Degradation of Riparian Forest Affects Soil Properties and Ecosystem Services Provision in Eastern Amazon of Brazil

Abstract

Brazil's riparian forests are continuously threatened by conversion into agricultural areas, causing not only degradation and loss of vegetation but also negative changes in soil properties and ecosystem services. In order to select vegetation and soil variables that are affected by degradation and to evaluate whether forest structure can be used as a proxy for soil ecosystem services, two watersheds in eastern Amazon were chosen as a study area in which four degradation levels were identified (very high, high, moderate and low), based on forest canopy openness and height. Vegetation structural characteristics, water infiltration rates, and soil properties were evaluated in 24, 1,000 m2 permanent plots. Results indicated that forest degradation significantly reduced soil carbon, phosphorus, cation exchange capacity, silt proportion, total porosity, and water content as well as water infiltration rate. Vegetation structure was a good proxy for monitoring soil ecosystem services (i.e. regulation of water flow, erosion control and life-supporting). Tree height and basal area, as well as herb biomass, were identified as the best vegetation indicators for changes in soil properties that underlie ecosystem services. Application of this strategy may facilitate the monitoring and modeling of riparian forest ecosystem services across broader spatial scales, to help guide efficient restoration efforts and conservation policies. Copyright © 2016 John Wiley & Sons, Ltd.