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1.
Public interest prompted the California State Legislature to provide needed authority and precedent-setting mandates for the management and protection of its non-game wildlife resources. Newly established activities and regulations include: research and field surveys on species-specific problems; the introduction of protective categories for threatened or unique species; bag limits and seasons on the taking of any unprotected animal; a moratorium on mountain lion hunting; measures to promote increases in the numbers of the rare Tule elk; curtailment of imported wildlife; a ban on the trade in endangered species; protective measures for intertidal organisms; and land acquisition of areas with important habitats. These constitute a comprehensive programme that merits wider adoption in the USA.  相似文献   

2.
Agricultural intensification in Northern Ireland has brought about large-scale changes to the landscape with a detrimental effect on biodiversity. Between 1996 and 1998, we surveyed a stratified random sample of 1 km squares for bats using a spot-sample technique and time expansion bat detector to establish linear and area habitat associations. Bats strongly selected water bodies with bankside vegetation, treelines, and deciduous and mixed woodland edge, avoiding open areas such as upland/unimproved grassland and improved grassland. Of three sympatric pipistrelle species (Pipistrellus pipistrellus, P. pygmaeus and P. nathusii), two were shown to forage in different habitats; P. pipistrellus being more of a ‘generalist’, foraging in a wider variety of habitats than P. pygmaeus, a ‘specialist’ which foraged in a smaller range of habitats. Nyctalus leisleri selected parkland/amenity grassland, deciduous woodland edge and rivers/canals and avoided improved grassland, hedgerows, whilst Myotis spp. selected deciduous woodland centre, lake/reservoir margins and rivers/canals. Reduction in area and quality of inland water, deciduous woodlands and field boundaries in Northern Ireland may impact on bat populations. Habitat management should focus on improving those habitats which are selected by bats, including the maintenance and enhancement of connecting linear habitats.  相似文献   

3.
One of the most important, and yet difficult, conservation problems in the world is the conservation of lowland tropical rain-forest, that of south-east Asia probably being the most complex terrestrial ecosystem which has ever existed. In West Malaysia such forest is rapidly being cleared, due to a high rate of national development largely consequent upon tremendous population growth. Reasons why the rain-forest is threatened, and why some should be conserved, are given. The current conservation situation is outlined, and future prospects are discussed. Finally, the writer, whilst acknowledging that it is obviously right for the exploitation and conservation of Malaysia's resources to be fully controlled by the Malaysian people, lists those areas in which he believes the international community can assist in this great conservation task.  相似文献   

4.
Soil degradation threatens environmental quality and sustainable food production. As a result of efforts to promote soil conservation, farmers in Canada are thought to be reasonably aware of both the importance of conservation and the existence of remedial and preventive practices. Despite this, the adoption of conservation practices has been less than overwhelming. Forces other than awareness and positive attitude seem to be constraining many land managers from employing available conservation methods. This paper presents the findings from an empirical investigation of the use of soil conservation practices and barriers to their adoption in the southwestern region of Ontario, Canada. The analysis is set in the context of literature on technology adoption. A scheme for measuring farm-level conservation effort is developed, and barriers to adoption are derived from an analysis of a range of independent physical, personal, and economic factors, and from the obstacles or constraints identified by producers themselves. Key barriers relate to economic pressures, the complexity and compatibility of practices, and perceptions regarding the actual need for practices. The findings have relevance for the design of public policies and programs, notably the importance of supplying information on farm-level implications of conservation methods and the need for a stable economic environment for agriculture to allow longer-term planning.  相似文献   

5.
In response to the dust bowls of the mid-thirties in the USA, soil and water conservation programmes involving reduced tillage were promoted to control land degradation, particularly soil erosion. The farming and land management practices that were considered to adequately address soil and water conservation objectives were based on no-till seeding and maintenance of soil mulch cover. This collection of practices led to what became known as conservation tillage, although no-till systems by definition avoid soil disturbance by no-till direct seeding, and maintain an organic mulch cover on the soil surface.This article is an overview of achievements in soil and water conservation on agricultural lands through the experience derived from the adoption and spread of Conservation Agriculture (CA) world-wide. CA is an agro-ecological approach to sustainable production intensification. It involves the application of three inter-linked principles that underpin agricultural production systems based on locally formulated practices: (i) permanent no or minimum mechanical soil disturbance, which in practice entails direct seeding through mulch into no-till soils; (ii) maintenance of soil cover with crop residues and green manure crops, particularly legumes; and (iii) diversified cropping system involving annuals and perennial in rotations, sequences and associations.In 2011, CA had spread over 125 million hectares (9% of the global cropped land) across all continents and most agro-ecologies, including small and large farms. In addition, there is a significant area of CA orchards in the Mediterranean countries. CA is now considered to be a practical agro-ecological approach to achieving sustainable agriculture intensification. It offers environmental, economic and social advantages that are not fully possible with tillage-based production systems, as well as improved productivity and resilience, and improved ecosystem services while minimizing the excessive use of agrochemicals, energy and heavy machinery. While there are challenges to the adoption of CA, there is also increasing interest from producers, the civil society, donors and private sector institutions to further promote and service the uptake and spread of CA globally.  相似文献   

6.
Effective biodiversity conservation requires an analysis of the existing reserve system. In temperate and boreal regions, plant diversity has a strong positive association with soil pH. Consequently, in order to protect plant diversity effectively, a relatively large proportion of protected areas should be on high pH soils. Since biodiversity data are never complete for all taxa, biodiversity indicators, e.g., threatened species, should be used. We studied soil pH distributions in protected areas in Northern Europe and tested whether soil pH requirement differs between threatened and non-threatened bryophyte and vascular plant species. As result, the proportion of high pH soils in protected areas was significantly greater than the proportion of these soils in general. This ensures that a large regional pool of plant species preferring high pH soils is relatively well protected. Threatened and non-threatened species in Northern Europe did not differ in their soil pH requirements, but threatened species required a narrower soil pH range than non-threatened species. Consequently, threatened species diversity can be used for indicating overall plant diversity.  相似文献   

7.
8.
The identification of priority sites that ensure the achievement of conservation goals is key to direct conservation efforts. An estimation of the level of vulnerability of each priority area allows the identification of sites that need urgent conservation action. We present a systematic reserve selection for 1654 African mammals and amphibians that uses habitat suitability models as estimates of the area occupied by each species. These are based on the geographic range and habitat preferences for each species, which we collected in the framework of the World Conservation Union (IUCN) Global Amphibian Assessment and IUCN Global Mammal Assessment. Our results showed that in addition to existing protected areas, approximately 2.8 million km2 of land is irreplaceable to achieve the protection of 10% of the area occupied by all amphibians and mammals. This figure is higher than previous estimates from other studies. Most irreplaceable sites are located in the sub-Saharan region. More than half (55%) of the irreplaceable sites have high human population density; for only 17% the human population density is low. African amphibians and mammals have therefore to be conserved in densely populated areas where innovative management policies will be required to accommodate conservation successfully.  相似文献   

9.
Previously, there has not been any in situ conservation sites for crop germplasm within the United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Plant Germplasm System (NPGS). Using morphologic and molecular (SSR markers) techniques, we assessed the genetic variation present in populations of rock grape (Vitis rupestris Scheele), a native American grape species, throughout its range. We identified seven in situ conservation sites for rock grape using a strategy based on morphologic and molecular data, taxonomic information, population size and integrity, and landholder commitment. In collaboration with federal and state landholding agencies, we have established the first NPGS in situ conservation sites for American wild relatives of a crop.  相似文献   

10.
Information on breeding waterfowl, habitat and food chains, gathered from acid-sensitive lakes in Ontario, was used to develop a model of effects of acid deposition on waterfowl and their response to predicted sulphur dioxide (SO2 emission reductions in eastern North America. The Waterfowl Acidification Response Modelling System (WARMS) is composed of an acidification model linked to fish and waterfowl models. WARMS uses pH, area, dissolved organic carbon, total phosphorus, and presence of fish to calculate estimates of pre-acidification, present and eventual steady-state values for pH, fish presence and waterfowl breeding parameters under proposed SO2 emission scenarios. We used WARMS to estimate chemical and biotic responses to scenarios simulated in three regions of Ontario where biomonitoring studies are underway. For pH and fish presence, WARMS predicts the greatest improvements in the highly damaged Sudbury region, slight improvements in Algoma, and that the strongest proposed emission reductions will be required to maintain current conditions in Muskoka. For waterfowl, species-specific differences are evident among regions. We discuss implications of these assessments of biological recovery for watersheds in eastern Canada.  相似文献   

11.
中国北方保护性耕作条件下深松效应与经济效益研究   总被引:53,自引:19,他引:53  
保护性耕作技术是适应中国北方农业发展的一种新型耕作技术,它可以通过深松作业来消除因多年免耕出现的土壤变硬问题。目前对保护性耕作条件下深松的效应和经济效益缺乏深入的研究,在玉米深松过程中还出现的伤苗,功耗大和经济效益低等问题。该文试验研究了在中国北方保护性耕作示范基地上,从1993年开始,通过10多年的时间对保护性耕作条件下的深松效应,测定了传统耕作、深松覆盖和免耕覆盖3种不同耕作方式下的土壤容重、含水率,水分利用率和产量等数据,试验结果表明,在保护性耕作条件下,每4年对土壤深松一次可以解决土壤变硬问题,持续保持作物高的水分利用率和产量,并不需要年年深松。相对深松覆盖(年年深松),4年免耕覆盖+1年深松的耕作方式能提高25%左右的经济效益。同时,针对玉米深松过程中的问题,提出了玉米免耕播种和深松联合作业的方案,试验表明,玉米免耕播种和深松联合作业能有效解决玉米深松过程中出现的一系列问题,促进玉米生长,提高玉米产量,建议在中国北方玉米产区推广这一联合作业技术。  相似文献   

12.
We investigated the extent of visitation of underground sites during late summer and autumn (‘swarming’) by bats. Bats were captured at eight cave, mine and tunnel sites in southern England over 6 years (1995-2000). A total of 3077 bats representing 11 of Britain's 16 species was caught. Myotis bats predominated in autumn. At some sites these are rarely seen during winter hibernation counts. Myotis nattereri and M. daubentonii were most common. However, species composition changed seasonally. At one site, M. brandtii dominated early in the season and at all sites peak activity of M. daubentonii was earlier than in M. nattereri. Relatively high numbers of internationally vulnerable species such as M. bechsteinii and Barbastella barbastellus were recorded. There was a strong male bias in captures of swarming species. Swarming probably has an important reproductive function, most males are reproductively active at this time and such sites may be important for outbreeding. Due to this and the large number of individuals and species concerned, the conservation of ‘swarming sites’ is vitally important. Clearly swarming sites merit special consideration in conservation management strategies for cave-dwelling bats.  相似文献   

13.
14.
闽北不同类型毛竹林水源涵养功能研究   总被引:5,自引:0,他引:5  
以中亚热带杉木纯林(Ⅰ)和常绿阔叶林(Ⅴ)为对照,对闽北地区竹杉混交林(Ⅱ)、毛竹纯林(Ⅲ)、竹阔混交林(Ⅳ)3种不同类型毛竹林的林冠层截留、枯落物持水性能、土壤渗透性能及蓄水能力进行了研究。结果表明,各林分林冠截留率排序为Ⅴ(31.33%)>Ⅱ(28.17%)>Ⅳ(23.48%)>Ⅲ(22.88%)>Ⅰ(22.29%);枯落物持水能力排序为Ⅰ(26.8 t/hm2)>Ⅴ(12.1 t/hm2)>Ⅱ(11.3 t/hm2)>Ⅳ(11.1 t/hm2)>Ⅲ(9.2 t/hm2);土壤总蓄水量大小顺序为Ⅴ(1 125.67 t/hm2)>Ⅳ(1 064.30 t/hm2)>Ⅱ(1 050.60 t/hm2)>Ⅲ(1 015.13 t/hm2)>Ⅰ(1 008.87 t/hm2);土壤渗透性优劣次序表现为Ⅴ>Ⅳ>Ⅱ>Ⅰ>Ⅲ。并采用Topsis法对不同林分的水源涵养功能进行综合评价,水源涵养功能优劣顺序为Ⅴ>Ⅱ>Ⅳ>Ⅰ>Ⅲ,表明常绿阔叶林的涵养水源综合能力最好,毛竹混交林优于杉木纯林,而毛竹纯林最差。  相似文献   

15.
In Tigray (Northern Ethiopia), soil moisture has been identified as the most limiting factor in agricultural production; on the other hand, loss of rain water through runoff as well as the induced soil loss has been determined as a critical problem in the region in the last two to three decades. To alleviate the above paradox, the government has mobilized communities and resources for the construction of physical soil and water conservation structures (stone bunds, terraces) in almost all land uses. However, yield improvement was mainly concentrated within the vicinity of the structures and runoff continued to overtop the structures, as no measures for in situ soil conservation were taken. The terwah system, consisting of traditional ploughing followed by making every 1.5–2 m contour furrows, and permanent raised beds with contour furrows at 60–70 cm interval treatments, were considered and evaluated as practices that could increase the efficiency of in situ water utilization and soil conservation. An experiment was started in Gum Selasa, which is one of the drought prone areas in Tigray, whereby runoff volume and sediment load were measured after every rain event. Permanent raised beds with contour furrows at 60–70 cm interval significantly (P < 0.05) reduced runoff volume, runoff coefficient and soil loss as compared to traditional ploughing: 255, 381 and 653 m3 ha−1 runoff was recorded from permanent bed, terwah and traditional ploughing, respectively during the whole cropping season. The above runoff induced 4.7 t ha−1 soil loss from permanent bed, 7.6 t ha−1 from terwah and 19.5 t ha−1 from traditional ploughing. Overall, contour furrows and permanent raised beds can be part of the ongoing intensification process which includes physical soil and water conservation, slope reforestation, irrigation development and agro forestry in crop lands. Moreover, the use of permanent raised beds if combined with crop mulching and crop diversification is an important component for the development of sustainable conservation agriculture practices in the region.  相似文献   

16.
中国GIAHS保护试点: 价值、问题与对策*   总被引:8,自引:4,他引:8  
中国农业文明历史悠久,留存了丰富的农业文化遗产。它们不仅体现了中国的传统哲学思想,同时也对全球可持续农业产生积极影响,并成为现代生态农业发展的基础。2002年,联合国粮农组织(FAO)发起了全球重要农业文化遗产(GIAHS)保护项目,旨在对全球重要的、受到威胁的传统农业文化与技术遗产进行保护。目前我国已有4个GIAHS保护试点,即浙江青田稻鱼共生系统、云南哈尼稻作梯田系统、江西万年稻作文化系统和贵州从江县侗乡稻鱼鸭系统,2个候选试点,即云南普洱古茶园和茶文化及内蒙古敖汉旱作农业系统。本文基于FAO对GIAHS项目价值标准的解释,系统梳理了这6个试点的概况、价值、面临的威胁以及保护建议等,以期为我国农业文化遗产的保护提供指导依据。GIAHS的价值主要包括生态价值、经济价值、社会和文化价值、科研与示范价值等。目前农业文化遗产面临的主要威胁包括比较效益降低、适龄劳动力大量外流、现代观念的冲击和多重价值认识不足等。文章还提出了对GIAHS试点保护的建议,主要为引入动态保护途径,增加农民收入;加强宣传力度,建立科学的保护理念;完善制度建设,形成可持续的保护机制;调动农民的积极性,建立多方尤其是社区参与机制以及建立农业文化品牌,形成动态的保护机制等。  相似文献   

17.
We compiled and summarized current literature on S input/output budgets for intensively studied sites and soil plots in the U.S. and Canada and found S retention to be related to both soil order and extent of the last glaciation (Wisconsinan). Zero net retention is associated with Spodosols and was found only at sites north of the limit of Wisconsinan glaciation. Sites south of the limit of glaciation appear to be retaining from 20 to 90% of incoming S. These findings support the hypothesis that there exist regional variations in S retention in North America. Such variations are important in determining and predicting effects of acidic deposition on surface water chemistry.  相似文献   

18.
Stewardship programs providing financial incentives for conservation on private lands are increasingly common. We estimate the potential costs of a stewardship program in the Daly River catchment, Northern Territory, which would underwrite the cost difference between routine land management and the additional requirements of conservation management on grazing properties. Based on survey responses from landholders, we first assess the current costs of land management in the catchment and use regression to identify key drivers of spatial variation in both routine land management costs and conservation-oriented management costs. We define conservation-oriented management costs as the costs required to meet objectives for both routine property management and conservation. We then estimate the additional costs of conservation management over and above routine land management at an average of $1.99 per ha. We conclude that, if the most cost-effective properties are targeted, an annual budget of $1 million would support stewardship agreements covering 90% of the catchment’s area. Much of the cost-effectiveness of stewardship payments would come from the significant economies of scale in managing large pastoral properties and leveraging the costs of routine land management already met by landholders.  相似文献   

19.
攀援植物在北方水土保持生态修复中的应用   总被引:6,自引:0,他引:6  
水土保持生态修复过程中,陡坡和垂直陡壁一直是治理的难题。我国北方地区山多,坡多,坡陡,是生态环境较难修复的原因之一。就攀援植物在坡面、垂直陡壁的绿化方面进行了探讨研究,筛选了5种北方常见的攀援植物,分别对其生长特性、优缺点等方面做出了评价,并根据坡面的不同特性阐述了植物配置的原则和配置的种类,提出了栽植中宜采取的一些辅助措施。  相似文献   

20.
赣南山地水土保持生物措施效益研究   总被引:1,自引:0,他引:1       下载免费PDF全文
为查明崇墩沟小流域生物措施治理效益,采用径流小区及水文测站方法,对不同生物措施的水土保持效益进行监测。结果表明:马尾松低效林中,木荷补植、灌木补植、草本补植措施减水、减沙、保肥效果都显著,木荷补植效果最显著;封山育林和阔叶树荒山造林,林木生长较快,覆盖较高,径流量和侵蚀量少,在研究区内,减水、减沙、保肥效益最显著。种植黄栀子生物埂果园的径流量和侵蚀量逐年减少,但果园保水保肥明显比封山育林和阔叶树荒山造林差。崇墩沟小流域2007年径流量比2006年径流量少12.92%,减沙1万367t,生物措施治理水土流失效益显著。  相似文献   

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