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陕西境内的沙生植物集中分布在毛乌素沙地南缘的榆林市,包括榆阳、神木、横山、定边、靖边、府谷、佳县7个县区,东西长420公里,南北宽12-120公里,沙生植被总面积约有80万公顷。该地是我国沙生植物最重要的分布区之一,也是我国干旱、半干旱地区甚至是世界温带草原沙旱生灌木植物的分布中心,物种区域优势极为明显,现有野生及引种成功的沙生植物物种87科,200属,468种。保护好这些沙旱生植物物种,对于保护该区域的生物多样性,改善毛乌素沙地生态环境有着极为重要的现实意义。为了改善生态环境,保护沙生植物资源,国家在这一区域相继实施了天然林… 相似文献
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山东海岸在砂质海岸和基岩海岸的港湾沙滩上,分布着特殊意义的海岸沙生植被。植被的特点是:组成种类及结构简单,群落类型单纯,并具有显著的镶嵌性等特点。另外,因海岸沙滩生境条件特殊,生长的植物具有很强的抗旱、耐瘦、耐热、耐盐能力,且群落的自然演替缓慢。根据海岸沙生植被的特点和人为经济活动的作用,对本岸区沙生植被的恢复、发展和防止生态平衡失调等问题进行了生态评价,并从植物生态学的角度提出该地区的开发、利用及沙生植被的保护等问题的设想。 相似文献
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西北干旱荒漠区,属典型的温带大陆性极端干旱荒漠气候,境内气候多受戈壁、沙漠影响,霜冻、大风、沙尘暴及干热风等自然灾害频繁,沙生植被恢复显得尤为重要。枸杞因其具有耐干旱、耐盐碱、耐瘠薄、耐沙埋、经济价值高等特点,已经成为西北干旱地区沙生植被恢复利用中的首选树种,在改善生态环境、农业可持续发展中发挥着举足轻重的作用。沙生植被的恢复对于西部地区荒漠化加剧、草场退化问题改善具有重要意义,研究发现,枸杞能够很好地适应西部干旱少水的气候环境,并且具有很好的防风固沙作用,加之其巨大的经济效益,若能就这些特点,加以人为的协助,使其对沙生植被恢复作用的潜力予以充分发挥,必然为改善当地生态环境起到巨大作用。 相似文献
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福建平潭砂质海岸植物资源与研究进展 总被引：1，自引：0，他引：1
《林业调查规划》2017,(5)
考察福建平潭砂质海岸植物资源与植被、防护林研究等文献报道,了解平潭植物资源种类与分布,并结合实地考察,提出资源保护与合理利用的建议。结果认为,平潭砂质海岸植物资源主要包括防护林与天然沙生植被资源,共22科44属58种,其中药用植物22科42属34种;对平潭植物资源的研究主要为沿海生态构建中物种的配置;平潭砂质海岸具备优质的沙滩资源,可作为濒危沙生植物的保护与繁育基地。 相似文献
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山东半岛砂质海岸占全省海岸线的８０％。在砂质海岸和部分基岩海岸的沙滩上分布着特殊意义的海岸沙生植被，其组成种类有很强的抗旱、耐瘠薄、耐热、耐盐能力，对沿海防护林建设、改善生态环境有重大作用，本文在研究砂质海岸特点、沙生植被特征的基础上，对恢复、发展和保护沙生植被，防止生态平衡失调等问题进行了生态评价，并从生态学角度提出了砂质海岸的开发设想。 相似文献
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为加强滨海沙生植物资源保护与合理开发利用，在对海南岛滨海沙生植物资源调查的基础上，运用多维价值理论和层次分析法(AHP),构建海南岛滨海沙生植物开发利用综合评价模型，筛选出具有潜在开发或应用价值的植物。结果表明：海南岛滨海沙地共调查到沙生植物148种，隶属58科126属，其中最多的为禾本科，其次为豆科、菊科、莎草科、大戟科、旋花科，占总科数的38.3%;单科种占总科数的60.34%,除番薯属、苦荬菜属、九里香属、结缕草属、黄细心属、刀豆属、大戟属、刺葵属、蟛蜞菊属、藜属、月见草属、露兜树属、马齿苋属、飘拂草属、莎草属、薹草属、龙舌兰属、砂引草属外，其他108属均为单属单种，占总属数的85.71%;基于沙生植物5个准则层以及其涵盖的11个指标层因子综合评比，适应性强的热带沙地生长的本土植物有椰子、马鞍藤、长春花、露兜、仙人掌等；景观价值较高的有绿玉树、仙人掌、长春花、龙珠果、椰子、剑麻。本文研究结果可为海南岛滨海沙地植物配置、植被恢复以及开发利用提供科学依据。 相似文献
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沙生灌木切断机的设计 总被引：1，自引：0，他引：1
根据沙生灌木自身的特性研制了往复式沙生灌木切断机，该机的进料机构采用平顶输送链和不完全齿轮间歇强制进料，切削机构采用曲柄连杆带动刀具进行往复运动，实现对沙柳材的端向切削。试验结果表明，该机结构简单，安装方便，工作平稳，可以将沙生灌木加工成高质量、合格的木片，很好地解决了沙生灌木在切片过程中存在的质量问题。 相似文献
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民勤沙生植物园病害调查研究 总被引：1，自引：0，他引：1
沙生植物是分布在西北荒漠地区的重要植物种类。通过调查。描述了发生在民勤沙生植物园内１４种沙生植物上的１６种真菌病害，并对其症状，病原及寄主名称进行了简述，为防治病害提供了依据。 相似文献
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C. A. Campbell 《Agroforestry Systems》1993,22(1):17-24
This paper discusses the extent to which Australian agriculture is integrating trees into farming systems and concludes that while broad environmental awareness and concern may have increased, Australian agriculture exemplifies essentially the same attitudes to native vegetation as those held by the first European settlers. It is suggested that for real change to occur, land users require three key ingredients — commitment, knowledge and resources. The state of play with respect to each of these key factors is reviewed and suggestions for reform mooted. 相似文献
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Sophie Gachet Alain Leduc Yves Bergeron Thuy Nguyen-Xuan Francine Tremblay 《Forest Ecology and Management》2007
The aim of this study was to evaluate if and how the previous land use (here: agriculture versus forest) has influenced the floristic composition now observed in the understory of jack pine plantations of Abitibi-Temiscamingue (North-Eastern Canada). Floristic inventories were conducted in jack pine plantations which had been established on forest sites after logging and on sites previously utilized for agriculture. These were compared to one another and to inventories conducted in natural forests and on agricultural sites which had not (not yet) been planted with trees (old fields). The vegetation community composition of the sites is analysed using several multivariate techniques. Results show that the flora of plantations on old agricultural fields is markedly different than that of plantations established on sites which were previously forested and that the two types of plantation are unlikely to become floristically the same before the anticipated harvest time. Comparing old and young plantations and old fields in light of natural forests sites, we show that the previous land-use is a key determinant of future compositional differences in plantations. This must be considered when we evaluate the impact of establishing plantations on sites with different land-use histories. 相似文献
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主要通过研究密云水库水源保护区上游和消落区的不同特征植被在降雨产流后对产流水质进行化验分析,比较不同特征植被产流水质的优劣。结果表明:森林植被覆盖率高,人为活动干扰少的水质优良,反之水质就较差;消落区种草区产流水质优良,农业种植区水质最差,各项指标都超出饮用水标准。由此得出不同特征植被的产流水质与森林覆盖率有一定的正相关性,人为活动也对水质有较大影响。同时对如何更好地保持密云水库水质提出了合理化建议。 相似文献
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Weed suppression is an important reason for fallowing in swidden systems. Recently, in Laos, an increase in weeds and resulting increase in labor input has become a problem; however, causal factors influencing weed growth and weeding labor other than fallow period have yet to be fully examined. Therefore, an experimental research on swidden weeds, combining a forest survey and interviews with local farmers, was conducted in a mountain village in northern Laos where swidden agriculture is practiced as a major means of livelihood. Weed amount, weed composition and time required for weeding were found to be more influenced by fallow vegetation than fallow period. Bushy vegetation in a short fallow field was shown to lead to abundance of herbaceous weeds, resulting in higher labor input. There was a possibility that increases in some bamboo species were a cause of recent weed increases. Based on the results, we suggest that maintaining a minimum fallow period of forest fallowing, with fallow management to suppress bamboo and promote tree growth may be effective in reducing labor input in swidden agriculture. 相似文献
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高光谱遥感在植被特征识别研究中的应用 总被引：4，自引：0，他引：4
总结了高光谱遥感在植被物种识别、结构特征分析、理化信息提取等主要领域的应用研究现状; 分析了高光谱遥感在植被特征识别中所涉及的光谱特征优化、混合光谱分解、图像分类识别等关键性技术环节的最新进展; 剖析了目前研究中存在的主要问题, 并对今后的发展态势进行了展望。 相似文献
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Agroforestry is a traditional land use system that may contribute to the solution of environmental problems in agriculture. Agroforestry is the practice of deliberately integrating woody vegetation (trees or shrubs) with crops and/or animal systems to benefit from the resulting ecological and economic interactions. Recent research indicates that a wider adoption of agroforestry principles and practices is a key means by which the global agri-food sector might achieve more sustainable methods of food and fiber production by producing both economic benefits for farmers and environmental benefits for society. Agroforestry provides numerous provisioning, regulating, cultural and supporting ecosystem services and environmental benefits while promoting eco-intensification based on a more efficient use of the resources. Nevertheless, there is only little published recent information on the contribution of agroforestry to the environment in general and on climate change, carbon sequestration and forest fires in particular. In this special issue a number of articles are included that provide a kaleidoscope of the environmental benefits that agroforestry provides to the environment.
相似文献20.
黄土高原退耕还林条件下的土壤干化问题* 总被引：8，自引：0，他引：8
介绍了土壤干化的概念及其对黄土高原生态环境的严重危害和对退耕还林还草工程的不利影响 ,说明了黄土高原地区土壤干化现象的出现是树 (草 )种选择不当和过分追求经济效益的结果 ,论述了黄土高原的植被建设几十年来没有取得成效的原因在于人类活动的逆向作用 ,包括植被类型选择失当 ,群落生产力过高 ,忽视了生物多样性在植被恢复演替中的重要作用等。这些不合理的措施一方面导致了大面积低效低产林的形成 ,另一方面又恶化了植被赖以生存的水分生态条件 ,加速了土壤干化现象的出现。由于其对植被建设的严重不良影响 ,必然影响到黄土高原生态环境的重建 ,在此意义上 ,解决土壤干化问题是目前退耕还林 (草 )工程面临的最为关键的课题之一。 相似文献