Nitrogen cycling in United Kingdom forests: the relevance of basic ecological research

作者：O. W. Heal, Michael J. Swift, Jan Mary Anderson · 发表于：Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 年份：1982 · DOI：10.1098/rstb.1982.0018 · 被引用次数：35 · 研究领域：Forest Ecology and Biodiversity Studies、Soil Carbon and Nitrogen Dynamics、Peatlands and Wetlands Ecology

Abstract Following recent reviews on nutrient cycling in temperate and British forests, two aspects of N cycling are selected for examination because of their fundamental importance and their relevance to management—ecosystem research and mobilization of N during decomposition. Despite the early work by J. D. Ovington and P. J. Rennie, only two major forest ecosystem studies have been developed in Britain. Summaries from these ecosystems show that they span the range of temperate forests in the N cycling characteristics. The Pinus nigra plantation on Culbin Sands is functioning on a low capital with low rates of transfer and shows N deficiency after 40 years. In contrast, the mixed deciduous Meathop Wood has a much larger capital of N and higher rates of transfer. The Pinus ecosystem retained a high proportion of added fertilizer N in the biomass and forest floor, and increased growth rates can be explained through N recycling within the trees. Basic concepts of N mineralization are reviewed and it is shown that they need to be modified for application to forests. Uptake by saprophytic and mycorrhizal fungi from the pool of soluble organic N can short-circuit the ammonification pathway and N can be released from substrates with a high C:N ratio by lysis of microbial tissues and faunal feeding. Some examples of evidence of these processes are given, stressing the spatial and temporal mosaic of substrates acting as sinks and sources of N. Management practices can have a marked ...