云南松林分与小蠹虫的竞争状态研究

云南松林遭小蠹虫危害以后,常由于林分抵御功能的不同而形成区域性的蠢害林分系统,即在"虫群区域"内存在着"衰退"和"发展"两种林分演变过程,若按"演变属性"来分析,则看到蓄积量下降、蓄积量停滞、蓄积量上升等3种林分演变过程是蠹害林分系统的普遍性特征,前2种属于"衰退状态",后1种属于"发展状态"。对3个蠢害林分系统的"演变属性"用二项分布P(衰退概率)+Q(发展概率)=1来描述,那么二项式(P+Q)3方程中的系数1、3、3、1成为系统中不同"演变属性"的概率论判断。由人为因素、虫群因素、环境因素引起的林分"衰退"和"发展"当然是随机的,但从分析中看到人的正、反两面行为都会引起林分与虫群相互作用的变化。

Study on the State of Competition Between Pinus yunnanensis and Tomicus piniperda L.

When harmed by Tomicus piniperda L, Pinus yunnanensis forests always form regional suffered stand systems due to their different defense ability, namely there exist two succession processes of stands in the "pests regions", which are degeneration and development. If analyzing the process from aspect of "succession attribute", it can be seen the phenomena of volume decrease, volume stasis and volume increase, which of the former two belong to degeneration state and the later one belongs to development state. Using binomial distribution P (degeneration probability) + Q (development probability) = 1 to describe "succession attribute" of three suffered stand systems, the coefficients of 1, 3, 3, 1 in the binomial equation of (P+Q)3 will become assessment of probability in different attributes of systems. The "degeneration" and "development" of stands caused by people factor, pest population factor and environment factor is random. However, it can be seen in the analysis that both positive and negative activities of people will lead to the change of interaction between stands and pest populations.