Premium
Impact of elevated atmospheric CO 2 concentration on soil microbial biomass and activity in a complex, weedy field model ecosystem
Author(s) -
Kampichler Christian,
Kandeler Ellen,
Bardgett Richard D.,
Jones T. Hefin,
Thompson Lindsey J.
Publication year - 1998
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1046/j.1365-2486.1998.00157.x
Subject(s) - biomass (ecology) , soil biology , biota , ecosystem , environmental science , terrestrial ecosystem , ecology , herbivore , soil water , agronomy , cycling , population , environmental chemistry , biology , chemistry , geography , forestry , demography , sociology
Although soil organisms play an essential role in the cycling of elements in terrestrial ecosystems, little is known of the impact of increasing atmospheric CO 2 concentrations on soil microbial processes. We determined microbial biomass and activity in the soil of multitrophic model ecosystems housed in the Ecotron (NERC Centre for Population Biology, Ascot, UK) under two atmospheric CO 2 concentrations (ambient vs. ambient + 200 ppm). The model communities consist of four annual plant species which naturally co‐occur in weedy fields and disturbed ground throughout southern England, together with their herbivores, parasitoids and soil biota. At the end of two experimental runs lasting 9 and 4.5 months, respectively, root dry weight and quality showed contradictory responses to elevated CO 2 concentrations, probably as a consequence of the different time‐periods (and hence number of plant generations) in the two experiments. Despite significant root responses no differences in microbial biomass could be detected. Effects of CO 2 concentration on microbial activity were also negligible. Specific enzymes (protease and xylanase) showed a significant decrease in activity in one of the experimental runs. This could be related to the higher C:N ratio of root tissue. We compare the results with data from the literature and conclude that the response of complex communities cannot be predicted on the basis of oversimplified experimental set‐ups.