黄土高原不同植被带油松人工林生态化学计量特征及其影响因素  

Ecological Stoichiometric Characteristics and Its Influential Factors in Pinus tabuliformis Plantation under Different Vegetation Zones in the Loess Plateau

作　　者：董从国 乔雨宁 曹扬 陈云明[1,2] 吴旭 薛文艳[1] DONG Cong-guo;QIAO Yu-ning;CAO Yang;CHEN Yun-ming;WU Xu;XUE Wen-yan(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学水土保持研究所,黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨陵712100 [2]中国科学院水利部水土保持研究所,陕西杨陵712100

出　　处：《西北林学院学报》2020年第3期1-8,共8页Journal of Northwest Forestry University

基　　金：国家自然科学基金“抚育间伐调控黄土丘陵区刺槐人工林水分养分机理研究”(41771556);国家重点研发计划课题“黄土丘陵沟壑区植被功能提升与山地果园管理关键技术及示范”(2016YFC0501703);陕西省水保研发项目“秦巴山地坡面近自然水土保持关键技术集成与示范”(2017sbkj-01).

摘　　要：为阐明油松人工林生态系统化学计量特征空间差异,分析其随气候因素变化的响应机制,以陕北黄土高原森林带、森林草原带和草原带油松人工林为研究对象,分析叶片、凋落物和土壤C、N、P化学计量特征及其与气候因子的关系。结果表明:1)油松叶片、凋落物C含量以草原带最高,但其土壤C含量最低,叶片与土壤N含量均表现为森林带>森林草原带>草原带,叶片P含量以森林带最高,但其土壤P含量最低。2)叶片C∶N和C∶P以森林带最低,油松人工林生产力水平随降水梯度的升高而增加;森林草原带叶片N∶P为15.57,植被生长受到N、P元素共同限制,而森林带和草原带叶片N∶P均<14,油松生长受到N限制;土壤C∶P表现为森林带>森林草原带>草原带,森林带P素释放潜力差。3)油松人工林叶片C含量随年均降水量增加而降低,N、P含量情况则相反;年平均降水、气温与土壤C、N含量间存在极显著正相关关系(P<0.01),而与土壤P含量间表现为显著负相关(P<0.05),气候条件变化对油松人工林生长有着明显的影响。In order to elucidate the differences of stoichiometric characteristics in Pinus tabuliformis plantation in spatial scales,and to clarify their response mechanisms to climatic factors,P.tabuliformis plantations occurring in three typical vegetation zones(forest zone,forest-grass zone and grass zone)of the Loess Plateau in northern Shaanxi Province were taken as the research objects,the stoichiometry of carbon(C),nitrogen(N)and phosphorus(P)in leaf,litter,soil and their relationship with climatic factors were analyzed.The results showed that 1)P.tabuliformis plantations in grass zone had the highest C content in leaf and litter,and lowest in soil.The N contents in leaf and soil gradually reduced from forest zone to grass zone.The leaf P content in forest zone was highest while soil P content was lowest.2)The ratios of C∶N and C∶P in leaf was lowest in forest zone,indicating that the productivity of P.tabuliformis plantation increased as precipitation increased.The leaf N∶P ratio in forest-grass zone was 15.57,indicating that the individual growth was limited by N and P.In contrast,the leaf N∶P ratios in forest and grass zones were less than 14,indicating that the growth of P.tabuliformis was restricted by N.Soil C∶P ranked as forest zone>forest-grass zone>grass zone,indicating that the P release potential was poor in forest zone.3)The content of C in leaf decreased with the increase of annual precipitation,but the contents of N and P were opposite.Annual average precipitation,annual average temperature were positively correlated with soil C and N content(P<0.01)and negatively correlated with soil P(P<0.05).Climate changes had a significant influence on the growth of P.tabuliformis plantations.

关 键 词：化学计量学 油松人工林 植被带 叶片-凋落物-土壤连续体 

分 类 号：S154.1[农业科学—土壤学]