Forest Structure Research Papers - Academia.edu (original) (raw)

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- Forest Ecology And Management, Biological Sciences, Seasonality, Environmental Sciences
- by Md. Mizanur Rahman
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- Regeneration, Biology, Agroforestry, Biodiversity

Ecosystem management of protection forests aims at maintaining forests near a state during which effective protection is secured. As the evolution of a dynamic forest ecosystem cannot be stopped, silvicultural measures are required which aim at maintaining both the ecosystem integrity and the protective function of mountain forests. Ecosystem integrity is defined as the system's capacity to maintain structure and ecosystem functions using processes and elements characteristic for its ecoregion. Here, ecosystem functions also reflect the capability of the ecosystem to provide functions of value to humans. Ecosystem integrity of a protection forest implies that the stability (mainly the property resilience is addressed) of the forest is high, because that is required to provide a high level of protection in the long term. The main conditions promoting natural evolutionary processes and ecological stability in protection forests are: (1) a diverse composition of species; (2) sufficient natural regeneration; (3) an optimal forest structure. The first example in this chapter explains how these conditions might be achieved by silvicultural interventions in a forest that mainly protects against rockfall in the Austrian Alps. The second example deals with socioeconomic aspects of ecosystem integrity of a forest that also protects against rockfall, but then in the French Alps. Both examples show that forest authorities are aware of techniques to improve the stand stability of protection forests, but the problem is that current forest management is often a kind of trial and error, because the exact consequences of interventions for forest ecosystem dynamics are not known. Therefore, it is proposed that forest ecosystem research should shift focus from protection forest dynamics to the geo-ecosystem functioning of protection forests, including the effects of natural and human disturbances. For this, the concept of panarchy may be a promising way forward.

The effects of prescribed burning, herbicide application, and thinning treatments were examined in upland Quercus stands with a replicate block field study. Two site types were analyzed: (1) nonsuccessional with a Quercus overstory and Quercus understory, and (2) successional with a Quercus overstory and an Acer saccharum understory. Treatments were examined for their effects on vegetation structure and composition, especially with respect to altering the natural succession from Quercus communities to mesophytic species. In addition, impacts of burning on soil nutrients were examined prior to and immediately following burn treatments. Results from the study indicate that fire had little effect on A horizon soil nutrients following burns. The data suggest fire plays a more important role as a decomposer for nutrient release in February burns than in November burns. Natural precipitation and leaching from the litter layer in the fall rendered similar nutrient dynamics as burning in November. The structural changes to vegetation following fire were more noticeable than compositional changes. Thinning of the canopy was generally necessary for the understory to respond to burning treatments. Burning did not affect stems >3.8 cm dbh (diameter at breast height). Density of most woody species <3.8 cm dbh decreased with burning, but increased with burning and thinning, indicating the stress of shaded conditions. Thus, burning prior to thinning may be an effective method for controlling an A. saccharum invasion into Quercus stands. Herbaceous, seedling, sapling, and overstory strata diversity were unaffected by the treatments. Data indicated that the community responds with species extant at the time of treatment. Thus, the initial conditions prior to disturbance were important factors in the response of the stand to disturbance. Although fire has played a major role in upland forest dynamics prior to settlement, forest structure and composition can no longer be maintained by fire. Succession without fire has resulted in a different structure and composition to oak forests, altering both fuels and fuel moisture levels. Species normally considered intolerant of fire have reached size classes large enough that they tolerate cool to moderate burns. More severe disturbance techniques, or combinations of techniques, are necessary for sustainable oak forest management in the central hardwood region.

Aim The Brazilian Atlantic forest covers c. 10% of its original extent, and some areas are still being logged. Although several ecological studies in Atlantic forest have been published over the past two to three decades, there has been little research on forest dynamics and there is a particular lack of information on the effects of disturbance. The aim of the present study was to assess the impact of selective logging on forest structure, floristic composition soil nutrients, litterfall and litter layer in a seasonally dry Atlantic forest.

- by Luiz Aragão
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- Earth Sciences, Biogeography, Nutrient Cycling, Biological Sciences

By allowing the estimation of forest structural and biophysical characteristics at different temporal and spatial scales, remote sensing may contribute to our understanding and monitoring of planted forests. Here, we studied 9-year time-series of the Normalized Difference Vegetation Index (NDVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on a network of 16 stands in fast-growing Eucalyptus plantations in São Paulo State, Brazil. We aimed to examine the relationships between NDVI time-series spanning entire rotations and stand structural characteristics (volume, dominant height, mean annual increment) in these simple forest ecosystems. Our second objective was to examine spatial and temporal variations of light use efficiency for wood production, by comparing time-series of Absorbed Photosynthetically Active Radiation (APAR) with inventory data.

- by Daniel Epron
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- Remote Sensing, Production, Structure, Time Series

Interest in the contributions to biological diversity of old-growth forests has increased in many regions of the world. In the Pacific Northwest of the United States, concern for the contributions has lead to proposals to extend the rotation between timber harvests from the conventional 40-80 years to 150 years and longer. However, the implications of such a change for Ž both development of old-growth structure and timber production are unknown. We examined long-term records up to 82 . Ž . years from permanent plots established in 20 stands of Pseudotsuga menziesii Mirb. Franco in western Oregon and Washington that are approaching these proposed rotation ages. Similarity to old-growth structure was assessed by comparing the observed values of four structural variables to published mean values for young and old-growth forest. The assessment of similarity to old-growth structure was limited to characteristics of the live forest stand, due to the lack of measurements of snags and downed logs at initiation of the permanent plots. Timber production was assessed by examining trends in mean Ž . annual increment MAI of cubic volume. Development towards old-growth structure was rapid up to about age 80 years, and gradual thereafter. About half of the transition from young to old-growth forest structure occurred by age 100 years. Stands least similar to old-growth in early observations had relatively high tree densities and relatively small trees of uniform size. In later observations, stands most similar to old-growth structure were those with higher densities of large Ž . ) 100 cm DBH P. menziesii. In general, MAI declined gradually, averaging about 0.3% per year. Thus, longer rotations may not result in large declines of timber growth while providing for forest structure similar to old-growth. Early control of tree density may serve to hasten development of old-growth structure. Our approach to understanding the development of old-growth forest structure could be applied to long-term plot data from forests in other regions, as long as there is adequate information on old-growth and other forest stages. q 1998 Elsevier Science B.V.

Although forest fires have become a critical question in Mexico following the fire season of 1998, there is little knowledge regarding the effects of fire events on forest structure, composition, and dynamics in mixed pine-oak forests in... more

- by OSCAR AGUIRRE
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- Geography, Fire Ecology, Forest fire, Sustainable forest management

The ecological processes and interactions that involve plants at the seed level may be altered in a fragmented forest, with consequences on plant recruitment and forest structure. We studied seed production, pre-dispersal seed predation and germination of non-damaged and damaged seeds of the endemic and vulnerable Nothofagus glauca tree, in small fragments and in a continuous area of the Maulino forest, in the Mediterranean coast of Central Chile. Pre-dispersal seed predation was evaluated in seeds produced throughout two consecutive seasons (2005-2006), while germination was evaluated in the field in the year 2005. During 2006, seed production was 16 times lower in the small fragments and 2.6 times lower in the continuous forest than in 2005. In 2005 there was a similar seed production in continuous forest and small fragments, while in 2006 seed production was significantly lower in small fragments. The microlepidopteran larvae, Perzelia sp., was confirmed as a pre-dispersal seed predator of N. glauca. Pre-dispersal seed predation occurred in the 57% of N. glauca seeds, and it was similar in both the continuous forest and fragments. Germination was low (<3%), and did not vary among small fragments and continuous forest. As expected, germination of non-damaged seeds was significantly higher than preyed upon seeds; nevertheless there were some damaged seeds that germinated. There was no relationship among seed production or intensity of pre-dispersal seed predation with the diameter at breast height, height of tree and the distance to the nearest flowering conspecific. Similarly, there was no relationship among seed germination and canopy openness or soil humidity. Our results, along with those from previous studies, suggest that N. glauca populations might be depressed in small remnants of the Maulino forest, because of a decreased seed production and an increased post-dispersal seed predation.

- by A. Grez
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- Forest Ecology And Management, Biology, Ecology, Seed germination

A face detection system is presented. A new classification method using forest-structured Bayesian networks is used. The method is used in an aggregated classifier to discriminate face from non-face patterns. The process of generating non-face patterns is integrated with the construction of the aggregated classifier. The face detection system performs well in comparison with other well-known methods.

- by Marcel Worring
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- Cognitive Science, Face Detection, Bayesian Network, Forest Structure

We studied forest structure, composition and tree species diversity of eight plots in an environmental matrix of four altitudes (700, 1700, 2700 and 3100 m) and two types of geological substrates (ultrabasic and non-ultrabasic rocks) on Mount Kinabalu, Borneo. On both substrate series, forest stature, mean leaf area and tree species diversity (both ≥ 4.8 cm and ≥ 10 cm diameter at breast height [dbh]) decreased with altitude. The two forests on the different substrate series were similar at 700 m in structure, generic and familial composition and tree species diversity, but became dissimilar with increasing altitude. The decline in stature with altitude was steeper on the ultrabasic substrates than on the non-ultrabasic substrates, and tree species diversity was generally lower on ultrabasic substrates than on non-ultrabasic substrates at ≥ 1700 m. The forests on non-ultrabasic substrates at higher altitudes and those on ultrabasic substrates at the lower altitudes were similar in dbh versus tree height allometry, mean leaf area, and generic and familial composition at ≥ 1700 m. These contrasting patterns in forest structure and composition between the two substrate series suggested that altitudinal change was compressed on the ultrabasic substrates compared to the non-ultrabasic substrates. Tree species diversity was correlated with maximum tree height and estimated aboveground biomass, but was not with basal area, among the eight study sites. We suggest that forests with higher tree species diversity are characterized by greater biomass allocation to height growth relative to trunk diameter growth under more productive environment than forests with lower tree species diversity.

- by Shin-ichiro Aiba
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- Plant Ecology, Plant Biology, Ecology, Rain forest

Contrary to the general trend in the tropics, forests have recovered in Puerto Rico from less than 10% of the landscape in the late 1940s to more than 40% in the present. The recent Puerto Rican history of forest recovery provides the opportunity to study the ecological consequences of economic globalization, reflected in a shift from agriculture to manufacturing and in human migration from rural to urban areas. Forest structure rapidly recovers through secondary succession, reaching mature forest levels of local biodiversity and biomass in approximately 40 years. Despite the rapid structural recovery, the legacy of pre-abandonment land use, including widespread abundance of exotic species and broadscale floristic homogenization, is likely to persist for centuries.

- by Jess Zimmerman
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- Exotic Species, Puerto Rico, Bioscience, Land Use Change

This paper is a comprehensive review of spatial forest-planning initiative that has been carried out in forest-management planning over the last 2 decades. It describes, first of all, the conceptual framework of spatial forest planning by identifying spatial and non-spatial forest-planning concepts. The paper focuses on the spatial considerations or problems of spatial configuration of patches including their size (opening size) and distribution, shape, adjacency or green-up delay, connectivity, proximity, and core area that make the conventional forest-management planning "spatial" powered by geographical information systems (GIS). Then, the paper explains various management approaches to conceptualize the spatial forest planning and analytical decision-making techniques, such as simulation, mathematical optimization and meta-heuristic techniques to solve the spatial forest management problem. It also provides information to measure the performance of various meta-heuristic techniques, when solving large-scale spatial problems. Also, some apparent new requirements, important needs for spatial forest planning, and important unresolved problems in spatial forest planning are identified. In conclusion, development of a hybrid-modeling technique, identification of target landscape structure, characterization of various forest values, such as biodiversity, water production, recreation, visual quality, erosion control, and an enthusiasm to implement the approach are identified important future development to spatial forest modeling.

- by Emin Baskent
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- Decision Making, Modeling, Multidisciplinary, Ecological Modelling
- by Pauline Grierson
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- Structure, Biomass, Fire Ecology, Forest Ecology And Management

A solution is demonstrated to an infinite-horizon, discrete-time utility model describing the consumption and cutting behavior of a nonindustrial private landowner who is managing a multiple age-class forest and who values both consumption derived from harvesting the trees and amenity derived from the standing trees. A policy rule is derived to attain a normal forest from any initial age-class distribution. It is demonstrated that a noncyclical forest allowing a constant periodic harvest is typically not a normal forest. Therefore, an even-flow timber harvesting is not tied to the existence of a normal forest structure.

- by Jari Kuuluvainen
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- Applied Economics, Dynamic Analysis, Forest Structure, Discrete Time Systems

In response to the urgent need for improved mapping of global biomass and the lack of any current space systems capable of addressing this need, the BIOMASS mission was proposed to the European Space Agency for the third cycle of Earth Explorer Core missions and was selected for Feasibility Study (Phase A) in March 2009. The objectives of the mission are 1) to quantify the magnitude and distribution of forest biomass globally to improve resource assessment, carbon accounting and carbon models, and 2) to monitor and quantify changes in terrestrial forest biomass globally, on an annual basis or better, leading to improved estimates of terrestrial carbon sources (primarily from deforestation); and terrestrial carbon sinks due to forest regrowth and afforestation. These science objectives require the mission to measure above-ground forest biomass from 70°N to 56°S at spatial scale of 100-200 m, with error not exceeding ± 20% or ± 10 t ha − 1 and forest height with error of ± 4 m. To meet the measurement requirements, the mission will carry a P-Band polarimetric SAR (centre frequency 435 MHz with 6 MHz bandwidth) with interferometric capability, operating in a dawn-dusk orbit with a constant incidence angle (in the range of 25°-35°) and a 25-45 day repeat cycle. During its 5-year lifetime, the mission will be capable of providing both direct measurements of biomass derived from intensity data and measurements of forest height derived from polarimetric interferometry. The design of the BIOMASS mission spins together two main observational strands: (1) the long heritage of airborne observations in tropical, temperate and boreal forest that have demonstrated the capabilities of P-band SAR for measuring forest biomass; (2) new developments in recovery of forest structure including forest height from Pol-InSAR, and, crucially, the resistance of P-band to temporal decorrelation, which makes this frequency uniquely suitable for biomass measurements with a single repeat-pass satellite. These two complementary measurement approaches are combined in the single BIOMASS sensor, and have the satisfying property that increasing biomass reduces the sensitivity of the former approach while increasing the sensitivity of the latter. This paper surveys the body of evidence built up over the last decade, from a wide range of airborne experiments, which illustrates the ability of such a sensor to provide the required measurements. At present, the BIOMASS P-band radar appears to be the only sensor capable of providing the necessary global knowledge about the world's forest biomass and its changes. In addition, this first chance to explore the Earth's environment with a long wavelength satellite SAR is expected to make yield new information in a range of geoscience areas, including subsurface structure in arid lands and polar ice, and forest inundation dynamics.

- by Fabio Rocca
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- Arid Land Ecology, Carbon Cycle, Feasibility Study, Geomatic Engineering

The role of different agroforestry systems in the conservation of plant diversity and forest structure has not been directly compared in many agricultural dominated landscapes. In this study, we investigated tree diversity and forest structure in a complex agroforestry landscape traditionally grown for cocoa and mixed food crops and compared these to the natural forest in southeastern Ghana. The study

- by Daniel Tetteh
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- Management, Sustainable agriculture, Strategic Management, Agroforestry

- by Kenny Ribbeck
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- Forest Ecology And Management, Forest Ecology, Biological Sciences, Tree Mortality

Invasive alien species pose one of the highest threats to biodiversity, especially in isolated oceanic islands where high rates of both endemism and extinction risk also usually prevail. Few studies have investigated the impact of invasive alien plants on butterflies in insular ecosystems, despite butterflies representing a key indicator group for terrestrial arthropod diversity. Using the Pollard Technique, we quantified butterfly species richness and abundance in eight wet lowland forest areas invaded by alien plants, principally the strawberry guava (Psidium cattleianum Sabine) on the tropical volcanic island of Mauritius, and compared the results with paired adjacent forest plots that had been weeded of alien plants between 2 and 12 years previously. Butterfly assemblages in weedinfested and weeded forests were distinctly different with higher species richness and much higher butterfly abundance in the latter. At least some of these differences seemed attributable to weed removal effects on forest structure, but understanding the precise

- by Claudia Baider
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- Ecology, Biodiversity, Biodiversity Conservation, Invasive Alien Species

Resumen Se instalaron 13 parcelas de 0.1 ha (10 m x 100 m) en el bosque amazónico preandino del sector del Río Quendeque (14°58"S 67°47"W; con 367 m en promedio) del Parque Nacional Madidi con el objetivo de evaluar la estructura y diversidad florística mediante un análisis de la importancia ecológica de las plantas leñosas. En los levantamientos se midieron todos los individuos con diámetro a la altura del pecho (DAP) > 2.5 cm. El bosque estudiado presenta una estructura horizontal o distribución diamétrica en forma de "J" invertida, la cual expresa la dinámica del bosque. La curva área vs. especie o de riqueza florística no llegó a un punto de inflexión, donde las especies nuevas dejaron de ser encontradas, debido a que una gran parte de las especies son raras como consecuencia de ser poco abundantes y por tener baja frecuencia o distribución espacial irregular. Se registraron 2.776 individuos, pertenecientes a 64 familias y 294 especies de plantas leñosas, con un área basal de 42.7 m 2 . Las familias con mayor riqueza de especies fueron Fabaceae ), Rubiaceae (21), Sapotaceae (16), Moraceae (14) y Myrtaceae (14). Las familias Arecaceae, Moraceae, Annonaceae, Sapotaceae y Rubiaceae, así como las especies Pentaplaris davidsmithii, Brosimum alicastrum, Socratea exorrhiza, Rheedia acuminata, Iriartea deltoidea y Duguetia spixiana fueron las de mayor importancia ecológica en función al Índice de Valor de Importancia (IVI), lo que significa que tienen mayor adaptación en el sitio. Palabras clave: Bosque húmedo neotropical, Estructura, Composición florística, Quendeque, Madidi, Bolivia.

- by Narel Paniagua-Zambrana
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- National Park, Forest Structure

La biomasa es fundamental para realizar estimaciones de carbono en bosques y conocer su estado de conservación. En este trabajo, se realiza un estudio multitemporal de imágenes satelitales para evaluar su uso en la estimación de biomasa del bosque seco del Parque Chaqueño de Argentina. Se estimó biomasa aérea a partir de datos de campo que se correlacionó con información espectral. El principio de la estación seca resultó ser la mejor época para vincular datos satelitales con estructura del bosque, ya que los pastos y arbustos se ven más afectados por el déficit hídrico que los árboles.

- by Nestor Ignacio Gasparri and +1
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- Forest Structure, Carbon Stock, THERMAL INFRARED REMOTE SENSING DATA, Landsat-7 ETM +

We studied patterns of tree regeneration in relation to canopy structure in a 1-ha plot damaged by an intermediate windstorm in 1983 and a 1-ha control plot regulated by small-scale canopy gaps in an old-growth Fagus sylvatica-Abies alba forest, southeastern Slovenia. In the windthrow plot, a maze of interconnected gaps covered 55% of the plot, while more discrete canopy openings covered 27% of the control plot. The different canopy structures resulted in marked differences in the density and spatial patterns of tree regeneration in the two plots. Fagus dominated the regeneration layer in both plots, while Abies occurred infrequently. For Fagus, there were nearly six-fold less seedlings, but twice as many saplings and understory trees in the windthrow plot compared to the control plot. Overall, the spatial patterns of Fagus seedlings, saplings, and understory trees were clumped in both plots, but only saplings and understory trees were aggregated under canopy gaps in the control plot, whereas saplings in the windthrow plot were distributed irrespective of canopy gaps. Abies individuals also had an aggregated spatial distribution, but were growing under a closed canopy. We suggest that infrequent, intermediate windstorm disturbance plays an important role in the structure and dynamics of central European forests by creating more coarse-grained forest structures than in stands regulated by smaller-scale gap processes. #

Forests characterized by mixed-severity fires occupy a broad moisture gradient between lower elevation forests typified by low-severity fires and higher elevation forests in which high-severity, stand replacing fires are the norm. Mixed-severity forest types are poorly documented and little understood but likely occupy significant areas in the western United States. By definition, mixed-severity types have high beta diversity at meso-scales, encompassing patches of both high and low severity and gradients in between. Studies of mixed-severity types reveal complex landscapes in which patch sizes follow a power law distribution with many small and few large patches. Forest types characterized by mixed severity can be classified according to the modal proportion of high to low severity patches, which increases from relatively dry to relatively mesic site conditions. Mixed-severity regimes are produced by interactions between top-down forcing by climate and bottom-up shaping by topography and the flammability of vegetation, although specific effects may vary widely across the region, especially the relation between aspect and fire severity. History is important in shaping fire behavior in mixed-severity landscapes, as patterns laid down by previous fires can play a significant role in shaping future fires. Like low-severity forests in the western United States, many dry mixed-severity types experienced significant increases in stand density during the 20th century, threatening forest health and biodiversity, however not all understory development in mixed-severity forests increases the threat of severe wild fires. In general, current landscapes have been homogenized, reducing beta diversity and increasing the probability of large fires and insect outbreaks. Further loss of old, fire tolerant trees is of particular concern, but understory diversity has been reduced as well. High stand densities on relatively dry sites increase water use and therefore susceptibility to drought and insect outbreaks, exacerbating a trend of increasing regional drying. The need to restore beta diversity while protecting habitat for closed-forest specialists such as the northern spotted owl call for landscape-level approaches to ecological restoration.

- by Paul Hessburg
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- Landscape Ecology, Fire Ecology, Forest Ecology And Management, Forest Ecology

The alarming rate of deforestation in Madagascar is driving some endemic primates to extinction. Surprisingly, anthropogenic habitat disturbance is not always deleterious. The effect of disturbance on lemur abundance may be related to diet, with frugivorous species more prone to population declines than folivores or insectivores. To test the effects of disturbance on lemur abundance and group size, we surveyed 2 sites within contiguous forest at Ranomafana National Park, 1 lightly disturbed primary forest (Vato) and 1 heavily logged forest (Tala). We quantified forest structure variables along 6 survey routes and conducted 68 diurnal and 42 nocturnal lemur surveys. Canopy closure, canopy height, and understory visibility were greater in Vato than in Tala. We encountered 2 frugivorous lemurs (Eulemur rufifrons, Varecia variegata) and 1 folivore (Avahi peyrierasi) significantly more frequently in Vato than in Tala, whereas the opposite was true for the insectivorous Microcebus rufus. Rates did not differ statistically for 1 frugivore (Eulemur rubriventer) and 2 folivores (Propithecus edwardsi, Hapalemur griseus). Comparisons across the 6 survey routes suggest that the abundance was heterogeneous within as well as between sites. Neither group size nor composition differed between sites. Encounter rates for Varecia variegata were positively related to canopy closure, and encounter rates for Avahi peyrierasi were positively related to canopy height. Encounter rates for Microcebus rufus were negatively related to canopy closure, height, and understory visibility. Similar to other studies, the results suggest that some lemurs, including folivores, may cope with anthropogenic disturbance better than others, including some frugivores. Lemur abundance is heterogeneous, though, even on small spatial scales.

- by Elise Lauterbur
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- Zoology, Primatology, Anthropogenic Disturbance, Spatial Scale
- by Vinod Kumar
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- Forestry, Remote Sensing, Airborne Laser Scanning, Fire Management

al sur del estado Veracruz, forma parte del patrimonio natural de México y del mundo. Actualmente, se encuentra inscrito en la Lista Ramsar con el número 1342. Su importancia se reconoce en términos biológicos, culturales y económicos. Su valor biológico está fundamentado en el papel que este ecosistema representa para numerosas especies animales y vegetales, al funcionar como hábitat, refugio y zona de anidación y desove. Una característica distintiva de este manglar son las dimensiones estructurales que presentan sus especies arbóreas así como la presencia de otras plantas asociadas a este ecosistema, principalmente epífitas y orquídeas, muchas de ellas amenazadas con la extinción. Actualmente, su valor cultural está subestimado, aunque la zona del manglar de Sontecomapan tuvo relevancia desde la época prehispánica con la cultura Olmeca. A nivel económico, este manglar es fuente de alimentación e ingresos para numerosas familias. Sin embargo, presenta algunos problemas que pueden poner en riesgo su conservación, como son la tala inmoderada, el azolve, la caza furtiva y el saqueo de especies, entre otros. Este manglar constituye un área natural protegida a cargo de la Universidad Veracruzana, por lo cual, se plantea como estrategia inicial, la formulación de un Plan de manejo que intente cumplir con los objetivos de investigación, educación y conservación de este ecosistema.

- by Jorge Morales Mávil
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- Geography, Productivity, Soil Salinity, Cultural value

Forest structure Predation a b s t r a c t

- by Luca Cistrone
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- Ecology, Forest Management, Spatial Scale, Forest Structure

Lichens are composite organisms consisting of a symbiotic association of a fungus with a photosynthetic partner. Although the photobiont type is a key life-history trait, tests of the potential differential role of the main photobiont types in shaping large-scale patterns of lichen species richness are still absent. The aim of the study was to test the influences of forest structure and climate on epiphytic lichen species richness across Italy and to see whether these relationships change for groups of species sharing different photobiont types. Regional species richness of epiphytic lichens divided into three main photobiont types (i.e. chlorococcoid green algae, cyanobacteria, and Trentepohlia algae) was retrieved for each of the 20 administrative regions. Multiple linear regression was used to quantify the effect of climate and forest structure, and their potential interaction, on the regional species richness for the three photobiont types, accounting also for the effect of regional area. Regional species richness was associated with both climate and forest structure variables but the relationships with both factors were largely photobiont dependent. Regional area and precipitation were the only predictors included in all the models, confirming the strong dependence of lichens on atmospheric water supply, irrespective of the photobiont type. Number of species with chlorococcoid green algae were further positively associated with cover of high forest, whilst lichens with Trentepohlia were further enhanced by warm temperatures. Cyanolichen species richness was only related to area and precipitation. Our study shed light on the relative importance of climate and forest structure on lichen species richness patterns at the macroscale, showing a differential response of the photobiont types to various environmental determinants. This differential response suggested that the current and future impacts of global change on lichens cannot be generalized and that species richness response will be likely dependent on the photobiont type.

- by Juri Nascimbene
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- Phylogeography, Photosynthesis, Cyanobacteria, Environmental Monitoring

Question: Thousands of small isolated forest fragments remain around churches (''church forests'') in the almost completely deforested Ethiopian Highlands. We questioned how the forest structure and composition varied with altitude, forest area and human influence. Location: South Gondar, Amhara National Regional State, Northern Ethiopia. Methods: The structure and species composition was assessed for 810 plots in 28 church forests. All woody plants were inventoried, identified and measured (stem diameter) in seven to 56 10 m x 10-m plots per forest. Results: In total, 168 woody species were recorded, of which 160 were indigeneous. The basal area decreased with tree harvest intensity; understorey and middle-storey density (o5 cm DBH trees) decreased with grazing; overstorey density (45 cm DBH trees) increased with altitude. The dominance of a small set of species increased with altitude and grazing intensity. Species richness decreased with altitude, mainly due to variation in the richness of the overstorey community. Moreover, species richness in the understorey decreased with grazing intensity. Conclusions: We show how tree harvesting intensity, grazing intensity and altitude contribute to observed variations in forest structure, composition and species richness. Species richness was, however, not related to forest area. Our study emphasizes the significant role played by the remaining church forests for conservation of woody plant species in North Ethiopian Highlands, and the need to protect these forests for plant species conservation purposes.

- by Alemayehu Wassie
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- Plant Biology, Ecology, Species Composition, Species Richness

We overview the recent development of oak dendrochronology in Europe related to archaeology and arthistory. Tree-ring series of European oaks (Quercus robur and Q. petraea) have provided a reliable framework for chronometric dating and reconstruction of past climate and environment. To date, long oak chronologies cover almost the entire Holocene, up to 8480 BC and the network over the entire area in which the two oaks grow is being improved. We present the main characteristics of oak ring series and discuss the latest methodological advances in defining the calendar year in which the tree-rings were formed and in interpreting such dating in terms of the age of a wooden object. Dendrochronology has established itself as a standard dating tool and has been applied in a wide variety of (pre-)historical studies. Archaeological wood, historical buildings, works of art (such as panel paintings and sculptures) have been successfully investigated. Recent advances in dendro-provenancing have helped to obtain more information on the timber trade in the past. Information on past forest structures, silviculture and timber use have become available through scrutinizing historical and contemporary ring-width patterns.

- by Kristof Haneca
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- Archaeology, Geochemistry, Art History, Cultural Heritage

The adequate protection and sustainable management of a tropical rain forest requires a good knowledge of its biodiversity. Although considerable parts of Guyana's North-West District have been allocated as logging concessions, little has been published on the forest types present in this region. The present paper reviews the floristic composition, vegetation structure, and diversity of well-drained mixed and secondary forests in northwest Guyana. Trees, shrubs, lianas, herbs and hemi-epiphytes were inventoried in four hectare plots: two in primary forests, one in a 20-year-old secondary forest and one in a 60-year-old secondary forest. The primary forests largely corresponded with the Eschweilera-Licania association described by Fanshawe, although there were substantial variations in the floristic composition and densities of dominant species. The late-succession forest contained the highest number species and was not yet dominated by Lecythidaceae and Chrysobalanaceae. There is a need for updating the existing vegetation maps of northwest Guyana, as they were based on limited information. Large-scale forest inventories may provide a fair indication of species dominance and forest composition, but do not give a reliable insight in floristic diversity. Although previous reports predicted a general low diversity for the North-West District, the forests plots of this research were among the most diverse studied in Guyana so far. These results will hopefully influence the planning of protected areas in Guyana.

- by Tinde van Andel
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- Ecology, Biodiversity Conservation, Forest Structure, Sustainable Management

Forest thinning and prescribed fires are practices used by managers to address concerns over ecosystem degradation and severe wildland fire potential in dry forests. There is some debate, however, about treatment effectiveness in meeting management objectives as well as their ecological consequences. The purpose of this study was to assess changes to forest stand structure following thinning and prescribed fire treatments, alone and combined, in the eastern Cascade Mountains of Washington State. Treatments were applied to 12 management units, with each treatment combination replicated three times (including untreated controls). Thinning modified forest structure by reducing overall tree density by >60% and canopy bulk density by 50%, and increased canopy base height by $4 m, thereby reducing susceptibility to crown fire. The prescribed fire treatment, conversely, did not appreciably reduce tree density or canopy fuel loading, but was effective at increasing the density of standing dead trees, particularly when combined with thinning (37 snags/ha increase). Prescribed fire effects were more pronounced when used in combination with thinning. Thinning was more reliable for altering stand structure, but spring burning was lower in intensity and coverage than desired and may have led to results that downplay the efficacy of fire to meet forest restoration goals.

- by Nicholas Povak
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- Forestry, Restoration Ecology, Forest Ecology And Management, Wildland Fire

Mangrove forest structure is the result of interactions between species responses to abiotic stress factors, disturbance, dispersal and competition. The combination of abiotic conditions and disturbance history may determine the growth potential of the species, whereas dispersal, competition and external or biogenic changes in abiotic conditions may tune their succession. Even in forests with only a few species, this set of factors can create multiple species compositions. For example, pure stands of the mangrove Laguncularia are common in newly colonized areas, but they may evolve into mixed stands dominated by Rhizophora or Avicennia. We demonstrate such an evolution with a field study of mangroves established in abandoned rice fields. We use an individual-based simulation model to understand how species-dependent dispersal, growth rate and shade tolerance lead to the observed patterns in horizontal and vertical forest structure. We find that the initially dominating species will be gradually replaced in the canopy. This alteration cannot be explained exclusively by shade tolerance of the succeeding species. Rather, it is essential to assume that the height growth rate of the pioneer species slows down relative to those of the later species. A decrease in nutrient availability may be responsible for these relative changes in the growth rates of different species.

- by Uta Berger
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- Evolutionary Biology, Plant Biology, Ecology, Abiotic Stress

1. This paper reviews and compares the effects of forest fire and timber harvest on mammalian abundance and diversity, throughout successional time in the boreal forest of North America. 2. Temporal trends in mammal abundance and diversity are generally similar for both harvested and burned stands, with some differences occurring in the initiation stage (0-10 years post disturbance). 3. Small mammals and ungulates are most abundant immediately post disturbance, and decrease as stands age. Lynxes and hares utilize mid-successional stands, but are rare in young and old stands. Bats, arboreal sciurids and mustelids increase in abundance with stand age, and are most abundant in old growth. 4. Substantial gaps in the data exist for carnivores; the response of these species to fire and harvest requires research, as predator-prey interactions can affect mammal community structure in both early and late successional stages. 5. The lack of explicit treatment of in-stand forest structure post disturbance, in the reviewed literature made comparisons difficult. Where forest structure was considered, the presence of downed woody material, live residual trees and standing dead wood were shown to facilitate convergence of mammal communities to a pre-disturbance state for both disturbance types. 6. Mammalian assemblages differed considerably between successional stages, emphasizing the importance of maintaining stands of each successional stage on the landscape when implementing forest management strategies.

- by Jason T. Fisher
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- Zoology, Ecology, Predator-prey interaction, Forest fire

Page 1. 115 Introduction Forest adaptation to climate and site conditions is a basic prerequisite for the mainte-nance of structure, vitality, and ecosystem functioning of European woodlands; this includes their harvesting and carbon... more

- by Magnus Löf and +1
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- Climate Change, Forest Planning, Sustainable forestry, Forest Management

Forest structure and productivity was investigated in a 12-year-old Rhizophora mucronata Lam. plantation at Gazi Bay, Kenya. Sampling was carried out in 22, 10 m Â 10 m quadrats laid along belt transects perpendicular to the waterline. Within each quadrat all trees with stem diameter greater than 2.5 cm were identified, position marked and counted. Vegetation measurements included tree height (m), canopy cover (%) and stem diameter measured at 1.3 m above the ground (D 130 ); from which were derived basal area (m 2 /ha); stand density (stems/ha) and biomass (t/ha). Information regarding composition and distribution of juveniles was derived using linear regeneration sampling (LRS). The replanted forest had a stand density of 5132 stems/ha; with a mean canopy height and stem diameter of 8.4 AE 1.1 m (range: 3.0-11.0 m) and 6.2 AE 1.87 cm (range: 2.5-12.4 cm), respectively. The total juvenile density was 4886 saplings per hectare; 78.6% of which constituted the parental canopy. The standing biomass for the 12-year-old R. mucronata plantation was 106.7 AE 24.0 t/ha, giving a biomass accumulation rate of 8.9 t/(ha year). #

The forests of Central Africa enjoy world-wide recognition for their spectacular wildlife and also harbor an abundance of high quality timber. With mismanagement and the conversion of large tracts of West African forest to agricultural production, Central African forests are experiencing increased harvesting pressures. This is particularly true for species of African mahogany (Entandrophragma spp.).

- by Dave Harris
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- Forest Ecology And Management, Biodiversity, Forest Ecology, Biological Sciences
- by Jennifer Swenson and +1
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- Forestry, Remote Sensing, Structure, Forest Ecology And Management

In this study are proposed impacts, management and functional planning criterion of forest road network system in rural and urban landscapes of Turkey. Road spacing and road density have been inspected concerning forest roads in production, reforestation, national parks and protection forests of rural and urban landscapes of Turkey. The forest road network was the most expensive human activity in the forests both in terms of economics and environmental effects. Public opinion about the environment has increased in recent years. Sustainable land use planning creates a great challenge for rural and urban road network planning. Further improvements of the network are necessary, to provide for people's needs in the near future. Harmful effects of road network conflict with the principles of sustainability. When making use of the forest ecosystem for various purposes, care must be taken not to spoil the forest structure. To achieve this, forests must be used according to forestry techniques. So, there is a need for a new planning approach, serving the interests of both accessibility and sustainable environment. In rural landscapes, forest road planning standards (slope, width, pavement, drainage etc.) are different in production, forestation, national parks and protection forests. The need for total forest roads in Turkey was 201,810 km, and that 133,693 km portion of which, corresponding to 66.25%, was constructed by the end of 2005. With a view to be capable of conducting modern forestry activities, our country's forests should be provided with a systematic road network by completing as soon as possible the construction of the remaining portion of such roads.

- by Murat Demir
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- Public Opinion, Urban And Regional Planning, Forest road, Environmental Effect

Forest fire is often considered a primary threat to California spotted owls (Strix occidentalis occidentalis) because fire has the potential to rapidly alter owl habitat. We examined effects of fire on 7 radiomarked California spotted owls from 4 territories by quantifying use of habitat for nesting, roosting, and foraging according to severity of burn in and near a 610-km 2 fire in the southern Sierra Nevada, California, USA, 4 years after fire. Three nests were located in mixed-conifer forests, 2 in areas of moderate-severity burn, and one in an area of lowseverity burn, and one nest was located in an unburned area of mixed-conifer-hardwood forest. For roosting during the breeding season, spotted owls selected low-severity burned forest and avoided moderate-and high-severity burned areas; unburned forest was used in proportion with availability. Within 1 km of the center of their foraging areas, spotted owls selected all severities of burned forest and avoided unburned forest. Beyond 1.5 km, there were no discernable differences in use patterns among burn severities. Most owls foraged in high-severity burned forest more than in all other burn categories; high-severity burned forests had greater basal area of snags and higher shrub and herbaceous cover, parameters thought to be associated with increased abundance or accessibility of prey. We recommend that burned forests within 1.5 km of nests or roosts of California spotted owls not be salvage-logged until long-term effects of fire on spotted owls and their prey are understood more fully.

- by Monica L Bond and +1
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- Forest fire, Biological Sciences, Resource Selection Function, Environmental Sciences

The aim of this paper is to investigate differences in plant species composition between managed and unmanaged forests, and to assess if these difference give rise to a higher plant diversity in the unmanaged forest. Furthermore our aim is to relate forest structure to differences in plant species composition, identifying the structural attributes more strongly related to the unmanaged forest vegetation. We compared an old-growth forest and a managed highforest in the Abruzzo Lazio and Molise National Park (Central Italy). Plant species composition and diversity, deadwood components and live structure have been analyzed. We used permutational multivariate analysis of variance to test the response of species composition to management factor; furthermore, we compared species richness and beta diversity. Redundancy analysis has been used to relate plant species abundances to structural variables; the importance of dead and living wood components has been compared through variation partitioning. Plant species composition proved to be significantly different in the two sites, and the old-growth stand showed a higher plant diversity. From a structural point of view, we found differences especially in the amount and quality of deadwood, and in the diameter class distribution. These variables are also the most important in determining the old-growth stand plant species composition according to redundancy analysis. Variation partitioning confirmed the greater importance of the deadwood variables. Our results suggest that including deadwood surveys in traditional forest inventories could help in finding forests with both structural and floristic old-growth properties to be considered in conservation programmes. The imitation of natural dynamics, through the creation of gaps avoiding deadwood removal, could be an effective strategy for restoring oldgrowth conditions, also in terms of plant diversity.

- by marco marchetti
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- Plant Biology, Ecology, Plant Diversity, Beta diversity
- by Marieke Baeten
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- Forest Ecology And Management, Agroforestry, Forest Ecology, Homogenization
- by Alemayehu Wassie
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- Seed germination, Biodiversity Conservation, Soil moisture, Rare species