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

Systematic, phylogeny and biogeography of Thinouia Triana & Planch. (Sapindaceae)

Paullinieae é uma tribo predominantemente Neotropical, com exceção de poucas espécies que ocorrem na região paleotropical do globo. A tribo possui cerca de 475 espécies agrupadas em seis gêneros, Cadiospermum L., Lophostigma Radlk., Paullinia L., Serjania Mill., Thinouia Triana & Planch. e Urvillea Kunth. É caracterizada morfologicamente pelo hábito lianescente e pela presença de estípulas e gavinhas, além de ser corroborada em análises filogenéticas que utilizam caracteres moleculares. Apesar dos avanços, as relações genéricas na tribo ainda não estão completamente esclarecidas, sobretudo no que diz respeito ao posicionamento de Thinouia e a sinonimização de Allosanthus. Estes gêneros foram revisados pela última vez por Radlkofer em 1931 e necessitam de uma avaliação na circunscrição de seus táxons e sua nomenclatura, além da necessidade de elaborar hipóteses filogenéticas e biogeográficas. Dessa forma, este trabalho tem o objetivo apresentar uma atualização no conhecimento de Thinouia e da tribo Paullinieae. A partir de material obtido em expedições botânicas e visita a herbários, uma nova filogenia para a tribo foi produzida para testar o monofiletismo de Thinouia e seu posicionamento na tribo. Uma revisão taxonômica para Thinouia é apresentada, juntamente com um trabalho biogeográfico para a tribo Paullinieae. A nova filogenia recuperou Thinouia como monofilética e corroborou seu posicionamento como grupo irmão de todos os demais gêneros; também confirmou a sinonimização de Allosanthus em Thinouia. Como resultado da revisão de Thinouia 13 espécies são reconhecidas (sendo duas novas), apresentamos uma visão geral da morfologia e distribuição do gênero, descrição das espécies, chave de identificação, ilustrações, avaliações dos status de conservação, comentários ecológicos e nomenclaturais. Para os resultados biogeográficos, identificamos a região ocidental da Amazônia adjacente aos Andes formada por um corredor desde o norte da Colômbia ao norte da Bolívia como centro de diversidade da tribo e identificamos 12 áreas de endemismo. Além disso, identificamos que as variáveis ambientais possuem um grande papel na predição da riqueza de espécies da tribo, especialmente a sazonalidade da temperatura, que se mostrou um importante mecanismo como preditor de riqueza para a tribo.The Paullinieae comprise a predominantly Neotropical tribe, with few species in the Paloeotropics. The tribe has about 475 species grouped into six genera: Cardiospermum L., Lophostigma Radlk., Paullinia L., Serjania Mill., Thinouia Triana & Planch. and Urvillea Kunth. It is morphologically characterized by the lianescent habit and the presence of stipules and tendrils; this is corroborated in phylogenetic analyses using molecular characters. Despite recent advances, the generic relationships in the tribe are still not completely clarified, especially regarding the positioning of Thinouia and the synonymization of Allosanthus. The genus Thinouia was last revised by Radlkofer in 1931 and require a re-evaluation of the circumscription of their taxa and their nomenclature, which will make it possible to develop new phylogenetic and biogeographic hypotheses. As part of that undertaking, the current work aims to present an update of the knowledge of Thinouia and tribe Paullinieae. From material obtained in botanical expeditions and herbarium studies, a new phylogeny for the tribe was produced to test the monophyly of Thinouia and its position in the tribe. A taxonomic revision for Thinouia is presented, along with an examination of the biogeography of the Paullinieae tribe. The new phylogeny recovered Thinouia as monophyletic and confirmed its position sister to all other genera in the tribe; it also confirmed the synonymization of Allosanthus in Thinouia. The revision of Thinouia recognized 13 species, two of them new; we present an overview of the morphology and distribution of the genus, species descriptions, an identification key, illustrations, conservation status assessments, and ecological and nomenclatural comments. The biogeographic study identified the eastern piedmont of the Andes from northern Colombia to northern Bolivia as the tribe\'s center of diversity, and we identified 12 areas of endemism. In addition, we determined that environmental variables play a large role in predicting the species richness of the tribe, especially the seasonality of temperature, which proved to be an important mechanism as a predictor of wealth for the tribe

A new species of Thinouia (Paullinieae, Sapindaceae) from the Amazon and its phylogenetic placement

Thinouia is a Neotropical genus of lianas with approximately 12 species and is the only genus in tribe Paullinieae with actinomorphic flowers. During a taxonomic revision of the genus and fieldwork in south-western Amazonia, we found a new species that appears similar to Thinouia trifoliata (ex Allosanthus) because of its racemiform inflorescence. However, before describing the new species, we had to confirm that Allosanthus was congeneric with Thinouia so we could place the new species in the correct genus. The results of the phylogenetic analysis, based on molecular data (trnL intron and ITS sequences), show that Allosanthus should be included in Thinouia. Thus, the new taxon is described here as Thinouia cazumbensis sp. nov. The new species is described, illustrated and phylogenetic trees showing relationships within supertribe Paulliniodae and Thinouia and the congeneric Allosanthus are given

Tree mortality, recruitment and growth in a bamboo dominated forest fragment in southwestern Amazonia, Brazil

Forest fragmentation affects the structure and dynamics of plant communities, leading to biodiversity loss in forest remnants. In this paper we show that in a bamboo (Guadua weberbaueri Pilger) dominated forest fragment in southwestern Amazonia edge effect may be confounded by bamboo effect, which also occur inside the forest. We measured growth, mortality and, recruitment rate of trees with DBH ≥ 10 cm, in a fragment of bamboo dominated open forest in southwestern Amazonia, state of Acre, Brazil, in 15 plots at the forest edge and 15 plots inside the forest fragment, 500 m away from the border. Time interval between censuses was 1.8 years. The average diameter growth rate differed significantly between edge (3.82 ± 0.10 mm a-1) and interior (2.39 ± 0.18 mm a-1); but there were no differences in annual mortality rate (edge = 3.8 ± 2.5 % a-1 CV = 65.7%; interior = 3.6 ± 2.6% a-1 CV = 72.2%) or in annual recruitment rate (edge = 7.1 ± 3.2% a-1 CV = 45%; interior = 8.9 ± 7.9% a-1 CV = 88.7%). Diameter growth rate, particularly of pioneer and fast-growing trees, is favored by the environmental conditions of the edge, where bamboo abundance is higher. However, the absence of an edge effect on mortality and recruitment could be due to the particular dynamics of bamboo patches, which could be mimicking forest edges and therefore masking possible edge effect in this fragment. We speculate that the mortality and recruitment patterns in fragmented forests of southwestern Amazonia is different from other areas in Amazonia and that bamboo is one of the key controllers of successional processes in these fragments

Trade-offs among forest value components in community forests of southwestern Amazonia

Contemporary conservation interventions must balance potential trade-offs between multiple ecosystem services. In tropical forests, much attention has focused on the extent to which carbon-based conservation provided by REDD+ policies can also mitigate biodiversity conservation. In the nearly one-third of tropical forests that are community owned or managed, conservation strategies must also balance the multiple uses of forest products that support local livelihoods. Although much discussion has focused on policy options, little empirical evidence exists to evaluate the potential for trade-offs among different tropical forest value components. We assessed multiple components of forest value, including tree diversity, carbon stocks, and both timber and nontimber forest product resources, in forest communities across the trinational frontier of Brazil, Peru, and Bolivia. We installed 69 0.5-ha vegetation plots in local communities, and we characterized 15 components of forest value for each plot. Principal components analyses revealed two major axes of forest value, the first of which defined a trade-off between diversity of woody plant communities (taxonomic and functional) versus aboveground biomass and standing timber volume. The second axis described abundance of commercial species, with strong positive loadings for density of timber and nontimber forest products, including Brazil nut (Bertholletia excelsa) and copaiba oil (Copaifera spp.). The observed trade-off between different components of forest value suggests a potential for management conflicts prioritizing biodiversity conservation versus carbon stocks in the region. We discuss the potential for integrative indices of forest value for tropical forest conservation

Effects of road infrastructure on forest value across a tri-national Amazonian frontier

International audienceRoad construction demonstrably accelerates deforestation rates in tropical forests, but its consequences for forest degradation remain less clear. We estimated a series of forest value metrics including components of biodiversity, carbon stocks, and timber and non-timber forest product resources, along the recently paved Inter-Oceanic Highway (IOH) integrating Brazil and Peru along the Bolivian border. We installed 69 vegetation plots in intact terra firme forests representative of local community holdings near and far from the IOH, and we characterized 15 components of forest value for each plot. We observed strong geographic gradients in forest value components across the region, with increases from west to east in aboveground biomass and in the abundance of timber and non-timber forest product trees and regeneration. Plots in communities in Pando, Bolivia, where the IOH remains in part unpaved, had the highest aboveground biomass, standing timber volumes and Brazil nut tree density. In contrast, communities in Madre de Dios, Peru, where settlements and unpaved portions of the IOH have existed for decades, and in Acre, Brazil, where paving of the IOH has been underway for more than a decade, were more degraded. Seven of the fifteen forest value components we measured increased with increasing distance from the IOH, although the magnitude of these effects was weak. Landscape scale remote sensing analyses showed much stronger effects of road proximity on deforestation. We suggest that remote sensing techniques including canopy spectral signatures might be calibrated to characterize multiple components of forest value, so that we can estimate landscape scale-impacts of infrastructure developments on both deforestation and forest degradation in tropical regions. (C) 2015 Elsevier B.V. All rights reserved