Can differences in soil community composition after peat meadow restoration lead to different decomposition and mineralization rates?

• Published in: Soil biology & biochemistry 2009-08, Vol.41 (8), p.1717-1725
• Main Authors: van Dijk, Jerry, Didden, Wim A.M., Kuenen, Frans, van Bodegom, Peter M., Verhoef, Herman A., Aerts, Rien
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; biodegradation; Biological and medical sciences; carbon; Chemical, physicochemical, biochemical and biological properties; Collembola; community structure; diversity; Enchytraeidae; Food web; food webs; fresh-water wetlands; Fundamental and applied biological sciences. Psychology; grassland soils; Groundwater level; land restoration; Micro-organisms; microbial communities; Mineralization; Nitrogen; nitrogen mineralization; northern wetlands; Nutrient cycling; nutrient dynamics; peat soils; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Protozoa; scots pine forest; soil arthropods; soil bacteria; soil fungi; soil microorganisms; soil organic matter; soil pH; Soil science; water table; Wetland; wetlands; Zoology (interactions between soil fauna and agricultural or forest soils)
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2009.05.016

Reducing decomposition and mineralization of organic matter by increasing groundwater levels is a common approach to reduce plant nutrient availability in many peat meadow restoration projects. The soil community is the main driver of these processes, but how community composition is affected by peat meadow restoration is largely unknown. Furthermore, it is unclear whether restoration induced changes could lead to altered decomposition and mineralization rates. We determined soil community composition in restored peat meadows with different groundwater levels and soil pH. This composition was subsequently used in food web model calculations of C and N mineralization rates to assess whether differences in soil community composition may have contributed to differences in decomposition and mineralization rates observed between these meadows. Community composition of micro-organisms, Collembola and Enchytraeidae differed considerably between meadows and were correlated with differences in groundwater levels and soil pH. Collembolan and enchytraeid species from wet and neutral environments were more abundant at meadows with higher groundwater levels. Lower fungal to bacterial PLFA ratios and higher numbers of protozoa indicated an increased importance of the bacterial part of the food web at meadows with higher groundwater levels. Food web model calculations suggested that the observed changes in community composition would lead to higher rates of C and N mineralization at meadows with high groundwater levels. Results from modeling were consistent with field measurements of C mineralization, but not with measurements of N mineralization. We conclude that understanding changes in soil community composition in response to specific restoration measures may help us to better understand ecosystem responses to wetland restoration schemes, especially regarding soil biogeochemical processes.