共查询到20条相似文献，搜索用时 46 毫秒
1.
S.D.Puntsukova 《世界地质(英文版)》2009,12(4):194-199
The author studied the issues of the present-day status of forest resources and forest management of the Selenge River Basin on the transboundary territory of the Buryat Republic and Mongolia. It is necessary to establish a good policy for wood cutting of the main and secondary use and reforestation. 相似文献
2.
S.D.Puntsukova 《东北亚地学研究》2009,(4):194-199
The author studied the issues of the present-day status of forest resources and forest management of the Selenge River Basin on the transboundary territory of the Buryat Republic and Mongolia. It is necessary to establish a good policy for wood cutting of the main and secondary use and reforestation. 相似文献
3.
Eui-gyeong KIM Dong-jun KIM 《山地科学学报》2005,2(2):164-172
This study analyzed the causes of forest devastation, the characteristics of forest rehabilitation process, and the success factors of reforestation. And it reviewed the management of rehabilitated forest resources and identified the income sources of mountain villages in South Korea. The devastation of forest starting from the early twentieth century was continued to the 1950＇s. The main causes of deforestation were the illegal cutting of trees for fuel and the slash-and-burning agriculture in forest. The success factors of reforestation were the decrease in the dependence on forest of fuel source, strict administration system and national participation. Sustainable forest management could be made possible through the practical use of social issues like public work project for prevention of landslide damages caused by the thinned logs left in the forest. Also it could be possible by making people realize that the public benefit was obtained from forest and the income sources of mountain villages were supplemented by non-timber forest products and tourism. Food and Agriculture Organization indicated Korea as the country that forestation was succeeded in a very short period. Korea seems to be not ordinary because economic growth was accomplished with rehabilitating natural environment. Korean forestation can become a good prototype of combining environmental rehabilitation and economic development. 相似文献
4.
加拿大北方森林火烧迹地遥感分析 总被引：1，自引：0，他引：1
森林火灾是加拿大北方森林地区最主要的扰动因素,对北方生态系统起着主导作用。基于MODIS数据,采用全球扰动指数算法(MGDI),对加拿大萨斯喀彻温省和亚伯达省2004-2011年的森林火烧迹地进行检测和分析。通过与MODIS标准火烧迹地产品以及加拿大林业局数据进行比较,扰动指数算法检测的火烧迹地面积比MODIS标准产品更接近于林业局的统计数据。分析表明,在2004-2011年间,由于火灾原因,整个研究区森林面积平均每年减少76.36万hm2,占该区域森林总面积的3.36%。萨斯喀彻温省平均每年燃烧的森林面积为46.83万hm2,亚伯达省为29.53万hm2。其中,2006、2008、2010和2011年是火灾的高峰年份。火烧迹地主要集中在生态交错带的北方保护区、针叶林保护区、针叶林平原区,以及北方平原东北部的伍德布法罗国家森林保护区。 相似文献
5.
贝塞尔曲线在虚拟森林景观单树几何模型构建中的应用 总被引：10，自引：0，他引：10
虚拟景观模型的生成,需要对实际景观进行抽象和简化。树几何模型和数字高程模型(DEM)是构成虚拟森林景观的两大要素。而树几何模型的构建又是林业GIS三维可视化的基础。在树几何建模中,树干及树枝形状的可视化表达具有突出意义。由于实际树种的复杂性,在计算机中建树模型,通常采用基于过程建模的方式,而这将面临用户如何对模型进行交互式控制的问题：参数太少,不足以描述树形态特征,而参数太多,则模型难以生成和理解。为了解决这个问题,我们引进贝塞尔(Bezier)曲线这种基于控制点的自由曲线来描述树木中的树干以及树枝形状,利用对曲线控制点的变动来控制曲线的形状,进而生成形态各异的树形状,对此,我们基于ActiveX技术生成Bezier曲线控件。结果表明,该方法能够表示多种形状的树干与树枝,具有操作简捷、计算速度快,可视化效果良好的优点。 相似文献
6.
Succession Features and Dynamic Simulation of Subalpine Forest in the Gongga Mountain, China 总被引：2，自引：0，他引：2
CHENGGenwei LUOJi 《山地科学学报》2004,1(1):29-37
The Gongga Mountain of eastern Tibet Plateau is a representative of the alpine regions with high peaks and deep valleys. Climate change over the last thousand years has controlled the dynamics of glacier and debris flow occurrence, which resulted in substantial changes in the mountainous environment. The authors surveyed the community structure of primary forests in Gongga Mountain and forest successign processes in woodland plots. The changing features in the subalpine environment are discussed in this paper. Tree species and sizes between the glacier shrinking areas and debris flow fans in Hailuogou Valley are compared. The pioneer species that settle in debris flow fans and the glacier shrinking areas are Salix spp. and Populus purdomii. Abies fabri and Picea brachytyla are the climax tree species. The succession process of primary vegetation in Hailuogou (2700 ～ 3200 m) can be divided into four stages: 相似文献
7.
Mangrove forests occur extensively in the tropic areas rich in wildlife and other nonforestry resources and provide a wide array of raw materials for livelihood and production processes and have been a major source of income generation and subsistence for the local people.Exploitation of timber, fuel wood, poles, industrial raw material, and many other non-wood products from the mangrove forests give rise to large scale economic activity and income generation. At present, mangrove forests are facing great peril. Reckless exploitation and swampland reclamation result in their gradual degradation. This article deals with the world‘s mangrove forest resources and their benefit to people ; describes the cmrrent status, points out the main causes of the destruction of these forests, presents proposals for protecting mangrove forests, and discusses international cooperation in protecting the world‘s mangrove forests. 相似文献
8.
BASIC FEATURES OF FOREST STEPPE IN THE LOESS PLATEAU OF CHINA 总被引：2，自引：0，他引：2
朱志诚 《中国地理科学(英文版)》1995,5(2):170-174
ＢＡＳＩＣＦＥＡＴＵＲＥＳＯＦＦＯＲＥＳＴＳＴＥＰＰＥＩＮＴＨＥＬＯＥＳＳＰＬＡＴＥＡＵＯＦＣＨＩＮＡ￥ＺｈｕＺｈｉｃｈｅｎｇ（朱志诚）（ＤｅｐａｒｔｍｅｎｔｏｆＢｉｏｌｏｇｙ．ＮｏｒｔｈｗｅｓｔＵｎｉｖｅｒｓｉｔｙ，Ｘｉａｎ７１００６９，ＰＲＣ）Ａ... 相似文献
9.
Biomass carbon sequestration by planted forests in China 总被引：2，自引：1，他引：1
The planted forest area and carbon sequestration have increased significantly in China, because of large-scale reforestation
and afforestation in the past decades. In this study, we developed an age-based volume-to-biomass method to estimate the carbon
storage by planted forests in China in the period of 1973–2003 based on the data from 1209 field plots and national forest
inventories. The results show that the total carbon storage of planted forests was 0.7743 Pg C in 1999–2003, increased by
3.08 times since the early 1970s. The carbon density of planted forests varied from 10.6594 Mg/ha to 23.9760 Mg/ha and increased
by 13.3166 Mg/ha from 1973–1976 to 1999–2003. Since the early 1970s, the planted forests in China have been always a carbon
sink, and the annual rate of carbon sequestration was 0.0217 Pg C/yr. The carbon storage and densities of planted forests
varied greatly in space and time. The carbon storage of Middle South China was in the lead in all regions, which accounted
for 23%–36% of national carbon storage. While higher C densities (from 17.79 Mg/ha to 26.05 Mg/ha) were usually found in Northeast
China. The planted forests in China potentially have a high carbon sequestration since a large part of them are becoming mature
and afforestation continues to grow. 相似文献
10.
漳平市森林可燃物类型变化遥感动态监测 总被引：4，自引：0，他引：4
森林可燃物类型的空间分布是林火蔓延、灭火可视化建模与仿真中需要考虑的重要因素之一。在对森林可燃物类型划分的研究进行回顾的基础上,提出了考虑树种信息的分类方法。根据漳平市2003年小班图层中的优势树种信息,获得该市2003年四种森林可燃物类型即竹林、阔叶树、杉木林以及马尾松的空间分布专题图。在此基础上,采用面向对象分类技术,对ASTER影像进行分类,探测每种可燃物类型的内部变化和外部变化。该技术利用影像分割技术构建分类对象,使每个对象具有光谱信息的同时,具备大小、形状、拓扑关系、类别层次等诸多信息。对分类结果进行评价的结果表明,利用面向对象分类技术,充分利用了光谱特征以及类别相关特征,提高了分类精度,分类的面积精度达到89.3%。由于影像分割过程应用了专题图层,对象的边界不会超越专题图层的边界,使得对现有图层的更新尤为容易。最后,利用矢量格式的遥感分类结果对原森林小班图层进行更新,获得新的可燃物类型图层,作为林火可视化模型的输入图层。该研究不仅提供了现势性强的森林可燃物类型图层,而且在不破坏原小班边界的基础上,对发生变化的区域进行刻画。对于森林资源管理者,提供了实地调查过程的目标区域的信息。 相似文献
11.
Matthias Schmidt 《山地科学学报》2005,2(2):91-104
Using political ecology as its conceptual framework, this paper focuses on the changes in forest utilisation and management of South Kyrgyzstan＇s walnut-fruit forests over the last century The aim of this study on human-environment interactions is to investigate the relationship between actors on the one side, their interests and demands, and the forests and forested lands on the other. Forest resource utilisation and management - and even the recognition of different forest products as resources - are connected with political and socioeconomic conditions that change with time. The walnut-fruit forests of South Kyrgyzstan are unique, characterised by high biodiversity and a multiplicity of usable products; and they have been utilised for a long time. Centralised and formal management of the forests started with the Russian occupation and was strengthened under Soviet rule, when the region became a part of the USSR. During this era, a state forest administration that was structured from Moscow all the way down to the local level drew up detailed plans and developed procedures for utilising the different forest products. Since the collapse of the Soviet Union, the socio-political and economic frame conditions have changed significantly, which has brought not only the sweeping changes in the managing institutions, but also the access rights and interests in the forest resources. At present, the region is suffering from a high unemployment rate, which has resulted in the forests＇ gaining considerable importance in the livelihood strategies of the local population. Political and economic liberalization, increased communication and transregional exchange relations have opened the door for international companies and agents interested in the valuable forest products. Today, walnut wood and burls, walnuts, wild apples and mushrooms are all exported to various countries in the world. Scientists and members of various international organisations stress the ecological value of the forests and are trying to establish nature conservation areas. Nevertheless, it is to fear that a multiplicity of interrelated factors - the present transformation and globalization processes, the appearance of new actors, the local population＇s insecure economic situation and the erosion of managing institutions - are all leading to an intensified and unregulated exploitation of the forests, resulting in their degradation. 相似文献
12.
Anthropogenic Pressure on Structure and Composition of a Shola Forest in Kerala, India 总被引：1，自引：0，他引：1
U.M. Chandrashekara P.K. Muraleedharan V. Sibichan 《山地科学学报》2006,3(1):58-70
Introduction Tropical region is endowed with a vast tract of diverse vegetation (Gentry 1992). Among different types of forests, the montane forests, due to their unique features including rich biodiversity andprominent ecological services, have always attracted biologists, bio-geographers, ecologists and forest managers (Doumenge et al. 1995). In India, montane forests covering 7.9 % of total forest area occur in the Himalayan, northeastern and southern parts of the country (Lal 1989). In s… 相似文献
13.
森林植被碳密度是衡量森林生态系统服务功能和产品供给功能高低的一个重要指标.本文以四川省石棉县为例,在森林资源二类调查数据的基础上,提出建立森林植被生物量、碳量及其密度GIS数据库,开展其碳密度分布知识发现的研究,从中发现了该县碳密度分布知识.该县有林地森林植被碳量达到364万t,冷杉、云杉、铁杉和桦木占总碳量的83％;... 相似文献
14.
Introduction Dead wood is an important structural and functional component of a forest ecosystem(Fridman and Welheim 2000). Recent studies also indicate that dead wood is important for maintaining both plant and animal diversity in different forest ecosystems (Grove 2001) as it serve as an energy source (Bray and Gorham 1964) and habitat for an array of organisms. Dead wood can also help reduce erosion, increase soil organic matters (McFee and Stone 1966), and suitable conditions for seedli… 相似文献
15.
采用机载LiDAR数据估算森林结构参数是当前林业遥感中的研究热点。本文以福建省长汀县朱溪河流域为示范区,探讨了随机森林算法（RF）在机载LiDAR数据林分平均树高估测中的适用性。首先,通过渐进三角网（TIN）算法进行点云滤波并获取相应林分样地的植被点云子集和高程归一化的植被点云;然后,从归一化后的植被点云提取出高度分位数变量以及点云统计特征值等24个变量参数;最后,根据提取的变量参数和野外实测林分均高数据建立研究区林分平均高随机森林回归估测模型。研究结果表明,模型估测的样地平均树高与实测值具有明显线性相关关系,线性回归系数为0.938,相关系数达到0.968。对样地的估测精度都在86%以上,总体平均精度达到了93.17%。研究认为,基于植被点云变量参数的随机森林模型估测林分平均树高具有较高的可靠性。 相似文献
16.
Cloud forests are unusual and fragile habitats, being one of the least studied and least understood ecosystems. The tropical Andean dominion is considered one of the most significant places in the world as regards biological diversity, with a very high level of endemism. The biodiversity was analysed in an isolated remnant area of a tropical montane cloud forest known as the "Bosque de Neblina de Cuyas", in the North of the Peruvian Andean range. Composition, structure and dead wood were measured or estimated. The values obtained were compared with other cloud forests. The study revealed a high level of forest biodiversity, although the level of biodiversity differs from one area to another: in the inner areas, where human pressure is almost inexistent, the biodiversity values increase. The high species richness and the low dominance among species bear testimony to this montane cloud forest as a real enclave of biodiversity. 相似文献
17.
ZHOU Lei WANG Shaoqiang Georg KINDERMANN YU Guirui HUANG Mei Robert MICKLER Florian KRAXNER SHI Hao GONG Yazhen 《中国地理科学(英文版)》2013,23(5):519-536
It is critical to study how different forest management practices affect forest carbon sequestration under global climate change regime. Previous researches focused on the stand-level forest carbon sequestration with rare investigation of forest carbon stocks influ- enced by forest management practices and climate change at regional scale. In this study, a general integrative approach was used to simulate spatial and temporal variations of woody biomass and harvested biomass of forest in China during the 21st century under dif- ferent scenarios of climate and CO2 concentration changes and management tasks by coupling Integrated Terrestrial Ecosystem Carbon budget （InTEC） model with Global Forest Model （G4M）. The results showed that forest management practices have more predominant effects on forest stem stocking biomass than climate and CO2 concentration change. Meanwhile, the concurrent future changes in cli- mate and CO2 concentration will enhance the amounts of stem stocking biomass in forests of China by 12%-23% during 2001-2100 relative to that with climate change only. The task for maximizing stem stocking biomass will dramatically enhance the stem stocking biomass from 2001~100, while the task for maximum average increment will result in an increment of stem stocking biomass before 2050 then decline. The difference of woody biomass responding to forest management tasks was owing to the current age structure of forests in China. Meanwhile, the sensitivity of long-term woody biomass to management practices for different forest types （coniferous forest, mixed forest and deciduous forest） under changing climate and CO2 concentration was also analyzed. In addition, longer rotation length under future climate change and rising CO2 concentration scenario will dramatically increase the woody biomass of China during 2001~100. Therefore, our estimation indicated that taking the role of forest management in the carbon cycle into the consideration at regional or national level is very important to project the forest carbon sequestration under future climate change and rising atmospheric CO2 concentration. 相似文献
18.
Driving factors for forest fire occurrence in Durango State of Mexico: A geospatial perspective 总被引：3，自引：2，他引：1
Diana Avila-Flores Marin Pompa-Garcia Xanat Antonio-Nemiga Dante A Rodriguez-Trejo Eduardo Vargas-Perez Javier Santillan-Perez 《中国地理科学(英文版)》2010,20(6):491-497
Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management
worldwide. Identifying the driving factors and understanding the contribution of each factor are essential for the management
of forest fire occurrence. The objective of this study is to identify variables that are spatially related to the occurrence
and incidence of the forest fire in the State of Durango, Mexico. For this purpose, data from forest fire records for a five-year
period were analyzed. The spatial correlations between forest fire occurrence and intensity of land use, susceptibility of
vegetation, temperature, precipitation and slope were tested by Geographically Weighted Regression (GWR) method, under an
Ordinary Least Square estimator. Results show that the spatial pattern of the forest fire in the study area is closely correlated
with the intensity of land use, and land use change is one of the main explanatory variables. In addition, vegetation type
and precipitation are also the main driving factors. The fitting model indicates obvious link between the variables. Forest
fire was found to be the consequence of a particular combination of the environmental factors, and when these factors coexist
with human activities, there is high probability of forest fire occurrence. Mandatory regulation of human activities is a
key strategy for forest fire prevention. 相似文献
19.
广西森林旅游资源多达 816 .7万hm2 ,景点 2 80个 ,内容丰富 ,前景广阔 ,加强广西森林旅游资源特色的开发 ,有利于促进广西旅游业可持续发展 ,有利于经济、社会、环境效益的提高及人们的文化素质和生活质量的提高。 相似文献
20.
基于随机森林的遥感干旱监测模型的构建 总被引：1，自引：0，他引：1
利用遥感数据进行大面积旱情监测是现有干旱监测的重要方法之一,然而传统的遥感干旱监测方法主要侧重于对土壤湿度或植被状况等单一干旱响应因子进行监测,对综合多因子的干旱监测研究较为有限。随机森林是一种机器学习方法,具有学习过程快速、运算速度快、稳定性好、预测精度高的优点,近年来被应用于生态环境等多个领域。本文利用2001-2010年4-9月的MODIS数据提取的植被状态指数（VCI）、温度状态指数（TCI）和土地覆盖类型（LC）,TRMM降水资料计算的TRMM-Z指数及SRTM-DEM、土壤有效含水量（AWC）等多个遥感及土壤资料提取的干旱因子为自变量,以气象站点的综合气象干旱指数（CI）为因变量,利用随机森林模型构建遥感干旱监测模型,并以河南省为研究区进行了评价和分析。该模型在2009-2010年的监测值和实测CI值的具有显著的相关性,并且二者干旱等级的一致率为81%。在2001-2010年4-9月间,模型监测值与气象站点的标准降水蒸散发指数（SPEI）总体干旱等级一致率为74.9%,较为一致,其中9月的模型结果与SPEI的干旱等级一致率最高,达到82.4%,空评估率和漏评估率最低;与10 cm土壤相对湿度的相关系数在0.475-0.639之间,达到极显著水平。河南省2011年4-6月干旱事件同样验证了本文构建的模型旱情监测结果,说明本模型能较好地就应用于监测区域旱情监测。 相似文献