Warning signals of biodiversity collapse across gradients of tropical forest loss

We evaluate potential warning signals that may aid in identifying the proximity of ecological communities to biodiversity thresholds from habitat loss—often termed “tipping points”—in tropical forests. We used datasets from studies of Neotropical mammal, frog, bird, and insect communities. Our findings provide only limited evidence that an increase in the variance (heteroskedasticity) of biodiversity-related parameters can provide a general warning signal of impending threshold changes in communities, as forest loss increases. However, such an apparent effect was evident for amphibians in the Brazilian Atlantic Forest and Amazonian mammal and bird communities, suggesting that impending changes in some species assemblages might be predictable. We consider the potential of such warning signs to help forecast drastic changes in biodiversity

MACROINVERTEBRADOS AQUÁTICOS COMO BIOINDICADORES NO PROCESSO DE LICENCIAMENTO AMBIENTAL NO BRASIL

Licenciamento ambiental no Brasil é um procedimento com vários níveis e etapas, concebido como ferramenta preventiva aos potenciais danos ambientais causados pela implantação de empreendimentos. Embora este procedimento seja obrigatório desde meados da década de 1980, ainda é limitado no que diz respeito ao uso de informações biológicas para a avaliação e o monitoramento de ambientes aquáticos. Neste processo, o órgão licenciador (federal, estadual ou municipal) define as variáveis a serem medidas, tendo como referência o tipo e a magnitude do empreendimento e as características específicas do local proposto para sua instalação. Respostas biológicas devem ser usadas para medir os impactos sobre ecossistemas aquáticos e os macroinvertebrados constituem um grupo que apresenta vantagens como bioindicadores, sendo os mais utilizados para este fim. Em 2011, o Grupo de Trabalho Intersetorial em Biomonitoramento foi criado para discutir o uso de macroinvertebrados em programas de monitoramento. Este trabalho apresenta as reflexões e propostas deste grupo e fornece subsídios para a inclusão destes organismos nos termos de referência a serem aplicados nos processos de licenciamento ambiental no Brasil

A comparative analysis reveals weak relationships between ecological factors and beta diversity of stream insect metacommunities at two spatial levels.

The hypotheses that beta diversity should increase with decreasing latitude and increase with spatial extent of a region have rarely been tested based on a comparative analysis of multiple datasets, and no such study has focused on stream insects. We first assessed how well variability in beta diversity of stream insect metacommunities is predicted by insect group, latitude, spatial extent, altitudinal range, and dataset properties across multiple drainage basins throughout the world. Second, we assessed the relative roles of environmental and spatial factors in driving variation in assemblage composition within each drainage basin. Our analyses were based on a dataset of 95 stream insect metacommunities from 31 drainage basins distributed around the world. We used dissimilarity-based indices to quantify beta diversity for each metacommunity and, subsequently, regressed beta diversity on insect group, latitude, spatial extent, altitudinal range, and dataset properties (e.g., number of sites and percentage of presences). Within each metacommunity, we used a combination of spatial eigenfunction analyses and partial redundancy analysis to partition variation in assemblage structure into environmental, shared, spatial, and unexplained fractions. We found that dataset properties were more important predictors of beta diversity than ecological and geographical factors across multiple drainage basins. In the within-basin analyses, environmental and spatial variables were generally poor predictors of variation in assemblage composition. Our results revealed deviation from general biodiversity patterns because beta diversity did not show the expected decreasing trend with latitude. Our results also call for reconsideration of just how predictable stream assemblages are along ecological gradients, with implications for environmental assessment and conservation decisions. Our findings may also be applicable to other dynamic systems where predictability is low

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

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

Response to correspondence letter “species responses to oil palm: cautionary considerations for multi-site extrapolation”

We appreciate the correspondence related to our paper (Pardo et al., 2018a), which raises three main concerns about our work: 1) an apparent extrapolation of the information we gathered in the Llanos region of Colombia to the entire country; 2) a putative limitation in our study design; and 3) a criticism of what was characterized as a misleading focus on non-threatened species. Below we address each criticism in turn

Response to correspondence letter "Species responses to oil palm: Cautionary considerations for multi-site extrapolation"

[Extract] We appreciate the correspondence related to our paper (Pardo et al., 2018a), which raises three main concerns about our work: 1) an apparentextrapolation of the information we gathered in the Llanos region of Colombia to the entire country; 2) a putative limitation in our study design; and 3) a criticism of what was characterized as a misleading focus on non-threatened species. Below we address each criticism in turn

Identifying critical limits in oil palm cover for the conservation of terrestrial mammals in Colombia

As oil palm plantations continue to expand in Neotropical regions, identifying critical transitions in land use, at which animal communities can be drastically altered, is crucial for conservation planning. Here, we investigated potential unexpected change points (thresholds) in the response of terrestrial mammal's richness and community composition to increasing oil palm cover in the Llanos region of Colombia. We deployed camera traps to detect species across 56 sites (landscapes of ~220 ha each) and used segmented regression and Threshold Indicator Taxa Analysis (TITAN) for the identification of these thresholds. We found a negative linear relationship between the proportion of oil palm and species richness, but no evidence of a threshold. In contrast, we found strong signs of a community threshold when oil palm cover in the study area reached 45–75%, at which mammalian species composition (taxon-specific changes of abundance and occurrence frequency) drastically changed. When species were assessed individually, a significant threshold relationship to oil palm cover was found to occur in 10 of the 15 examined species, with four (squirrel, agouti, spiny rat, common opossum) having a negative drastic change at approximately 45% oil palm cover. Five species showed no evidence for any critical threshold (giant and lesser anteater, jaguarondi, white-tailed deer and raccoon). We used the community threshold identified above as a baseline to evaluate the conservation status of the four oil palm production zones in Colombia. We found that approximately 41% of the total area covered by oil palm in Colombia has crossed the identified threshold of 45–75%, suggesting urgent need for forest restoration to increase its extent if a collapse of their resident mammal communities is to be avoided. These findings provide guidance for the design of sustainable landscapes within production areas in Colombia to promote the conservation of terrestrial mammals

Brazil's worst mining disaster_EcollAppl tradução.pdf

Em novembro de 2015, uma grande barragem de rejeitos de mineração no Brasil, pertencente à empresa Samarco rompeu, gerando uma onda expressiva de lama tóxica que se espalhou por todo Rio Doce abaixo matando 19 pessoas, afetando a biodiversidade ao longo de vários quilômetros do rio, bem como áreas ripárias e costa do oceano Atlântico. Além das perdas desastrosas de vidas humanas e perdas socio-econômicas, estimamos perdas de serviços ambientais regionais em torno de R$1,694 bilhões por ano. Embora nossa estimativa seja conservativa, é seisvezes maior do que as multas impostas à Samarco pelo IBAMA. Para reduzir essas discrepâncias entre perdas estimadas e multas aplicadas, defendemos uma política em prol de “caução ambiental” que considere o risco potencial e os serviços ambientais que poderiam ser afetados em casos de irresponsabilidades nas atividades em áreas de mineração. Cauções e seguros ambientais são instrumentos políticos comumente utilizados em muitos países, mas não há políticas claras a este respeito no Brasil. Cauções ambientais são possivelmente mais efetivos em assegurar a reparação ambiental do que multas pósdesastres, as quais geralmente são inadequadas e não pagas. Estimamos também que pelo menos 126 represas de contenção podem se romper nos próximos anos. Esses eventos podem possivelmente ter consequências ambientais e sociais graves, evidenciando a necessidade de estratégias de gestão de desastres para grandes escalas de operações de mineração