氮沉降对杉木人工林生长及林下植被碳库的影响  

Effects of nitrogen deposition on tree growth and understory carbon pools in Chinese fir plantation

作　　者：黄玉梓[1] 樊后保[2] 李燕燕[2] 高春芬[2,3] 刘文飞[2] 

机构地区：[1]福建农林大学生命科学学院,福建福州350002 [2]南昌工程学院生态与环境科学研究所,江西南昌330099 [3]江西农业大学园林与艺术学院,江西南昌330045

出　　处：《生态环境学报》2009年第4期1407-1412,共6页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(30771714);江西省自然科学基金项目(0630101)

摘　　要：在12年生的杉木(Cunninghamia lanceolata)人工林中开展5年的模拟氮沉降试验,氮沉降水平分别为N0(对照)、N1、N2、N3,N沉降量依次为0、60、120、240kg·hm-2·a-1,研究氮沉降增加对林木胸径、树高生长及林下植被碳库的影响。在氮沉降试验的前3年,N0、N1、N2、N3处理样地林木平均胸径年增长率分别为3.52%、3.77%、4.32%和4.55%,表明胸径增长随氮沉降水平的增加而增加。各处理样地平均树高年增长率依次为9.95%、10.02%、9.34%和7.99%,说明中-高氮处理(N2、N3)抑制了树高的生长;在氮沉降试验的后2年,各处理样地林木平均胸径年增长率分别为3.65%、4.52%、2.46%和3.55%,树高年增长率分别为7.19%、8.28%、6.41%和6.33%,表明低氮处理(N1)促进了林木的生长,而中-高氮处理在一定程度上抑制了林木生长。各处理样地的林下植被碳储量由大到小的顺序为N0、N1、N2、N3,与对照相比,N1、N2、N3处理使林下植被碳储量分别降低了0.164、0.373和0.482t?hm-2,平均每年减少C0.041、0.093和0.120t?hm-2,相当于N1、N2和N3处理使林下植被每年吸存的二氧化碳量减少了0.151、0.342和0.441t?hm-2。To study forest tree growth and its understory carbon reserves responsing to nitrogen deposition, a field experiment had been conducted in a 12-year-old Chinese fir plantation for five years in Sanming, northwestern Fujian. Nitrogen loadings were designed at 4 levels as N0, N1, N2 and N3, which were respecitively at the doses of 0, 60, 120 and 240 kg.hm^-2.a^-1, and respectively, with three replicates in each treatment. After three years of simulated nitrogen depostion, the nitrogen loading of N0, N1, N2 and N3 was found to promote the growth of tree DHB by 3.52%, 3.77%, 4.32% and 4.55% every year in the respectively plot, and this result showed that the higher levels of nitrogen deposition, the more tree DBH grow; while the yearly growth rate of forest tree height were 9.95%, 10.02%, 9.34% and 7.99% respectively in the plots treated with N0, N1, N2 and N3, and this showed that middle or high levels of nitrogen deposition inhibited the growth of forest tree height. At the last two years treatments of nitrogen deposition, the yearly growth rate of DBH in the plots treated with N0, N1, N2 and N3 were 3.65%, 4.52%, 2.46% and 3.55%, and the yearly growth of forest tree height were 7.19%, 8.28%, 6.41% and 6.33%; and the results showed that N2 and N3 inhibited the growth of Chinese fir, but N1 still promoted the tree to grow. The stocks of understory in plot stands were as follow order： N0〉N1〉N2〉N3, and compared to the control treatment, the carbon stock in understory were declined by 0.164, 0.373 and 0.482 t.hm^-2 respectively in Chinese fir plots treated by N1, N2 and N3, about 0.041, 0.093 and 0.120 t.hm^-2 declined in every year, which mean that the amount of CO2 aborted by the understory of Chinese fir plantation was decline 0.151, 0.342 and 0.441 t.hm^-2 in the plots respectively.

关 键 词：氮沉降 杉木人工林 林木生长 林下植被碳库 

分 类 号：Q948[生物学—植物学]