Sponsor
This research was supported by the U.S. National Science Foundation grants (DEB 0919047—Ecosystem Studies, DEB 0423259—Hubbard Brook Long Term Ecological Research, EAR 1014507 and DBI/EAR 0754678
Published In
Journal of Geophysical Research: Biogeosciences
Document Type
Article
Publication Date
5-1-2014
Subjects
Forest biogeochemistry, Biogeochemical prospecting, Hardwoods, Forests and forestry
Abstract
Understanding and predicting the extent, location, and function of biogeochemical hot spots at the watershed scale is a frontier in environmental science. We applied a hydropedologic approach to identify (1) biogeochemical differences among morphologically distinct hydropedologic settings and (2) hot spots of microbial carbon (C) and nitrogen (N) cycling activity in a northern hardwood forest in Hubbard Brook Experimental Forest, New Hampshire, USA. We assessed variables related to C and N cycling in spodic hydropedologic settings (typical podzols, bimodal podzols, and Bh podzols) and groundwater seeps during August 2010. We found that soil horizons (Oi/Oe, Oa/A, and B) differed significantly for most variables. B horizons (>10 cm) accounted for 71% (±11%) of C pools and 62% (±10%) of microbial biomass C in the sampled soil profile, whereas the surface horizons (Oi/Oe and Oa/A; 0–10 cm) were dominant zones for N-cycle-related variables. Watershed-wide estimates of C and N cycling were higher by 34 to 43% (±17–19%) when rates, horizon thickness, and areal extent of each hydropedologic setting were incorporated, versus conventionally calculated estimates for typical podzols that included only the top 10 cm of mineral soil. Despite the variation in profile development in typical, bimodal, and Bh podzols, we did not detect significant differences in C and N cycling among them. Across all soil horizons and hydropedologic settings, we found strong links between biogeochemical cycling and soil C, suggesting that the accumulation of C in soils may be a robust indicator of microbial C and N cycling capacity in the landscape.
Rights
Copyright 2014 by the American Geophysical Union
DOI
10.1002/2013JG002589
Persistent Identifier
http://archives.pdx.edu/ds/psu/12555
Citation Details
Morse, J. L., S. F. Werner, C. P. Gillin, C. L. Goodale, S. W. Bailey, K. J. McGuire, and P. M. Groffman (2014), Searching for biogeochemical hot spots in three dimensions: Soil C and N cycling in hydropedologic settings in a northern hardwood forest, J. Geophys. Res. Biogeosci., 119, 1596–1607, doi:10.1002/2013JG002589
Description
This is the publisher's final version of the record archived with author and publisher permission and made available six months from the date of publication.