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101.
城市土地利用下的植物物种资源特征分析   总被引:14,自引:0,他引:14  
江源  刘硕 《自然资源学报》1999,14(4):359-362
根据对前联邦德国卡尔斯鲁厄市城市自生植被的调查资料,分析了城市植物区系的特征及其与人类活动影响的关系。结论为:①城市植物区系在优势科组成和生态特征方面与其所在地区自然植被明显不同,并在城市之间表现出较大的相似性;②人类活动和城市热岛效应对城市植物区系及其生态特征的作用明显;③城市土地利用和城市绿地管理对许多物种的生存构成威胁  相似文献   
102.
安太堡露天矿南排土场滑体植被治理技术   总被引:1,自引:0,他引:1  
论述了安太堡矿南排土场滑体整治模式,通过植被减少滑体侵蚀及水土流失,改善了滑体的生态景观,对滑体安全起到了良好作用。  相似文献   
103.
本文探讨了一个通过土壤有效水分含量来确定土地等级和土地生产力的方法。这个方法采用倍增参量形式来确定土壤有效水分。其变量包括潜水位、土层厚度、土壤质地、坡度和盐分。此项研究证明用这种方法获得的土地初级生产力与实测值比较一致。因此,我们可以在类似环境下用这种方法估测土地生产潜力。  相似文献   
104.
Conservation easements are a standard technique for preventing habitat loss, particularly in agricultural regions with extensive cropland cultivation, yet little is known about their effectiveness. I developed a spatial econometric approach to propensity‐score matching and used the approach to estimate the amount of habitat loss prevented by a grassland conservation easement program of the U.S. federal government. I used a spatial autoregressive probit model to predict tract enrollment in the easement program as of 2001 based on tract agricultural suitability, habitat quality, and spatial interactions among neighboring tracts. Using the predicted values from the model, I matched enrolled tracts with similar unenrolled tracts to form a treatment group and a control group. To measure the program's impact on subsequent grassland loss, I estimated cropland cultivation rates for both groups in 2014 with a second spatial probit model. Between 2001 and 2014, approximately 14.9% of control tracts were cultivated and 0.3% of treated tracts were cultivated. Therefore, approximately 14.6% of the protected land would have been cultivated in the absence of the program. My results demonstrate that conservation easements can significantly reduce habitat loss in agricultural regions; however, the enrollment of tracts with low cropland suitability may constrain the amount of habitat loss they prevent. My results also show that spatial econometric models can improve the validity of control groups and thereby strengthen causal inferences about program effectiveness in situations when spatial interactions influence conservation decisions.  相似文献   
105.
Land systems are described based on various characteristics, including land cover composition and agricultural production. However, it is uncertain to what extent livestock, particularly monogastric livestock, determines land systems. We included monogastrics in a land system classification, and statistically analyzed the land cover composition and agricultural production of otherwise similar land systems with and without monogastric livestock. The results indicate that land systems with monogastrics are statistically different from their counterparts in the classification without monogastrics in terms of grassland area and crop yields, but are less different in terms of tree area, crop area, and ruminant livestock production. We then used a land systems map that includes monogastrics in the classification and a similar map that does not include monogastrics to project future changes in a novel manner that integrates livestock as a determinant of land systems. The results show that including monogastrics in otherwise similar projections yields less cropland intensification and more cropland expansion in several world regions, including Northern Africa and the Middle East. Other regions, such as Europe and Australia, were characterized by less decrease or more increase in tree area in the application with monogastrics, mainly due to the occurrence of open forests with monogastrics. This study prompts a call for improved characterization of land systems for land use and cover change (LUCC) assessments in order to better represent LUCC driven by monogastric livestock.  相似文献   
106.
Land use/land cover (LULC) change affects the provision of ecosystem services for humans and habitat for wildlife. Hence, it is crucial to monitor LULC particularly adjacent to protected areas. In this study, we measured LULC change in Rombo, Tanzania, an area with high-potential agro-ecological zones that is dominated by human–elephant conflicts (HECs). We used remote sensing and geographical information system techniques, questionnaires and village meetings to assess spatio-temporal patterns of the LULC changes in the study area. Using Landsat imagery, digital elevation model (DEM) and ground truthing, we classified and monitored changes in LULC from the years 1987 to 2015. We found that within Rombo, settlements were increasing, while agricultural and agroforestry lands were decreasing and respondents’ perceptions varied along the altitudinal gradient. Patterns of HEC and LULC were observed to change along the gradient and the later threatened the agricultural land and ecological integrity for elephant habitat, leading to high tension and competition between elephants and people. This research offers baseline information for land use planning to balance wildlife conservation with livelihood development in Rombo and highlights that managing the impacts of LULC changes on HEC and elephant habitat loss is a matter of urgency.  相似文献   
107.
破坏耕地行为有违宪法、刑法和民法等规定,但无可直接引用的破坏耕地罪专门条款。应以附属刑法的方式设立破坏耕地罪。论述了破坏耕地罪的概念和构成及其刑事责任,并指出适用破坏耕地罪时应注意的问题,如罪与非罪的界限以及破坏耕地罪与侵占土地罪、破坏土地资源罪、破坏自然资源罪等的界限。  相似文献   
108.
目前耕地“占用”严重,有必要从法律上界定耕地“转用”,建立耕地转用许可法律制度,按合法,公开,效率,合理原则和法定程序确定耕地转用。  相似文献   
109.
Eco-environmentalinformationsystemofTianjinCity─Design,implementationandapplicationsHuXiaolin;YangBangjie;ZongYaoguang;LuLi(R...  相似文献   
110.
海南省旅游地评价及其开发研究   总被引:9,自引:2,他引:9  
旅游地资源评价和开发研究,是进行旅游开发宏观决策,确定对应的旅游活动类型和接待规模,指导旅游市场开发与景区、景点设计时一项重要的基础研究工作。本文以海南省为例,对旅游地资源的评价制图和旅游开发用地预测方法,进行了有益的探讨。  相似文献   
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