东北地区主要森林生态系统凋落量的比较

Litterfall in main forest ecosystems of Northeast China.

以东北地区不同纬度带上4个区域内的典型森林类型为研究对象,采用直接收集法对森林凋落量进行连续3年的观测研究,结果表明,同一地区不同林型间的年凋落量差异显著,凋落量年变化不显著;落叶量占总量的比例最大,在70%以上,落枝和花果皮各占总量的20%以下,落枝量和落叶量之间存在正相关关系,相关系数为0.82;长白山区5种森林类型不同时期内凋落量统计结果显示,秋、冬季的凋落量明显大于春、夏季,前者为后者的2.62～9.14倍.不同凋落组分之间凋落动态不同,落叶以秋季为主,落枝和花果皮则年内分布比较均匀.同一林型的凋落量随纬度增加而减少,并建立了总体森林凋落量和白桦凋落量随纬度变化的数学关系式;总体森林凋落量和白桦林凋落量与温度均呈正相关,相关系数分别为0.95和0.91.

A three-year investigation on the litterfall of 15 forests in 4 different regions of Northeast China showed that the annual litterfall had a significant difference among forest types in the same region,but no significant difference was found between years.In the litterfall,leaf occupied 70% and more,while branch,flower and fruit were less than 20%.The branch production correlated positively with leaf production,and the correlation coefficient was 0.82.According to the investigation of 5 forest types in Changbai Mountain,the litterfall was 2.62～9.14 times higher in autumn and winter than in spring and summer.The peak of leaf-fall appeared in autumn,while that of branch and others withered evenly during a year.The litterfall of same forest type decreased with increasing latitude,and the relationships of the total and birch litterfall with latitude were established.Both the total and the birch litterfall were positively related to annual mean temperature,with the correlation coefficient 0.95 and 0.91,respectively.