常绿阔叶林凋落物量及养分对氮沉降的响应  

Response of Nitrogen Deposition Simulation on Litter Production and Macronutrients of Evergreen Broad-Leaved Forest

作　　者：周佳佳[1] 崔珺[1] 杨佳[1] 李鹏[2] 徐小牛[1] 

机构地区：[1]安徽农业大学,合肥230036 [2]北京大学

出　　处：《东北林业大学学报》2013年第12期47-51,127,共6页Journal of Northeast Forestry University

基　　金：国家“973”(2010CB950602);中科院战略性先导科技专项(XDA0505020401)

摘　　要：通过野外模拟试验,研究了氮沉降增加对安徽祁门亚热带常绿阔叶林凋落物量及养分季节动态的影响。试验设计为对照（CK,0）、高氮（T1,100 kg·hm-2·a-1）、高氮＋磷（T2,100 kg·hm-2·a-1＋50 kg·hm-2·a-1）3种处理。通过1 a监测,结果表明：（1）中坡3种处理的年凋落量分别是6.87、5.48和6.72 t·hm-2,T1、T2处理一定程度上抑制了凋落物量的增加。坡顶3种处理的年凋落量分别是6.80、5.66和7.01 t·hm-2,T2处理增加凋落物产量,T1与之相反。（2）凋落物中各组分所占比例从大到小顺序为：叶〉枝〉花果〉杂质。（3）3种处理月凋落特征相似。（4）主要元素年均质量分数从大到小顺序为：N、K、Ca、Mg、P,落叶中主要养分质量分数最高。T1、T2处理显著增加了凋落物N质量分数,增幅为7.81%~22.33%,且效果T2〉T1。T1处理降低了P、K、Mg质量分数,T2处理增加了P、Mg质量分数,降低了K质量分数。从凋落量及养分含量两方面来说,向森林生态系统输入植物生长必需的营养元素可以缓解氮沉降的影响。A field simulated test was conducted to study the effects of nitrogen deposition on litter production and nutrients of a subtropical evergreen broad-leaved forest in Qimen,southern Anhui. The treatments were designed as CK（ 0 kg hm2·a-1 N）,T1（ 100 kg hm2·a-1N） and T2（ 100 kg hm2·a-1N＋50 kg hm2·a-1P）. For one year observation,annual litter production averaged 6. 87,5. 48 and 6. 72 t·hm-2for CK,T1,T2 on the middle slope,respectively. High N deposition inhibited litter production. However,on the flat ridge,annual litter production averaged at 6. 80,5. 66 and 7. 01 t·hm-2 for CK,T1 and T2,respectively. T2 treatment increased the litter production compared with CK although no significant difference appeared between CK and T2. The litter components ranked by their amounts consistently are in the following order： foliagebranches sexual organs miscellaneous. The seasonal patterns of litterfall were similar among the different treatments. Therefore,the nitrogen deposition can not change the eco-physiological characteristic of dominant trees. The nutrient input by litterfall is NKCaMgP. T1 and T2 treatments elevated the average N concentrations by ranging from 7. 81% to 22. 33% in the litterfall compared with CK. T1 reduced the average concentrations of P,K and Mg,but negatively to T2 for P and Mg. The nitrogen deposition harms to litter production and its chemistry of this subtropical evergreen broad-leaved forest. In order to alleviate the adverse effect of high nitrogen deposition,other necessary elements should be input.

关 键 词：亚热带常绿阔叶林 凋落物量 养分 氮沉降 

分 类 号：Q948.3[生物学—植物学]