Climate Variation and Soil Carbon and Nitrogen Cycling Processes in a Northern Hardwood Forest |
| |
Authors: | Peter M Groffman Janet P Hardy Melany C Fisk Timothy J Fahey Charles T Driscoll |
| |
Institution: | (1) Cary Institute of Ecosystem Studies, Box AB, Millbrook, New York 12545, USA;(2) Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire 03755, USA;(3) Department of Zoology, Miami University, Oxford, Ohio 45056, USA;(4) Department of Natural Resources, Cornell University, Ithaca, New York 14853, USA;(5) Department of Civil and Environmental Engineering, Syracuse University, Syracuse, New York 13244, USA |
| |
Abstract: | We exploited the natural climate gradient in the northern hardwood forest at the Hubbard Brook Experimental Forest (HBEF)
to evaluate the effects of climate variation similar to what is predicted to occur with global warming over the next 50–100 years
for northeastern North America on soil carbon (C) and nitrogen (N) cycle processes. Our objectives were to (1) characterize
differences in soil temperature, moisture and frost associated with elevation at the HBEF and (2) evaluate variation in total
soil (TSR) and microbial respiration, N mineralization, nitrification, denitrification, nitrous oxide (N2O) flux, and methane (CH4) uptake along this gradient. Low elevation sites were consistently warmer (1.5–2.5°C) and drier than high elevation sites.
Despite higher temperatures, low elevation plots had less snow and more soil frost than high elevation plots. Net N mineralization
and nitrification were slower in warmer, low elevation plots, in both summer and winter. In summer, this pattern was driven
by lower soil moisture in warmer soils and in winter the pattern was linked to less snow and more soil freezing in warmer
soils. These data suggest that N cycling and supply to plants in northern hardwood ecosystems will be reduced in a warmer
climate due to changes in both winter and summer conditions. TSR was consistently faster in the warmer, low elevation plots.
N cycling processes appeared to be more sensitive to variation in soil moisture induced by climate variation, whereas C cycling
processes appeared to be more strongly influenced by temperature. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|