Evidence for Edge Enhancements of Soil Respiration in Temperate Forests

Abstract

Forest fragmentation impacts carbon uptake and storage; however, the magnitude and direction of fragmentation impacts on soil respiration remain poorly characterized. We quantify soil respiration rates along edge-to-interior transects in two temperate broadleaf forests in the eastern United States that vary in climate, species composition, and soil type. We observe average soil respiration rates 15–26% higher at the forest edge compared to the interior, corresponding to large gradients in soil temperature. We find no significant difference in the sensitivity of soil respiration to temperature between the forest edge and interior. Fragmentation and resultant shifts in microenvironment alter forest productivity and soil respiration near forest edges. Ecosystem models do not currently represent edge dynamics, but given the prevalence of landscape fragmentation and its effect on carbon cycling along forest edges, this omission likely introduces an important source of uncertainty in our understanding of terrestrial carbon dynamics with a changing landscape and climate.