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

Alien fishes in lakes of the Doce river basin (Brazil): Range, new occurrences and conservation of native communities

The present study shows the distribution of alien fish species in tropical lakes in the middle Doce river basin, southeastern Brazil, obtained from a rapid assessment program. The causes for their introductions were sport-fishing improvement in some specific lakes and aquaculture in the studied basin. Presently, these species have a wide distribution occurring in 41 of the 54 lakes studied, representing an actual threat to regional native fish community. The natural connection among lakes and streams during the rainy season and the dispersal mediated by local people are the main invasion agents for alien fishes. The success of these invaders is probably due to absence of pre-existing effective competitors or top-predators in the invaded communities. We consider that the eradication of alien fishes by means of the available management tools may be very difficult due to the large number of lakes invaded and to the wide spectrum of lake conditions and resources exploited by these alien species. We recommend the use of environmental education as a tool to stop the human-mediated dispersion of aliens and to improve conservation of native fish community in lakes where these alien species are not present yet. © 2004 Instituto de Ciências Biológicas - UFMG

Synthesis of the first 10 years of long-term ecological research in Amazonian Forest ecosystem - implications for conservation and management

Made available in DSpace on 2016-02-17T21:43:06Z (GMT). No. of bitstreams: 5 synthesis.pdf: 1646334 bytes, checksum: 67faa6cbd2b9c2444f68e0f088cee141 (MD5) license_url: 49 bytes, checksum: 4afdbb8c545fd630ea7db775da747b2f (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license.txt: 120 bytes, checksum: c5ec8a89f6203da160ca192812b3f657 (MD5) Previous issue date: 2015We present a synthesis of the first 10 years of Long Term Ecological Research project in Amazonian Forest. We elucidate the natural dynamics of forest ecosystem processes and associated biota, and its changes caused by distinct pressures of selective timber extraction and forest fragmentation. We found that, for both plants and animals, densities of individuals and distribution of species assemblages are spatially heterogeneous at the mesoscale, even in relatively undisturbed forests, and that associations with topo-edaphic variables allow prediction of a considerable part of this variation. For biological groups whose dynamics were studied in the short-term, levels of change in species composition and densities were relatively high, and these changes were generally in tune with spatial environmental variation. The impact of selective logging on assemblages and ecosystem processes was normally moderate, and around 19 years were needed for recovering forest biomass and tree size distribution. Continued studies are needed to determine the time required for recuperation of timber stocks and pre-logging floristic composition. Selective logging appears to be compatible with the biodiversity conservation, but reduction and better planning of road access may be more important than planned logging intensities. Habitat-loss' impact on organisms and ecosystem processes is large and long-lasting, since it induces the loss of many taxonomic groups and species, higher tree mortality and accelerated forest dynamics. There was a negative synergy between the impacts of habitat loss and climatic changes, and a better understanding of these processes can only be obtained through long-term research. (C) 2015 Associacao Brasileira de Ciencia Ecologica e Conservacao. Published by Elsevier Editora Ltda. All rights reserved