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71.
我国大树移植的现状与对策 总被引:8,自引:0,他引:8
上世纪未,伴随我国城市建设和城市绿化高速发展而来的滥挖滥移大树的歪风吹遍中华大地,使我国脆弱的生态系统雪上加霜,严重破坏了大树原生地的生态环境,制造了一大堆城市“景观垃圾”,同时也突显了我国苗圃技术和苗圃建设严重滞后的现实。几年以来,作者利用工作之便,对广东、浙江、上海、福建、海南、湖南等地的部分苗圃和城市绿地就“大树移植”问题进行了调研,收集了大量的资料、数据和现场照片;着重分析了这股歪风的缘起、发展和危害;并就如何解决这一问题作了深入的探讨,提出了一些对策和建议。 相似文献
72.
文章介绍了可持续发展评价指标体系的概念、功能,可持续发展评价指标体系构建常用的系统法、目标法、归类法,指标设置应遵循的原则,指标权重的确定方法以及指标的综合评价方法和发展展望。 相似文献
73.
人工林可持续经营认证标准与指标问题 总被引:2,自引:0,他引:2
阐述了森林认证对于人工林可持续经营的必要性。依据黑龙江森工林区人工林经营实践和森林认证在该地区的发展情况,讨论了FSC原则和标准框架下本区域森林可持续经营认证的人工林标准与指标问题。认为标准与指标应该针对本区域天然林破碎严重,人工林树种单一、稳定性差、生长量低、生态效益不好等一系列问题,提出了人工林标准与指标的基本内容。 相似文献
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From a conceptual point of view, national forest management standards in Latin American countries have progressed significantly in recent years. Examples include the Costa Rican Standards and Procedures for Sustainable Forest Management and Certification, developed by the National Commission for Forest Certification and in Nicaragua, the National Institute of Forestry proposal of principles, criteria and indicators for sustainable forest management. In line with general approaches worldwide, these national standards primarily focus on the fulfillment of sound forest practice. There is comparatively little emphasis on the assessment of management outcomes or changes in key components of the eco- and social-systems that result from management impacts. Essentially, there is little emphasis on adaptive management, though arguments that management cannot be sustainable if it is not adaptive are persuasive. This study sought to contribute to the development of standards that include elements for adaptive management that define, communicate and evaluate sustainable forest management in Costa Rica and Nicaragua. Elements from the national standards and the CIFOR generic C&I template (predominantly focused on forest management outcomes) were used as a starting point. The basic research process consisted of three phases of evaluation (in-office, desk and field). The evaluations were carried out by multidisciplinary, international groups of experts in forest ecology, management and policy. This study demonstrated the value of forums and workshops that facilitate exchange between forest scientists and policymakers; the innovation and application of a practical, applicable and scientifically based methodology for developing national level C&I; and acceptance of this methodology by key players in the fields of forest management and policy. These experiences and the resulting proposals of C&I for the evaluation of ecologically sustainable forest management are expected to be used as points of reference for future development of forest policy in Costa Rica and Nicaragua, and to contribute to the overall understanding of C&I development processes in the region. 相似文献
76.
通过多年的园林苗圃试验与生产实践 ,对一些厦门地区常见的绿化树种的采种期、种子处理、种子贮藏、育苗方法及苗木抚育等种苗培育技术进行了较为全面的探讨 相似文献
77.
介绍园林有机废物变栽培基质的原因、过程,产品应用实例,表明园林有机废物变栽培基质是节约型园林绿化发展的新途径,具有较好的社会效益和生态效益。 相似文献
78.
Adenosine protects Sprague Dawley rats from high‐fat diet and repeated acute restraint stress‐induced intestinal inflammation and altered expression of nutrient transporters 下载免费PDF全文
C. Y. Lee 《Journal of animal physiology and animal nutrition》2015,99(2):317-325
This study investigated the effect of repeated acute restraint stress and high‐fat diet (HFD) on intestinal expression of nutrient transporters, concomitant to intestinal inflammation. The ability of adenosine to reverse any change was examined. Six‐week‐old male Sprague Dawley rats were divided into eight groups: control or non‐stressed (C), rats exposed to restraint stress for 6 h per day for 14 days (S), control rats fed with HFD (CHF) and restraint‐stressed rats fed with HFD (SHF); four additional groups received the same treatments and were also given 50 mg/l adenosine dissolved in drinking water. Fasting blood glucose, plasma insulin, adiponectin and corticosterone were measured. Intestinal expression of SLC5A1, SLC2A2, NPC1L1 and TNF‐α was analysed. Histological evaluation was conducted to observe for morphological and anatomical changes in the intestinal tissues. Results showed that HFD feeding increased glucose and insulin levels, and repeated acute restraint stress raised the corticosterone level by 22%. Exposure to both stress and HFD caused a further increase in corticosterone to 41%, while decreasing plasma adiponectin level. Restraint stress altered intestinal expression of SLC5A1, SLC2A2 and NPC1L1. These changes were enhanced in SHF rats. Adenosine was found to alleviate HFD‐induced increase in glucose and insulin levels, suppress elevation of corticosterone in S rats and improve the altered nutrient transporters expression profiles. It also prevented upregulation of TNF‐α in the intestine of SHF rats. In summary, a combination of stress and HFD exaggerated stress‐ and HFD‐induced pathophysiological changes in the intestine, and biochemical parameters related to obesity. Adenosine attenuated the elevation of corticosterone and altered expression of SLC5A1, NPC1L1 and TNF‐α. 相似文献
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文章从广州地区城市绿化工程投标工作的实践经验出发,简要总结回顾了广州地区城市绿化工程招投标历程,分析了目前招投标市场竞争中存在问题的主要表现形式及原因,提出了规范市场机制、加强职能部门监管、相关参与者依法依规、行业维护自律和企业内部强化管理等相应的解决途径,并提出了实施企业备案市场准入制度、严格审查资格条件、强调企业综合实力和加强招投标对工程造价的控制作用等建议。 相似文献