毕节市森林生态系统健康度评价

Health Evaluation of Forest Ecosystem in Bijie City

分析毕节市森林生态系统健康度,旨在为区域林业发展提供理论支撑。本次研究在毕节市选择森林样地系统,对阔叶混交林(A)落叶松纯林(B)针叶混交林(C)落叶松中幼龄纯林(D)阔叶树纯林(E)人工针叶林幼林(F)灌木林地(G)等森林类型进行生态系统健康评价指标评价,调查样地健康等级,分析土壤理化性质和森林健康程度的关系。结果得知Shannon-Wiener多样性指数、Simpson多样性指数、Pielou均匀度指数、Margalef物种丰富度权重是0.15,无明显差异。阔叶混交林健康等级为A级,主要是因为天然林系统结构复杂,各要素之间形成良好生物循环,物种多样性丰富。落叶松纯林、针叶混交林种植范围广,其群落层次结构复杂,但生物多样性不足,需合理抚育。阔叶树纯林、人工针叶林幼林、灌木林地属于亚健康和非健康状态,密度过大、结构单一。土壤理化性质分析可知,全K含量速K含量、土壤含水量、土壤容重和森林健康评价结果有显著的相关性(P<0.05)。结果证实毕节市森林生态系统健康状况良好,天然林的健康状况优于人工林,近熟林和成熟林比例高。

The health degree of forest ecosystem in Bijie City was analyzed in order to provide theoretical support for regional forestry development.In this study,forest sample land system was selected in Bijie City,and ecosystem health evaluation indexes were evaluated for forest types such as broadleaf mixed forest(A)Larch pure forest(B)coniferous mixed forest(C)Larch middle and young pure forest(D)broadleaf pure forest(E)artificial coniferous young forest(F)shrub forest(G).The relationship between soil physical and chemical properties and forest health was analyzed.The results showed that the weight of Shannon-Wiener diversity index,Simpson diversity index,Pielou evenness index and Margalef species richness was 0.15 with no significant difference.The health grade of the mixed broad-leaved forest is A,mainly because of the complex structure of the natural forest system,the formation of a good biological cycle among various elements,and the rich species diversity.Larch pure forest and coniferous mixed forest are planted in a wide range,their community hierarchy is complex,but the biodiversity is insufficient,so it needs to be properly tended.Pure broadleaf forest,young artificial coniferous forest and shrub land belong to the sub-health and unhealthy state,the density is too large and the structure is single.The analysis of soil physical and chemical properties showed that there were significant correlations between total K content,soil water content,soil bulk density and forest health evaluation results(P<0.05).The results showed that the health of forest ecosystem in Bijie City was good,the health of natural forest was better than that of plantation forest,and the proportion of near mature forest and mature forest was higher.