油松针叶中营养元素含量与林分优势水平均高的关系

本文主要探讨了油松林分,林木针叶中营养元素含量与林分优势木平均高之间的关系及其变化规律。油松林木针叶中营养元素的含量与林分优势木平均高有较高的相关关系,针叶中 N、P、K 营养元素含量值与林分优势木平均高呈正相关关系,但针叶中 C_a营养元素含量值与林分优势木平均高呈负相关关系,针叶中 M_g营养元素含量值变化的幅度较微。将油松针叶采样林分标准地的优势木平均高分为四级,与其相对应的针叶中营养元素含量的平均值,既说明了林木的营养状况水平,又说明了林地立地条件的优劣和林地土埴生产力的水平。

THE RELATIONSHIP BETWEEN THE NUTRIEET CONTENT IN NEEDLES AND THE DOMINANT HEIGHT OF Pinus Tabulaeformis PLANTATION

The aim of the study was to investigate the relationship and the variation of the nutrient contents in needles and the dominant height of Pinus tabulaeformis plantation. Needles samples were taken from 12 stands of different dominant height at Shiyuan Forest Farm in the Taihang Mountain(37°10′—23′N,112°53′—113°04′E).The samples were analysed for N,P,K,Ca,and Mg.The results showed that the percentage contents of nutrient elements in needles were relatived closely to the dominant height,the percentage content of N,P,and K increased with the dominant height,whereas that of Ca decreased, and Mg varied little.The proportion of the nutrient contents of N,P,and K in needles is 1:0.095:0.375. Correlation and regression analysis were used to deal with the correlation between nutrient content and domi- nant height.We made up regression mold about the percentage contents of nutrient of needles and the dominant height.It was concluded that the important factor was N to growth.Ca was a main influence factor.Meanwhile, We classified the site quality,the dominant height and the nutrient content.