初冬园林树木养分含量变化特征

通过分析初冬园林树木枝条内养分含量变化和落叶内营养元素含量差异,为指导园林树木越冬养护实践和景观设计中科学选择树木种类提供理论依据。选择大庆市小游园5种园林树种,测定枝条养分和落叶养分含量。结果表明:10月26日至11月16日间,丁香枝条氮、磷含量分别降低了68.28%、35.61%;偃伏莱木枝条氮、钾含量分别降低了25.93%、37.40%;垂枝榆枝条氮、磷、钾含量变化表现为先升高后降低,11月较10月降低了24.08%、19.78%、9.32%;榆树枝条磷、钾含量表现为一直升高的变化,升高幅度分别为21.78%、123.86%;落叶中垂枝榆氮含量为1.88%,榆树磷含量为1.60%,榆叶梅钾含量为1.88%。初冬园林树木枝条内养分含量逐渐降低,落叶平衡补充了土壤营养元素。

Study on Change Characteristics of Nutrient Content of Garden Trees in Early Winter

Through analyzing the changes of nutrient contents in branches and the differences of nutrient contents in leaves of garden trees in early winter,and a theoretical basis has been provided for guiding the overwintering conservation of garden trees and scientific selection of tree species in landscape design.Chosen five kinds of tree species in small gardens in Daqing City,the nutrient contents in branches and leaves have been measured.The results show that from October 26 to November 16,the content of nitrogen and phosphorus in branches of Syringa oblata decreased by 68.28%and 35.61%,respectively.The content of nitrogen and potassium in branches of Cornus stolonifera decreased by 25.93%and 37.40%,respectively.The content of nitrogen,phosphorus and potassium in branches of Ulmus pumila var.pendula increased first and then decreased,which decreased by 24.08%,19.78%and 9.32%in November compared with that in October.The content of phosphorus and potassium in branches of Ulmus pumila increased all the time,the increasing range was 21.78%and 123.86%,respectively.The nitrogen content of Ulmus pumilain var.pendula in fallen leaves was 1.88%,the phosphorus content of Ulmus pumila was 1.60%,and the potassium content of Amygdalus triloba was 1.88%.According to the comprehensive analysis,the nutrient content in branches of garden trees decreased gradually in early winter,and the leaf balance supplemented soil nutrients element.