Dinâmica de nitrogênio em solos de florestas secundárias sob diferentes históricos de uso nos municípios de Santarém e Belterra, Amazônia Oriental

If the nutrient cycling through decomposition of organic material and the economy of the use of nutrients by the vegetation are factors that enable the maintenance of a large part of the primary forests in the Amazon, it is predictable that both factors are affected before anthropogenic changes that modify the vegetation, in order to output nutrients that was contained above the soil biomass. This work aimed to determine changes in the dynamics of nitrogen nutrient in secondary forest soils with the following historical usage: logging, management and burns, as well as, clear cutting in Santarém and Belterra Cities, Eastern Amazon. Among the evaluated parameters are: efficiency in the use of nitrogen, C: N rate in litterfall and floor, nitrate and ammonium in the soil, nitrogen mineralization rates and analysis of the 15N isotope. There was a trend to more efficient in the use of nitrogen in management treatments and burning and clearcutting, which resulted in lower quality of the fresh litterfall and floor, as well as lower mineralization rates. The availability of nitrogen showed a tendency to be higher in primary and managed forests. As a measure of integrating character to the dynamics of N in the soil, the isotopic analysis indicated a reduced dynamic in forests subjected to clearcutting in relation to primary forest. It is proposed for the studied areas a conceptual model of recovery of the N dynamics in the soil, in which the secondary forests of this work are outing of the initial phase of limitation in N, and evolving into the primary forest standards.Se a ciclagem de nutrientes através da decomposição da matéria orgânica e a economia do uso de nutrientes pela vegetação são fatores que permitem a manutenção de grande parte de florestas primárias na Amazônia, é previsível que ambos os fatores sejam afetados diante de alterações antrópicas que modificam a cobertura vegetal, tendo em vista a saída de nutrientes que estava contida na fitomassa acima do solo. Esta dissertação teve como objetivo verificar mudanças na dinâmica do nutriente nitrogênio em solos de florestas secundárias com os seguintes históricos de uso: extração de madeira, manejo e queima, bem como, corte raso, nos municípios de Santarém e Belterra, Amazônia Oriental. Dentre os parâmetros avaliados estão: eficiência no uso de nitrogênio, relações C:N em serapilheira fresca e de chão, nitrato e amônio no solo, taxas de mineralização de nitrogênio e análise do isótopo 15N. Houve uma tendência de maior eficiência no uso de nitrogênio nos tratamentos de manejo e queima e corte raso, o que resultou em menor qualidade da serapilheira fresca e de chão, bem como, menores taxas de mineralização. A disponibilidade de nitrogênio mostrou uma tendência de ser maior nas florestas primárias e manejadas. Como parâmetro integrador acerca da dinâmica de N no solo, a análise do isótopo 15N indicou uma dinâmica reduzida nas florestas submetidas ao corte raso, em relação à floresta primária. Propõe-se para as áreas estudadas um modelo conceitual de recuperação da dinâmica de N no solo, onde as florestas secundárias do presente trabalho estão saindo da fase inicial de limitação em N e evoluindo para os padrões de floresta primária

Pantropical modelling of canopy functional traits using Sentinel-2 remote sensing data

Funding Information: This work is a product of the Global Ecosystems Monitoring (GEM) network (gem.tropicalforests.ox.ac.uk). J.A.G. was funded by the Natural Environment Research Council (NERC; NE/T011084/1 and NE/S011811/1) and the Netherlands Organisation for Scientific Research (NWO) under the Rubicon programme with project number 019.162LW.010. The traits field campaign was funded by a grant to Y.M. from the European Research Council (Advanced Grant GEM-TRAIT: 321131) under the European Union‘s Seventh Framework Programme (FP7/2007-2013), with additional support from NERC Grant NE/D014174/1 and NE/J022616/1 for traits work in Peru, NERC Grant ECOFOR (NE/K016385/1) for traits work in Santarem, NERC Grant BALI (NE/K016369/1) for plot and traits work in Malaysia and ERC Advanced Grant T-FORCES (291585) to Phillips for traits work in Australia. Plot setup in Ghana and Gabon were funded by a NERC Grant NE/I014705/1 and by the Royal Society-Leverhulme Africa Capacity Building Programme. The Malaysia campaign was also funded by NERC GrantNE/K016253/1. Plot inventories in Peru were supported by funding from the US National Science Foundation Long-Term Research in Environmental Biology program (LTREB; DEB 1754647) and the Gordon and Betty Moore Foundation Andes-Amazon Program. Plots inventories in Nova Xavantina (Brazil) were supported by the National Council for Scientific and Technological Development (CNPq), Long Term Ecological Research Program (PELD), Proc. 441244/2016-5, and the Foundation of Research Support of Mato Grosso (FAPEMAT), Project ReFlor, Proc. 589267/2016. During data collection, I.O. was supported by a Marie Curie Fellowship (FP7-PEOPLE-2012-IEF-327990). GEM trait data in Gabon was collected under authorisation to Y.M. and supported by the Gabon National Parks Agency. D.B. was funded by the Fondation Wiener-Anspach. W.D.K. acknowledges support from the Faculty Research Cluster ‘Global Ecology’ of the University of Amsterdam. M.S. was funded by a grant from the Ministry of Education, Youth and Sports of the Czech Republic (INTER-TRANSFER LTT19018). Y.M. is supported by the Jackson Foundation. We thank the two anonymous reviewers and Associate Editor G. Henebry for their insightful comments that helped improved this manuscript.Peer reviewedPostprin