...孔材物理力学性质比较 关键词 ：人工林；天然林；环孔材；木材物理力学性质 [gap=6342]key words ：plantation；natural forest；ring porous wood；physical and mechanical properties of wood ...
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natural forest regeneration 自然森林更新 ; 天然林更新
natural forest protection project 天然林保护工程 ; 天保工程 ; 天然林资源保护工程
Natural forest protection 天然林保护
natural forest conservation 天然林保护
Natural forest art 天生林艺
natural forest resources 天然林资源
Natural forest Arts 天生林艺
tropical natural forest 热带天然林
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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