Discussões sobre a escala em ecologia de comunidades

Problemas relacionados às escalas espacial e temporal nos estudos em ecologia de comunidades vêm sendo amplamente discutidos desde o final do século XX. Vários autores tratam dessas questões de maneira provocativa, criticando não só como as comunidades ecológicas são definidas, mas também em que escalas elas são normalmente estudadas. Com o intuito de analisar algumas das principais desarmonias existentes na literatura científica, revisamos dois trabalhos-chave recentes sobre esse assunto, apresentando as diferentes concepções que eles possuem acerca do modo como as comunidades devem ser compreendidas. Ainda, discutimos sobre a escassez de dados de biogeográficos, filogenéticos, e sobre história de vida de organismos, indicando que a resolução de questões relacionadas a escalas está associada às disponibilidades desses dados. Por fim, aconselhamos que sempre devemosconsiderar as extensões espaço-temporais quando estudamos comunidades, assim como não esquecer das diferenças biológicas entre os organismos

Does logging and forest conversion to oil palm agriculture alter functional diversity in a biodiversity hotspot?

Forests in Southeast Asia are rapidly being logged and converted to oil palm. These changes in land-use are known to affect species diversity but consequences for the functional diversity of species assemblages are poorly understood. Environmental filtering of species with similar traits could lead to disproportionate reductions in trait diversity in degraded habitats. Here, we focus on dung beetles, which play a key role in ecosystem processes such as nutrient recycling and seed dispersal. We use morphological and behavioural traits to calculate a variety of functional diversity measures across a gradient of disturbance from primary forest through intensively logged forest to oil palm. Logging caused significant shifts in community composition but had very little effect on functional diversity, even after a repeated timber harvest. These data provide evidence for functional redundancy of dung beetles within primary forest and emphasize the high value of logged forests as refugia for biodiversity. In contrast, conversion of forest to oil palm greatly reduced taxonomic and functional diversity, with a marked decrease in the abundance of nocturnal foragers, a higher proportion of species with small body sizes and the complete loss of telecoprid species (dung-rollers), all indicating a decrease in the functional capacity of dung beetles within plantations. These changes also highlight the vulnerability of community functioning within logged forests in the event of further environmental degradation

The Effects of Restoring Logged Tropical Forests on Avian Phylogenetic and Functional Diversity.

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 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. This article is protected by copyright. All rights reserved

Impacts of selective logging on insectivorous birds in Borneo: The importance of trophic position, body size and foraging height

Habitat destruction and degradation are major drivers of biodiversity loss and attention is increasingly focused on how different traits of species affect their vulnerability. Dietary traits are critical in this respect, and are typically examined by assigning species to different feeding and foraging guilds. However, such guilds may mask large variation in species' trophic interactions, limiting our understanding of species' responses. Here we use stable isotopes to quantify trophic positions within a Family of insectivorous understory birds, the Timaliidae (babblers), within Bornean rainforests. We then relate changes in species' abundances following intensive selective logging of forest to their trophic positions, body sizes and foraging heights. We found that trophic positions within this single feeding guild spanned more than an entire trophic level. Moreover, changes in abundance following logging were significantly and independently related to mean trophic position in primary forest, body size and foraging height: large ground-feeding species occupying high trophic positions were more adversely affected than small understory-feeders with lower trophic positions. These three variables together explained 81% of the variance in species' responses to logging. The single most important predictor, however, was a species' mean trophic position. Species recorded in both habitats also had significantly higher trophic positions in logged forest. These data provide critical new understanding of species' responses to disturbance. They also indicate previously unrecognised functional changes to species assemblages following logging, highlighting the importance of numerical assessments of trophic position within individual feeding guilds

Environmental factors are stronger predictors of primate species’ distributions than basic biological traits

Understanding the neutral, biological and environmental processes driving species distributions is valuable in informing conservation efforts because it will help us predict how species will respond to changes in environmental conditions. Environmental processes affect species differently according to their biological traits, which determine how they interact with their environment. Therefore, functional, trait-based modelling approaches are considered important for predicting distributions and species responses to change but even for data-rich primate communities our understanding of the relationships between traits and environmental conditions is limited. Here we use a large-scale, high-resolution dataset of African diurnal primate distributions, biological traits and environmental conditions to investigate the role of biological traits and environmental trait filtering in primate distributions. We collected data from published sources for 354 sites, and 14 genera with 57 species across Sub-Saharan Africa. We then combined a three-table ordination method, RLQ, with the Fourth Corner approach to test relationships between environmental variables and biological traits and used a mapping approach to visually assess patterning in primate genus and species’ distributions. We found no significant relationships between any groups of environmental variables and biological traits, despite a clear role of environmental filtering in driving genus and species’ distributions. The most important environmental driver of species distributions was temperature seasonality, followed by rainfall. We conclude that the relative flexibility of many primate genera means that not any one particular set of traits drives their species-environment associations, despite the clear role of such associations in their distribution patterns

Methods matter: Different biodiversity survey methodologies identify contrasting biodiversity patterns in a human modified rainforest — A case study with amphibians

Understanding how well tropical forest biodiversity can recover following habitat change is often difficult due to conflicting assessments arising from different studies. One often overlooked potentially confounding factor that may influence assessments of biodiversity response to habitat change, is the possibility that different survey methodologies, targeting the same indicator taxon, may identify different patterns and so lead to different conclusions. Here we investigated whether two different but commonly used survey methodologies used to assess amphibian communities, pitfall trapping and nocturnal transects, indicate the same or different responses of amphibian biodiversity to historic human induced habitat change. We did so in a regenerating rainforest study site located in one of the world's most biodiverse and important conservation areas: the Manu Biosphere Reserve. We show that the two survey methodologies tested identified contrasting biodiversity patterns in a human modified rainforest. Nocturnal transect surveys indicated biodiversity differences between forest with different human disturbance histories, whereas pitfall trap surveys suggested no differences between forest disturbance types, except for community composition. This pattern was true for species richness, diversity, overall abundance and community evenness and structure. For some fine scale metrics, such as species specific responses and abundances of family groups, both methods detected differences between disturbance types. However, the direction of differences was inconsistent between methods. We highlight that for assessments of rainforest recovery following disturbance, survey methods do matter and that different biodiversity survey methods can identify contrasting patterns in response to different types of historic disturbance. Our results contribute to a growing body of evidence that arboreal species might be more sensitive indicators than terrestrial communities. © 2016 Elsevier Lt

The impact of natural resource use on bird and reptile communities within multiple-use protected areas: evidence from sub-arid southern Madagascar

Multiple-use protected areas, in which sustainable levels of extractive livelihood activities are permitted, play an increasingly important role in the global protected area estate, and are expected to rise in prevalence. However, we know little about their effectiveness at conserving biodiversity. We surveyed bird and reptile communities in three areas across a forest disturbance gradient resulting from charcoal production and shifting cultivation within a multiple-use protected area in Madagascar’s sub-arid spiny forest. We scored individual species using a Conservation Value Index (CVI; a simple metric based on rarity, threat and distinctiveness), and estimated the total conservation value of each treatment by calculating the sum of frequency-weighted CVI scores across all present species. Bird and reptile community responses to forest disturbance were idiosyncratic. Bird richness was greatest in the moderate-disturbance treatment, but the low-disturbance treatment had the superior conservation value due to higher frequencies of locally-endemic species. Reptile richness was the same in low- and moderate-disturbance treatments, but the conservation value of the latter was greater. The high-disturbance areas had lowest richness and conservation value for both groups. For birds, increasing disturbance levels were accompanied by community turnover from high-value to low-value species, a pattern highlighted by CVI that is masked by assessing species richness alone. Although some endemic species appear to be resilient to degradation, multiple-use protected areas in Madagascar may lose biodiversity since most endemic species are forest-dependent. Stricter protected area models may be more appropriate in areas where much of the high-value biodiversity is sensitive to habitat degradation

Conservation of functional and phylogenetic diversity: identifying patterns and defining priorities

Submitted by Luciana Ferreira ([email protected]) on 2015-01-30T11:36:14Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - José Hidasi Neto - 2014.pdf: 3792842 bytes, checksum: ac6893c5aaeb4d139717d30a68da2123 (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2015-01-30T14:38:51Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - José Hidasi Neto - 2014.pdf: 3792842 bytes, checksum: ac6893c5aaeb4d139717d30a68da2123 (MD5)Made available in DSpace on 2015-01-30T14:38:51Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - José Hidasi Neto - 2014.pdf: 3792842 bytes, checksum: ac6893c5aaeb4d139717d30a68da2123 (MD5) Previous issue date: 2014-10-29Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES(Sem resumo em outra língua)Listas Vermelhas de espécies ameaçadas categorizam os organismos vivos de acordo com a proximidade de serem extintos. Entretanto, essas listas ignoram diferenças ecológicas e evolutivas entre as espécies. Para determinar se ações conservacionistas baseadas em LV são efetivas para a proteção da diversidade funcional (FD, do inglês “functional diversity) e filogenética (PD, do inglês “phylogenetic diversity”) de comunidades naturais precisamos saber se categorias de ameaça das LV possuem espécies com atributos ecológicos e histórias evolutivas distintas. Além disso, como espécies normalmente interagem em escala local, essa escala seria a mais indicada para quantificar perdas consideráveis de FD e PD. Sendo assim, no Capítulo 1, utilizamos 21 características ecológicas e as relações filogenéticas para todas as aves do Brasil a fim de determinar se espécies em categorias de ameaça das Listas Vermelhas global da IUCN, brasileira, e de seis estados brasileiros representam perdas maiores de FD e PD do que seria esperado pela extinção aleatória de aves. Analisamos a eficiência das listas vermelhas em escala nacional, regional e local, esperando que a FD e PD de aves fosse melhor representada na escala local, pois é nela onde ocorrem as interações bióticas. Encontramos que, independente da escala, as categorias de ameaça das Listas Vermelhas capturaram, de maneira geral, perdas de FD e PD iguais ou menores ao esperado ao acaso. Portanto, ações conservacionistas baseadas somente nas categorias das Listas Vermelhas não protegem mais FD e PD das aves brasileiras do que se o mesmo número de espécies (em cada categoria) fosse preservado ao acaso. No capítulo 2, sugerimos uma forma de integrar o grau de ameaça, atributos ecológicos e história evolutiva para medir o nível de prioridade de conservação de espécies. Utilizamos esse protocolo para medir a prioridade de conservação dos mamíferos do mundo. De modo geral, espécies mais prioritárias tenderam a ser mais ameaçadas, além de estarem concentradas nas regiões de alguns hotspots de biodiversidade, como o Cerrado, Indo-Burma, Mata Atântica e Sundaland. Esses resultados possuem grandes consequências na conservação de espécies pois categorias de LV são normalmente utilizadas como ferramentas para a formulação de políticas relacionadas à conservação da biodiversidad

Functional and phylogenetic homogenization: aggregation of genotypes and phenotypes across space and time

Submitted by Liliane Ferreira ([email protected]) on 2019-05-09T12:13:40Z No. of bitstreams: 2 Tese - José Hidasi Neto - 2018.pdf: 3314615 bytes, checksum: 35a373c977680dd06a7e7932915d11cd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2019-05-09T13:35:58Z (GMT) No. of bitstreams: 2 Tese - José Hidasi Neto - 2018.pdf: 3314615 bytes, checksum: 35a373c977680dd06a7e7932915d11cd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2019-05-09T13:35:58Z (GMT). No. of bitstreams: 2 Tese - José Hidasi Neto - 2018.pdf: 3314615 bytes, checksum: 35a373c977680dd06a7e7932915d11cd (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-08-15Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESBiotic homogenization can be defined as the replacement of specialist (usually native) organisms by generalists (usually exotic) through biological invasions and local extinctions. This process is capable of homogenizing various components of biodiversity, reducing the taxonomic, functional, genetic and phylogenetic diversity of populations and communities. It is also known that the homogeneity of these components may undergo changes in a natural or induced (human) manner. In addition, in the face of the loss of diversity (or heterogeneity) of the components of biodiversity, studies are done to reduce unnatural effects caused by man. We will investigate the following questions: "Where are the most similar species or communities?", "What are the natural and human causes of this high similarity?", "What are the consequences of high similarity?", "How can we avoid high homogenization of biodiversity? ". In the first chapter we will test whether less abundant species are those phylogenetic and functionally more distinct. In the second chapter we will test whether phylogenetically isolated living islands (hosts) present communities of insects (colonizers) more taxonomically homogeneous than phylogenetically isolated islands. In the third chapter we will test if climatic changes will taxonomic, functional and phylogenetically homogenize communities of mammals in the Cerrado biome. We hope to contribute to the knowledge of the causes and consequences of high homogeneity in the environment. In addition, we hope that more conservation measures are planned globally and regionally in the face of the natural and anthropogenic processes responsible for biotic homogenization.A homogeneização biótica pode ser definida como a substituição de organismos especialistas (normalmente nativos) por generalistas (normalmente exóticos) por meio de invasões biológicas e extinções locais. Esse processo é capaz de homogeneizar vários componentes da biodiversidade, reduzindo a diversidade taxonômica, funcional, genética e filogenética de populações e comunidades. Sabe-se ainda que a homogeneidade desses componentes pode sofrer alterações de modo natural ou induzido (pelo homem). Além disso, em face à perda de diversidade (ou heterogeneidade) dos componentes da biodiversidade, estudos são feitos para reduzir os efeitos não naturais causados pelo homem. Investigaremos as seguintes questões: “onde se encontram as espécies ou comunidades mais similares entre si?”, “quais são as causas naturais e humanas dessa alta semelhança?”, “quais são as consequências da alta similaridade?”, “como podemos evitar a alta homogeneização da biodiversidade?”. No primeiro capítulo testaremos se espécies menos abundantes são aquelas filogenética e funcionalmente mais distintas (“mais especialistas”). No segundo capítulo testaremos se ilhas vivas (hospedeiros) filogeneticamente isoladas apresentam comunidades de insetos (colonizadores) mais taxonomicamente homogêneas do que ilhas filogeneticamente não isoladas. No terceiro capítulo testaremos se mudanças climáticas homogeneizarão taxonômica, funcional e filogeneticamente as comunidades de mamíferos no Cerrado. Esperamos contribuir para o conhecimento das causas e das consequências da alta homogeneidade no meio ambiente. Adicionalmente, esperamos que mais medidas de conservação sejam planejadas global e regionalmente em face aos processos naturais e antropogênicos responsáveis pela homogeneização biótica