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Biological soil crusts increase the resistance of soil nitrogen dynamics to changes in temperatures in a semi-arid ecosystem.
- Source :
-
Plant & Soil . May2013, Vol. 366 Issue 1/2, p35-47. 13p. 1 Chart, 6 Graphs. - Publication Year :
- 2013
-
Abstract
- Aims: Biological soil crusts (BSCs), composed of mosses, lichens, liverworts and cyanobacteria, are a key component of arid and semi-arid ecosystems worldwide, and play key roles modulating several aspects of the nitrogen (N) cycle, such as N fixation and mineralization. While the performance of its constituent organisms largely depends on moisture and rainfall conditions, the influence of these environmental factors on N transformations under BSC soils has not been evaluated before. Methods: The study was done using soils collected from areas devoid of vascular plants with and without lichen-dominated BSCs from a semi-arid Stipa tenacissima grassland. Soil samples were incubated under different temperature (T) and soil water content (SWC) conditions, and changes in microbial biomass-N, dissolved organic nitrogen (DON), amino acids, ammonium, nitrate and both inorganic N were monitored. To evaluate how BSCs modulate the resistance of the soil to changes in T and SWC, we estimated the Orwin and Wardle Resistance index. Results: The different variables studied were more affected by changes in T than by variations in SWC at both BSC-dominated and bare ground soils. However, under BSCs, a change in the dominance of N processes from a net nitrification to a net ammonification was observed at the highest SWC, regardless of T. Conclusions: Our results suggest that the N cycle is more resistant to changes in T in BSC-dominated than in bare ground areas. They also indicate that BSCs could play a key role in minimizing the likely impacts of climate change on the dynamics of N in semi-arid environments, given the prevalence and cover of these organisms worldwide. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0032079X
- Volume :
- 366
- Issue :
- 1/2
- Database :
- Academic Search Index
- Journal :
- Plant & Soil
- Publication Type :
- Academic Journal
- Accession number :
- 87087215
- Full Text :
- https://doi.org/10.1007/s11104-012-1404-3