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森林雨雪冰冻灾害原因分析及防范措施的探讨 总被引:2,自引:0,他引:2
通过对黄山区2008年雨雪冰冻灾害森林资源损失调查,分析了主要灾害类型、分布特征、灾害程度、灾害原因、发生次生灾害的隐患以及对林业产生的主要影响,提出了预防雨雪冰冻灾害的措施。 相似文献
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通过对黑龙江省林区主要生态灾害种类、频度、强度及危害程度的调查研究,综合分析了林区生态灾害的发生发展趋势、生态灾害之间的关联性、生态灾害的规律性,提出预防和减缓生态灾害的对策。 相似文献
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以山西太岳山林区冻雨灾害为例,分析了森林保险在面对重(特)大自然灾害时,调查与理赔中存在的问题,提出了调查方式确立、赔偿标准制定等对策,为同类型案例提供了可以借鉴的做法。 相似文献
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湖南省森林冰雪灾害调查 总被引:5,自引:0,他引:5
通过对典型冰雪灾害样地调查,分析了不同营林措施下,冰雪灾害对人工商品林的影响因素,提出了合理密度,加强抚育间伐,营造混交林等营林措施,从而提高林木抗冰雪灾害的能力。 相似文献
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通过现场调查、社区走访、资料收集等方式,对屏边林下草果遭受雪霜冰冻灾害情况进行调查与分析研究,针对目前受冰冻灾害影响后的草果产业现状,从栽培技术、管理方法入手,就如何栽培和管理林下草果,提出了新的发展思路与对策。 相似文献
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通过对被松突圆蚧不同程度危害的马尾松针叶内主要营养物质的测定,表明受害马尾松针叶内总糖和可溶性糖含量随着危害程度的加重先降低后增加;氨基酸含量随着危害程度的加重而下降。研究表明,马尾松针叶内主要营养物质的含量与松突圆蚧的不同危害程度有显著的相关性。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1-4):251-263
Although a good correlation has been found between the mean degree of damage and the increment trend of larger Norway spruce collectives, individual spruce trees often betray no relationship between crown damage and the development of the volume increment. Detailed investigations show that stem and crown dimensions, growing space as well as the competition of neighboring stems can substantially outweigh the influence of crown damage on the volume increment. Furthermore, current methods to determine crown parameters and needle loss are in many cases quite error‐prone. Use of more accurate techniques for measuring spruce trees produced a stronger relation between the volume increment per square meter crown surface area and the degree of crown damage (needle loss). 相似文献
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Rafał Podlaski 《European Journal of Forest Research》2004,123(3):229-237
This article presents a validation of a method, proposed in Podlaski (2003), for estimating the degree of tree damage. This method belongs to a group of small-area methods. To estimate the degree of tree damage in individual P3 sub-blocks of the SINUS system of information on the natural environment, a classification based on the degree of defoliation was used. Spatial distribution of the degree of tree damage was estimated through unrestricted simple random sampling. The maximum total estimation error for proportions of fir and beech with a damage degree of zero, and also with second and third degrees jointly, reached a maximum of 35.6% for fir, and 33.8% for beech. P3 sub-blocks characterised by the highest proportion of the healthiest trees (at least 15% being undamaged trees) occurred in patches in the case of fir, and in larger, compact areas in the case of beech. Because spatial diversification in the health of fir, and to a smaller degree in the case of beech, occurs at small scales, small-area methods for estimating tree condition are necessary. An analogous scheme, combining small-area with large-area methods (utilising sub-blocks of the network of large-area systems in a small-area inventory, and establishing a common database), could be used on a wider scale; for example, by supplementing the program of estimating tree health carried out by the United Nations Economic Commission for Europe (Lorenz et al. 2002) with local inventories. 相似文献
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