共和盆地15种植物叶片的元素化学计量学特征

Elemental stoichiometric characteristics of leaves of fifteen plant species in Gonghe Basin

为合理评价共和盆地常见植物的生长状况及生境的养分供给能力,通过野外采集共和盆地15种高寒荒漠植物的叶片,并对叶片中的C、N、P、K营养元素含量进行室内测定、对比并评价指标间的相关性。结果表明:植物叶片C含量的变化范围为390.70~514.70 mg·g^(-1),N含量的变化范围为19.46~44.50 mg·g^(-1),P含量的变化范围为1.36~3.48 mg·g^(-1),K含量的变化范围为11.06~34.85 mg·g^(-1)。两种生活型植物叶片之间的化学元素含量有所差异,其中叶片C、P含量表现为:灌木>草本;叶片N、K含量表现为:草本>灌木。植物叶片C∶N与N∶P之间呈负相关关系(r=-0.538),植物叶片N∶K与K∶P之间呈负相关关系(r=-0.599),植物叶片C∶P与N∶P之间呈正相关关系(r=0.588),植物叶片C∶N与叶片N含量之间呈负相关关系(r=-0.971),其余元素化学计量特征之间相关性不强。共和盆地两种生活型的植物叶片化学元素组成存在差异,15种植物生长过程主要受到N和P的限制,且相比而言更易受N的限制,基本不受K的限制。

In order to rationally evaluate the growth status of common plants and the nutrient supply capacity of habitats in the Gonghe Basin,through collected leaves of 15 desert plants in Gonghe Basin and analyzed the content of C,N,P,K of leaves in laboratory,then the their correlation coefficients were analyzed.The results indicated that the C content in the leaves of plants was ranged from 390.70 to 514.70 mg·g-1,the content of N varied from 19.46 to 44.50 mg·g-1,the content of P ranged from 1.36 to 3.48 mg·g-1,and the content of K varied from 11.06 to 34.85 mg·g-1.The content of leaves chemical elements in two different life styles were different.The content of C,P of leaves was shrub>herb,the content of N,K of leaves was herb>shrub.The correlation analysis showed that there was a negative correlation between C∶N-N∶P,N∶K-K∶P and C∶N-N of leaves(r=-0.538,r=-0.599 and r=-0.971),there was a positive correlation between C∶P-N∶P of leaves(r=0.588),in addition,there were no correlation among other stoichiometric characteristics.The chemical composition of plant leaves in different life forms of Gonghe Basin had significant difference.Most of the plant growth process is mainly limited by N and P,especially by N,other than by K.