The Health Assessment For The Forest Ecosystem In Songhua Lake Natural Reserve

Forest ecosystem health is a hot spot in forestry researches, though controversial,yet it is of great significance to the reasonable protection for the forest. Therefore, this article takes Songhua Lake Nature Reserve as an example to evaluate the forest ecosystem health and put forward Suggestions of health supervision. Specific evaluation processes are as follows:(1)According to the forest ecosystem health definition, this paper established a set of forest ecosystem health assessment index system in Songhua Lake Nature Reserve, and selected six categories including 29 indicators. Through SPSS software,we made principal component analysis for each index data of 69 pieces of samples.Take advantage of dimension reduction to get 11 principal components, and use cluster analysis, with statistic, half deviation, pseudo F statistic and false statistic to determine the clustering effect, which concluded the health levels. The four kinds of levels including the healthy, sub-healthy, generally healthy and unhealthy were better.(2)In the terms of cluster analysis, it was concluded that in the 69 pieces of samples, there were just 2 healthy plots(2.9%),1 sub-healthy one(1.5%),13 generally healthy plots(18.8%),and 53 unhealthy plots(76.8%).( 3) According to the statistics to the 69 plots, there were 26 core zones(37.7%)and 43 buffer communities(62.3%), among which the most were unhealthy accounting for 73.1% with only one sub-health population and no healthy community,suggesting that the forest ecosystem condition in Songhua Lake Nature Reserve was bad. In addition, through analysis for the distance of the survey samples from the water, there were 22 plots with healthy community accounting for 13.64% close to water, 11 plots with that accounting for 27.3% closer, 27 plots with that accounting for 11.1% far and 9 plots with that accounting for 44.4% further. The percentage of the unhealthy population, on the contrary, in terms of the plots closer, far, closer, and further from the water, is 86.4%, 81.5%, 63.6% and 55.6% respectively.(4)Through analyzing the forest ecosystem health condition in Songhua Lake Nature Reserve, this paper gave the corresponding adjusting suggestions for the generally healthy, unhealthy and sub-health community to maintain healthy group avoiding man-made destruction. Meanwhile, we should strengthen the management for the core zones and buffer communities to turn them into healthy trend in order to maintain the stability of ecosystem.