Decomposition and Nutrient Cycling in Rostkovia magellanica from Two Contrasting Bogs on South Georgia
The chemical composition of Rostkovia magellanica tillers was contrasted between a eutrophic seepage slope-mire and a mesotrophic basin-bog. Tillers in the slope-mire have higher concentrations of Ca (+214%), K (+17%), N (+13%) and Fe (+6%) but lower concentrations of Na (−22%), Mg (−54%) and Mn (−24%) than those in the basin-bog. These differences generally reflect the higher levels of exchangeable nutrients and pH in peat from the seepage-slope. Five elements are removed from senescing leaves (in the order K > P > N > Na > Mg), whereas 3 are accumulated (Fe > Ca > Mn). At both sites, initially rapid loss of weight of litterbag content was halted over winter. Weight loss in the second summer was much faster on the seepage-slope. The content of mobile elements (K, P, N, Na) decreased considerably overall through leaching and decomposition, but N and P contents increased during the second summer at the slope and bog sites, respectively, and this may represent fungal activity. Litterbags composed of different age classeś of leaves remained chemically distinct from each other (with the exception of K) during the 15-month trial.
KeywordsBiomass Hydrogen Peroxide Phosphorus Magnesium Acidity
Unable to display preview. Download preview PDF.
- Allen SE; Grimshaw HM; Parkinson JA; Quarmby C (1974) Chemical analysis of ecological materials. Blackwell, Oxford 563 ppGoogle Scholar
- Buckman HO; Brady NC (1960) The nature of properties of soils. Macmillan, New York, 653 ppGoogle Scholar
- Malmer M (1958) Chemical composition of mire plants and peat. Bot Not 11: 274–288Google Scholar
- Malmer N; Nihlgard B (1980) Supply and transport of mineral nutrients. Ecol Bull (Stockholm) 30: 63–95Google Scholar
- Smith RIL (1981) Types of peat and peat-forming vegetation on South Georgia. Br Antarct Sury Bull 53: 119–139Google Scholar
- Smith RIL; Walton DWH (1975) South Georgia, Subantarctic. Ecol Bull (Stockholm) 20: 399–423Google Scholar
- Smith VR (1977) The chemical composition of Marion Island soils, plants and vegetation. S Mr J Antarct Res 7: 28–39Google Scholar
- Swift MJ; Heal OW; Anderson JM (1979) Decomposition in terrestrial ecosystems. Blackwell, Oxford, 372 ppGoogle Scholar
- Walton DWH; Smith RIL (1979) The chemical composition of South Georgian vegetation. Br Antarct Sury Bull 49: 117–135Google Scholar