典型园林树种枝叶生态化学计量及其聚类特征

Ecological stoichiometry and cluster characteristics of branches and leaves of typical garden tree species

以太原市38个典型园林树种为研究对象,测定其当年生枝和叶碳(C)、氮(N)和磷(P)含量。结果表明,枝和叶C、N、P含量及其计量比在树种间呈极显著差异(P<0.01),枝C、N和P含量分别为506.77~589.37、2.00~14.25、0.73~4.14 g·kg^(-1),叶C、N和P含量分别为452.10~560.10、4.26~31.28、1.67~4.26 g·kg^(-1),不同树种具有不同的养分需求;枝和叶N∶P分别为0.94~7.66和1.48~10.51,均处倾向于受N限制状态。38个典型园林树种根据树种养分需求(C、N、P)的显著差异(P<0.05)分为中氮低磷、低氮中磷、中氮高磷和高氮中磷4种类型;根据树种单位营养元素固碳效率(C∶N、C∶P)的显著差异(P<0.05)分为高固碳效率、较高固碳效率、较低固碳效率和低固碳效率4种类型;根据树种氮限制倾向(N∶P)的显著差异(P<0.05)分为强氮限制倾向、较强氮限制倾向、较弱氮限制倾向和弱氮限制倾向4种类型。研究结果明确了树种类型之间的差异特征,可为城市园林绿地树种栽培应用提供理论依据。

In this study,38 typical garden tree species in Taiyuan were selected as the research object to determine the carbon(C),nitrogen(N),and phosphorus(P)contents in current-year branches and leaves.Results showed that the differences in C,N,and P contents and their stoichiometric ratios in branches and leaves were highly significant(P<0.01).The contents of C,N and P in the branches ranged from 506.77 to 589.37,2.00 to 14.25,and 0.73 to 4.14 g·kg^(-1),respectively.The contents of C,N,and P in the leaves ranged from 452.10 to 560.10,4.26 to 31.28,and 1.67 to 4.26 g·kg^(-1),respectively.Different tree species had different nutrient requirements.The N∶P ratio of branches and leaves ranged from 0.94 to 7.66 and from 1.48 to 10.51,respectively,and tended to be limited by the N content.Based on the significant differences(P<0.05)in nutrient requirements(C,N,P)of the tree species,they were divided into four types:medium N and low P,low N and medium P,medium N and high P,and high N and medium P.Based on the significant differences(P<0.05)in the carbon sequestration efficiency(C∶N,C∶P)of the tree species,they were divided into four types:high carbon sequestration efficiency,relatively high carbon sequestration efficiency,relatively low carbon sequestration efficiency,and low carbon sequestration efficiency.Based on the significant differences(P<0.05)in the nitrogen limiting tendency(N∶P)of the tree species,they were divided into four types:strong N-limitation tendency,relatively strong N-limitation tendency,relatively weak N-limitation tendency,and weak N-limitation tendency.These results clarified the differences among tree species and provided a theoretical basis for the application of tree species cultivation in urban green spaces.