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21.
Ann Carla Staver Paulo M. Brando Jos Barlow Douglas C. Morton C.E. Timothy Paine Yadvinder Malhi Alejandro Araujo Murakami Jhon del Aguila Pasquel 《Ecology letters》2020,23(1):99-106
Understory fires represent an accelerating threat to Amazonian tropical forests and can, during drought, affect larger areas than deforestation itself. These fires kill trees at rates varying from < 10 to c. 90% depending on fire intensity, forest disturbance history and tree functional traits. Here, we examine variation in bark thickness across the Amazon. Bark can protect trees from fires, but it is often assumed to be consistently thin across tropical forests. Here, we show that investment in bark varies, with thicker bark in dry forests and thinner in wetter forests. We also show that thinner bark translated into higher fire‐driven tree mortality in wetter forests, with between 0.67 and 5.86 gigatonnes CO2 lost in Amazon understory fires between 2001 and 2010. Trait‐enabled global vegetation models that explicitly include variation in bark thickness are likely to improve the predictions of fire effects on carbon cycling in tropical forests. 相似文献
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Colares Tamiris Gago de Figueiredo Camila Saggioro de Oliveira Jesus Souza Lucienne dos Santos Aline Araujo Giestal-de-Araujo Elizabeth 《Neurochemical research》2021,46(7):1701-1716
Neurochemical Research - Interleukin-2 (IL-2) is a classical pro-inflammatory cytokine known to display neuroprotective roles in the central nervous system including the retina. In the present... 相似文献
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Antônio B. Anderson Thiago M. J. Fiuza Gabriel S. Araujo Angela M. Canterle Luiza M. C. Canto Renato H. A. Freitas Otto B. F. Gadig Sergio R. Floeter 《Journal of fish biology》2021,99(6):2030-2034
Brazilian endemic batoid elasmobranch populations have declined dramatically in the past 40 years due to anthropic activities (e.g., overfishing). The Brazilian guitarfish, Pseudobatos horkelii, included in the IUCN red list of endangered species [Critically Endangered (CR)], has been captured as by-catch by trawling fishing boats to the edge of extinction. Despite governmental conservation initiatives, the species is still caught and commercialized along the Brazilian coast. In this study, the authors report three rare aggregation events for the Brazilian coast of P. horkelii, inside the only nearshore no-entry Brazilian marine protected area. Strategies for its protection are also discussed. 相似文献
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Henrique Barbosa Thais A. Costa-Silva Geanne A. Alves Conserva Adelson J. Araujo Ana Luísa L. Lordello Guilherme M. Antar Maiara Amaral Marisi G. Soares Andre G. Tempone João Henrique G. Lago 《化学与生物多样性》2021,18(4):e2001022
One new aporphine, dicentrine-β-N-oxide ( 1 ), together with five related known alkaloids dehydrodicentrine ( 2 ), predicentrine ( 3 ), N-methyllaurotetanine ( 4 ), cassythicine ( 5 ), and dicentrine ( 6 ) were isolated from the leaves of Ocotea puberula (Lauraceae). Antiprotozoal activity of the isolated compounds was evaluated in vitro against trypomastigote forms of Trypanosoma cruzi. Among the tested compounds, alkaloid 1 exhibited higher potential with EC50 value of 18.2 μM and reduced toxicity against NCTC cells (CC50>200 μM – SI>11.0), similar to positive control benznidazole (EC50 of 17.7 μM and SI=10.7). Considering the promising results of dicentrine-β-N-oxide ( 1 ) against trypomastigotes, the mechanism of parasite death caused by this alkaloid was investigated. As observed, this compound reached the plasma membrane electric potential directly after 2 h of incubation and triggered mitochondrial depolarization, which probably leads to trypomastigote death. Therefore, dicentrine-β-N-oxide ( 1 ), reported for the first time in this work, can contribute to future works for the development of new trypanocidal agents. 相似文献
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Jonathan A. Myers Jonathan M. Chase Iván Jiménez Peter M. Jørgensen Alejandro Araujo‐Murakami Narel Paniagua‐Zambrana Renate Seidel 《Ecology letters》2013,16(2):151-157
Site‐to‐site variation in species composition (β‐diversity) generally increases from low‐ to high‐diversity regions. Although biogeographical differences in community assembly mechanisms may explain this pattern, random sampling effects can create this pattern through differences in regional species pools. Here, we compared assembly mechanisms between spatially extensive networks of temperate and tropical forest plots with highly divergent species pools (46 vs. 607 species). After controlling for sampling effects, β‐diversity of woody plants was similar and higher than expected by chance in both forests, reflecting strong intraspecific aggregation. However, different mechanisms appeared to explain aggregation in the two forests. In the temperate forest, aggregation reflected stronger environmental correlations, suggesting an important role for species‐sorting (e.g. environmental filtering) processes, whereas in the tropics, aggregation reflected stronger spatial correlations, more likely reflecting dispersal limitation. We suggest that biogeographical differences in the relative importance of different community assembly mechanisms contribute to these striking gradients in global biodiversity. 相似文献
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