Comment on "International conservation policy delivers benefits for birds in Europe"

Donald et al. (Reports, 10 August 2007, p. 810) assessed the impact of the European Union's Birds Directive, a conservation policy enacted in 1979, and reported evidence for positive population changes in targeted species. We argue that their conclusions are overstatements based on unsuitable data and inappropriate analyses.     

Environmental and economic costs of soil erosion and conservation benefits

Soil erosion is a major environmental threat to the sustainability and productive capacity of agriculture. During the last 40 years, nearly one-third of the world's arable land has been lost by erosion and continues to be lost at a rate of more than 10 million hectares per year. With the addition of a quarter of a million people each day, the world population's food demand is increasing at a time when per capita food productivity is beginning to decline.     

上海市奉贤区黄浦江水源涵养林鸟类调查

对上海市奉贤区黄浦江水源涵养林的4次野生鸟类调查结果表明:调查地区共有鸟类44种,分属7目17科;其中留鸟14种(31.8%),冬候鸟16种(36.4%),旅鸟7种(15.9%),夏候鸟7种(15.9%)。共记录到鸟类707只,其中留鸟308只(43.6%),冬候鸟344只(48.7%),旅鸟25只(3.5%),夏候鸟30只(4.2%)。迁徙鸟类的种类占68.2%,数量占56.4%。以迁徙鸟类为主的调查结果与上海市鸟类记录情况一致。调查期间还记录到上海市重点保护鸟类4种88只。     

新疆保护性农业发展中的政策作用与特点浅析

随着我国加入WTO和西部大开发战略的实施和深入,可持续发展成为新疆农业发展的热点问题,以保护性耕作为基础的保护性农业成为迫切需要.政策是影响农业发展的最重要因素,研究试图对新疆保护性农业发展中的政策作用与特点进行初步分析,并提出一些政策建议.     

新桥国际机场昆虫群落与鸟类发生的相关性

掌握昆虫群落及其与机场飞鸟的关系可以从生态学角度出发,通过控制昆虫的发生进而降低鸟击频率。通过对新桥国际机场昆虫群落连续3年的调查（2016—2018年,共鉴定30 102 头昆虫）,发现群落由12目89科184种昆虫构成,半翅目和鞘翅目为优势类群,每年的6—8月是昆虫高发期。机场鸟类共记录6目19科39种,雀形目为优势类群,以食虫鸟和杂食鸟为主,活动高峰期是7—8月,与昆虫的高发期高度吻合。冗余分析进一步表明,杂食鸟和食虫鸟数量与昆虫生物量呈显著正相关,半翅目和鞘翅目是影响鸟类数量的主要昆虫类群。聚类分析揭示出新桥机场主要有3类生境,围界内草坪和围界外草地是防治的重点区域。这些研究结果为机场防范鸟击事件从传统的物理化学手段到生态综合治理的发展提供了思路。     

黄土高原沟壑区不同树种的水土保持效益及其适应性评价

【目的】研究黄土高原沟壑区不同树种幼林的水土保持效益及其适应性。【方法】以草地为对照,对黄土高原沟壑区刺槐、油松、沙棘、侧柏纯林及其混交林径流小区的产流产沙情况、土壤水分状况及各树种的生理特性进行了分析。【结果】造林初期,各树种及其不同造林方式的水土保持效益均比较差,处于水土保持功能低下阶段,土壤侵蚀的差异主要是由植被的不同覆盖度引起的,二者呈二次多项式关系;回归分析表明,当覆盖度达53%时土壤侵蚀较为轻微。草地和各树种林下0~250 cm土层土壤水分变化较大,其中以刺槐消耗土壤水分最多,其次是侧柏,油松、沙棘和草地之间差异不明显;刺槐纯林与其混交林下土壤水分的差异比较明显,而其他树种不同造林方式下的土壤水分无明显差异。各树种叶片的水分利用效率表现为侧柏>油松≈沙棘>刺槐,油松与沙棘混交造林后两者的水分利用效率都有显著提高;各树种叶片的蒸腾速率表现为刺槐≈沙棘>油松>侧柏,沙棘与油松或刺槐混交后,油松与刺槐的蒸腾速率均有所降低,而沙棘变化不显著。【结论】综合考虑树种的水保效益及其适应性可以发现,沙棘与油松混交可能是黄土高原沟壑区较为适宜的一种造林方式。     

南极海洋保护区:科学与政策博弈中的养护之路

南极海洋保护治理事务向来是全球公海保护领域的标杆,它通过海洋保护区提案的实现和相关工作的推进致力于维护南大洋生态环境健康。但归咎于海洋环境的动态性和保护效果显现的时滞性,海洋保护区这一在南极广泛应用并规划的保护路径,其实际效果和推进现状在当前缺乏长期监测数据和完备评估体系的大背景下依旧难以量化。本文整合挖掘了近年来国际上有关AMPA事务的研究,并基于部分南极海洋生物资源养护委员会（CCAMLR）公开报告和资料,从MPA的规划效率、科学依据、需求性、保护区的监测评估、对海洋资源合理利用的兼顾、南极资源治理问题的管理特殊性等多角度探析并呈现AMPA事务推进过程中科学与政策的博弈。研究显示,尽管南极海洋保护在国际公海保护领域无出其右,但自身纵向比较结果表明它的发展依旧处于初级阶段,规划进程缓慢、科学依据不足、国家间利益诉求协调困难、监测研究机制羸弱、保护需求和效果争议等问题相对突出。今后的研究应着重推进科学数据与海洋管理政策的联动、研究与监视计划的完善等,以期兼容不同主体的多元化诉求并探索出高效科学的海洋管理策略与资源规制模式。     

Institutional support and in situ conservation in Mexico: biases against small-scale maize farmers in post-NAFTA agricultural policy

One of the major adjustments brought on by the North American Free Trade Agreement (NAFTA) was a change in the relationship between Mexican agricultural support institutions and the small-scale agricultural sector. Post-NAFTA restructuring programs sought to correct previous inefficiencies in this sector, but they have also had the effect of marginalizing the producers who steward and manage the country’s reserve of maize (Zea mays) genetic diversity. Framed by research suggesting that certain maize varieties in a rain-fed farming region in southern Sonora are in danger of loss due chiefly to long-term drought, this article explores the ramifications of post-NAFTA agricultural policies for in situ maize diversity conservation. Qualitative methods, including semi-structured interviews with agricultural support institutions and participant observation with farmers, were used to gather data on dryland farmers’ access to research and extension, as well as possibilities for collective action. In southern Sonora, agricultural support is oriented primarily toward high-tech production, and there are structural barriers to small-scale farmers’ access to research and extension institutions. Further, collective action around agriculture is limited. These circumstances represent significant limitations to farmers’ options for accessing new techniques which might help maintain maize diversity in the context of economic and environmental change.     

滇中高原不同植被的蓄水保土效应及对土壤有机碳的影响

【目的】研究滇中高原不同植被的蓄水保土效应及对土壤碳库的影响,为当地的植被建设与小流域综合治理提供科学依据。【方法】采用标准径流小区观测法,于2006-2012年在云南省玉溪市尖山河小流域,对云南松次生林、云南松-蓝桉人工林、灌草丛及坡耕地小区的坡面产流、产沙情况和土壤碳库变化进行观测。【结果】1)灌草丛小区和云南松次生林小区的减流率分别为91.87%和91.61%,云南松-蓝桉人工林小区的减流率为77.45%。灌草丛、云南松次生林和云南松-蓝桉人工林的减沙率分别为99.17%,98.76%和96.45%。2)5-10月4种不同类型植被小区的径流量占全年径流量的83%以上,土壤侵蚀量占全年土壤侵蚀量的90%以上。3)与坡耕地相比,3种不同类型植被小区的表层(0~20cm)土壤有机碳含量增加幅度为42.27%~108.19%,土壤碳储量增加幅度为55.53%~145.27%。4)相关分析结果表明,蓄水减流效应与土壤碳库指标总体存在着显著的正相关关系。【结论】灌草丛小区和云南松次生林小区蓄水减流效益显著,3种不同类型植被的保土减沙效益表现为:灌草丛云南松次生林云南松-蓝桉人工林;5-10月为当地水土保持的关键期;3种不同植被均具有增加土壤碳库的作用;有效的蓄水减流可明显增加土壤有机质含量。     

Integrating culture and community into environmental policy: community tradition and farm size in conservation decision making

Community research by anthropologists and sociologists details the effects that centralization of decision making has on local communities. As governance and regulation move toward global scales, conservation policy has devolved to the local levels, creating tensions in resource management and protection. Centralization without local participation can place communities at risk by eroding the environmental knowledge and decision making capacity of local people. Environmental problems such as water quality impairments require perception, interpretation, and ability to act locally. Through a presentation of findings from farm communities in the Sugar Creek Watershed (Northeast Ohio, USA), this paper examines tradition, social scale, and land use among Anabaptist and other farm households, and refocuses on-farm conversation away from conventional individual metric-based studies and toward a systems approach. This new approach frames conservation behavior in a socio-cultural system that is influenced by tradition in on-farm decision making. Data from four subwatersheds are used to probe the effects of these variables on conservation adoption, explore the optimal farm size concept, and discus the roles of tradition and local and non-local knowledge in sustainability.     

保护性耕作现状分析及宁夏发展保护性耕作的前景

概括保护性耕作提出的背景,阐述西方国家保护性耕作与我国保护性耕作概念的区别,总结保护性耕作的内容、效果及西方国家保护性耕作存在的问题与不足,并结合宁夏目前发展保护性耕作的意义和推广应用情况,分析宁夏保护性耕作发展中存在的具体问题以及适合宁夏不同地区发展的少耕、免耕、秸秆覆盖、砂石覆盖和垄膜集水等保护性耕作措施的前景与策略.