典型荒漠草原不同林龄下柠条灌丛碳氮磷化学计量特征

Carbon,Nitrogen and Phosphorus Stoichiometry of Caragana korshinskii Shrub Under Different Ages in the Typical Desert Steppe

以典型荒漠草原区察哈尔右翼前旗的不同林龄(3、5、7、10年)柠条(Caragana korshinskii Kom.)灌丛为试材,采用空间代替时间的方法,研究了林龄对柠条叶、枝以及灌下草的碳氮磷化学计量特征的影响,以期为荒漠区植物养分平衡、荒漠区植被恢复等提供参考依据。结果表明:1)柠条叶、枝以及灌下草的C、N、P含量随林龄的增加呈现不同趋势,但均在林龄为10年时达到最大值。2)林龄的延长促使柠条叶、枝以及灌下草的C∶N、C∶P和N∶P总体呈下降趋势,研究区内植物受到P的限制。3)林龄延长显著增加了柠条以及灌下草的C、N、P贮量,且均在第10年时达到最大值。4)不同林龄下柠条枝、叶和灌下草的C、N、P贮量两两相比均呈显著正相关关系。综上,林龄的延长增加了植物碳氮磷的储量,适当增加林龄有利于提高灌草植物化学计量平衡和养分水平。

Taking different ages(3,5,7,and 10 years)of Caragana Korshinskii shrub in a typical desert grassland area of Chahar as test materials,the effects of age on the stoichiometry of carbon,nitrogen and phosphorus of caragana Korshinskii leaves,branches,and grass growing under shrubs were studied by using the method of space instead of time.The ecological stoichiometric characteristics of C,N,P of Caragana korshinskii were investigated,in order to provide reference for plant nutrient balance in desert areas and vegetation restoration in desert areas.The results showed that,1)the C,N,and P contents of Caragana korshinskii leaves,branches,and grass growing under shrubs showed different trends with the increase of stand age,but all reached the maximum value at 10 years of stand age.2)With the extension of stand age,C/N,C/P,and N/P in leaves,branches and grass growing under shrubs of Caragana korshinskii decreased,and the plants in the study area were limited by P.3)The C,N,P storage of Caragana korshinskii and grass growing under shrub significantly increased with the extension of stand age,and all reached the maximum value in the 10th year.4)The C,N,and P storage of Caragana korshinskii branches,leaves,and grass growing under shrubs were significantly positively correlated despite stand ages.To sum up,The prolongation of stand age increased the carbon,nitrogen and phosphorus reserves of plants,and the appropriate increase of stand age was beneficial to improve the stoichiometric balance and nutrient levels of shrub and grass plants.