Marshall, John
- University of Idaho
Abstract
Litter respiration (R-L) represents a significant portion of whole-soil respiration (R-S) in forests, yet climatic correlations with R-L have seldom been examined. Because R-L is reduced at low humidities and R-S is reduced at low temperatures, these components may show divergent trends with elevation in western North American forests. Using a litter-removal experiment along a forested 750 m elevation gradient in the Rocky Mountains of northern Idaho, USA, we measured R-S on soils from which litter had been removed (R-NL) and, by difference, R-L. Mean R-L represented 16% (SE = 2%) of mean R-S from July through October of 2007 and 2008. R-S was highest at warmer times and sites, and was not suppressed by low soil moisture. In contrast, R-L was highest at cooler times, when humidity and gravimetric litter water content were highest. R-L was highest at mid-elevations, representing neither the warmest nor wettest sites. Sixty-three percent of variability in site R-L was explained by both mean annual temperature (MAT) and mean annual relative humidity (MARH), including a positive interaction effect between MAT and MARH. Our results imply that the equilibration of litter with atmospheric humidity is an important control over litter respiration rates.
Keywords
relative humidity; carbon; carbon dioxide; temperature; moisture
Published in
Canadian Journal of Forest Research
2014, volume: 44, number: 5, pages: 432-440
Publisher: CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS
SLU Authors
UKÄ Subject classification
Forest Science
Publication identifier
- DOI: https://doi.org/10.1139/cjfr-2013-0334
Permanent link to this page (URI)
https://res.slu.se/id/publ/89287