冀北山地杨桦低效林改造的效益分析

Reform Benefits of Inefficient Poplar and Birch Stands in Mountainous Area of Northern Hebei Province

[目的]分析研究冀北山地杨桦低效林改造的成果,为该地区的森林健康经营理论提供参考。[方法]采用生态疏伐后人工林下更新的方式进行改造,并以定量计算的方式对改造后样地和未改造对照样地分别从林地生产力、固碳释氧功能、水源涵养功能3方面进行效益分析。[结果]改造后的样地较对应的对照样地在总体效益方面具备很大优势,具体高出值分别为25 008.89和14 802.17元/hm2,增长率分别为16.6%,14.6%。其中林地生产力价值分别高于对照样地44.9%,73.11%;固碳释氧价值分别高出13.4%,9.2%;涵养水源价值分别高出5.4%,2.6%。[结论]对杨桦低效林进行生态疏伐、人工林下更新改造后,林分质量得到显著改善,提高了林地生产力和林分生态功能的同时,带来了经济效益的增长。

[Objective] The objective of this study was to analyze the result of reforming inefficient poplar and birch stands in order to provide a theory reference for the forest health management for the region.[Methods] We reformed the stands by the means of ecological thinning and regeneration under forest canopy, and analyzed the benefits from reformed plots in comparison with the control plots by quantitative calculation from three indices, including forestland productivity, carbon fixation and oxygen release and water conservation function.[Results] Compared with the corresponding control plots, the reformed plots of poplar and birch stands had a increased benefit of 25 008.89 yuan/hm^2 and 14 802.17 yuan/hm^2 respectively, and the corresponding benefit rate were 16.6% and 14.6%, indicating that the reformed plots have better advantage than the control plots. The values of forestland productivity had raised by 44.9% and 73.11%, respectively in comparison with the control plots. The values of carbon fixation and oxygen release function had raised by 13.4% and 9.2%. Similarly, the values of water conservation function had raised by 5.4% and 2.6%.[Conclusion] The qualities of inefficient poplar and birch stands were significantly improved after reforming by the means of ecological thinning and regeneration under forest canopy. The reforming not only brought the growth of economic benefit, but also improved forestland productivity and ecological functions.