干旱化对樟子松固沙林氮磷循环的影响  

Effects of aridification on nitrogen and phosphorus cycles in a Pinus sylvestis var. mongolica sand-fixation plantation

作　　者：谢尧 赵琼[1] 李炎真 于占源[1] 林贵刚[1] 曾德慧[1] XIE Yao;ZHAO Qiong;LI Yan-zhen;YU Zhan-yuan;LIN Gui-gang;ZENG De-hui(Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院沈阳应用生态研究所,沈阳110016 [2]中国科学院大学,北京100049

出　　处：《生态学杂志》2019年第12期3593-3600,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41877341)资助

摘　　要：为研究半干旱区进一步干旱化对森林生态系统氮磷循环的影响,以科尔沁沙地樟子松(Pinus sylvestris var.mongolica)人工固沙林为对象,分析了3种不同降雨量条件下(天然降雨、降雨量减少30%、降雨量减少50%)氮磷养分在一个生长季内的吸收、归还和分解释放3组流通量及其对应的流通率。结果发现,降雨减少30%处理下,樟子松对氮的归还量与归还率显著下降27.3%和37.3%,其余流通量与流通率变化不显著。降雨减少50%处理下,氮的吸收、归还与分解释放量显著下降59.9%、36.0%和50.3%,磷的归还量显著下降38.1%,氮归还与分解释放率显著下降39.9%和32.7%,而地表枯落物层中的磷含量则显著上升27.4%,磷的吸收量和氮磷吸收率变化不显著。降雨减少引起氮磷归还与分解释放率的下降,预示着干旱化导致沙地樟子松固沙林存在养分循环失衡的风险。A field experiment with three rainfall reduction levels(natural rainfall,30%reduction in rainfall,and 50%reduction in rainfall)was conducted in a Pinus sylvestis var.mongolica sandfixation plantation in Keerqin Sandy Lands to investigate the effects of aridification on the nitrogen(N)and phosphorus(P)cycles.The forest ecosystem was divided into three compartments(tree,soil and aboveground litter layer).The amount and rate of N and P absorption(from soil to tree),return(from tree to litter layer)and decomposition(from litter layer to soil)were measured and calculated.The results showed that,compared with natural rainfall,30%reduction in rainfall significantly reduced the amount and rate of N return by 27.3%and 37.3%,and did not affect N absorption and decomposition and P cycling.The 50%reduction in rainfall significantly decreased the amount of N absorption,return and decomposition by 59.9%,36.0%and 50.3%,P return amount by 38.1%,N return and decomposition rate by 39.9%and 32.7%,increased litter P content by 27.4%,and did not affect the amount of P absorption,N and P absorption rates.The decreases in the rates of N and P return and decomposition following rainfall reduction indicated that aridification would bring the risk of nutrient imbalance to pine forest.

关 键 词：降雨减少 沙地生态系统 氮磷养分循环 流通率 水分胁迫 

分 类 号：S71[农业科学—林学]