杉木人工林凋落物大量元素含量与通量对模拟氮沉降的响应  

Macronutrient concentrations and fluxes in the litterfall of Chinese fir in response to simulated nitrogen deposition

作　　者：高春芬[1,2] 樊后保[2] 刘文飞[2] 

机构地区：[1]江西农业大学园林与艺术学院,江西南昌330045 [2]南昌工程学院生态与环境科学研究所,江西南昌330099

出　　处：《福建林学院学报》2009年第3期237-242,共6页Journal of Fujian College of Forestry

基　　金：国家自然科学基金资助项目(3037025930771714)

摘　　要：在杉木人工林中开展野外模拟氮沉降试验,以探讨森林凋落物对氮沉降增加的响应。通过对凋落物的化学分析发现,4种氮沉降[(N0)0、(N1)60、(N2)120、(N3)240 kg.hm-2.a-1]处理下5种大量元素的年平均含量大小顺序表现为N>Ca>K>Mg>P。相对于N0,N1、N2、N3处理增加了落叶中N、K、Mg的含量,其中使N平均含量分别增加了3.85%、7.69%、28.30%;但在一定程度上降低了P、Ca含量。经N0、N1、N2、N3处理,凋落物中N的年归还量分别为6.93、7.74、8.70、8.50 kg.hm-2;P为0.63、0.70、0.70、0.60 kg.hm-2;K为3.67、4.29、4.50、4.11 kg.hm-2;Ca为4.72、5.09、5.06、4.47kg.hm-2;Mg为2.14、2.63、2.35、2.05 kg.hm-2。N1、N2处理提高了凋落物中5种元素的年归还量,而N3处理则降低P、Ca、Mg的年归还量。各大量元素归还量在1 a中均出现2个高峰期,其中第1次峰值出现在4月份,第2次峰值出现在6月或7月份。A field experiment was conducted to study the effect of simulated nitrogen on litterfall in a Chinese fir plantation. Urea [ CO（ NH2 ）2 ] was added at three doses, N1, N2 and N3, 60, 120 and 240 kg. hm^-2·a^-1, respectively. The results showed that the annual average concentrations of the macronutrients in litteffall decreased consistently in the following order N 〉 Ca 〉 K 〉 Mg 〉 P. All N treatments elevated the average concentrations of N, K and Mg, but reduced P and Ca in the litterfall; among them N increased by 3.85%, 7.69% and 28.30%, respectively, compared with the control （NO）. Through litterfall production, the annual N flux to the forest floor under the four treatments （ NO, N1, N2 and N3） was estimated, respectively, at 6.93, 7.74, 8.70 and 8.50 kg · hm^-2 ;P at 0.63, 0.70, 0.70 and 0.60 kg · hm^-2; K at 3.67, 4.29, 4.50 and 4.11 kg· hm^-2; Ca at 4.72, 5.09, 5.06 and 4.47 kg · hm-2; Mg at 2.14, 2.63, 2.35 and 2.05 kg · hm^-2. The data suggested that the annual flux of the five elements responded positively to N1 and N2 treatments, but negatively to N3 for the P, Ca, Mg elements. The maeronutrient flux through litterfall exhibited two pronounced peaks in the year, the first one occurring consistently in April, the second in June or July.

关 键 词：氮沉降 杉木人工林 凋落物 大量元素 

分 类 号：S718.55[农业科学—林学]