探明石漠化区水源涵养林凋落物与土壤化学计量特征有助于深入了解养分状况。以喀斯特高原山地区云南松(Pinus yunnanensis)+光皮桦(Betula luminifera)+银白杨(Populus alba)林、栓皮栎(Quercus variabilis)+川榛(Corylus heterophylla)林、银白杨(Populus alba)+光皮桦(Betula luminifera)林、杜鹃(Rhododendron simsii)+银白杨(Populus alba)林、光皮桦(Betula luminifera)林为对象,研究凋落物与土壤OC,TN,TP化学计量特征及内在关联。结果表明:1)表层土壤OC,TN,TP含量分别是25.02,1.56,0.33mg/g;凋落物OC,TN,TP含量分别为407.09,16.07,2.06mg/g。2)土壤C:N为15.13,C:P为78.40,N:P为5.17;凋落物C:N为25.67,C:P为212.87,N:P为8.38;C:N,C:P,N:P均呈凋落物层>土壤层。3)凋落物层、土壤层C:P与N:P均呈极显著正相关,土壤C:N与凋落物C:N,N:P分别呈极显著正、显著负相关。4)该区土壤N,P养分亏缺,凋落物呈低C高N高P格局,土壤固持养分能力不强。

It is helpful to understand the nutrient status by ascertaining stoichiometric characteristics of the litter and soil of water conservation forests in the rocky desertification area.In this paper,the forests of Pinus yunnanensis,Betula luminifera and Populus alba,Quercus variabilis and Corylus heterophylla,Populus alba and Betula luminifera,Rhododendron simsii and Populus alba and Betula luminifera in the karst plateau mountainous were used to study the organic C,TN,TP stoichiometry and intrinsic association of litter and soil.The results show that soil organic C,TN and TP in Karst communities occurred primarily in the top 0~20 cm soil layer,at 25.02 mg/g C,1.56 mg/g N and 0.33 mg/g P,with ratios of 15.13 for C:N,78.40 for C:P and 5.17 for N:P.The litter organic C,TN,TP content were estimated at 407.09 mg/g,16.07 mg/g,2.06 mg/g,and the corresponding C:N,C:P and N:P were 25.67,212.87 and 8.38,respectively.In general,litter layer had higher C:N,C:P and N:P than soil layer.There is a significant positive correlation between C:P and N:P in litter layer or soil layer,the correlation between soil C:N and litter C:N was negative.Besides,there was a significant negative correlation between soil C:N and litter N:P.Nutrition of N and P in soil is deficient,the litter has a clear structure of low C,high N and high P.The capacity of holding nutrient for soil is not strong.