Use of a gradient of N-deposition to calculate effect-related soil and vegetation measures in deciduous forests

Research output: Contribution to journalArticle

Abstract

Deposition of N and S has increased since the 1950s in most European countries and N accumulates in ecosystems that are not N saturated. This study shows long-term effects of a (modelled) N deposition of 7-17 kg N ha(-1) per year on biological and chemical processes in soil, vegetation composition, and functional types of field-layer plant species in deciduous forests. Soil pH largely determined the response of the soil processes, emphasising the importance to compare soils of similar acidity regarding the effects of N deposition. The most pronounced effects were demonstrated for the most acid study plots. When we compared regions with a deposition of 7 and 17 kg N ha(-1) per year we found a 40-80% higher soil N mineralisation rate, 2-90% higher nitrification rate and 10-25% lower C:N ratio in the region with the highest deposition. Similar but smaller differences were indicated when regions with a deposition of 7 and 10 kg N ha(-1) per year were compared. Number of species was lower in the regions with the highest deposition. Literature data for plants on N concentration, nitrate reductase activity (NRA), growth rates, morphology and height were calculated on a site basis. They varied to different extent between the regions. The N concentration was 7-24% higher in the regions with the highest N deposition. We argue that the effect-related critical load based on our results should be set to a N deposition of 7-10 kg N ha(-1) per year. Critical loads for a subdivision of deciduous forests would give lower critical loads for the most acid soils compared to less acid soil.

Details

Authors
  • Ursula Falkengren-Grerup
  • M Diekmann
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Ecology
Original languageEnglish
Pages (from-to)113-124
JournalForest Ecology and Management
Volume180
Issue number1-3
Publication statusPublished - 2003
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Plant Ecology and Systematics (Closed 2011) (011004000)