Can mango orchards rehabilitate degraded areas by nutrient cycling?

Degradation of areas reduces nutrient cycling in the environment, and mango tree (Mangifera indica L.) cultivated in orchard could act as an alternative for degrading areas rehabilitation. The aim of this study was to evaluate the nutrients contribution to soil via litter in mango orchard, which was used as an alternative for degrading areas rehabilitation in the northeast of Pará, Brazil.

Tree Regeneration Under Different Land-Use Mosaics in the Brazilian Amazon's "Arc of Deforestation".

We studied the tree-regeneration patterns in three distinct agricultural settlements in the Eastern Amazon to test the influence of land-use mosaics. The following questions are addressed: are the floristic structure and composition of regenerating trees affected by the various land-use types applied in the agricultural settlements? Do tree-regeneration patterns respond similarly to distinct land-use mosaics? Is there a relationship between tree regeneration and soil characteristics among the land-use types? The regeneration was inventoried at 45 sampling points in each settlement. At each sampling point, fourteen soil variables were analyzed.

Effects of water and nutrient availability on fine root growth in eastern Amazonian forest regrowth, Brazil.

*Fine root dynamics is widely recognized as an important biogeochemical process, but there are few data on fine root growth and its response to soil resource availability, especially for tropical forests. *We evaluated the response of fine root dynamics to altered availability of soil water and nutrients in a 20-yr-old forest regrowth in eastern Amazonia. In one experiment the dry season reduction in soil moisture was alleviated by irrigation.

Altered resource availability and the population dynamics of tree species in Amazonian secondary forests.

Despite research demonstrating that water and nutrient availability exert strong effects on multiple ecosystem processes in tropical forests, little is known about the effect of these factors on the demography and population dynamics of tropical trees. Over the course of 5 years, we monitored two common Amazonian secondary forest species-Lacistema pubescens and Myrcia sylvatica-in dry-season irrigation, litter-removal and control plots. We then evaluated the effects of altered water and nutrient availability on population demography and dynamics using matrix models and life table response experiments.