Divergence of Ant Communities Over Time in a Fragmented Atlantic Rain Forest Landscape

Habitat fragmentation changes biological communities and its spatiotemporal dynamics – which may lead to either biotic homogenization or heterogenization along time and space. Both processes can occur by addition, replacement or loss of species within communities, altering compositional similarity across the landscape. We investigated which of these two processes (biotic homogenization or heterogenization) occurs, and its possible underlying mechanism, over 15 years in an Atlantic Forest landscape using ants as model organisms. We sampled ants in 17 forest fragments across three different years, compared their composition similarity, species richness, and species richness of groups classified according to their habitat preferences. We sampled a total of 132 ant species. Ant communities in fragments diverged over time, suggesting they experienced an idiosyncratic structuring process. This biotic heterogenization occurred through an additive process, as ant species richness increased over time, mainly due to an increase of generalist ant species, and a decrease of forest specialist ant species. These changes occurred despite the higher forest cover in the landscape along years. Since different species can perform different functions in ecosystems, this biotic heterogenization may have implications for ecosystem functioning. Investigating how disturbances structure biological communities over time, especially those performing important ecosystem functions, can shed light to our understanding of possible changes in ecosystem functions and consequently for forest regeneration

A Quantitative Baseline of Ants and Orchid Bees in Human-Modified Amazonian Landscapes in Paragominas, PA, Brazil.

The lack of effective biodiversity baselines is a major impairment to implement conservation plans. Hence, constructing and updating species lists provides vital information about species distribution records. The Sustainable Amazon Network (in Portuguese Rede Amazônia Sustentável; RAS) is an interdisciplinary research initiative that aims to evaluate land-cover changes effects in eastern Brazilian Amazonia. Within the scope of this project, we sampled ants and orchid bees and herein present a list of species collected in Paragominas, PA, Brazil; the most complete lists of species published to date of these groups for the eastern Amazon. We sampled these insects across several land-cover types, from undisturbed primary forest, through varyingly disturbed primary and secondary forests to production areas (silviculture, pastures and arable fields). In total we recorded 285 species of ants and 36 species of orchid bees. Species richness was higher in primary forests for both groups, followed by production areas. Orchid bees reached their highest richness in secondary forests. For orchid bees, production areas were dominated by a few hyper-dominant species, such as Eulaema nigrita. We acknowledge that the use of different sampling methods would collect additional species, and we recommend this for future assessments if the aim is to make a complete inventory. We expect this study can be used as a baseline for understanding the effectiveness of ongoing changes in forest conservation and land management practices. Finally, this list is of suitable importance in determining conservation status for several taxa described here

Redescoberta da espécie supostamente extinta de formigas, Simopelta minima (Brandão) (Hymenoptera, Formicidae), com uma discussão sobre raridade e estado de conservação de espécies de formigas

Simopelta minima (Brandão, 1989) was originally described based on four workers collected in soil samples from a small cocoa plantation in Ilhéus, state of Bahia, northeastern Brazil. In the subsequent years after the description, this cocoa plantation was eliminated and the species was then considered extinct by the Brazilian environmental institutions. The recent rediscovery of S. minima workers in subterranean pitfall trap samples from Viçosa, state of Minas Gerais, southeastern Brazil, over 1.000 km distant from type locality, suggests that the rarity and vulnerability status of some ant species may be explained by insufficient sampling of adequate microhabitats, in time and space.Simopelta minima (Brandão, 1989) foi originalmente descrita com base em quatro operárias coletadas em amostras de solo provenientes de uma pequena plantação de cacau localizada em Ilhéus, Estado da Bahia, nordeste do Brasil. Nos anos seguintes à descrição, esta pequena plantação de cacau foi eliminada e a espécie passou a ser considerada extinta pelas instituições ambientais brasileiras. Recentemente foram coletadas operárias de Simopelta minima em amostras de armadilhas subterrâneas do tipo "pitfall", em Viçosa, Estado de Minas Gerais, sudeste do Brasil, a mais de 1.000 km de distância da localidade tipo. Esta redescoberta sugere que o status de raridade e/ou vulnerabilidade atribuído a algumas espécies de formigas pode ser explicado pela amostragem insuficiente de microhabitats adequados, no tempo e no espaço.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNPqFAPEMIGFAPES

How pervasive is biotic homogenization in human-modified tropical forest landscapes?

Abstract Land-cover change and ecosystem degradation may lead to biotic homogenization, yet our understanding of this phenomenon over large spatial scales and different biotic groups remains weak. We used a multi-taxa dataset from 335 sites and 36 heterogeneous landscapes in the Brazilian Amazon to examine the potential for landscape-scale processes to modulate the cumulative effects of local disturbances. Biotic homogenization was high in production areas but much less in disturbed and regenerating forests, where high levels of among-site and among-landscape b-diversity appeared to attenuate species loss at larger scales. We found consistently high levels of b-diversity among landscapes for all land cover classes, providing support for landscape-scale divergence in species composition. Our findings support concerns that b-diversity has been underestimated as a driver of biodiversity change and underscore the importance of maintaining a distributed network of reserves, including remaining areas of undisturbed primary forest, but also disturbed and regenerating forests, to conserve regional biota

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Anthropogenic disturbance in tropical forests can double biodiversity loss from deforestation

© 2016 Macmillan Publishers Limited. All rights reserved. Concerted political attention has focused on reducing deforestation, and this remains the cornerstone of most biodiversity conservation strategies. However, maintaining forest cover may not reduce anthropogenic forest disturbances, which are rarely considered in conservation programmes. These disturbances occur both within forests, including selective logging and wildfires, and at the landscape level, through edge, area and isolation effects. Until now, the combined effect of anthropogenic disturbance on the conservation value of remnant primary forests has remained unknown, making it impossible to assess the relative importance of forest disturbance and forest loss. Here we address these knowledge gaps using a large data set of plants, birds and dung beetles (1,538, 460 and 156 species, respectively) sampled in 36 catchments in the Brazilian state of Pará. Catchments retaining more than 69-80% forest cover lost more conservation value from disturbance than from forest loss. For example, a 20% loss of primary forest, the maximum level of deforestation allowed on Amazonian properties under Brazil's Forest Code, resulted in a 39-54% loss of conservation value: 96-171% more than expected without considering disturbance effects. We extrapolated the disturbance-mediated loss of conservation value throughout Pará, which covers 25% of the Brazilian Amazon. Although disturbed forests retained considerable conservation value compared with deforested areas, the toll of disturbance outside Pará's strictly protected areas is equivalent to the loss of 92,000-139,000 km2 of primary forest. Even this lowest estimate is greater than the area deforested across the entire Brazilian Amazon between 2006 and 2015 (ref. 10). Species distribution models showed that both landscape and within-forest disturbances contributed to biodiversity loss, with the greatest negative effects on species of high conservation and functional value. These results demonstrate an urgent need for policy interventions that go beyond the maintenance of forest cover to safeguard the hyper-diversity of tropical forest ecosystems

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Efeitos de mudanças no use da terra sobre a biodiversidade de florestas tropicais: uma avaliação em múltiplas escalas na Amazônia Brasileira

A Amazônia Brasileira compreende cerca de 40% das florestas tropicais do globo, abrigando uma enorme parte da biodiversidade mundial. Todavia, taxas alarmantes de desmatamento são encontradas por toda a região amazônica. Demandas cada vez mais altas por recursos naturais são uma das maiores ameaças a este ecossistema e portanto conservacionistas necessitam de informações precisas sobre a biodiversidade e processos do ecossistema, bem como dados da esfera socioeconômica. Dentro das necessidades desta agenda, uma iniciativa de pesquisa denominada Rede Amazônia Sustentável foi desenvolvida. O objetivo desta rede é gerar dados que possam subsidiar planos de conservação para a região. Esta tese traz os resultados de alguns dos objetivos ligados à biodiversidade componentes desta rede. No primeiro capítulo nosso objetivo é fornecer a mais completa lista de espécies até o momento de formigas, abelhas de orquídeas e besouros rola-bostas para a região de Paragominas, bem como descrever os padrões de diversidade de espécies ao longo do gradiente de uso da terra da região. No segundo capítulo, nosso objetivo é responder à pergunta de como as mudanças no uso da terra alteram a composição e a riqueza da comunidade de formigas em Paragominas? Também é nosso objetivo explorar quais os fatores ambientais regula a riqueza de espécies de formigas em escalas local e regional. Por fim, para o terceiro capítulo nossa pergunta é até que ponto existe um processo em andamento de homogeneização biótica acontecendo em consequência do processo de desflorestamento e degradação florestal? Para tal, pesquisamos cinco taxa (plantas, aves, besouros rola-bostas, formigas e abelhas de orquídeas), nos municípios de Paragominas e Santarém. Os resultados do primeiro capítulo incluem a lista de espécies, a qual esperamos possa ser uma referência para estudos de monitoramento do estado de conservação, bem como iniciativas de recuperação florestal, as quais estão em fase inicial em Paragominas. Ainda, encontramos que a diversidade de espécies dos três grupos (formigas, besouros e abelhas) foi reduzida pelo desflorestamento e degradação florestal. No segundo capítulo, observamos uma clara mudança na composição deespécies da comunidade de formigas com a mudança no uso da terra, bem como um processo de perda de espécies. Estes padrões de riqueza são principalmente explicados pela cobertura de floresta primária remanescente, que foi uma importante variável na explicação dos padrões encontrados. Por f1m, no terceiro capítulo encontramos um padrão geral de perda de espécies em escala local com a intensificação do uso da terra. Por outro lado, em escalas maiores, só observamos perda de espécies quando comparamos áreas florestas versus áreas não florestais. Os padrões de diversidade B só foram afetados pelo uso da terra em escalas menores (entre locais), sendo que a mesma é maior em áreas florestais e menor em áreas desflorestadas. Há entretanto um padrão marcado de maior contribuição de aninhamento para a diversidade B em áreas não florestais em ambas as escalas. Portanto, como conclusão geral, encontramos que as mudanças no uso da terra implementadas pelo uso humano estão depauperando a biodiversidade e que, se nenhuma ação for tomada prontamente para proteger as áreas ainda existentes de floresta primária, podemos testemunhar um processo ainda mais severo de perda de espécies. Como uma rede de pesquisa multidisciplinar, esperamos que os resultados apresentados nesta tese possam compor estratégias conjuntas, considerando as esferas ecológicas e sociais, os quais podem culminar em um processo mais razoável e sensato de planejamento de conservação para a região.Conselho Nacional de Desenvolvimento Científico e TecnológicoThe Brazilian Amazon comprises around 40% of all tropical forests in the world, harbouring a gigantic part of the world s biodiversity. Yet, alarming rates of deforestation are spread across the Amazon. Increasing rates of resource demands harm this ecosystem and conservationists need precise information about biodiversity and ecosystem processes, as well as socioeconomic data. Within the needings of this agenda, a research initiative called Sustainable Amazon Network was developed, aiming to generate data that can foster conservation plans for the regions. This thesis brings results regarding some of the biodiversity aims of this research network. In the first chapter we aim to provide the most comprehensive species list of ants, orchid bees and dung beetles to date to the region of Paragominas, as well as describe patterns of species diversity across the different land-use types in the region. In the second chapter, we aimed to answer how land-use changes affect ant species composition and richness in Paragominas? We also aim to explore which environmental variables regulate ant species richness at local and regional scales. Finally, for the third chapter we ask whether there is an ongoing process of biotic homogenization happening with forest degradation and conversion to production landscapes. We surveyed five taxa (plants, birds, dung beetles, ants and orchid bees) in this chapter, across the municipalities of Paragominas and Santarém. In the first chapter we provided the list, which we hope will be a baseline for the monitoring of forest conservation initiatives taking place in the region. We also found that species richness of the three groups is being reduced by deforestation and forest degradation. In the second chapter, we observe a marked shift in species composition with land-use changes, as well as a process of species loss, highly associated with primary forest cover, being this the variable with the highest importance in explaining species richness. Lastly in the third chapter, we found a general pattern of steady decrease in local diversity with land-use intensifrcation whereas at larger scales this loss can only be noticed for forest versus non-forest comparisons. We found that B diversity is affected only at smaller scales, being higher in forests than in non-forest areas. There is, however, a marked increase in the contribution of nestedness to B diversity in non-forest habitats at both scales. Thus, as a general conclusion, we found that land-use changes are eroding biodiversity and if any action is readily implemented in the region to protect the extant forest patches, we can witness a severe biodiversity loss that is already being observed at the local scale. We do expect as a multidisciplinary network that our results can nurture joint strategies, considering natural and socioeconomic sides, which can culminate in a more wise conservation planning to the region

Ant diversity partitioning in a fragmented landscape

Eventos de fragmentação florestal são caracterizados como uma das maiores ameaças à biodiversidade e são a causa primária de perda de espécies nas florestas tropicais. Formigas são organismos que apresentam diversas características favoráveis ao seu uso em trabalhos ecológicos, o que as torna frequentes em estudos sobre fragmentação. Portanto, o objetivo deste estudo é responder a seguinte pergunta: Por que há mais espécies de formigas nos fragmentos florestais em relação ao entorno? Para responder a essa questão, hipóteses explicativas foram lançadas, baseadas em recursos e condições. Além disso, diferenças nas respostas em diferentes microhabitats foram analisadas. A amostragem foi realizada em quatro fragmentos florestais e quatro entornos adjacentes na cidade de Viçosa, Minas Gerais, Brasil. As formigas foram amostradas nos microhabitats epi- e hipogéicos, com armadilhas pitfall sem iscas. Foram coletadas amostras de solo para obter variáveis explicativas. A diversidade de formigas foi particionada seguindo a equação γ = α + β. O pressuposto, de que o fragmento é mais diverso que o entorno foi testado através de ANOVA. As variáveis explicativas foram testadas através de partição hierárquica, para detectar as variáveis mais importantes na explicação da diversidade e estas variáveis foram testadas através de glm para demonstrar a relação e a tendência. Estimativas de riqueza de espécies foram realizadas para se estimar o efeito na escala de paisagem. A composição de espécies foi testada através deNMDS, e a significância acessada através de ANOSIM. Nosso pressuposto se confirmou apenas a nas escalas de diversidade β e γ e para o hábitat epigéico. Além disso, as variáveis mais importantes para explicação foram %areia (-); CTC (+); concentração de ferro (-)e matéria orgânica do solo (unimodal). Além disso, estas variáveis apresentam o mesmo padrão de variação que o pressuposto, sendo fortes candidatas a fatores causais. A composição de espécies variou, sendo distinta quando comparamos fragmento vs. entorno e quando comparamos entre microhabitats epi- e hipogéicos. No último, observamos resposta apenas para o ambiente florestal. A confirmação do nosso pressuposto, bem como a explicação provida pelas variáveis ambientais suportam o fato de que alterações causadas na qualidade do ambiente pela fragmentação são responsáveis pela perda de espécies observada. Ainda, a composição de espécies revelou que existem subconjuntos de espécies específicos de cada local, matrizes e florestas. Ainda, a ausência de diferença na composição de espécies entre os microhabitats na matriz revela uma acentuada perda de algumas espécies que existiam no ambiente florestal, mas que não mais estão presentes.Forest fragmentation events have been characterized as one of the main threats to biodiversity in modern times, and are the primary cause of species loss in tropical forests. Ants are organisms that present many suitable traits to be used in ecological studies, therefore they are frequently used in fragmentation surveys. However only epigaeic microhabitat have been considered in these studies, neglecting other important microhabitats. Hence, with this study we aimed to answer the following question: Why are there more ant species in forest remnants compared to matrices? We made explanatory hypotheses, in which environmental variables were taken as surrogates of resources and conditions. The study was carried out in four forest remnants and four surrounding matrices in Viçosa municipality, Minas Gerais state, Brazil. Ants were sampled with pitfall traps in two microhabitats, epigaeic and hypogaeic, with unbaited pitfall traps. The diversity was partitioned, following the equation γ = α + β. An ANOVA was made at each scale to test the assumption that fragment harbour more species than matrices. Explanatory variables were analysed through hierarchical partitioning to find out which variables are more important in explaining species richness and using GLM to depict the relationships among variables. Estimators of species richness were employed to asses the effect of fragmentation in the landscape. Species composition was tested through NMDS and significance values were obtained by ANOSIM. We confirmed our assumption only for β and γ diversity. The most important variables to explain diversity were %Sand (-), CEC (+), iron concentration (-) and soil organic matter (unimodal). Variation among environmental parameters in relation to fragmentation explained the variations in species richness. We found differences in species composition, with forest habitats being distinct from matrices at both epi- and hypogaeic microhabitats. A distinction between epigaeic/hypogaeic communities was found only in forest environments. We confirmed our assumption and confirmed that some variables are important for explaining species loss caused by fragmentation. It give support to the fact that alterations caused on environmental quality are important and must beconsidered. Moreover, species composition revealed that there are specific subsets in each local, matrices and forests. Still, the lack of difference in species composition between microhabitats in matrices reveals the strong effect of fragmentation on some hypogaeic species, that should depend on litter, that is not available after vegetation clearance.Conselho Nacional de Desenvolvimento Científico e Tecnológic

A quantitative baseline of ants and orchid bees in human-modified Amazonian landscapes in Paragominas, Pará, Brazil

The lack of effective biodiversity baselines is a major impairment to implement conservation plans. Hence, constructing and updating species lists provides vital information about species distribution records. The Sustainable Amazon Network (in Portuguese Rede Amazônia Sustentável; RAS) is an interdisciplinary research initiative that aims to evaluate land-cover changes effects in eastern Brazilian Amazonia. Within the scope of this project, we sampled ants and orchid bees and herein present a list of species collected in Paragominas, PA, Brazil; the most complete lists of species published to date of these groups for the eastern Amazon. We sampled these insects across several land-cover types, from undisturbed forested habitats, through varyingly disturbed forested habitats and secondary forests to production areas (silviculture, pastures and arable fields). In total we recorded 285 species of ants and 36 species of orchid bees. Species richness was higher in primary forests for both groups, followed by production areas. Orchid bees reached their highest richness in secondary forests. For orchid bees, production areas were dominated by a few hyper-dominant species, such as Eulaema nigrita. For future assessments if the aim is to make a complete inventory, we recommend the use of additional sampling methods. Finally, we expect this study can be used as a baseline for understanding the effectiveness of ongoing changes in forest conservation and land management practices and in determining conservation status for several taxa described here