论文部分内容阅读
研究了北方阔叶树木中固氮和非固氮树种间养分元素含量的差异及季节变化趋势．在生长旺盛期到落叶期固氮和非固氮树种叶片之间Ｎ、Ｍｇ含量始终存在明显差异；固氮树种叶片中Ｎ、Ｋ含量降低的趋势明显低于非固氮树种，所研究的其它５个元素和灰分的季节变化率即累积的趋势则高于非固氮树种．在Ｆ检验和Ｔ检验的基础上，选择Ｎ、Ｐ、Ｍｇ、Ｓｉ４个营养元素为参数进行的数量化分类，成功地区分了固氮和非固氮树种．
The differences and seasonal variations of nutrient elements in nitrogen-fixing and non-nitrogen-fixing species in the north broad-leaved trees were studied. There was a significant difference in the contents of N and Mg between the leaves of nitrogen-fixing and non-nitrogen-fixing species during the vigorous growth period to the deciduous period. The N and K contents in leaves of nitrogen-fixing species decreased significantly, compared with those of non-nitrogen-fixing species. The seasonal change rate of ash, ie, the cumulative trend, is higher than that of non-nitrogen-fixing species. On the basis of F test and T test, the quantitative classification of four nutrient elements of N, P, Mg and Si was selected as parameters, and the nitrogen and non-nitrogen-fixing species were successfully distinguished.