Nitrogen saturation of terrestrial ecosystems: some recent findings and their implications for our conceptual framework
Emmett, Bridget A.. 2007 Nitrogen saturation of terrestrial ecosystems: some recent findings and their implications for our conceptual framework. Water, Air and Soil Pollution: Focus, 7 (1-3). 99-109. 10.1007/s11267-006-9103-9Full text not available from this repository.
The consequences of nitrogen (N) enrichment for terrestrial and freshwater ecosystems are of increasing concern in many areas due to continued or increasing high emission rates of reactive N. Within terrestrial ecosystems various conceptual frameworks and modelling approaches have been developed which have enhanced our understanding of the sequence of changes associated with increased N availability and help us predict their future impacts. Here, some recent findings are described and their implications for these conceptual frameworks and modelling approaches discussed. They are: (a) an early loss of plant species that are characteristic of low N conditions as N availability increases and a loss of species with high N retention efficiencies (so called N ‘filters’), (b) suppression of microbial immobilisation of deposited due to increased availability in the early stages of N saturation, (c) the early onset of leaching due to these changes (a and b above) in both plant and microbial functioning, (d) reduced sensitivity of vegetation to N additions in areas with high historical N deposition, (e) delayed changes in soil C:N changes due to increased net primary productivity and reduced decomposition of soil organic matter. Some suggestions of early indicators of N saturation are suggested (occurrence of mosses; ratio in surface soils) which indicate either a shift in ecosystem function and/or structure.
|Programmes:||CEH Programmes pre-2009 publications > Biogeochemistry|
|Additional Keywords:||diversity, eutrophication, nitrate leaching, nitrogen saturation, microbial immobilisation, soil C:N ratio, species composition|
|NORA Subject Terms:||Agriculture and Soil Science
Ecology and Environment
|Date made live:||20 Dec 2007 10:12|
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