期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
种下一粒绿色种子——乌杜邦峡谷牧场保护区(ARBC)的公众环境教育
1
作者 Maurice A.Schwartz 常城 《环境教育》 2001年第5期23-25,共3页
导语:在美国,志愿者是社会生活中的一部分,在环境教育领域也是一样。在美国旧金山市,一个很小的民间自然保护区——乌杜邦峡谷牧场中就活跃着一批环境教育志愿者。这些志愿者的热情参与是这个小小民间环境组织运作成功的重要因素之一,... 导语:在美国,志愿者是社会生活中的一部分,在环境教育领域也是一样。在美国旧金山市,一个很小的民间自然保护区——乌杜邦峡谷牧场中就活跃着一批环境教育志愿者。这些志愿者的热情参与是这个小小民间环境组织运作成功的重要因素之一,也许大家在阅读中会得到一些启发。 展开更多
关键词 公众环境教育 乌杜邦峡谷牧场保护 环境保护
下载PDF
内蒙古自治区成立初期防治荒漠化的努力 被引量:2
2
作者 于永 《广播电视大学学报(哲学社会科学版)》 2006年第1期100-103,共4页
内蒙古自治区成立初期,基于日常生产、生活的经验教训,对环境恶化问题有了比较深的感性认识,采取了一系列措施防治荒漠化。东部的内蒙古自治区政府在1951年、西部的绥远省政府在1952年先后落实“保护牧场、严禁开荒政策”,封闭了不宜耕... 内蒙古自治区成立初期,基于日常生产、生活的经验教训,对环境恶化问题有了比较深的感性认识,采取了一系列措施防治荒漠化。东部的内蒙古自治区政府在1951年、西部的绥远省政府在1952年先后落实“保护牧场、严禁开荒政策”,封闭了不宜耕作的土地。东部内蒙古自治区政府从1949年、西部绥远省政府从1950年,开始封山育林,植树造林。鉴于河水泛滥的巨大危害,东部内蒙古自治区政府从1948年、西部的绥远省政府从1950年,开始整治河道。东部重点整治了西辽河,西部重点整治了内蒙古境内的黄河,上述努力均产生了很好的防治效益。 展开更多
关键词 保护牧场 严禁开荒 植树造林 整治河道 荒漠化防治
下载PDF
Decline of Traditional Landscape in a Protected Area of the Southwestern Alps:the Fate of Enclosed Pasture Patches in the Land Mosaic Shift 被引量:1
3
作者 Matteo GARBARINO Emanuele SIBONA +1 位作者 Emanuele LINGUA Renzo MOTTA 《Journal of Mountain Science》 SCIE CSCD 2014年第2期544-554,共11页
【Title】【Author】【Addresses】1Traditional landscape elements such as pasture patches enclosed in a forest matrix are progressively disappearing throughout the European Alps. We assessed the land mosaic shift of a p... 【Title】【Author】【Addresses】1Traditional landscape elements such as pasture patches enclosed in a forest matrix are progressively disappearing throughout the European Alps. We assessed the land mosaic shift of a protected area located in the western Italian Alps. In particular, the dynamics of pasture patches were studied at both landscape and stand level. Land-cover mapping through object-oriented analysis of historical aerial photographs was used to assess land-cover changes between 1954 and 2000. Spatial statistics were used to quantify landscape patterns, and field samplings within pasture patches were used to explore tree regeneration structure and composition. Our results showed a significant increase in the number of pasture patches caused by their fragmentation following forest expansion. The total surface area of pasture patches decreased by 43% and their core area decreased by 94%. The encroachment of trees on less accessible areas of the pasture patches caused a reduction of patch shape at landscape scale. The gap filling process started 40-50 years ago and began with an early invasion of light demanding species like sycamore maple (Acer pseudoplatanus L.) and common ash (Fraxinus excelsior L.), followed by European beech (Fagus sylvatica L.) and secondarily silver fir (Abies alba Mill.). Traditional land-use and population decline in the Pesio Valley led to a reduction in ecotone areas. A transition to a more homogeneous landscape is expected in the next decades. Given the cultural and productive nature of these mountain meadow-pasture communities, extensive livestock grazing systems could be used to manage their future conservation. 展开更多
关键词 Landscape structure Secondary succession Historical ecology Pesio Valley Traditional land-use
下载PDF
Pore Size Distribution as a Soil Physical Quality Index for Agricultural and Pasture Soils in Northeastern Iran 被引量:4
4
作者 H.SHAHAB H.EMAMI +1 位作者 G.H.HAGHNIA A.KARIMI 《Pedosphere》 SCIE CAS CSCD 2013年第3期312-320,共9页
Assessment of soil quality is important for optimum production and natural resources conservation. Agricultural and pasture soil qualities of Deh-Sorkh region located at south of Mashhad, northeastern Iran were assess... Assessment of soil quality is important for optimum production and natural resources conservation. Agricultural and pasture soil qualities of Deh-Sorkh region located at south of Mashhad, northeastern Iran were assessed using the integrated quality index (IQI) and Nemero quality index (NQI) models in combination with two datasets, i.e., total data set (TDS) and minimum data set (MDS). In this study 6 soil properties considered as MDS were selected out of 18 properties as TDS using principle component analysis. Soil samples were divided into 3 groups based on optimum ranges of 8 soil physical quality indicators. Soil samples with the most indicators at optimum range were selected as group 1 and the samples having fewer indicators at optimum range were located in groups 2 and 3. Optimum ranges of soil pore size distribution functions were also determined as soil physical quality indices based on 8 soil physical quality indicators. Pore size distribution curves of group 1 were considered as the optimum pore size functions. The results showed that relatively high organic carbon contents could improve pore size distribution. Mean comparisons of soil physical quality indicators demonstrated that mean weight diameter of wet aggregates, structural stability index, the slope of moisture retention curve at inflection point, and plant available water content in agricultural land use decreased significantly in relation to pasture land use. In addition, the results demonstrated that the studied MDS could be a suitable representative of TDS. 78% of pasture soils had the optimum pore size distribution functions, while this parameter for agricultural soils was only 13%. In general, the soils of the studied region showed high limitations for plant growth according to the studied indicators. 展开更多
关键词 integrated quality index land use minimum data set Nemero quality index soil quality
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部