Effect of Nitrogen Deposition on CH_4 Uptake in Forest Soils in Hokkaido, Japan(Environment)

概要

論文の詳細を見る
It has been well documented by short-term artificial experiments that the CH_4 uptake is inhibited by N input, especially NH_4^+-N input. To investigate the effect of the natural N input by throughfall and other factors on the CH_4 uptake in forest soils, we measured the CH_4 uptake rates for 6 months during the snow-free period of the year and N input by throughfall throughout the year at 10 sites in Hokkaido, Japan, from 1997 to 2002. Waterfilled pore space (WFPS) and pH values in the soils varied widely among the sites (38-93% and 3.9-6.2, respectively). The rates of NH_4^+-N and NO_3^--N inputs ranged from 1.3 to 6.9 kg N ha^<-1> year^<-1> and from 0.8 to 2.9 kg N ha^<-1> year^<-1>, respectively. The NH_4^+-N input was generally higher than the NO_3^--N input. Total N input by throughfall amounted to 2.3-9.4 kg N ha^<-1> year^<-1>. The highest CH_4 uptake rate occurred within the period from July to September (41-215 μg CH_4 m^<-2> h^<-1>) each year at most sites. CH_4 uptake rate was relatively low (〜50 μg CH_4 m^<->2 h^<-1>) at northern sites, while a high CH_4 uptake rate was observed throughout the year (≧100 μg CH_4 m^<-2> h^<-1>) at southern sites. The mean CH_4 uptake rates were significantly different among the sites. Cumulative CH_4 uptake ranged from 1.4 to 6.6 kg CH_4 ha^<-1> [184 d]^<-1> with a mean values of 3.22 ± 1.36 kg CH_4 ha^<-1> [184 d]^<-1>. Cumulative CH_4 uptake increased with increasing temperature and decreased with an increase in precipitation (Rain), NH_4^+-N input (TF_<NH4>), WFPS, soil total C (TC), and total N (TN). There was a quadratic relationship between the CH_4 uptake and NO_3^--N input (TF_<N03>), soil pH, and C/N ratio in soil. A regression equation was obtained as follows to predict the CH_4 uptake in forest soils : Cumulative CH_4 uptake=0.47/Rain+0.38/TF_<NH4>+0.34/TC-0.30/TF_<N03> (R^2=0.74,p=0.0001). This equation indicates that atmospheric N input into forest soils is one of the main factors that control cumulative CH_4 uptake with precipitation, total carbon content in soil in Hokkaido, Japan.
社団法人日本土壌肥料学会の論文

Effect of Nitrogen Deposition on CH_4 Uptake in Forest Soils in Hokkaido, Japan(Environment)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク