Soil depth was from 10 to 20cm for most plantations and from 20 to 30cm for natural forest.
从土壤土层厚度来看,大部分人工林主要分布在土层1020cm,天然林主要分布在土层2030cm。
参考来源 - 北京山区森林景观与立地因子关系研究The research also do some empirical work take the natural forest protection project (NFPP) for instance.
研究以天然林资源保护工程为例,展开了实证分析。
参考来源 - 中国林业生态工程项目风险管理研究·2,447,543篇论文数据,部分数据来源于NoteExpress
But in general, for positive impact, forest management practices should mimic natural forest processes.
但一般而言,为了产生积极影响,森林管理做法应模仿自然森林过程。
Natural forest stand structure of Pinus tabulaeformis was studied.
对油松天然林的林分结构进行了研究。
Indeed, it is worse, for natural forest promotes cloud formation and local rainfall, and thus helps nearby farmers.
而且更糟的是荒地破坏了原自然森林促成的云层和地区降雨,影响到邻近原来受益的农夫。
The trees surrounding Biltmore look like a natural forest.
VOA: special.2009.11.16
The Forest Service is protecting the area from too much human activity so it will return to its natural wild condition.
VOA: special.2009.07.20
About thirteen million hectares of forest were cut down or lost through natural causes each year in the last ten years.
VOA: special.2010.04.06
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