Pablo José Francisco Pena Rodrigues (original) (raw)

Papers by Pablo José Francisco Pena Rodrigues

Revista Árvore

Habitat fragmentation is one of the leading causes of edge genesis and its effects. Functional tr... more Habitat fragmentation is one of the leading causes of edge genesis and its effects. Functional tree traits such as wood density, height, and diameter are essential variables from which it is possible to infer several ecological processes. This study assessed the variability of the functional traits of trees over two habitats (edge and interior) of a forest remnant. The hypothesis tested were i) the functional traits would have lower values at the edges than the interior, and ii) environmental variables would influence such differences. This study was carried out in the largest Atlantic Forest remnant within Serra da Tiririca State Park, Brazil, by establishing ten plots (50 × 20 m) among different habitats. Within each plot, wood samples were taken from all trees with a diameter of ≥ 10 cm. It was recorded the altitude, distance from the plots to the edge, and fire records as possible explanatory variables (environmental variables). Wood density was obtained using the immersion meth...

Scientia Forestalis

Fires and habitat fragmentation are responsible for devastating large ecosystems around the biosp... more Fires and habitat fragmentation are responsible for devastating large ecosystems around the biosphere. The increasing use of remote sensing allows fire patterns to be identified and plays an essential role in preventing fires. In this context, this study aimed to describe the variation in evidence of fire between the edge and the interior of an Atlantic Forest remnant in southeastern Brazil and infer its effects on vegetation. Fire records were acquired between 2010 and 2020 from the Instituto Nacional de Pesquisas Espaciais database and United States Geological Survey satellite images. For each scene, the images were processed and the normalized difference vegetation index (NDVI) was calculated. To assess the variation, records were classified and compared according to the year, month, hours, and habitat type (edge and interior). To verify the influence of fires on vegetation, simple linear regressions were performed based on the fire risk due to the NDVI-year-habitat interaction. The data included 748 fire records, with the highest occurrences from April to August, and 51% of the fires occurred between 15h and 20h, indicating periods with more intense solar radiation. The relationship between fire risk and NDVI-year-habitat was significant (F = 30.35; R 2 = 0.26; p < 0.0001), and the edges were more vulnerable to fire risk. This study shows that in an Atlantic Forest remnant, areas with lower vegetation indices, such as edges, are more vulnerable to fire than areas with dense forest vegetation.

Rodriguésia, 2006

RESUMO Este estudo teve por objetivo descrever a estrutura e composição florística arbórea de doi... more RESUMO Este estudo teve por objetivo descrever a estrutura e composição florística arbórea de dois fragmentos naturais de florestas periodicamente inundadas na Reserva Biológica de Poço das Antas e compará-los a outros tipos florestais da região. Seis parcelas de 30 m x 20 m foram alocadas em cada fragmento. Todas as árvores (DAP ≥ 10 cm) foram amostradas. Os dois fragmentos, denominados ARI e CM, apresentaram estrutura muito similar. Ao todo foram amostradas 628 árvores pertencentes a 31 espécies e 16 famílias, com forte dominância de espécies heliófilas tolerantes à inundação, como Calophyllum brasiliense, Symphonia globulifera (Clusiaceae) e Tabebuia cassinoides (Bignoniaceae). Estas três espécies foram responsáveis por 73% do valor de cobertura em ARI e 67% em CM. Os índices de diversidade de espécies (H' = 1,75 e 1,99, para ARI e CM respectivamente) foram próximos aos de outras florestas inundáveis do sudeste brasileiro. Os fragmentos apresentaram elevada similaridade florí...

arXiv: Populations and Evolution, 2018

Anthropogenic changes of the biota and human hyper-dominance are modulating the evolution of life... more Anthropogenic changes of the biota and human hyper-dominance are modulating the evolution of life on our planet. Humankind has spread worldwide supported by cultural and technological knowledge, and has already modified uncountable biological interactions. While numerous species have been extinguished by human actions, others are directly favored, such as alien species, hybrids, and genetically modified organisms. These biodiversity shifts have generated new interactions among all living organisms in anthropized or anthropogenic ecosystems, with the consequent establishment of novel evolutionary pathways. Thus, humans have created a strong evolutionary bias on Earth, leading to unexpected and irreversible outcomes. Anthropogenic changes and novelty organisms are shifting the evolutionary paths of all organisms towards the Biological Anthropocene, a new concept of our imprint on biodiversity and evolution.

Journal of Geoscience and Environment Protection, 2023

The palm Euterpe edulis was historically very exploited by humans and even today, many individual... more The palm Euterpe edulis was historically very exploited by humans and even today, many individuals are cut down by collectors to harvest the edible palm hearts. The ecological aspects of this anthropogenic pressure and its related effects are poorly understood. Here we investigate if linear canopy openings in a fragment of Brazilian Atlantic Forest can cause edge effects and facilitate predatory harvesting by humans. We sampled in Tinguá Biological Reserve (Southeastern Brazil) native palm populations at forest edges adjacent to two linear canopy openings, and in the forest interior far from any edge. Our 8-year monitoring showed that the linear canopy openings negatively affected
the palm populations reducing its density and regeneration mainly on edges, but no local extinction was observed. Thus, the direct human impact from harvesting, adverse survival conditions on edges and interspecific competition causes population declines with no local extinction, so this suggests that E. edulis may resist even under strong anthropogenic pressure.

Biological Theory, 2019

Anthropogenic changes in the biosphere, driven mainly by human cultural habits and technological ... more Anthropogenic changes in the biosphere, driven mainly by human cultural habits and technological advances, are altering the direction of evolution on Earth, with ongoing and permanent changes modifying uncountable interactions between organisms, the environment, and humankind itself. While numerous species may go extinct, others will be favored due to strong human influences. The Bio-Evolutionary Anthropocene hypothesizes that directly or indirectly human-driven organisms, including alien species, hybrids, and genetically modified organisms, will have major roles in the evolution of life on Earth, shifting the evolutionary pathways of all organisms through novel biological interactions in all habitats. We anticipate that, in future scenarios, novel organisms will be continuously created, and contemporary native organisms with no obvious economic use will decline-while anthropogenic-favored and novel organisms will spread. The Bio-Evolutionary Anthropocene hypothesis therefore predicts that humankind and novel organisms will interact within a strong evolutionary bias that will lead to unexpected, and probably irreversible, outcomes for the evolution of life on our planet.

New Forests, Apr 29, 2017

The ecological resilience of abandoned pastures has important implications for the potential of p... more The ecological resilience of abandoned pastures has important implications for the potential of passive restoration in the Brazilian Atlantic Forest, especially in the face of the ambitious restoration targets for this biodiversity hotspot. In the present study, we aimed to investigate the influence of past land-use on natural regeneration in two secondary forests that established on abandoned pastures with different land use histories (Abandoned ? Fire-15 years since the last fire event and Abandoned-36 years ago) in a lowland Brazilian Atlantic Forest. Both secondary forests exhibit low resilience for the three analyzed attributes: vegetation structure, richness, and species composition. Secondary forests affected by fire have the lowest values for species richness, aboveground biomass and leaf area index compared to old-growth forests. Secondary forests were dominated by Moquiniastrum polymorphum-Asteraceae, which was absent from the oldgrowth forests. Fire resistance, capacity to establish in nutrient-poor soils and efficient seed dispersal in human-modified landscapes are important attributes that may explain the dominance of this species. We demonstrate that even in sites considered appropriate for passive restoration a priori (e.g. located in a protected area, 36 years since abandonment and close to old-growth forests), secondary forests exhibited low aboveground biomass and communities were dominated by few species. Therefore, our results highlight the effects of past land-use on natural regeneration and suggest the necessity to use interventions such as enrichment plantings, nucleation techniques and assisted natural regeneration in order to accelerate forest restoration.

Advances in Forestry Science

The Atlantic Forest is one of the richest and most threatened biomes in Brazil. However, the stru... more The Atlantic Forest is one of the richest and most threatened biomes in Brazil. However, the structure and floristic composition of many of its remnants are still unknown. This study assessed the structure and tree composition of the Serra da Tiririca – SET coastal remnant, is the largest remnant in Serra da Tiririca State Park – PESET (Atlantic Forest, RJ). In ten 50 × 20 m plots installed between the edges and the interior of the remnant, we registered 403 trees distributed in 29 families, 59 genera, and 126 species. The richest and most abundant families were Fabaceae, Myrtaceae, and Meliaceae, while the most representative species were Gallesia integrifolia towards the interior of the remnant and Piptadenia gonoacantha towards the edges. The remnant had an average Shannon-Wiener Diversity of 3.69, a total basal area of 19.3 m2/ha, and an average diameter and height of 20.42 cm and 11.8 m, respectively. This study shows that the SET remnant is floristically heterogeneous and ha...

arXiv (Cornell University), Dec 29, 2021

Humankind has spread worldwide supported by cultural and technological knowledge, but the environ... more Humankind has spread worldwide supported by cultural and technological knowledge, but the environmental sustainability on the human niche evolution depends on a new human beings relationship with the biosphere. Human lifestyles nowadays are very "Antropocentric" and in many ways deleterious to the other life forms. Here we try to identify future scenarios, where the less deleterious is the "Natural-Technological Model" that points the urgent need to change the evolutionary direction of the human niche seeking the resumption of original ecological relations. New cultural habits and novel technologies, thereby, would reverse the current anthropogenic impacts. The middle way is the Bio-Anthropogenic Model that predicts the success of the emerging ecosystems and the symbiotic relationship of humans and anthropogenic-favored species, hybrids, aliens and genetically modified organisms. For such, we must also change our way of life and adopt new conscious ways of consumption aiming at the socio-environmental good. Lastly, the Wear Out Model, which depends only on maintaining current patterns of human expansion. The lack of investments on new technologies and new cultural habits, added to the current patterns of human niche evolution that are based on the massive exploitation of world resources, will lead to a fearsome scenario with a precarious global health, biodiversity losses and food scarcity. This theoretical models indicates some pathways and can help us to choose a better future.

Biological Conservation, 2021

Ciência Florestal, 2019

Os núcleos de vegetação são estruturas formadas espontaneamente por pequenos agrupamentos de indi... more Os núcleos de vegetação são estruturas formadas espontaneamente por pequenos agrupamentos de indivíduos arbustivos e arbóreos, que, ao evoluírem em pastagens perturbadas, podem contribuir na sucessão ecológica. Para compreender a evolução dos processos de restauração florestal passiva em ecossistemas tropicais, depois de paralisada a pecuária extensiva, foram estudados ambientes com baixa oferta de atributos ambientais localizados na vertente norte dos morrotes isolados entre planície de inundação. Após 40 anos de abandono, os núcleos de vegetação colonizaram 20% dos ecossistemas graminoides amostrados, apresentando-se em estágio moderado de perturbação. A composição florística dos estratos superior e regenerante evidenciou que núcleos com duas ou mais espécies florestais pioneiras e com síndrome de dispersão anemocórica, como Moquiniastrum polymorphum, apresentam alta probabilidade de terem seus processos de restauração catalisados no tempo. Núcleos desenvolvidos apresentam riqueza...

Forests, 2018

The timing, duration, magnitude and synchronicity of plant life cycles are fundamental aspects of... more The timing, duration, magnitude and synchronicity of plant life cycles are fundamental aspects of community dynamics and ecosystem functioning, and information on phenodynamics is essential for accurate vegetation classification and modeling. Here, we recorded the vegetative and reproductive phenodynamics of 479 individuals belonging to 182 tree species monthly over two years in a lowland Atlantic Forest in southeastern Brazil, and assessed the relationship between local climatic conditions and the occurrence and intensity of phenophases. We found a constant but low intensity of occurrence of both leaf fall and leaf flush with respect to canopy cover, resulting in an evergreen cover throughout the year. The timing of the reproductive phenophases was irregular between the two years of observation, and their amplitude was low. In addition, flowering and fruiting phenograms of activity, intensity and intensity corrected by the basal area did not overlap. These results suggest that a combination of phenological records and community-structure parameters allows for the obtainment of more accurate estimates of resource availability over time. We found that differences in growing degree-days (GDD), photoperiod and precipitation over time were related to temporal variation in leaf fall, leaf flush and flowering, with a large consistency in responses across tree species in this lowland Atlantic Forest. Moreover, there was only a weak relationship between climatic conditions and the dynamics of fruit formation and ripening, which were more strongly related to flowering phenodynamics, which is suggestive of indirect effects of climatic conditions on fruiting. Finally, the association we found between the number of days with precipitation and leaf fall dynamics agrees with the view that the greater potential for extreme events may impair plant growth in tropical forests. This reinforces the growing concerns regarding the risk of ecological collapse of tropical forests due to fragmentation and global climate change.

Journal of Tropical Ecology, 2018

Isotopic composition of leaf carbon (δ 13 C) and nitrogen (δ 15 N) is determined by biotic and ab... more Isotopic composition of leaf carbon (δ 13 C) and nitrogen (δ 15 N) is determined by biotic and abiotic factors. In order to determine the influence of leaf habit and site on leaf δ 13 C and δ 15 N in the understorey of two Atlantic forests in Brazil that differ in annual precipitation (1200 and 1900 mm), we measured these isotopes in the shaded understorey of 38 tropical tree species (20 in the 1200-mm site and 18 in the 1900-mm site). Mean site values for δ 15 N were significantly lower at the 1200-mm site (−1.4‰) compared with the 1900-mm site (+3.0‰), and δ 13 C was significantly greater in the 1200-mm site (−30.4‰) than in the 1900-mm site (−31.6‰). Leaf C concentration was greater and leaf N concentration was lower at 1200-mm than at 1900-mm. Leaf δ 15 N was negatively correlated with δ 13 C across the two sites. Leaf δ 13 C and δ 15 N of evergreen and deciduous species were not significantly different within a site. No significant phylogenetic signal for any traits among the study species was found. Overall, site differences were the main factor distinguishing traits among species, suggesting strong functional convergence to local climate and soils within each site for individuals in the shaded understorey.

Plant Ecology & Diversity, 2017

Background: Variation in the distribution and abundance of woody plants as consequence of disturb... more Background: Variation in the distribution and abundance of woody plants as consequence of disturbances such as fire may be explained by lineage age. Aims: We tested whether lowland tropical tree lineages that colonise secondary forests are more late-diverging than clades from old-growth forests, and whether tree phylogenetic beta diversity from old-growth to secondary forests is higher in burned than non-burned secondary forests. Methods: We sampled tree communities in old-growth forests and in secondary forests with distinct disturbance histories (burned and unburned). We calculated mean family age in each plot, and tested for differences among forest types using ANOVA. A phylogenetic fuzzy-weighting procedure was employed to generate a matrix describing the abundance of tree clades per plot, which was then analysed using a principal coordinate analysis. Results: Most clades found in old-growth forests were underrepresented in secondary forests, which have been heavily colonised by a single species from a young lineage that is not found in old-growth forests. Phylogenetic beta diversity was higher between unburned secondary forests and old-growth forests than between burned secondary forests and old-growth forests. Conclusions: The capacity of Neotropical trees to colonise secondary forests and persist after fire disturbance may be related to the age of distinct lineages.

Journal of Geoscience and Environment Protection, 2016

The Atlantic forest has historically been severely deforested, and only fragments currently remai... more The Atlantic forest has historically been severely deforested, and only fragments currently remain that are subject to a wide variety of anthropogenic impacts, including edge effects that can cause structural and functional degradation. The Tinguá Biological Reserve-RJ comprises approximately 26,000 hectares of well-preserved Atlantic Forest, but it is subject to impacts caused by two canopy openings along oil pipelines. Comparisons were made between pipeline edges and forest interiors to evaluate edge effects on the structure and dynamics of those tree communities. Tree densities were higher along forest edges, apparently increasing over time. Tree basal areas, on the other hand, have decreased along edges due to higher mortality rates. Linear canopy opening edges showed higher densities of small trees, while the interior had more very large trees, indicating changes in successional processes and community structural patterns due to edge effects.

Rodriguésia, 2009

Caesalpinia echinata Lam. an endangered species, occurs in forest fragments of the Cabo Frio regi... more Caesalpinia echinata Lam. an endangered species, occurs in forest fragments of the Cabo Frio region, in Rio de Janeiro, Brazil. Data from four sub-populations were used to describe local population patterns and one-year dynamics. In each subpopulation, 0.1 ha-plots were set up and all C. echinata trees were mapped, and diameter and height were measured. The fragments sampled had different sizes and were subjected to various degrees of man-made disturbance, representing a succession gradient from an earlier (small fragment) to a later stage (large fragment). We compared the sub-populations as regards density, size structure, spatial distribution, germination and mortality, to identify short-term responses to mechanical injuries (broken stems, sand burial and man-made cuts). Matrix analysis considering the four C. echinata sub-populations together showed a slight tendency for population expansion (λ = 1.0211) if injury patterns do not lead to habitat extinction. On the other hand, sub...

Rodriguésia, 2010

Artocarpus heterophyllus Lam. (jackfruit) was man made introduced in Tijuca National Park (TNP) i... more Artocarpus heterophyllus Lam. (jackfruit) was man made introduced in Tijuca National Park (TNP) in the mid- 1800s. Native from Southeast Asia, nowadays densely colonizes the TNP. Here we analyze some jackfruit population parameters that probably allowed the local colonization followed by successful invasion of the new habitat. Based on 20 sampleplots, randomlyplaced inside 5 sitescolonizedby jackfruit, we described subpopulations hierarchical size diameter structures. Gini’s coefficient values turned around 0.64 and Lorenz’s asymmetry coefficient around 1.03, indicating that size hierarchies were very similar between sites. The five sites were also compared and do not differ based on jackfruit basal area, number of species, Shannon’s index and canopy openness. Jackfruit may, therefore, be considered invasive in all these sites and the low tree diversity values (H’ overall mean 0.74) also indicates that this exotic species locally excludes native ones.

Botanical Journal of the Linnean Society, 2009

Fragmentação florestal: breves considerações teóricas sobre efeitos de borda) Os processos de fra... more Fragmentação florestal: breves considerações teóricas sobre efeitos de borda) Os processos de fragmentação florestal atualmente representam um dos principais riscos à biodiversidade global. Neste contexto é muito importante considerar estas transformações artificiais aos ecossistemas para compreender até mesmo padrões e processos ecológicos naturais. Neste trabalho é feita uma sinopse teórica que inclui o desenvolvimento de alguns conceitos e uma análise crítica destes, mesmo na falta de um arcabouço conceitual unificador sobre fragmentação florestal. São discutidas algumas teorias sobre limites (i.e. bordas) artificiais e naturais tendo como base as transformações ao longo do tempo e fenômenos de retração e expansão de comunidades e ecossistemas. A sucessão ecológica é brevemente discutida com base nas visões conflitantes de Clements e Gleason e mencionamos a importância de rever alguns modelos sucessionais para elucidar determinados aspectos dos efeitos de borda. Sobre estes efeitos é esboçada uma breve perspectiva histórica da evolução de alguns conceitos. Embora exista um conhecimento relativamente vasto sobre os efeitos de borda afirmamos que ainda é muito difícil prever a trajetória dos processos ecológicos em bordas assim como as transformações nos padrões naturais. Palavras-chave: desmatamento, extinção, sucessão, teoria ecológica, limites. ABSTRACT (Forest fragmentation: brief theoretical considerations about edge effects) Forest fragmentation is one of the main threats to global biodiversity. Considering artificial changes in ecosystems is essential to understand even natural ecological patterns and processes. A theory overview is performed, including the improvement of concepts and critical analysis, despite the lack of a unifying conceptual framework about forest fragmentation. We also discuss some theories about natural and artificial limits (i.e. boundaries) based on transformations over time and communities/ecosystems retraction and expansion. Ecological succession is briefly discussed using some aspects of Clement's and Gleason's conflicting viewpoints and pointing out the need for reviewing some succession models in order to understand some edge effects. About these effects we draft a concise historical perspective regarding the evolution of some concepts. Despite the relatively wide knowledge on edge effects we argue that it is very difficult to predict ecological processes pathways on edges as well as changes on natural patterns.