Energy flow and nutrient cycling in the Marion Island terrestrial ecosystem : 30 years on

摘要: This article is a sequel to word-model description of the ecosystem sub-Antarctic Marion Island, published in this journal 30 years ago (Smith 1977). It expands on qualitative considerations patterns energy flow and nutrient cycling presented that paper, by providing quantitative information from subsequent research at island. Primary production island's lowland plant communities high an annual basis, because vegetation has long growing season due lack severely cold winters or drought. Daily productivity actually low radiation levels cool season. The particularly efficient regarding its use nutrients for growth, but still requires substantial amounts support production. Seabirds seals import large quantities ocean when they breed moult They markedly enhance soil status areas which occur, also adjacent areas. However, far greater part inland not directly influenced birds most required growth are provided decomposition litter peat. Soil invertebrates crucial facilitators processes, otherwise restricted temperatures moisture contents. Introduced house mice have invaded almost all parts island predate heavily invertebrates, thus affecting mineralisation. threatens only functioning (lowered availability leading slower lower quality, more decomposition-recalcitrant litter), structure (an altered balance between leads change relation peat formation degradation, important determinant succession) ecosystem. suggested may affect ecology predating seabird chicks.