Impact of litter species diversity on decomposition processes and communities of soil organisms

• Published in: Soil biology & biochemistry 2011, Vol.43 (1), p.9-19
• Main Authors: Szanser, M., Ilieva-Makulec, K., Kajak, A., Górska, E., Kusińska, A., Kisiel, M., Olejniczak, I., Russel, S., Sieminiak, D., Wojewoda, D.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Algae; Algal biomass and production; Biochemistry and biology; biodegradation; Biological and medical sciences; carbon nitrogen ratio; Chemical, physicochemical, biochemical and biological properties; Collembola; Dactylis glomerata; Festuca rubra; field experimentation; forage; fulvic acids; Fundamental and applied biological sciences. Psychology; humic acids; humus; humus formation; Litter species diversity; Micro-, meso- and macrofauna; Microbial activity; Microbiology; Nematoda; Organic matter; pasture plants; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plant litter; polypropylenes; predators; soil depth; soil fauna; Soil humus; soil invertebrates; soil nematodes; Soil science; species diversity; Trifolium pratense; vegetation; Zoology (interactions between soil fauna and agricultural or forest soils)
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2010.08.031

The effect of plant species diversity and the C/N ratio of litter on soil processes were analysed in mesocosms in a three year field experiment. Plots 0.5 × 0.5 m with a depth of 15 cm containing sand mixed with loam were used to compare five natural and one artificial litter type (polypropylene string). Natural litters were either monospecific (I: Dactylis glomerata; II: Festuca rubra and III: Trifolium pratense) or were species mixtures (IV: mixture of three species I, II and III; V: mixture of twelve species, IV and nine other meadow plants). Differences among treatments in the litter decomposition rate, humic acid content and nematode density depended on the litter quality (C:N ratio) in most cases. By contrast, most of the differences among treatments found in the substratum below the litter cover resulted from litter diversity. The largest increase of carbon and nitrogen amount during growing season was found under litter mixtures (IV, V) and the highest fulvic acid content under the most diverse litter (V). Similarly, the production of algae in the substratum also significantly increased with litter diversity. Higher taxonomic diversity of Nematoda and Collembola and the most mature community of nematodes were observed under the most complex litter. Epigeic macrofauna, both dwelling in and penetrating the litter, did not differ significantly between experimental treatments. However, the highest share of predators was found in the treatment with the richest plant species diversity. In general, the results suggest that the decomposition of diverse plant litter enhances humus acid accumulation in soils. It is likely that algae participate in the process of humus formation.