多年生樟子松人工纯林生长衰退及地力衰退原因分析

对章古台地区不同林龄樟子松生长状况和土壤肥力状况进行调查，结果证实多年生樟子松人工纯林存在生长衰退及地力衰退问题。应用双重筛选逐步回归方法，找出影响樟子松树高和胸径生长的主导因子分别为土壤中速效磷含量、最大持水量及土壤有机质含量和全氮含量。对40年生樟子松纯林和樟子松杨树混交林进行比较分析，发现混交林中樟子松生长量和林地土壤肥力均较纯林高，因此营造混交林是防治樟子松生长衰退及地力衰退的有效措施之一。

Decline Reasons of Pure Pinus Sylvestris var.mongolica and Siol Fertility

Pinus sylvestris var.mongolica's growing and soil fertility have been founded on the decline in Zhanggutai area. By ASSHG method, organic matter,total nitrogen,readily available phosphorus and maximum moisture capacity were considered as the main causes of affecting the Pinus'growing.It was discovered that the Pinus'growth increment and soil fertility in mixed forest was all higher than that in pure forest compared with 40-year-old pure Pinus and Populus simonii Carr mixed forest. So the conclusion can be drawn that planting mixed forest is an effective measure against the declines of Pinus'growth and land capability.