Contrasting response of summer soil respiration and enzyme activities to long-term warming and drought in a wet shrubland (NE Wales, UK)

Dominguez, Maria T.; Holthof, Eva; Smith, Andrew R.; Koller, Eva; Emmett, Bridget A. ORCID: https://orcid.org/0000-0002-2713-4389. 2017 Contrasting response of summer soil respiration and enzyme activities to long-term warming and drought in a wet shrubland (NE Wales, UK). Applied Soil Ecology, 110. 151-155. https://doi.org/10.1016/j.apsoil.2016.11.003

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Official URL: http://dx.doi.org/10.1016/j.apsoil.2016.11.003

Abstract/Summary

Evaluating the response of soil organic matter decomposition to warming and changes in rainfall is critical to assess the likelihood of proposed positive feedbacks from the terrestrial to the atmospheric system. The response of soil respiration and extracellular activities (EEAs) to long-term warming and recurrent summer drought was studied in a wet shrubland ecosystem in Wales (UK), after 13 years of climate change simulation in a whole-ecosystem experiment. Over a year soil respiration, temperature and moisture was monitored in the field. During the summer season, coinciding with maximum soil respiration rates, soil inorganic N and P, microbial biomass and the extracellular activities (EEAs) of a selection of enzymes involved in C, N and P cycling were analysed. Based on previous field measurements of C and N mineralization, we expected a stronger response of C-cycling EEAs, in comparison to N-cycling EEAs, to drought and warming, and a greater sensitivity of C-cycling EEAs to drought than to warming. Drought had a clear impact on soil respiration during the summer season. However, the availability of inorganic N or P was not significantly affected by the treatments. Microbial biomass and C:N ratio also remained unchanged. In contrast to one of our hypothesis, C-cycling EEAs measured under non-optimal conditions that simulated soil environment in the field (pH of 4.1 and with a temperature incubation of 10 °C) showed no significant differences due to long-term warming and recurring drought treatments. Possibly, this assay approach may have obscured treatment effects on the soil enzyme pool. Our results highlight the need for developing methods for the in-situ analysis of EEAs to determine rates of reactions.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1016/j.apsoil.2016.11.003
UKCEH and CEH Sections/Science Areas:	Emmett
ISSN:	0929-1393
Additional Keywords:	climate change, soil C, Calluna vulgaris, phenol-oxidase, β-glucosidase, microbial C:N
NORA Subject Terms:	Agriculture and Soil Science
Date made live:	13 Dec 2016 10:40 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/515429

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1016/j.apsoil.2016.11.003

UKCEH and CEH Sections/Science Areas:

Emmett

ISSN:

0929-1393

Additional Keywords:

climate change, soil C, Calluna vulgaris, phenol-oxidase, β-glucosidase, microbial C:N

NORA Subject Terms:

Agriculture and Soil Science