桉树人工林生态目标量化评价指标体系的应用

Analyses of Ecological Quantitative Evaluation Indices for Eucalyptus Plantation on the Leizhou Peninsula

桉树人工林生态量化评价指标体系建立的科学性和必要性已在前期研究成果得到体现,本研究把桉树人工林生态目标量化评价指标体系应用于雷州林业局桉树人工林生态效益及实现情况。雷州林业局生态目标量化评价的总得分是0.681 4（满分为1）,说明雷州林业局桉树人工林的生态经营水平处于中上水平,总体能较好地发挥其生态效益。在36个三级指标的得分中,得分在0.8以上有7个指标,占全体指标的19.44%,分别是景观类型数量、郁闭度、年平均耗水量、火灾发生率、平均蓄积量、病虫害发生率和乔木层平均碳储量,说明雷州林业局桉树人工林在这几方面表现优秀,其中乔木层碳储量明显高于其他地区桉树人工林。得分在0.5~0.8之间的指标占多数,有24个指标,占66.67%,这反映了雷州林业局桉树人工林生态效益的总体水平,同时也反映了本指标体系的合理性。得分在0.5以下的指标有5个,占13.89%,分别是土壤微生物数量、土壤层碳密度、凋落物层碳密度、有机质含量和物种数量,其中物种数量得分低是因其与热带（海南）地区桉树林的物种数量比较相对较少。

The establishment of a quantitative index system for evaluation of Eucalyptus plantation ecology is scientific and necessary, as shown by previous research results. Ecological quantitative evaluation indicators for Eucalyptus plantation as used by Leizhou Forestry Bureau have achieved good results. They have enabled efficient evaluation of ecological quality of Eucalyptus plantations. The total score of ecological quantitative evaluation in Leizhou Forestry Bureau was 0.681 4（out of a possible score of 1）. This result indicates that the quality of Leizhou Forestry Bureau＇s ecological management is of reasonable quality. The Eucalyptus plantations of Leizhou can provide many ecological benefits. In the scores of 36 third-level indicators, there were 7 indicators that had scores exceeding 0.8 and these accounted for 19.4% of the total score; these indicators included the number of landscape types, canopy density, average annual water consumption, fire incidence, the average timber volume, pest and disease incidence, and carbon storage by the trees. The latter trait was higher than Eucalyptus plantations in many other regions. There were 24 third-level indicators that achieved scores ranging from 0.5 to 0.8, and they accounted for 66.7% of the total score. This diversity of third-level indicators reflects the overall level of eco-efficiency in Leizhou and the rationality of this evaluation system. There were 5 indicators under 0.5, and these accounted for only 13.9% of the total score; these included soil microbial quantity, soil carbon density, litter carbon density, soil organic matter, and number of species. Comparing with more tropical environments（such as Hainan）, the number of species in Leizhou was lower.