before and after logging. We did not find a clear correlation between the forest horizontal structure and the canopy architecture. Despite this, there was an increase in CO and decrease in LAI and fAPAR after logging. The variation in CO and fAPAR were affected by logging intensity, but LAI did not show the same pattern. We suggest a conservative maximum logging intensity of 30% of the basal area and tree density.
Stocks of Carbon in Logs and Timber Products from Forest Management in the Southwestern Amazon
Forests, 2020
Amazon forest management plans have a variety of effects on carbon emissions, both positive and negative. All of these effects need to be quantified to assess the role of this land use in climate change. Here, we contribute to this effort by evaluating the carbon stocks in logs and timber products from an area under forest management in the southeastern portion of Acre State, Brazil. One hundred and thirty-six trees of 12 species had DBH ranging from 50.9 cm to 149.9 cm. Basic wood density ranged from 0.3 cm−3 to 0.8 g cm−3 with an average of 0.6 g cm−3. The logs had a total volume of 925.2 m3, biomass of 564 Mg, and carbon stock of 484.2 MgC. The average volumetric yield coefficient (VYC) was 52.3% and the carbon yield coefficient (CYC) was 53.2% for logs of the 12 species. The sawn-wood products had a total volume of 484.2 m3, biomass of 302.6 Mg, and carbon stock of 149.9 MgC. Contributions of the different species to the total carbon stored in sawn-wood products ranged from 2.2%...
Hydrobiologia, 2021
We evaluated the effects of changes in habitat structure resulting from conventional logging (CL) and reduced-impact logging (RIL) on the ecomorphological structure of stream fish assemblages in the eastern Brazilian Amazon, investigating (1) which habitat characteristics are influenced by different logging methods, (2) the differences in the ecomorphological structure of fish assemblages between two logging methods and undisturbed forest (UF), and (3) the relationships between ecomorphological traits of fish assemblages and habitat variables. We measured 13 habitat variables and characterized 11 ecomorphological traits of 55 fish species collected in 34 sampling sites (stream stretches) located in CL, RIL, and UF. In logged areas, the streams present a fine sediment increase and reduced vegetation cover, while in the UF a greater amount of natural shelter and more cover vegetation were observed. These environmental changes selected ecomorphological traits of stream fish assemblages, recording a greater relative width of the mouth in UF, higher ventral flattening index in RIL, or greater relative head length, and higher caudal peduncle compression index in CL. In this sense, we recommend that logging practices, including RIL, should be reviewed as a means of adopting better strategies to minimize human disturbances in streams.
PLOS ONE, 2018
Retention forestry aims to mitigate impacts of native forestry on biodiversity, but data are limited on its effectiveness for threatened species. We used acoustics to investigate the resilience of a folivorous marsupial, the koala Phascolarctos cinereus, to timber harvesting where a key mitigation practice is landscape exclusion of harvesting. We deployed acoustic recorders at 171 sites to record male bellows (~14,640 hours) for use in occupancy modelling and for comparisons of bellow rate (bellows night-1). Surveys targeted modelled medium-high quality habitat, with sites stratified by time since logging and logging intensity, including old growth as a reference. After scanning recordings with software to identify koala bellows, we found a high probability of detection (~0.45 per night), but this varied with minimum temperature and recorder type. Naïve occupancy was~64% across a broad range of forests, which was at least five times more than expected based on previous surveys using alternative methods. After accounting for imperfect detection, probability of occupancy was influenced by elevation (-ve), cover of important browse trees (+ve), landscape NDVI (+ve) and extent of recent wildfire (-ve, but minor effect). Elevation was the most influential variable, though the relationship was non-linear and low occupancy was most common at tableland elevations (> 1000 m). Neither occupancy nor bellow rate were influenced by timber harvesting intensity, time since harvesting or local landscape extent of harvesting or old growth. Extrapolation of occupancy across modelled habitat indicates that the hinterland forests of northeast NSW support a widespread, though likely low density koala population that is considerably larger than previously estimated. Retention forestry has a significant role to play in mitigating harvesting impacts on biodiversity, including for forest specialists, but localised studies are needed to optimise prescriptions for koalas.
Condition of Illegally Logged Stands Following High Frequency Legal Logging in Bago Yoma, Myanmar
Forests, 2021
The restoration of degraded forests is the focus of global attention. Effective restoration requires information on the condition of degraded forests. This study aimed to understand the conditions of illegally logged stands that had also experienced inappropriately short rotations between legal logging cycles in natural production forests in Myanmar. Four rectangular plots (each 0.64 ha) were established in 2013. The plots included illegally logged stumps in three compartments where the latest legal logging was conducted in 2011 after very short rotations between legal logging cycles (up to five harvests between 1995 and 2011, compared with a recommended 30-year logging cycle). Using data from the field measurements in 2013 on the legal and illegal stumps and living trees, we reconstructed stand structure just before and after legal logging in 2011. Before the legal logging in 2011, there were variations in stand structure and the composition of commercial species among four plots. ...
Ant and termite communities in isolated and continuous forest fragments in Singapore
Insectes Sociaux, 2017
The conservation of tropical rainforest biodiversity is a pressing issue, due to the rapid rate of deforestation. Secondary forests may provide a useful alternative to old growth forests, as they often contain a substantial proportion of the original biodiversity. In this study, we investigate species richness, density and composition of ants and termites in six forest sites in Singapore, each differing in habitat isolation and landuse history. The six sites include an old growth forest, a selectively logged old growth forest, and four secondary forests: either located on abandoned agricultural lands or in abandoned villages, and either isolated or adjacent to old growth forests. We found that the old growth forest had significantly higher species density of ants and termites than any other site. Rarefaction curves showed that ant and termite species richness 2 were highest in the old growth forest followed by the selectively logged forest albeit these results were not significantly different from other sites. Ant species composition changed along a gradient of fragment isolation. Termite community composition in the old growth forest shared a higher proportion of species with the adjacent secondary forest, than with the selectively logged old growth forest, suggesting that the species pool of adjacent habitats is important for species re-colonisation of regenerating habitats. Our results suggest, albeit without replications, that secondary forests differ in conservation value and that disturbed habitats in continuous forest fragments recover more rapidly than isolated ones. Further, we emphasise the importance of old growth forest fragments within man-made ecosystems as sources of original biodiversity.
Selective Logging Detection in the Brazilian Amazon
Floresta e Ambiente, 2019
Selective logging activities are commonly observed in the Brazilian Amazon and are responsible for high forest impact. In this study, selective logging detection techniques and the spatiotemporal extension of forests impacted by logging activities between 2003 and 2014 in portions of the states of Mato Grosso, Pará, and Rondônia were assessed using remotely sensing data. Based on results obtained, it was estimated that the overall accuracies are greater than 91% for techniques applied to detect forests impacted by selective logging in the study areas. Forests impacted by selective logging increased in Western state of Mato Grosso and Northern state of Rondônia, which indicates a stage high forest activity in these regions. In contrast, in Eastern state of Pará, a decrease in forests impacted by logging activities was observed, which indicates collapsed stage of logging activities resulting from deforestation and predatory logging in that region.
Silvicultural assessment of enrichment planting with commercial tree species after selective logging
Journal of Ecology and The Natural Environment
The integrity of forest stands in logging concessions depends on the logging method. Selective logging is the most commonly used method in the tropics, disturbing a considerable proportion of soil and canopy cover creating distinct sites for plant establishment. The objective of this study was to evaluate the silvicultural requirements in terms of light and moisture of seedlings of some commercial tree species used for enrichment planting. This study was carried out in two Forest Management Units in the East Region and a shade house at the University of Buea campus in the South West Region of Cameroon. 15 of the 20 most exploited species were selected for the assessment of their seedling functional performance. Nineteen log yards with their corresponding skid trails were selected randomly for enrichment planting. Monthly height measurements of the seedlings were recorded for 34 months. The shade house experiment had an unbalanced factorial experiment incorporating light and moisture. The growth rate in height was significantly higher in log yards (3.8 cm/month) and least under the forest canopy (1.2 cm/month). The growth rate in height was highest under high light and high moisture in Pterocarpus soyauxii (13.3 cm/month) and least under low light and high moisture in Entandrophragma cylindricum (0.7 cm/month). Mortality was highest under the forest canopy (11.1%) and least in the skid trails (0%). The results indicated that plant species should be planted according to their light and moisture requirements during enrichment planting at the seedling stage and for a sustainable forest management.
Forest Ecology and Management, 2021
Can heavily logged Amazonian dense forests produce commercial timber for a second harvest under a 25-35-year cutting cycle? To address this question, we evaluated the forest capacity to recover the volume extracted 32 years after heavy logging (90 m 3 ha − 1) in a 144-ha research area located in the Tapajós National Forest, Brazil (03 • 18 ′ 31 ′′ to 03 • 19 ′ 21 ′′ S; 54 • 56 ′ 28 ′′ to 54 • 56 ′ 15 ′′ W). Abundance (number of trees ha − 1), basal area (m 2 ha − 1) and volume (m 3 ha − 1) were assessed in two censuses, one year before logging (1981) and 32 years after logging (2014) to evaluate the status of the timber stock. Canopy openings caused by logging and silvicultural treatments increased sunlight in the forest and boosted the growth of trees 5-45 cm in DBH. Light-demanding species accounted for most of the increase in density and timber volume in the study area after logging. Our findings indicated that 32 years after the first cut, the forest was not able to replace the volume extracted. Considering the present Brazilian forest management regulations, which allow a logging intensity of 30 m 3 ha − 1 in a 35-year cutting cycle, this volume could only be harvested if new species not logged in the first cut were included in the new species logging list.
Highlighting a New Morphospecies within the Dialium Genus Using Leaves and Wood Traits
Forests
During inventories of lesser-known timber species in eastern Gabon, a new Dialium morphospecies was discovered. To discriminate it from the two other 2–5 leaflets Dialium species, 25 leaf traits were measured on 45 trees (16 Dialium pachyphyllum, 14 Dialium lopense, 15 Dialium sp. nov.). Nine wood chemical traits, as well as infrared spectra, were also examined on harvestable trees (four Dialium pachyphyllum and four Dialium sp. nov.). This study revealed seven discriminant leaf traits that allowed to create a field identification key. Nine significant differences (five in sapwood and four in heartwood) in terms of wood composition were highlighted. The use of the PLS-DA technique on FT-IR wood spectra allowed to accurately identify the new morphospecies. These results provide strong support for describing a new species in this genus. Implications for sustainable management of its populations are also discussed.
A Natural Forest of Commercial Timber Species: Logging or Not Logging
Small-scale Forestry, 2018
Most tropical forests outside protected areas have been or will be selectively logged because the timber industry is a main income-generating resource for many developing countries. Therefore, understanding the composition of commercial timber species and logging types is key for sustainable forest management in countries like Vietnam as they move toward fulfilling Reducing Emissions from Deforestation and Forest Degradation (REDD+) agreements. Seven 1-ha plots were surveyed in the Central Highland of Vietnam, and 18 commercial tree species from these plots, whose timber is widely used by local people for housing and furniture making and timber is easily sold at local markets for high prices, were analyzed. In total, 151 tree species with a diameter at breast height (DBH) of ≥ 10 cm were recorded. The 18 commercially valuable species assessed in this study accounted for 33.2% of all stems (total of 524 stems ha −1 for all species), 47.1% of basal area (total of 34.35 m 2 ha −1 for all species), and 50.8% of aboveground biomass/AGB (total of 262.68 Mg ha −1 for all species). Practicing diameter-limit harvesting of all commercially valuable species with DBH of ≥ 40 cm, which is widely performed in Vietnam, will reduce the number of stems by 7%, basal area by 31.6%, and AGB by 38.2%. Because such harvesting practices cause severe ecological impacts on the remaining forest, logged forests may require > 40 years to recover the structure status of a pre-logged forest. In addition, the recovery of the 18 commercially valuable species may require a much longer time because they comprised 33.2% of stems. Permission for logging natural forests should be given in Vietnam to sustain lives of local communities, where logging has been prohibited. However, alternative harvesting systems, such as reduced-impact logging systems, should be considered. The systems selected must simultaneously generate economic returns for local people and respect the REDD+ agreements with regard to protecting biodiversity and reducing carbon emissions.
Active restoration accelerates the carbon recovery of human-modified tropical forests
Science, 2020
More than half of all tropical forests are degraded by human impacts, leaving them threatened with conversion to agricultural plantations and risking substantial biodiversity and carbon losses. Restoration could accelerate recovery of aboveground carbon density (ACD), but adoption of restoration is constrained by cost and uncertainties over effectiveness. We report a long-term comparison of ACD recovery rates between naturally regenerating and actively restored logged tropical forests. Restoration enhanced decadal ACD recovery by more than 50%, from 2.9 to 4.4 megagrams per hectare per year. This magnitude of response, coupled with modal values of restoration costs globally, would require higher carbon prices to justify investment in restoration. However, carbon prices required to fulfill the 2016 Paris climate agreement [$40 to $80 (USD) per tonne carbon dioxide equivalent] would provide an economic justification for tropical forest restoration.
New Forests, 2018
Despite inception of carbon-conservation forestry programs, information about total above-ground woody biomass (TAGB) in Vietnamese secondary lowland rainforests is still scarce. We elucidated major factors influencing local variation of TAGB within an anthropogenically modified hillside forest in Thừa Thiên-Huế Province. On forty 400 m 2 sized plots all tree species were recorded, and their biomass was calculated using allometric equations. In addition, bio-physical parameters relating to terrain and soils were measured. Effects of bio-physical variables on forest TAGB were assessed using multivariate regression methods. Forest TAGB (average 117 Mg ha −1) was primarily explained by forest structural variables, i.e. tree densities and average heights, in particular presence of large trees. TAGB was largely determined by the biomass of a few species which dominated different forest parts (ridges or hill base); TAGB was hardly influenced by species diversity. Many dominant trees were light-demanding species; these were characterised by scarce rejuvenation and high tree mortality. Bio-physical patterns indicated that previous logging impacts persisted and continued to influence seedling establishment, sapling growth/survival, and-ultimately-species composition. Nutrient patterns were mostly explained by interactions with certain tree species and tree foliage cover, as modulated by terrain and logging impacts. Development trajectories of TAGB over the next 10-20 years could not Field data was collected by Van Thi Yen, and Ngo Tri Dung helped with species identification and data management. Statistical analyses were mainly conducted by Roland Cochard. The authors wrote the manuscript collaboratively.
Forest Systems
Aim of study: To compare the diversity and biomass of logged forests, with different ages after harvesting and the risk of their degradation to liana forests. Area of study: We studied 18 plots at the central zone of the Imataca Forest Reserve (Guayana shield), Venezuela. Material and methods: We used 1-ha plots, to measure individuals with dbh > 10 cm in control plots (0 years) and in logged plots with 3, 9, 12, 15 and 18 years after logging. The main variables evaluated were enlarge importance index (EII), richness (R), Shannon-Weaner index (H´), Alpha Fischer (α), basal area for commercial species (BA_comm), above-ground carbon (C) and lianas abundance at the understory (Lianas_%Au). Main results: Diversity variables (R: 62-77 spp ha-1, p: 0.117-0.838; H´: 2.8-3.4, p: 0.181-0.677; α: 18.6-25.4, p: 0.293-0.922) and biomass (89.6-180.2 MgC ha-1, p: 0.171-0.895) did not have significant differences between control and most of the logged plots. Only the 18 years-old forests had st...
Optimized Floating Refugia: a new strategy for species conservation in production forest landscapes
Biodiversity and Conservation, 2013
Timber production forests can support diverse ecological communities, but existing conservation strategies fail to maximize this potential. While methods for limiting logging damage and locating biological reserves have been developed, strategies focused on the sequence and arrangement of harvest units are lacking, particularly for situations in which species-specific knowledge is limited. We present a new landscape-level approach to forest conservation that anticipates local extinctions and focuses on facilitating re-colonization via strategic spatiotemporal harvest plans (which are informed by species occurrence data only). As a proof of concept, we applied our framework to data from four tropical forest sites and found clear benefits of optimized spatiotemporal harvest plans relative to nonoptimized harvest plans (random and three pattern-based plans). Our proposed approach, termed the Optimized Floating Refugia strategy, requires minimal species-specific knowledge and can be used to enhance existing conservation efforts (e.g. biological reserve establishment, reduced-impact logging). The approach effectively prioritizes logging-sensitive habitat specialists with restricted ranges and thus provides the largest benefits to the most extinction-prone species. This simple but novel method shows promise as a general strategy to improve biodiversity conservation in species-rich production forest landscapes.
Biodiversity and Conservation, 2018
Tropical forests account for more than half of the global carbon forest stock and much of the biological diversity on Earth. However, disturbances such as deforestation and forest degradation threaten the maintenance of these ecosystem services. This study aimed to understand how different disturbance histories affect the forest stand biomass, as well as species and functional diversity, and to what extent these differences can change the relationships between biomass and their drivers. We used data from forests with clear-cut and selectively logged disturbance histories, and from old-growth forests, situated in the Brazilian Atlantic forest. Forests with logging disturbances showed significant losses in their aboveground biomass compared to those of old-growth forests (50% loss in selectively logged forests and 80% loss in clear-cut forests). Interestingly, only clear-cut secondary forests showed differences in species and functional diversity, and were dominated by species with acquisitive trait values, commonly found early in succession. Shifts in stand biomass drivers were observed in selectively logged forests. The mass-ratio hypothesis (mainly through the functional trait of maximum height) was the most important biomass driver in clear-cut secondary and old-growth forests, whereas the importance of the niche complementarity hypothesis (through functional richness and dispersion) was higher in selectively logged forests. Our study highlights that disturbance histories can affect forest aboveground biomass and its drivers. Moreover, our results reinforce the need for conservation of intact forests but highlight the importance of including degraded forests in conservation mechanisms based in carbon stocks, as these forests retain high values of species and functional diversities that are crucial to biomass and consequently carbon stock acquisition.
Reduced-Impact Logging Maintain High Moss Diversity in Temperate Forests
Forests, 2021
Forestry harvesting represents an important economic activity around the world. Habitat degradation due to forest harvesting contributes to biodiversity loss; therefore, it is necessary to implement logging management aimed at reducing its impact. Forest management by reduce-impact logging (RIL) involves cutting trees following regulations focused on diminishing the impact on biodiversity by following harvesting plans based on forestry inventories and participation of trained workers. In Mexico, RIL is applied mainly in temperate habitats and its effectiveness has been assessed based on vascular plants. In this study, we analyzed the diversity and community structure of terrestrial and epiphytic mosses in managed (sites number = 3) and conserved (sites number = 3) sites in the temperate forest of Sierra Juárez, Oaxaca, Mexico. Likewise, we evaluated the potential function of mosses as indicators of habitat degradation. Environmental variables were also quantified at local (canopy co...
Land
The Mayombe tropical forest has experienced dramatic changes over several decades due to human activities. However, the impact of these changes on tree biodiversity and ecosystem services has not been studied yet. Such a study could advance the current knowledge on tree biodiversity and carbon storage within the Mayombe forest, which is presently under high anthropogenic pressures. This information could benefit decision-makers to design and implement strategies for biodiversity conservation and sustainable natural resource utilization. As such, biodiversity surveys were conducted within the forest under different land utilization regimes. To evaluate the effect of human utilization on tree biodiversity and ecosystem services (carbon storage), land was classified into three categories based on the intensity of human utilization: low utilization, moderate utilization, and high utilization. Additionally, the study evaluated the recovery potential of the disturbed forest under both mod...
Environment, Development and Sustainability, 2021
The empirical link between governance and illegal logging is widely accepted amongst scientist, although a minority still purports that illegal logging does not necessarily prevail because of poor governance. However, the nexus linking governance, illegal logging and carbon emission is not well enshrined in scientific literature. This paper seeks to review the literature on illegal logging and governance and empirically investigate the effect of illegal logging and governance effectiveness on carbon emission. Using panel dynamic ordinary least square method on data covering three Congo Basin timber-producing countries and three Asian timber-producing countries, this paper further investigates disaggregated effects between these two groups of countries. The empirical evidence underscores that Congo Basin timber-producing countries are characterised by increasing trend of illegal logging, poor governance effectiveness and corruption. Panel regression reveals a positive and significant impact of illegal logging, governance effectiveness and corruption on carbon emission. Asian producing countries depict a reducing trend in illegal logging and improvements in governance and corruption. There is a positive but not significant impact of illegal logging on carbon emission, and governance effectiveness reduces carbon emission. Thus, the dynamics of governance, illegal logging and carbon emission is not the same between timber-producing countries in Asia and Congo producing counties, thus suggesting the ability of institutions to curb illegal logging and enforce laws to reduce the effects of carbon emission. Multi-stakeholder consultations, government engagement, partnerships and training of control staff can help curb corruption. Legality checks should go beyond having legal documents to effectively check and control of timber concessions and small-scale logging.
Journal of Tropical Ecology, 2022
Peru contains the second largest surface area of the Amazon biome. The Peruvian Amazon is threatened by logging, illegal crops, mining, and agricultural expansion. While a number of national parks exist in the Amazon region, privately managed areas like Conservation Concessions can be an attractive complement to existing parks. We compare medium and large mammal communities in a Conservation Concession in Ucayali with the nearby Parque Nacional Sierra del Divisor National Park and describe species relative abundance and richness of both protected areas. Results suggest that Conservation Concessions can harbour an important diversity of mammal species and could provide connections to larger protected areas. However, they are no substitutes for large protected areas, especially for sensitive and threatened species. Further research is needed to demonstrate their complementarity and improve landscape-level connectivity between conservation models.
Opportunities and Conditions for Successful Foreign Aid to the Forestry Sector
Springer eBooks, 2017
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Logging drives contrasting animal body-size effects on tropical forest mammal communities
Forest Ecology and Management, 2021
Anthropogenic disturbance of tropical ecosystems can re-configure mammalian communities, frequently through a process of differential impact on animal species, whereby medium-and large-bodied animals are more impacted than small-bodied animals, which often are even favored. Here we examine if logging-a prevalent activity in the tropics-drives a pattern of differential defaunation in a Neotropical forest managed by a community of indigenous people. Using a match-paired design, we conducted mammalian surveys during four consecutive years in three independent sites, each one including (1) areas for logging practiced by Maya communities of the Yucatan Peninsula (selective and interspaced harvesting), and (2) adjacent areas set aside as reserves. We found that in logged areas the abundance of medium and large mammals decreased (4.3-fold, overall), while the abundance of small mammals increased (2.5-fold, overall). We posit that these changes result from a combination of factors, including: (1) facilitated access for hunters of medium-and large-sized game, comprising both predators (potentially leading to small-prey release) and competitors of small-bodied species; (2) changes in vegetation (e.g., more shelter and food for rodents); and (3) contrasting animal life history traits (population growth rate, home range size). We conclude that although non-intensive logging interventions have negative consequences for the mammalian community (for at least ten years after harvesting), the indigenous practices of rotational harvesting and maintaining reserves help to prevent the landscape-wide mammalian declines known to occur under large-scale industrial logging.
The carbon sink of secondary and degraded humid tropical forests
Nature, 2023
The globally important carbon sink of intact, old-growth tropical humid forests is declining because 33 of climate change, deforestation and degradation from fire and logging 1-3. Recovering tropical 34 secondary and degraded forests now cover about 10% of the tropical forest area 4 , but how much 35 carbon they accumulate remains uncertain. Here we quantify the aboveground carbon sink of 36 recovering forests across three major continuous tropical humid regions: the Amazon, Borneo and 37 Central Africa 5,6. Based on satellite data products 4,7 , our analysis encompasses the heterogenous 38 spatial and temporal patterns of growth in degraded and secondary forests, influenced by key 39 environmental and anthropogenic drivers. In the first twenty years of recovery, regrowth rates in 40 Borneo were up to 45% and 58% higher than in Central Africa and the Amazon, respectively. This is 41 due to variables such as temperature, water deficit and disturbance regimes. We find that regrowing 42 degraded and secondary forests accumulated 107 Tg C yr-1 (90 to 130) between 1984-2018, 43
Antipoaching standards in onshore hydrocarbon concessions drawn from a Central African case study
Conservation Biology, 2016
Unsustainable hunting outside protected areas is threatening tropical biodiversity worldwide and requires conservationists to engage increasingly in antipoaching activities. Following the example of ecocertified logging companies, we argue that other extractive industries managing large concessions should engage in antipoaching activities as part of their environmental management plans. Onshore hydrocarbon concessions should also adopt antipoaching protocols as a standard because they represent a biodiversity threat comparable to logging. We examined the spatiotemporal patterns of small-and large-mammal poaching in an onshore oil concession in Gabon, Central Africa, with a Bayesian occupancy model based on signs of poaching collected from 2010 to 2015 on antipoaching patrols. Patrol locations were initially determined based on local intelligence and past patrol successes (adaptive management) and subsequently with a systematic sampling of the concession. We generated maps of poaching probability in the concession and determined the temporal trends of this threat over 5 years. The spatiotemporal patterns of large-and small-mammal poaching differed throughout the concession, and likely these groups will need different management strategies. By elucidating the relationship between site-specific sampling effort and detection probability, the Bayesian method allowed us to set goals for future antipoaching patrols. Our results indicate that a combination of systematic sampling and adaptive management data is necessary to infer spatiotemporal patterns with the statistical method we used. On the basis of our case study, we recommend hydrocarbon companies interested in implementing efficient antipoaching activities in their onshore concessions lay the foundation of longneeded industry standards by adequately measuring antipoaching effort; mixing adaptive management and balanced sampling; setting goals for antipoaching effort; pairing patrols with large-mammal monitoring; supporting antipoaching patrols across the landscape; Antipoaching in hydrocarbon concessions This article is protected by copyright. All rights reserved. 4 restricting access to their concessions; performing random searches for bushmeat and mammal products at points of entry; controlling urban and agricultural expansion; supporting bushmeat alternatives; and supporting land-use planning.
Forests, 2019
Long-term studies of the dynamics of managed forests in tropical regions are lacking. This study aimed to evaluate the dynamics of a tropical forest, over a 25-year period, that was experimentally logged in 1987 and 1988 and submitted to three different cutting intensities. All trees with diameter at breast height (DBH) ≥ 10 cm have been measured annually since 1990. The three logging intensities that were applied were: light (T1)-trees harvested with DBH ≥ 55 cm; medium (T2)-DBH ≥ 50 cm; and heavy (T3)-DBH ≥ 40 cm. Control plots (T0) were also monitored. The highest mean annual mortality rates (1.82% ± 0.38), recruitment rates (2.93% ± 0.77) and diameter increments (0.30 ± 0.02 cm) occurred in the T3 treatment. Shifts in dynamics of the forest were mainly caused by a striking increase in a fast-growing pioneer species and their high mortality rates. The loss in stocking caused by mortality was greater than to that of replacement by recruitment. The results demonstrated that selecti...
Tree Genetics & Genomes, 2016
Selective logging systems have been used to prevent the rapid decline of forest resources in Southeast Asia, but little is known about the impacts of selective logging on the genetic diversity of Southeast Asian rainforests. We evaluated the effects of silvicultural systems with differing cutting rotations and enrichment planting regimes on the genetic diversity of Shorea parvifolia, an abundant and ecologically important tree in Southeast Asian rainforests. Our result showed that in most respects the genetic diversity is not significantly different between primary forest and the other silvicultural systems; however, the proportion of private alleles is significantly different between them. Intensive secondrotation (L3) harvesting of individuals >40 cm in diameter at breast height (dbh) resulted in a sizable reduction in the number of reproductive trees and a dramatic decrease in the numbers of rare and private alleles, suggesting a negative impact on the genetic diversity of the remaining tree population. Enrichment planting with S. parvifolia in the logged forest improved some genetic parameters, significantly increasing the number of rare alleles in L3 in particular. We conclude that the genetic diversity of logged tropical forests gradually decreases depending on logging rotation times, especially with respect to sensitive genetic parameters such as the numbers of rare and private alleles, and that enrichment planting with native dipterocarps can maintain or even increase the genetic diversity of logged tropical forests in Southeast Asia.
Impacts of logging roads on tropical forests
Biotropica, 2017
Road networks are expanding in tropical countries, increasing human access to remote forests 2 that act as refuges for biodiversity and provide globally important ecosystem services. Logging is one of the main drivers of road construction in tropical forests. We evaluated 4 forest fragmentation and impacts of logging roads on forest resilience and wildlife, 5 considering the full life cycle of logging roads. Through an extensive evidence review we 6 found that for logging road construction, corridors between 3 and 66 m (median 20 m) width 7 are cleared, leading to a loss of 0.6 to 8.0 percent (median 1.8%) of forest cover. More severe 8 impacts are increased fire incidence, soil erosion, landslides and sediment accumulation in 9 streams. Once opened, logging roads potentially allow continued access to the forest interior, 10 which can lead to biological invasions, increased hunting pressure and proliferation of 11 swidden agriculture. Some roads, initially built for logging, become converted to permanent, 12 public roads with subsequent in-migration and conversion of forest to agriculture. Most 13 logging roads, however, are abandoned to vegetation recovery. Given the far-reaching 14 impacts of the roads that become conduits for human access, its control after the end of 15 logging operations is crucial. Strategic landscape planning should design road networks that 16 concentrate efficient forest exploitation and conserve roadless areas.