Laboratorio Of Analise Of Sistemas Sustentaveis

Belém, Brazil

Laboratorio Of Analise Of Sistemas Sustentaveis

Belém, Brazil
SEARCH FILTERS
Time filter
Source Type

da Silva C.M.,Federal University of Pará | da Silva C.M.,Federal Rural University of Amazonia | Vasconcelos S.S.,Laboratorio Of Analise Of Sistemas Sustentaveis | Mourao Junior M.,Laboratorio Of Analise Of Sistemas Sustentaveis | And 4 more authors.
Acta Amazonica | Year: 2016

The soil carbon dioxide (CO2) efflux dynamics and its controlling factors of Amazonian agroforestry systems are poorly understood. The objective of this study was to evaluate the temporal variation of soil CO2 efflux in oil palm-based agroforestry systems and the relation between efflux and biotic (microbial and total soil carbon, microbial respiration, fine roots, individual components of agroforestry systems (AFS)) and abiotic factors (soil moisture and temperature). The measurements were taken during the less rainy (December 2010) and rainy (May 2011) periods. The soil CO2 efflux was highest during the rainy season, probably due to increased microbial activity influenced by climatic factors coupled with biotic factors. The soil CO2 efflux correlated positively with soil moisture and microbial biomass carbon and negatively with soil temperature and metabolic quotient, but these correlations were weak. The soil CO2 efflux was sensitive to the type of agroforestry system and to rainfall seasonality. © 2015, Instituto Nacional de Pesquisas da Amazonia. All rights reserved.


da Maia R.S.,Federal University of Pará | Vasconcelos S.S.,Laboratorio Of Analise Of Sistemas Sustentaveis | de Carvalho C.J.R.,Laboratorio Of Analise Of Sistemas Sustentaveis
Acta Amazonica | Year: 2015

The availability of soil nutrients (especially phosphorus) and soil water strongly infuence mycorrhizal symbiosis in forest ecosystems. The aim of this study was to evaluate the impact of litter removal and increased soil moisture availability on the spore density and mycorrhizal colonization of apogeotropic and non-apogeotropic roots of a secondary forest stand in eastern Amazonia. We determined the percentage of mycorrhizal colonization of apogeotropic and non-apogeotropic (0-10 cm soil depth) fine roots (diameter ≤ 2 mm), spore density, glomalin concentration, and soil phosphorus availability. Litter removal did not reduce soil phosphorus availability. The spore density was not afected by litter removal. In general, the variables varied on a seasonal basis, except the mycorrizal colonization of non-apogetropic roots and glomalin concentration, but were not afected by irrigation. Mechanical damage to the apogeotropic root system, inherent to the fortnightly litter removal, may have contributed to decrease mycorrhizal colonization of both apogeotropic and non-apogeotropic roots and, consequently, soil glomalin. Our results suggest that the reduction of soil cover may have negative impact over the fungus-plant symbiosis. © 2015, Instituto Nacional de Pesquisas da Amazonia. All Rights Reserved.

Loading Laboratorio Of Analise Of Sistemas Sustentaveis collaborators
Loading Laboratorio Of Analise Of Sistemas Sustentaveis collaborators