摘要
从2008年1月至2010年1月,对华西雨屏区撑绿杂交竹(Bambusa pervariabilis×Dendrocala mopsi)人工林进行了模拟氮沉降试验,氮沉降水平分别为对照(CK,0 g.m–.2a-1)、低氮(5 g.m–.2a-1)、中氮(15 g.hm–.2a-1)和高氮(30 g.m–.2a-1)。利用凋落袋法对杂交竹凋落叶和凋落箨进行原位分解试验,并在每月下旬定量地对各处理施氮(NH4NO3)。结果表明,自然状态下杂交竹凋落叶和凋落箨分解95%所需时间分别为2.9、1.5 a;氮沉降显著抑制了凋落叶的分解,在分解后期3个氮沉降处理凋落叶无灰分质量残留率均显著大于对照,氮沉降对凋落箨分解无明显影响;氮沉降显著抑制了凋落叶中木质素和纤维素的分解。杂交竹凋落叶在分解后期质量损失缓慢,处于较稳定状态,氮沉降的增加使得凋落物的残留率稳定在一个更高的水平,表明氮沉降的增加可能会使更多的凋落物残体和稳定有机质留存于杂交竹林土壤中,从而增加杂交竹林土壤碳贮存。
The human activities have substantially altered the nitrogen（N） cycle,and have greatly accelerated the formation and deposition of reactive N.The N cycle alteration has strongly affected the cycles of many other elements,especially the carbon（C） as well.The response of plant growth to N deposition is generally positive in forest ecosystems.However,total C storage of ecosystem depends on the balance between production and decomposition,both of which are affected by projected increase of N deposition.Thus the uncertainty regarding the decomposition response of litter to N deposition has often limited the evaluation of C balance response in ecosystem.Most studies regarding the effects of N deposition on litter decomposition have been conducted in coniferous forests.Bamboo forests are an important forest in the world,but to our knowledge,there has not yet been a study of the effect of N deposition on litter decomposition in bamboo ecosystems.Furthermore,bamboo forests/ plantations are mainly distributed in the southern provinces of China where there is considerable atmospheric N deposition.Therefore,understanding the effect of increasing N deposition on litter decomposition is critical for predicting how the carbon status of bamboo ecosystems will respond to human activities. From January 2008,a two year field experiment of simulated nitrogen deposition has been conducted in a Bambusa pervariabilis × Dendrocala mopsi plantation,Rainy Area of West China.The levels of simulated N deposition were control（CK,0 g·m–2·a-1）,low N（5 g·m–2·a-1）,medium N（15 g·m–2·a-1） and high N（30 g·m–2·a-1）.A field experiment using the litterbag method was conducted on the decomposition of leaf litter and sheath litter of B.pervariabilis × D.mopsi.In the end of each month,NH4NO3 was added into N-treated plots.The T95%（the time of 95% mass loss） of leaf litter and sheath litter were 2.9 and 1.5 years,respectively.Simulated nitrogen deposition significantly slowed the decomposition of leaf litter t
出处
《生态学报》
CAS
CSCD
北大核心
2011年第5期1277-1284,共8页
Acta Ecologica Sinica
基金
国家"十一五"科技支撑计划项目(2006BAC01A11)
四川农业大学"211"工程创新团队项目资助
关键词
氮沉降
凋落物分解
撑绿杂交竹
华西雨屏区
nitrogen deposition
litter decomposition
Bambusa pervariabilis×Dendrocala mopsi
Rainy Area of West China
