1) natural secondary forest
天然次生林
1.
Investigation on natural secondary forest community in Hefei area;
合肥地区天然次生林群落的调查研究
2.
Point pattern analysis of spatial distribution of natural secondary forest populations in mountainous area of Beijing: A case study of Wuling Mountain nature reserve;
北京山区天然次生林种群空间分布的点格局分析——以雾灵山自然保护区为例
3.
Thinning effect on growth status of natural secondary forest;
天然次生林抚育间伐效果
2) secondary forest
天然次生林
1.
Under the similar site condition, the secondary forest and the mixed plantations had greater water conservation function and better maintenance of soil fertility than the pure stands did.
在相同的立地条件下,天然次生林和混交林具有更好的维持地力作用和更高的水源涵养功能。
2.
Aims We studied root morphology across the first five branch orders of 20 hardwood tree species from secondary forest in northeastern China.
该文根据细根分枝等级划分方法,研究了东北帽儿山天然次生林20个阔叶树种1~5级根直径、根长和比根长等形态指标。
3) Natural secondary forests
天然次生林
1.
Nutrient distribution and accumulation patterns of natural secondary forests on the Loess Plateau of Shanxi Province.;
晋西黄土区天然次生林营养元素分配与积累研究
2.
The carbon density and storage in four types of natural secondary forests are studied,and the results show that: 1) the range of carbon density in different apparatus of natural secondary forests is from 0.
通过对帽儿山林场4类天然次生林碳素密度及储量的比较研究,结果表明:1)天然次生林主要树种不同器官中碳素密度变化范围在0。
3.
The soil water content of different natural secondary forests in eastern mountains of Heilongjiang Province was studied,and the results showed that:①The soil moisture of natural secondary forests in different terrains declined gradually as the soil depth increased;②The soil water contents varied most in the depth of 0~10 cm,up to 20.
对黑龙江省东部山地不同地形天然次生林土壤水分含量进行研究,结果表明:①不同地形天然次生林土壤含水量随土壤深度的增加逐渐减小;②在0~10 cm处各林型土壤平均含水量差异最大,达20。
5) Oak natural secondary forest
栎类天然次生林
1.
Study on the Quantitative Analysis of the Oak Natural Secondary Forest in Baotianman Nature Reserve;
宝天曼栎类天然次生林林分结构量化分析
2.
The Oak natural secondary forest in Baotianman National-level Nature Reserve is taken as the researching object,according to the survey materials of 32 samples,the structure characteristic,species diversity of Oa
选择宝天曼国家级自然保护区栎类天然次生林作为研究对象,根据32块样地的调查资料,详细的研究和分析了栎类天然次生林群落的结构特征、物种多样性,在此基础上,用稳定度指数法和主成分分析法分别分析和评价了栎类天然次生林的群落稳定性,最后根据研究结果针对该保护区的现状提出建议。
3.
Based on the 2×2 contingency table,association coefficient(AC) together with percentage co-occurrence(PC) and point correlation coefficient(φ)as well as Ka-Fang worth difference,the join relations of 26 major trees populations of in oak natural secondary forest are measured.
在对宝天曼地区乔木层树种的RA、RD、RF及IV分析的基础上,根据2×2联列表,运用联结系数、共同出现百分率、点相关系数以及卡方值分别测定了栎类天然次生林26个主要树木种群间的联结关系。
补充资料:次生林
次生林 secondary forest 原始森林经过多次不合理采伐和严重破坏后自然形成的森林。与原始林一起同属天然林,但其立地特点、树种组成、林分结构和起源与原始林、人工林不同。人工林采伐迹地上,栽培树种的萌生林与入侵树种形成的混交林,也属于次生林。次生林分布范围广,种类多,不仅可以生产木材、薪炭材和林副产品,而且在涵养水源、保持水土、调节气候和维持生态平衡等方面均起着重要的作用。中国次生林约占全国森林面积的46.2%。 次生林可划分为多种类型。①按发生时间分成早期次生林、中期次生林和晚期次生林。一般用以区别大范围内次生林的性质及恢复速度,供经营规划时参考。②按发生地区分成远山次生林和近山次生林。一般反映人为活动的强弱及经营次生林与农业的关系。③按经营措施分成抚育型、改造型、利用型和封护型等。④还可按森林自然特征分类,方法较多,有按优势树种和树种组成划分的,有以生态因子划分的,有以地形作为主导因子进行划分的,还有以立地条件和优势树种划分的。 次生林的经营措施应根据自然特征和经济条件(交通、劳力、产品销路等)选用:①抚育间伐。科学地确定采伐木和采伐强度,为目的树种生长创造有利的环境条件。②林分改造。是在密度小、经济价值低或病虫害严重的林分中全面或局部伐除原林分,再栽植珍贵树种,以调整林分组成,增加林分密度,提高林分生产力。③抚育改造。是抚育间伐与林分改造相结合的一种经营方式。④封山育林。利用树木自然繁殖能力恢复森林的措施。可分为全封、半封和轮封3种。封山期间禁止一切人为活动,开封片则允许在一定季节内进行林副业生产活动。主要用在交通不便和经营水平不高的地区。
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