Crust cover and prior soil moisture status affect the response of soil microbial community and function to extreme rain events in an arid area

Autor: A. Papapostolou, George P. Stamou, D.-W. Jones, Nikolaos Monokrousos, John Scullion, Effimia Papatheodorou
Rok vydání: 2020
Předmět:
Zdroj: European Journal of Soil Biology. 101:103243
ISSN: 1164-5563
DOI: 10.1016/j.ejsobi.2020.103243
Popis: Biological soil crusts (BSC) are an important multi-trophic component of arid ecosystems in the Mediterranean region, considered to have an important role in protecting the underlying soil from erosion and enhancing soil ecosystem functions. Using mesocosms in a 48 days glasshouse experiment, we investigated how previously hydrated (+W) and dried (-W) crust (+BSC) and uncrust (-BSC) -soil samples influenced microbial community structure, biomass and soil functionality of the underlying soils when exposed to two simulated extreme rain events. Community structure was assessed by phospholipid fatty acids analysis (PLFAs) and soil functionality by the activity of b-glucosidase, polyphenol oxidase, N-acetylglucosaminidase, acid phosphomoesterase and urease involve in C, P and N cycles. Crust increased the soil water content. In contrast, NH4 and NO3 were unaffected by the presence of the crust or its previous hydration status. N availability was affected by rain events; it declined from first to second event. Microbial biomasses were affected by the interaction crust x watering. Significant decline in biomasses was recorded in +BSC + W soils as a response to rain events. Little effects of treatments on soil enzymes were noticed; crust presence had a positive influence on the activity of phenol oxidase and a negative one on acid phosphomoesterase activity. The first rainfall had the greatest impact on microbial community structure, with communities in the previously hydrated crust affected most. These effects were less pronounced for the second rain event possibly due to microbial acclimation. Responses in enzyme profiles were consistent with those of communities, but delayed, with more marked responses following the second rainfall. We concluded that the effect of this lichen crust from the Mediterranean area on the response of soil microbial communities and enzymes to rainfall events depended strongly on the prior hydration status of the crust-soil complex.
Databáze: OpenAIRE
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