期刊文献+
共找到1,677篇文章
< 1 2 84 >
每页显示 20 50 100
Ecosystem Service Value Assessment of Wutong Mountain Rhododendron moulmainense Ecological Landscape Forest in Shenzhen City in 2021
1
作者 Rui CONG Kaiwen ZHANG +1 位作者 Xiaodan CHEN Dingyue WANG 《Agricultural Biotechnology》 CAS 2023年第4期88-92,共5页
Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accoun... Taking Wutong Mountain Rhododendron moulmainense ecological landscape forest in Shenzhen City as an example,the value of the forest was assessed by constructing an ecological service value assessment system and accounting method.The assessment results showed that the total ecosystem service value of R.moulmainense ecological landscape forest was 13.195 billion yuan,and the top three services included the value of forestry products,the value of biodiversity maintenance and the value of leisure and recreation,indicating that the ecosystem service of Wutong Mountain R.moulmainense ecological landscape forest in Shenzhen has great ecological and economic value,especially in forestry products,biodiversity maintenance,and leisure and recreation. 展开更多
关键词 Wutong Mountain Rhododendron moulmainense Ecological landscape forest Ecosystem services value assessment
下载PDF
Mapping landslide susceptibility at the Three Gorges Reservoir, China, using gradient boosting decision tree,random forest and information value models 被引量:9
2
作者 CHEN Tao ZHU Li +3 位作者 NIU Rui-qing TRINDER C John PENG Ling LEI Tao 《Journal of Mountain Science》 SCIE CSCD 2020年第3期670-685,共16页
This work was to generate landslide susceptibility maps for the Three Gorges Reservoir(TGR) area, China by using different machine learning models. Three advanced machine learning methods, namely, gradient boosting de... This work was to generate landslide susceptibility maps for the Three Gorges Reservoir(TGR) area, China by using different machine learning models. Three advanced machine learning methods, namely, gradient boosting decision tree(GBDT), random forest(RF) and information value(InV) models, were used, and the performances were assessed and compared. In total, 202 landslides were mapped by using a series of field surveys, aerial photographs, and reviews of historical and bibliographical data. Nine causative factors were then considered in landslide susceptibility map generation by using the GBDT, RF and InV models. All of the maps of the causative factors were resampled to a resolution of 28.5 m. Of the 486289 pixels in the area,28526 pixels were landslide pixels, and 457763 pixels were non-landslide pixels. Finally, landslide susceptibility maps were generated by using the three machine learning models, and their performances were assessed through receiver operating characteristic(ROC) curves, the sensitivity, specificity,overall accuracy(OA), and kappa coefficient(KAPPA). The results showed that the GBDT, RF and In V models in overall produced reasonable accurate landslide susceptibility maps. Among these three methods, the GBDT method outperforms the other two machine learning methods, which can provide strong technical support for producing landslide susceptibility maps in TGR. 展开更多
关键词 MAPPING LANDSLIDE SUSCEPTIBILITY Gradient BOOSTING decision tree Random forest Information value model Three Gorges Reservoir
下载PDF
Empirical Analysis of Forest Landscape Value Assessment:A Case Study of Huangshui Forest Park in Xining,Qinghai Province 被引量:2
3
作者 MA Shengde WANG Jianfeng 《Journal of Landscape Research》 2013年第6期27-28,共2页
Questionnaire survey and CVM were adopted to evaluate economic value of Huangshui Forest Park in Xining,Qinghai.Value of its forest landscapes was assessed,multiple linear regression was established to analyze correla... Questionnaire survey and CVM were adopted to evaluate economic value of Huangshui Forest Park in Xining,Qinghai.Value of its forest landscapes was assessed,multiple linear regression was established to analyze correlation between factors related to willingness-to-pay(WTP). 展开更多
关键词 LANDSCAPE value assessment WILLINGNESS-TO-PAY Huangshui forest PARK
下载PDF
Forest Ecosystem Services and Their Values in Beijing 被引量:21
4
作者 XIE Gaodi LI Wenhua +6 位作者 XIAO Yu ZHANG Biao LU Chunxia AN Kai WANG Jixing XU Kang WANG Jinzeng 《Chinese Geographical Science》 SCIE CSCD 2010年第1期51-58,共8页
As the most important ecosystem in Beijing, the forest supports a lot of ecosystem services to local and around communities, which plays a key role in the maintenance of urban ecological security.However, the valuatio... As the most important ecosystem in Beijing, the forest supports a lot of ecosystem services to local and around communities, which plays a key role in the maintenance of urban ecological security.However, the valuation on the forest ecosystem services based on regional scale could not provide precise and reasonable values for forestry sector management.In this study, we estimated the magnitudes and economic values of the forest ecosystem services in Beijing at sublot level.The economic value of forest ecosystem services in Beijing was estimated to be 19 339.71×10 6 yuan(RMB) in 2004.Among all the ecosystem services indicators we estimated in this study, only fruit, timber and part of the recreation(which only include the tourism income from the forest parks and scenic areas, but not include that from other forest types) were measured in the social economic system.As estimated in this study, more than 82.19% of the economic value of forest ecosystem services could not be measured in the socio-economic statistical system.The importance of forest ecosystem services in Beijing to human welfare was underestimated by the socio-economic system.Therefore, the policies about the eco-compensation of forest ecosystem services should be established to maintain the sustainable supply of the forest ecosystem services in Beijing. 展开更多
关键词 生态系统服务 森林生态系统 服务价值 北京 城市生态安全 经济价值 社会经济 部门管理
下载PDF
Value Assessment of Ecosystem Service Function of Ecological Public Welfare Forests in Wenchang City 被引量:1
5
作者 XUE Yang WANG Xiaoyan +2 位作者 SU Shaofeng LIN Zhipan LIN Mei 《Journal of Landscape Research》 2016年第4期59-62,共4页
Based on the measurement parameters and index in the Specifications for Assessment of Forest Ecosystem Services in China(LY/T 1721-2008),the value of ecological service functions of ecological public welfare forest in... Based on the measurement parameters and index in the Specifications for Assessment of Forest Ecosystem Services in China(LY/T 1721-2008),the value of ecological service functions of ecological public welfare forest in Wenchang City was evaluated and analyzed.The results show that the total value of ecosystem service function of ecological public welfare forests in Wenchang City is about 4.020 billion yuan,of which storage capacity,water purification,soil fixation,fertilizer(N,P and K fertilizer) conservation,carbon sequestration,oxygen release,forest nutrient accumulation,providing anion,absorbing SO_2,absorbing fluoride,absorbing NxO,absorbing soil heavy metals,dust retention,noise reduction,sterilization,forest protection,forest biodiversity protection,and forest recreation(ecological tourism) are about 1.510 billion,582.256 million,3.769 million,268.220 million,116.360 million,2.747 million,22.682 million,42.817 million,1.722 million,74,600,131,900,187.918 million,77.409 million,28.721 million,43.090 million,180.696 million,571.036 million,and 108.677 million yuan 展开更多
关键词 value assessment Ecosystem service function Ecological public welfare forest Wenchang City
下载PDF
THE ESTIMATE OF THE EFFECTIVE FUEL COMBUSTION VALUE OF FOREST COMMUNITY IN THE DAXINGAN MOUNTAIN
6
作者 刘自强 王希田 +1 位作者 陈大我 张明石 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1994年第1期59-63,共5页
Under the condition of absolute dry, more than thirty forest fuel pararneters,ash content. extract and burning point were measured. By the method of regression step by step. we found an experience formula which can es... Under the condition of absolute dry, more than thirty forest fuel pararneters,ash content. extract and burning point were measured. By the method of regression step by step. we found an experience formula which can estimate effective fuel high combusti on value of forest community from the Daxingan Mountain,and then,By means of modifying moisture content. we gave an approximate formula about actual heat releasing of forest fuels in the forest fire behavior. 展开更多
关键词 forest community Effective fuel Combustion value
下载PDF
Comparative Research on Zoning of High Conservation Value Forest and Ecological Forest
7
作者 ZHAO Jie HE Wei +1 位作者 LV Aihua WANG Hongchun 《Journal of Landscape Research》 2017年第1期75-79,共5页
High conservation value forest(HCVF) theory has aroused wide concerns among related forestry sectors in China,but the zoning and identification of HCVF only have been implemented in a few forest management units(FMUs)... High conservation value forest(HCVF) theory has aroused wide concerns among related forestry sectors in China,but the zoning and identification of HCVF only have been implemented in a few forest management units(FMUs). As there is no quantitative indicator for identifying and zoning HCVF in China,most FMUs are unable to have an exact zoning result. This paper introduced the concepts of HCVF and ecological forest,and compared their similarities and differences in terms of identification criteria,zoning methods and application scope. With four Chinese FMUs as case studies,some suggestions were proposed for establishing a zoning scheme of HCVF so as to promote the development of HCVF in China. 展开更多
关键词 High conservation value forest Ecological forest forest zoning Identification criteria China
下载PDF
Change of Forest Ecosystem Service Function and Its Value in Kanas Nature Reserve
8
作者 BAI Zhiqiang WANG Wendong +3 位作者 LI Huan LIU Duan GUO Zhongjun LIU Hua 《Journal of Landscape Research》 2019年第6期80-83,共4页
In order to clarify the service function and value of forest ecosystem in Kanas Nature Reserve, the ecological service function and its value of forest ecosystem in Kanas Nature Reserve in 2009 and 2014 were evaluated... In order to clarify the service function and value of forest ecosystem in Kanas Nature Reserve, the ecological service function and its value of forest ecosystem in Kanas Nature Reserve in 2009 and 2014 were evaluated by using the method of Specifications for Assessment of Forest Ecosystem Services in China(LY/T 1721-2008). The results showed that in 2014, the total value of forest ecosystem service function in Kanas Nature Reserve increased by 7.34% compared with that in 2009, and the value of water conservation and biodiversity accounted for the largest proportion. The increasing rate of functional value of shrub forest land was obviously higher than that of coniferous forest land and broad-leaf forest land. The service function and value of different forest types were obviously different. 展开更多
关键词 forest ECOSYSTEM service FUNCTION value assessment KANAS Nature RESERVE
下载PDF
Estimation of Biodiversity Conservation Value of Forest Ecosystem in Nyingchi Prefecture of Tibet
9
作者 Jia TANG Zhilan CHEN Jiangping FANG 《Asian Agricultural Research》 2017年第2期62-65,共4页
The estimation was made for the conservation value of forest ecosystem biodiversity in Nyingchi Prefecture of Tibet.The results showed that the annual economic benefits of biodiversity in Nyingchi Prefecture were abou... The estimation was made for the conservation value of forest ecosystem biodiversity in Nyingchi Prefecture of Tibet.The results showed that the annual economic benefits of biodiversity in Nyingchi Prefecture were about 21.4 billion yuan,and the annual economic benefits of global biodiversity were about 3 trillion USD.It indicated that the ecological value of forest ecosystem in Nyingchi Prefecture is high,forest ecosystem has extremely important ecological value.Therefore,in the decision-making process,it is necessary to strengthen the protection of forest ecosystem,with particular emphasis on the restoration of damaged ecosystem. 展开更多
关键词 BIODIVERSITY value estimation forest ecosystem Nyingchi Prefecture
下载PDF
Estimation of Economic Value of Agroforestry Systems at the Local Scale in Eastern Sudan
10
作者 Bashir Awad El Tahir Akshay Vishwanath 《Journal of Geoscience and Environment Protection》 2015年第9期38-56,共19页
The objective of this paper is to institute farmers’ own perceptions of the on-and off-farm benefits of agroforestry systems (AFS). Using use value approach, this paper presents empirical evidence on the use values o... The objective of this paper is to institute farmers’ own perceptions of the on-and off-farm benefits of agroforestry systems (AFS). Using use value approach, this paper presents empirical evidence on the use values of three types of AFS practiced by the refugees and their hosting communities in Eastern Sudan. The total economic value (TEV) was applied as a framework to estimate the ecosystem values of AFS under study. Goods values were estimated using specific market values, while the services values were qualitatively described according to local perceived values of the local communities. Perceived TEV of AFS includes marketable and non-marketable goods and services. The main direct marketable and sustainable high value products include: food, cash crops, firewood, gum, fodder, NTFPs medicine, fodder, and honey. The valuation results reveal that AFS in the project sites have significantly contributed to the livelihoods of the local communities. Overall, the average net direct-use value of marketable products across all sites was estimated at 7,346,000.0 SDG (1,335,636.36 US$) HH/annum. Gum Arabic alone accounted for 38%, followed by sorghum grain and fodder 35%, and cash crops (sesame) 18%. This value would be many time higher if other indirect values (non-marketable) services such as shade, aesthetic and recreation, environmental protection, biodiversity and carbon sequestration are quantified. The goods and services mentioned above provide sustainable income to the farmer directly and viable benefits to the region indirectly. Hence, AFS in the study sites shows the way to reconcile two conflicting goals: short-term food and livelihood needs with long-term environmental conservation and improvement. The study provides evidence that the high local perceived values of AFS in the study sites constitute a central means of livelihood, whereas its contribution to the local economy. The study stresses the need to quantify the monetary values of non-marketed products to consistently account for resource availability and usage to further sound policy decisions. Tenure security, farmer support services and human capital development were major areas identified for policy development. 展开更多
关键词 Local PERCEIVED valueS Marketable PRODUCTS Natural PRODUCTS Gum ARABIC Non-Timber forest PRODUCTS
下载PDF
Total Carbon Stock and Potential Carbon Sequestration Economic Value of Mukogodo Forest-Landscape Ecosystem in Drylands of Northern Kenya 被引量:1
11
作者 Nereoh C. Leley David K. Langat +2 位作者 Abdalla K. Kisiwa Geoffry M. Maina Meshack O. Muga 《Open Journal of Forestry》 2022年第1期19-40,共22页
Carbon sequestration is one of the important ecosystem services provided by forested landscapes. Dry forests have high potential for carbon storage. However, their potential to store and sequester carbon is poorly und... Carbon sequestration is one of the important ecosystem services provided by forested landscapes. Dry forests have high potential for carbon storage. However, their potential to store and sequester carbon is poorly understood in Kenya. Moreover, past attempts to estimate carbon stock have ignored drylands ecosystem heterogeneity. This study assessed the potential of Mukogodo dryland forest-landscape in offsetting carbon dioxide through carbon sequestration and storage. Four carbon pools (above and below ground biomass, soil, dead wood and litter) were analyzed. A total of 51<span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">(400</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">m<sup>2</sup>) sample plots were established using stratified-random sampling technique to estimate biomass across six vegetation classes in three landscape types (forest reserve, ranches and conservancies) using nested-plot design. Above ground biomass was determined using generalized multispecies model with diameter at breast height, height and wood density as variables. Below ground, soil, litter and dead wood biomass;carbon stocks and carbon dioxide equivalents (CO<sub>2eq</sub>) were estimated using secondary information. The CO<sub>2eq</sub> was multiplied by current prices of carbon trade to compute carbon sequestration value. Mean ± SE of biomass and carbon was determined across vegetation and landscape types and mean differences tested by one-way Analysis of Variance. Mean biomass and carbon was about 79.15 ± 40.22</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">TB</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">ha</span></span></span><span style="font-size:10px;"><span style="vertical-align:super;">-</span></span><span><span><span style="font-family:;" "=""><sup>1</sup> and 37.25 ± 18.89</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">TC</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">ha<sup><span style="font-size:10px;">-</span>1</sup> respectively. Cumulative carbon stock was estimated at 682.08</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">TC</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">ha<sup><span style="font-size:10px;">&#45;</span>1</sup>;forest reserve (251.57</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">TC</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">ha<sup>&#45;1</sup>) had significantly high levels of carbon stocks compared to ranches (209.78</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">TC</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">ha<sup><span style="font-size:10px;white-space:normal;">-</span>1</sup>) and conservancies (220.73</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">TC</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "="">ha<sup><span style="font-size:10px;white-space:normal;">-</span>1</sup>, <i>P</i> = 0.000). Further, closed forest significantly contributed to the overall biomass and carbon stock (58%). The carbon sequestration potential was about 19.9MTCO<sub>2eq</sub> with most conservative worth of KES 39.9B (US$40M) per annum. The high carbon stock in the landscape shows the potential of dryland ecosystems as carbon sink for climate change mitigation. However, for communities to benefit from bio-carbon funds in future, sustainable landscape management and restorative measures should be practiced to enhance carbon storage and provision of other ecosystem services.</span></span></span> 展开更多
关键词 Carbon Sequestration Carbon Stock Economic value Dryland forest-Landscape Kenya
下载PDF
Categorized Analysis of Forest Ecological Values in the China’s Conversion Cropland to Forest Program
12
作者 RONG Yanju YUAN Wenge +3 位作者 GU Jiancai LU Guiqiao ZHENG Jianwei WEN Zhehua 《Journal of Landscape Research》 2020年第6期21-29,34,共10页
The China’s Conversion Cropland to Forest Program(CCFP)is one of the largest national ecological construction programs,which has effectively improved ecological environment and produced large ecological benefi t.To p... The China’s Conversion Cropland to Forest Program(CCFP)is one of the largest national ecological construction programs,which has effectively improved ecological environment and produced large ecological benefi t.To provide references for further improving ecological benefi t of CCFP,we analyzed the features,differences and relationships of the categorized forest ecological“benefi t value”(B-V)s in 3 kinds of forest restoration ways in different regions in CCFP,using the data of Chinese Forest Ecosystem Research Network(CFERN)from 1999 to 2013 and the methods of the national standards of(LY/T1606-2003),(LY/T1721-2008)and(LY/T1952-2011).The result showed that annual B-Vs of unit area varied in the range of 3.5-10.0 e4 RMBs/hm2·a.Water conservation B-Vs and species conservation B-Vs are the 2 largest constituents,nutrient accumulation B-V was the least in total B-Vs.The B-Vs performed inconsistently among the forest restoration ways and different regions.The rank of average annual total B-Vs of unit area from high to low was“hillside forest conservation”,“returning cropland to forest”,“afforestation on suitable barren hills and wasteland”.Species conservation B-Vs and water conservation B-Vs in southern regions were higher than that of northern and northwestern regions in China.The hot and rainy regions could produce higher species conservation B-Vs.The regression analysis indicated that water conservation B-Vs had signifi cantly positive correlation with the relevant total B-Vs and positive correlation with the relevant atmosphere purification B-Vs whether in regional or in unit area scale.Unit area species conservation B-V was negatively correlated with the relevant nutrient accumulation B-Vs except the way of“afforestation on suitable barren hills and wasteland”.Regional total species conservation B-Vs had signifi cantly negative correlation with its relevant nutrient accumulation B-Vs except“hillside forest conservation”way.We suggest that suitable forest restoration ways must be selective according to the regional specifi c,B-V features and local ecological goals. 展开更多
关键词 Categorized analysis forest ecological benefi t value(B-V) Restoration way CFERN CCFP
下载PDF
Estimation of Relative Ecological Value of Returning Farmland to Forest & Mountain Enclosure for Grazing Prohibition——A case study in Yongxing Township of Jingyuan County,Gansu Province
13
作者 CHANG Zhao-feng CHEN Bin-pu +2 位作者 QIAO Juan CHANG Fang FAN Bao-li 《Animal Husbandry and Feed Science》 CAS 2013年第4期162-168,171,共8页
[Objective]Returning farmland to forest and mountain enclosure for grazing prohibition ecological effect and economy rationality were explored.[Methods]A case study of returning farmland to forest and barren hills gra... [Objective]Returning farmland to forest and mountain enclosure for grazing prohibition ecological effect and economy rationality were explored.[Methods]A case study of returning farmland to forest and barren hills grazing prohibition in Yongxing Township of Jingyuan County was used to discuss and estimate the relative ecological function and relative ecological value.[Results]1)The ecological value of the forest of returning farmland was far more than the sum of the ecological value of farm crops and the agricultural output,and also more than the national subsidy standard.So the state policy of returning farmland to forests is not only favorable to local eco-environment restoration,but also reasonable in economic development.2)The ecological value of mountain enclosure for grazing prohibition was less than the opportunity cost of prohibiting grazing,also less than the national subsidy standard.The sum of the relative ecological value of prohibiting grazing and the state subsidies was more than the opportunity cost of prohibiting grazing.However,the ecological value of new vegetation through returning farmland to forest project was greater than the China's average ecological value of grassland.[Conclusion]The relative ecological value can be used to solve the problems in the equivalent conversion among various ecological indexes and between ecological indexes and economic indexes. 展开更多
关键词 Returning farmland to forest Mountain enclosure for grazing prohibition Relative ecological function Relative ecological value Jingyuan County
下载PDF
A Review and Reflection of Value Account of Forest Resources
14
作者 Li Zhongkui Chen Shaozhi +3 位作者 Zhang Decheng Zhao Xiaodi Feng Qiya Wang Yu 《Journal of Environmental Science and Engineering(B)》 2016年第11期528-534,共7页
关键词 森林资源价值 资源价值核算 生态系统评估 生态系统服务 价值计算 指标体系 森林价值 社会效益
下载PDF
ASSESSMENT OF INDIRECT USE VALUES OF FOREST BIODIVERSITY IN YAOLUOPING NATIONAL NATURE RESERVE, ANHUI PROVINCE
15
作者 XUHui QIANYi +1 位作者 ZHENGLin PENGBu-zhuo 《Chinese Geographical Science》 SCIE CSCD 2003年第3期277-283,共7页
Direct use values of forest ecosystem have been recognized apparently due to its easy and convenient assessment, while indirect use values are usually neglected because they are not easy to be recognized by the public... Direct use values of forest ecosystem have been recognized apparently due to its easy and convenient assessment, while indirect use values are usually neglected because they are not easy to be recognized by the public. For a nature reserve with forest ecosystem, the most important economic values are the indirect use values, which provide human beings and other living things with beneficial services through ecological processes and functions. In this case study, a quantifying framework to estimate the annual indirect use values of forest ecosystem has been established in Yaoluoping National Nature Reserve based on alternative cost method and opportunity cost method. The ecological functions assessed in the study relate to six aspects: soil protection, water conservation, CO2 fixation, nutrient cycling, pollutant decomposition and disease and pest control. These ecological functions provide an economic value of 86.1×106 yuan (RMB) per year (US$10.37×106 ), which is 25 times higher than the opportunity cost for regular timber production. This study can contribute to the monetary assessment of indirect use values of forest biodiversity and to the conservation and sustainable use of nature reserves. 展开更多
关键词 间接评估 生物多样性 安徽 国家自然保护区 森林生态学 生态函数
下载PDF
Main Principles and Methods of Identification of High Conservation Value Forests in the Conditions of Mountainous Relief: Case of Armenia 被引量:2
16
作者 Zhirayr Vardanyan Tatyana Danielyan +1 位作者 George Fayvush Siranush Galstyan 《Journal of Life Sciences》 2017年第6期269-278,共10页
下载PDF
Dynamics of pH value and metal elements of rainfall within mixed forests in Japanese pine and cypress
17
作者 刘云国 曾光明 +6 位作者 Y.Katayama K.Nishimura A.Nakanishi H.Okazaki T.Anzai 李欣 G.Iwazubo 《中国有色金属学会会刊:英文版》 CSCD 2002年第3期549-554,共6页
The dynamics of forest ecology was studied. The pH values, electrical conductivities and concentrations of metal and nonmetal elements in rainfall, stream, through fall and stream flow were investigated based on the d... The dynamics of forest ecology was studied. The pH values, electrical conductivities and concentrations of metal and nonmetal elements in rainfall, stream, through fall and stream flow were investigated based on the data collected from a small mixed forest watershed of Pinus densifora sieb et Zucc, Pinus thunbergii Parh and Chamaecypari sobtusa sieb et Zucc ex Endl at Kiryu nature reserve and a small barren watershed at Jakujo nature reserve, Ootsu, Shiga, Japan. The results show that both the mixed forest ecosystems of pine and cypress and the soil draw from granite affect the pH values and metal elements of rainfall. And the contribution of the mixed forest is greater than that of the barren. Moreover, the amount of input of most elements is larger than that of output in the ecosystem, which shows the elemental accumulation in the related forest ecosystem. 展开更多
关键词 金属元素 松树 柏树 混和林 降水 pH值
下载PDF
Ecological Function Value of Tropical Forests in the Central Mountainous Areas of Hainan Island
18
作者 Jing GAO Zuguang ZHOU 《Asian Agricultural Research》 2013年第11期103-105,108,共4页
The integrated value of the ecological function of tropical forests in the central mountainous areas of Hainan Island was 33.064 8 billion yuan/a in 2010(soil improvement,soil consolidation,soil nutrient maintenance,w... The integrated value of the ecological function of tropical forests in the central mountainous areas of Hainan Island was 33.064 8 billion yuan/a in 2010(soil improvement,soil consolidation,soil nutrient maintenance,water storage and moisture regulation,water purification,carbon sequestration,oxygen releasing,air purification,biodiversity conservation,eco-tourism),equivalent to 16.1%of GDP in Hainan Province this year(205.212 billion yuan).The tropical forests in the central mountainous areas of Hainan Island make great contribution to Hainan Island's ecology,and play an important role in maintaining the stability of the ecological environment in Hainan Island.Through the understanding of major ecological function value of tropical forests,it is necessary to make people cherish the tropical forests in the central ecological function conservation areas of Hainan Province,and spontaneously throw themselves into the ecological environment protection and construction,to promote the rapid and sustainable development of construction in Hainan Province as an international tourism island. 展开更多
关键词 CENTRAL mountainous areas TROPICAL forestS Ecologi
下载PDF
An integrated method for matching forest machinery and a weight-value adjustment
19
作者 Dan Li 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第3期683-688,共6页
Proper matching of forestry machinery is important when raising mechanization levels for forestry production. In the matching process, forestry machinery needs not only expertise, but also improved methods for solving... Proper matching of forestry machinery is important when raising mechanization levels for forestry production. In the matching process, forestry machinery needs not only expertise, but also improved methods for solving problems. I propose combination of case-based reasoning (CBR) and rule-based reasoning (RBR) by calculating the similarity of quantitative parameters of various forestry machines in an analytical and hierarchical process. I calculated the similarity of machin-ery used in forest industries to enable better selection and matching of equipment. I propose a weight-value adjusting method based on sums of squares of deviations in which the individual parameter weights were modified in the process of application. During the process of system design, I put forward a design method knowledge base and generated a dynamic web reasoning framework to integrate the processes of forest industry machinery selection and weight-value adjustment. This enables expansion of the scope of the complete system and enhancement of the reasoning efficiency. I demonstrate the validity and practicability of this method using a practical example. 展开更多
关键词 forest industry machinery Selection and matching weight-value determination reasoning process integration method
下载PDF
Socioeconomic study and economic value of living fossil,Lingula sp.in mangrove ecosystem in Trat Province,Thailand 被引量:1
20
作者 Cheewarat Printrakoon Apiwan Kamlung-ek 《Chinese Journal of Population,Resources and Environment》 2013年第3期187-199,共13页
This paper is the first recorded economic value of living fossil,an evaluation of the basic economic value of Lingula,based on the direct utilization of households for food and sale.Twenty-one local fishermen who coll... This paper is the first recorded economic value of living fossil,an evaluation of the basic economic value of Lingula,based on the direct utilization of households for food and sale.Twenty-one local fishermen who collected Lingula in Trat Province were focused on by using interview questionnaires.The animal habitats are influenced by the encroachers'age,gender and harvest method.The total economic value in 2011 was around two million baht.Those who possess fishing gear and have more money can have greater access to the product The local communities in Nong Khunsong sub-district are successful in collecting the Lingula and in doing local business.The market channel analysis is conducted at local,provincial and national levels and short market chains are demonstrated in the form of a wholesale market in the Lingula trade.This represents significant consumption by the local communities.The study further recommends sustainable conservation and management efforts at a local scale. 展开更多
关键词 LIVING FOSSIL UTILIZATION MANGROVE forest value evaluation sustainable management
下载PDF
上一页 1 2 84 下一页 到第
使用帮助 返回顶部