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931.
油页岩废渣场植林修复过程中的土壤微生物生态   总被引:9,自引:1,他引:9  
对广东茂名油页岩工业固体废物堆置场裸露灰渣地与植林1年和16年灰渣地试验区的理化性质、土壤微生物数量及其生化活性进行对比分析。结果表明:植林16年的试验区土壤可培养微生物总数比裸地对照提高了约20倍,脲酶、磷酸酶、蔗糖酶活性以及土壤呼吸速率都明显增强,土壤理化性质也有所改善;但植林1年的试验区与裸地对照相差不大,在营林改造中,大叶相思对土壤改良效果要比桉树好。表2参11。  相似文献   
932.
彭羽  蒋高明  张倩 《生态环境》2006,15(3):551-554
运用生态系统能量10%定律,在浑善达克沙地退化生态系统,按照高级营养级能量需求,在实验区域1%的土地上建立了高产高效饲料基地,以向上一营养级(草食动物)提供足够的能量。结果表明,牲畜的压力逐步向高效地(小范围的土地)集中,而大面积的退化草地(99%),在围栏保护后借助自然力逐步恢复。群落生物量、平均高度和总盖度2年后均随恢复时间增加而增加(P<0.05)。植被组成方面,恢复前固定沙地以冷蒿(Artemisiafrigida)、糙隐子草(Cleistogenssquarrosa)和寸草苔(Carexduriuscula)等为主,恢复2年后冰草(Agropyronmichnoi)、木地肤(Kochiaprostrata)等占优势;滩地植被中,羊草(Leymuschinensis)、披碱草(Elymusdahuricus)等逐步取代了灰绿藜(Chenopodiumglaucum)和尖头叶藜(Chenopodiumacumi-natum)等,优质牧草比例提高。生态恢复不仅使自然生态系统得以保护,而且带动了社会经济的发展,项目中的正蓝旗巴音胡舒嘎查牧民,在实验示范以前后,由每年每户投入1万元买草养畜转变为每户得到2万斤优质牧草;幼畜成活率约提高10%;产奶量100%,牧民收入提高了32%。实验表明,高产高效基地建成后,生态系统能量流动趋于稳定,占试验区域71%的退化草地得到了恢复,从而带动了该地的可持续发展。  相似文献   
933.
Feral Goat Eradications on Islands   总被引:4,自引:0,他引:4  
Abstract:  Introduced mammals are major drivers of extinction. Feral goats ( Capra hircus ) are particularly devastating to island ecosystems, causing direct and indirect impacts through overgrazing, which often results in ecosystem degradation and biodiversity loss. Removing goat populations from islands is a powerful conservation tool to prevent extinctions and restore ecosystems. Goats have been eradicated successfully from 120 islands worldwide. With newly developed technology and techniques, island size is perhaps no longer a limiting factor in the successful removal of introduced goat populations. Furthermore, the use of global positioning systems, geographic information systems, aerial hunting by helicopter, specialized hunting dogs, and Judas goats has dramatically increased efficiency and significantly reduced the duration of eradication campaigns. Intensive monitoring programs are also critical for successful eradications. Because of the presence of humans with domestic goat populations on large islands, future island conservation actions will require eradication programs that involve local island inhabitants in a collaborative approach with biologists, sociologists, and educators. Given the clear biodiversity benefits, introduced goat populations should be routinely removed from islands.  相似文献   
934.
Postfire Management on Forested Public Lands of the Western United States   总被引:1,自引:0,他引:1  
Abstract:  Forest ecosystems in the western United States evolved over many millennia in response to disturbances such as wildfires. Land use and management practices have altered these ecosystems, however, including fire regimes in some areas. Forest ecosystems are especially vulnerable to postfire management practices because such practices may influence forest dynamics and aquatic systems for decades to centuries. Thus, there is an increasing need to evaluate the effect of postfire treatments from the perspective of ecosystem recovery. We examined, via the published literature and our collective experience, the ecological effects of some common postfire treatments. Based on this examination, promising postfire restoration measures include retention of large trees, rehabilitation of firelines and roads, and, in some cases, planting of native species. The following practices are generally inconsistent with efforts to restore ecosystem functions after fire: seeding exotic species, livestock grazing, placement of physical structures in and near stream channels, ground-based postfire logging, removal of large trees, and road construction. Practices that adversely affect soil integrity, persistence or recovery of native species, riparian functions, or water quality generally impede ecological recovery after fire. Although research provides a basis for evaluating the efficacy of postfire treatments, there is a continuing need to increase our understanding of the effects of such treatments within the context of societal and ecological goals for forested public lands of the western United States.  相似文献   
935.
1995-2004年河北省生态足迹分析与生态恢复措施   总被引:6,自引:0,他引:6  
高太忠  范勤  李秀荣 《生态环境》2007,16(2):609-612
生态足迹从具体的生物物理量角度研究自然资本消费的空间,为核算地区自然资本利用状况提供简明框架,进而可判断区域可持续发展状态。河北省正大力实施可持续发展战略,但在绿色战略问题上还面临一些难题。文章利用生态足迹模型,对河北省1995—2004年的生态足迹进行了时间序列的测度以及可持续发展的定量测算,根据计算结果进行分析提出相应对策。结果表明,10年间河北省的人均生态足迹增长率达47.9%,赤字增长率达58.5%,人类负荷超过其生态容量,生态承载力严重不能满足生态足迹的需求,区域的经济社会发展处于一种不可持续的发展状。从而加深了对河北省可持续发展状况的认识,对生态建设决策提供科学依据,并提出河北省生态恢复的措施。  相似文献   
936.
截污后深圳河落马洲段大型底栖动物群落的恢复过程   总被引:1,自引:0,他引:1  
2000年4月至2002年4月,对截污前后的深圳河落马洲段大型底栖动物进行两周年的季度监测.结果表明,截污前深圳河落马洲段没有发现大型底栖动物;截污后大型底栖动物种数、密度、生物量和种类多样性指数(H′)有随时间推移呈增加的趋势;截污后底泥中硫化物、总氮、总磷随时间推移呈下降趋势.由此可见,截污后深圳河落马洲段大型底栖动物从无到有,种数、密度和生物量从少到多,群落结构处于向多样性恢复的过程中.图6表2参11  相似文献   
937.
滇池湿地生态恢复研究   总被引:4,自引:1,他引:4  
湿地是一种特殊的土地资源和生态环境,开垦湿地和改变用途会引发一系列生态恶果。目前,滇池湿地面积大减,生态功能减弱,应抓紧时机,恢复重建滇池湿地,以维持其整体生态功能,促进整个滇池生态环境的恢复。  相似文献   
938.
1IntroductionNatureinitsbenevolenceproducedcomplexandinterelatedenvironmentalsystems,bothbioticandabiotic,whosefunctioningisc...  相似文献   
939.
Evaluating stream restoration projects   总被引:2,自引:3,他引:2  
River and stream restoration projects are increasingly numerous but rarely subjected to systematic postproject evaluation. Without conducting such evaluation and widely disseminating the results, lessons will not be learned from successes and failures, and the field of river restoration cannot advance. Postproject evaluation must be incorporated into the initial design of each project, with the choice of evaluation technique based directly upon the specific project goals against which performance will be evaluated. We emphasize measurement of geomorphic characteristics, as these constitute the physical framework supporting riparian and aquatic ecosystems. Techniques for evaluating other components are briefly discussed, especially as they relate to geomorphic variables. Where possible, geomorphic, hydrologic, and ecological variables should be measured along the same transects. In general, postproject monitoring should continue for at least a decade, with surveys conducted after each flood above a predetermined threshold. Project design should be preceded by a historical study documenting former channel conditions to provide insights into the processes suggest earlier, potentially stable channel configurations as possible design models.  相似文献   
940.
A new method of assessing cumulative effects of human activities on bird and mammal communities of riparian-wetland areas was developed by using response guilds to reflect how species theoretically respond to habitat disturbance on a landscape level. All bird and mammal species of Pennsylvania were assigned values for each response guild using documented information for each species, to reflect their sensitivity to disturbances; high guild scores corresponded to low tolerance toward habitat disturbance. We hypothesized that, given limited time and resources, determining how wildife communities change in response to environmental impacts can be done more efficiently with a response-guild approach than a single-species approach. To test the model, censuses of birds and mammals were conducted along wetland and riparian areas of a protected and a disturbed watershed in central Pennsylvania. The percent of bird species with high response-guild scores (i.e., species that had specific habitat requirements and/or were neotropical migrants) remained relatively stable through the protected watershed. As intensity of habitat alteration increased through the disturbed watershed, percentage of bird species with high response-guild scores decreased. Only 2%–3% of the neotropical migrants that had specific habitat requirements were breeding residents in disturbed habitats as compared to 17%–20% in reference areas. Species in the edge and exotic guild classifications (low guild scores) were found in greater percentages in the disturbed watershed. Composition of mammalian guilds showed no consistent pattern associated with habitat disturbance. Avian response guilds reflected habitat disturbance more predictively than mammalian response guilds.  相似文献   
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