Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications 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, 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

Caracterização química de compostos de lixo urbano de algumas usinas brasileiras.

Avaliacao das caracteristicas quimicas de compostos de lixo urbano e analise de esterco, calcario, superfosfato simples, KCl e ureia para comparacoes destes com o lixo urbano. Foram feitas determinacoes de M.O., C, N, P, K, Ca, Mg, Cu, Mn, Mo, Zn, Fe, Al, Ba, Cd, Co, Cr, Ni, Pb, Sr, Ti, e V. Houve diferencas nos teores de nutrientes entre os compostos, provavelmente devidas aos diferentes processo de compostagem, estando alguns deles acima dos niveis toleraveis em composto na Alemanha. Os demais elementos analisados, incuindo os metais pesados, estao dentro da faixa observada em lodo de esgotos na Inglaterra. De acordo com a legislacao alema, Pb, Cr, Ni e Cd estao acima dos valores toleraveis para compostos de lixo. Na maioria dos compostos analisados, os teores totais de nutrientes foram menores do que no esterco, mas a concentracao dos outros elementos, inluindo metais pesados, foi mais elevada do que no esterco. Embora os teores dos elementos avaliados nos compostaos seja os totais, e' necessario cautela para seu uso, ate que sejam obtidos resultados seguros sobre a "disponibilidade" desses elementos para as plantas.Made available in DSpace on 2014-11-27T08:13:20Z (GMT). No. of bitstreams: 1 21.pdf: 41033 bytes, checksum: aa4e595c35a43dab5c4a3829d6b38dd8 (MD5) Previous issue date: 1999-03-09199