安定同位体組成からみた森林の窒素循環

抄録

Natural abundance of ¹⁵N (δ¹⁵N) in nitrogen compounds in forest ecosystems is a useful parameter for analyzing the nitrogen cycle in forests. The δ¹⁵N value for nitrogen compounds is determined mainly by input of N (N-fixation and precipitation) originating from atmospheric N₂ less enrichment with ¹⁵N and output of N through denitrification and nitrate leaching, which leads to preferential ¹⁵N enrichment in ecosystems. Temporal and spatial variation in δ¹⁵N can provide useful information on changes in nitrogen cycling in terrestrial ecosystems. Some case studies using this technique are reviewed.