Landscape patterns of primary production reveal agricultural benefits from forest conservation

Abstract

Primary production (PP) is a fundamental ecosystem function that influences several ecosystem services. However, little is known about how changes in landscape structure resulting from agricultural expansion affects forest and cropland production. We investigated the effect of landscape composition and configuration on the PP of forests and sugarcane crops in an old agricultural frontier of the Brazilian Atlantic forest. Using satellite images and a comprehensive dataset of vegetation indices that are proxies of PP (NDVI and EVI), we sampled 1201-km2 landscapes during the rainy and dry seasons of 2011–2016. In each landscape we quantified the indices, the percentage of sugarcane crops, the density of forest edges, and the number of forest patches. The NDVI and EVI of the entire landscape were negatively influenced by the percentage of croplands in both seasons and weakly affected by edge density and number of forest patches. When analyzing the NDVI of forests and croplands separately, both were negatively affected by the percentage of croplands. This indicates that forests and croplands are less productive in more deforested landscapes. The spatial variability of NDVI and EVI within the landscapes, estimated with coefficients of variation, was not affected by landscape attributes. Our findings indicate that landscape composition (i.e. forest cover) is more important than spatial configuration in determining the PP of forest and sugarcane crops, reinforcing the need to conserve forests in agricultural landscapes. We recommend reducing deforestation, restoring abandoned fields, protecting forest remnants and avoiding forest fragmentation to sustain more productive environmental-friendly agricultural landscapes.

Keywords

• Ecosystem services
• Forest biomass
• Habitat loss
• Habitat fragmentation
• Human-modified landscapes
• Landscape composition