DOI: 10.5061/dryad.h9w0vt4kr
title: Edge effects increase soil respiration without altering soil carbon stocks in temperate broadleaf forests

description: Anthropogenic disturbance has left the world's forests highly
 fragmented, with a significant proportion of edge-affected area. Abiotic
 changes at forest edges are likely to affect forest soil carbon cycling,
 as higher temperatures and lower moisture availability in edge
 environments have well-documented effects on soil respiration. The present
 study sought to quantify persistent changes in soil carbon cycling in the
 fragmented broadleaf forests of southeastern Pennsylvania. At three sites
 with &gt;80 year old forest-field edges, three 100 m transects
 perpendicular to the edge were established. Monthly measurements of soil
 respiration, temperature, and moisture were made at fixede distances along
 each transect throughout the growing season. Soil carbon storage from 0-20
 cm depth, litter biomass, and decomposition rates were also assessed. Soil
 respiration was significantly higher at forest edges, relative to the
 interior, and this effect penetrated 60 m into the forest. Significantly
 elevated surface soil temperature and decreased soil moisture were also
 observed in edge environments. Despite elevated soil respiration at the
 edge, soil carbon storage, litter bssomass, and decomposition rates were
 invariant along edge to interior gradients. The temperature responsiveness
 of soil respiration was significantly higher in the forest interior (100
 m), relative to locations ≤60 m from the edge. Edge effects altering
 elements of the soil carbon cycle were apparent in the forests of
 southeastern Pennsylvania, and principally manifest as increased soil
 respiration rates and decreased temperature responsiveness of soil
 respiration. Lack of variation in soil carbon pools and decomposition
 rates from the forest edge to interior suggests that increased soil
 respiration may be related to changes in root and rhizosphere respiration
 at the edge. These findings contribute to a growing body of evidence
 documenting increased soil respiration in the edge environments of
 temperate broadleaf forests. Discounting the alterations imposed by forest
 fragmentation on carbon cycling has the potential to produce misleading
 estimates of land-atmosphere CO2 exchange and terrestrial carbon storage.
description: Soil respiration (average of three measurements made with a
 LI-6400), soil temperature (5 and 10 cm depth), and soil moisture data
 were collected monthly from May to October 2018 at three fragmented forest
 edges in southeastern Pennsylvania. Measurements were collected at three
 transects per site at distances of 5, 15, 30, 60, and 100 m from the edge.
 Decomposition of a common substrate (cellulose filter paper) was also
 measured over this time period. Additional samples were collected from
 each measurement location in June 2018 to determine soil carbon and
 nitrogen storage at 0-10 and 10-20 cm depth (using elemental analysis of
 soil carbon and nitrogen together with soil bulk density), as well as
 litter layer (O horizon) biomass.
description: See README.txt file for dataset usage notes.