Soil C0₂ efflux across four age classes of plantation loblolly pine (Pinus taeda L.) on the Virginia Piedmont

Abstract

Soil CO₂ efflux resulting from microbial and root respiration is a major component of the forest C cycle. In this investigation, we examined in detail how soil CO₂ efflux differs both spatially and temporally with respect to stand age for loblolly pine (Pinus taeda L.) plantations on the Virginia Piedmont. Throughout a 12-month period, efflux rates were measured both near the base of trees and midway between planting rows in stands of four age classes. Mean soil CO₂ efflux rates measured during the 12-month study were 1.72, 2.58, 2.84, and 2.90 µmol/m²/s for 1- to 2-year-old, 4- to 6-year-old, and 20- to 25-year-old stands, respectively. Time series analysis revealed that stand age had a significant effect on soil CO₂ efflux rate. Additionally, mean effect on soil CO₂ efflux rate. Mean soil CO₂ efflux rates, by position, for the 12-month study were 2.72 and 2.28 µmol/m²/s for the near and away measurement positions, respectively. Regression analysis was used to examine the influence of soil and climatic factors on seasonal changes in soil CO₂ efflux. The most influential factors affecting soil CO₂ efflex during the 12-month studywere soil temperature, soil moisture, stand age, and measurement position. We believe respiring roots significantly influence soil CO₂ efflux of plantation loblolly pine and account for differences observed between stand of different ages as well as spatial differences observed within a given stand.

Citation

Wiseman, P. Eric; Seiler, John R. 2004. Soil C0₂ efflux across four age classes of plantation loblolly pine (Pinus taeda L.) on the Virginia Piedmont. Forest Ecology and Management 192: 297-311