太湖地区典型轮作与休耕方式对稻田水稻季N2O和CH4排放量的影响

轮作休耕是实现"藏粮于地、藏粮于技"的重要途径之一,目前在太湖稻田区域主要推广紫云英(Astragalus sinicus L.)-水稻(Oryza sativa L.)、油菜(Brassica napus L.)-水稻和休耕-水稻典型轮作与休耕方式。在太湖地区典型稻田水稻生长季设置了6个处理:(1)紫云英-水稻轮作,不施N肥处理,MRN0;(2)紫云英-水稻轮作,当地常规施肥量(300 kg·hm^-2,以纯氮计,下同),MRN300;(3)油菜-水稻轮作,不施N肥处理,RRN0;(4)油菜-水稻轮作,当地常规施肥量(300 kg·hm^-2),RRN300;(5)休耕-水稻轮作,不施N肥处理,FRN0;(6)休耕-水稻轮作,当地常规施肥量(300 kg·hm^-2),FRN300。通过田间试验,研究了不同轮作与休耕方式对水稻产量、氮肥利用率及稻田温室气体CH₄和N₂O排放的影响,从而为综合评价轮作休耕方式提供科学依据。田间试验结果显示,与不施氮肥处理相比,在不同轮作休耕方式下施氮300 kg·hm^-2,可增加53.7%—60.0%的水稻产量,以MRN300处理水稻产量最高,与RRN300和FRN300处理相比,水稻产量分别提高了1.6%和6.0%。在不施氮水平下,MRN0、RRN0和FRN0各轮作处理间N₂O排放通量和累积排放量均值差异不显著(P>0.05)。而在施氮300 kg·hm^-2下,紫云英-水稻轮作可降低N₂O排放通量和累积排放量,与RRN300和FRN300处理相比,N₂O排放通量分别降低了36.0%(P<0.05)和2.1%(P>0.05)。在同一施氮水平下,紫云英-水稻轮作CH₄排放通量和累积排放量最小,与RRN300和FRN300处理相比,MRN300处理CH₄排放通量分别降低了1.1%和6.7%,CH₄和N₂O的全球增温潜势(GWP)分别降低了3.3%和6.5%,单位水稻产量温室气体排放强度(GHGI)分别降低了4.6%和11.6%。综上,紫云英-水稻轮作对提高水稻产量,降低温室气体排放效果最好。     

Protection of biota on nonpark public lands: Examples from the US Department of Energy Oak Ridge Reservation

Security buffers of Department of Defense (DoD) and Department of Energy (DOE) reservations provide long-term habitat protection for many rare and endangered species. The importance of these government-owned reservations as nationally valuable resources has been relatively unrecognized. During the last 50 years, the DOE Oak Ridge Reservation (ORR) has been a relatively protected island in a region of rapidly expanding urbanization and land clearing. Consisting of the Oak Ridge National Environmental Research Park and associated lands surrounding DOE facilities at Oak Ridge Tennessee, the unique nature of the ORR in the surrounding landscape is clearly visible from the air and has been documented using remote sensing data. Although forests dominate much of other regions of eastern Tennessee, this 15,000-ha tract of mostly natural forest habitat is unique in the southern Ridge and Valley physiographic province, which is otherwise widely developed for pasture, marginal cropland, woodlot, and urban uses. Twenty state-listed and federal-candidate plant species are known to be present on the ORR. This richness of species, which are provided protection by state and federal laws, exceeds that of the Great Smoky Mountains National Park on a species area basis and is an index of the value of the ORR both regionally and nationally in conserving biodiversity. With the end of the Cold War, changing DoD and DOE missions combined with increasing development pressure contribute to uncertainty in the future management of security reservations.     

Cooperation or conflict? Interagency relationships and the future of biodiversity for US parks and forests

Cooperation between the United States Department of Agriculture (USDA) Forest Service and the United States Department of Interior (USDI) National Park Service is most often advocated to protect biological diversity on national forests and parks, but the agencies, so far, have done little to implement the biodiversity mandates of such laws as the Endangered Species Act and the National Forest Management Act. The ideological and political history of the Forest Service and Park Service is explored to determine the roots of interagency conflicts. Several recent models of cooperative reform are also critiqued and found to be insufficient to stimulate better working relationships. To protect biodiversity, cooperation must be framed within conservation biology and must place primary emphasis on ecosystem patterns and processes as well as on individual species. Increased education of agency managers, ecosystem-level research, local and regional public participation, scientific oversight committees, new legislation, and enlightened leadership also play important roles. Ultimately, management policies must be reframed within a context of ecocentric values.     

哈尔滨市区绿地对交通噪声衰减效果研究

2007年4月6日-5月30日,采用HS-5633型数字声级仪分别对哈尔滨市区六处主要交通干道进行交通噪声测量,同时在干道周围的绿地进行对比测量,并将所得数据进行分析统计。结果表明,绿地（包括各类林地、草坪、隔离带及其不同组合）对交通噪声的衰减可达2dB（A）以上,减噪效果十分明显,减噪数值与绿地宽度和绿地植被组成有密切关系。因此,应对城市中各种类型的绿地及其组成的混合林地种植予以足够、有效的重视,如高大乔木＋灌木、常绿树＋草坪、乔木＋灌木＋草坪等配置紧凑的绿地类型,并应加大保护力度。     

长期施氮和水热条件对夏闲期土壤呼吸的影响

在黄土高原地区,夏季休闲期既是高温多雨期也是土壤微生物强烈活动期.研究该时期土壤呼吸变化与土壤水分、温度和施氮之间关系,有助于深入理解农田生态系统土壤呼吸的时空变异性及其影响因素.本研究以1984年设立在黄土旱塬区长期田间定位试验为平台,选取了5个不同施氮处理（N0、N45、N90、N135和N180）,于2009年夏...     

我国粮食生产的耕地资源环境效应特征与代价分析

我国粮食产量逐年增长,但伴随形成的水土资源消耗和耕地环境负荷令人担忧。本文综述了近年来我国粮食生产的耕地资源环境效应基本情况,总体结论是化肥、农药、地膜等农业投入品过量使用所带来的环境负荷日趋严重。同时,对休耕模式和粮食主功能区调整这两项国家战略政策的资源消耗与环境效应进行了重点分析,建议逐步扩大在水资源超采区、重金属污染区、生态退化区等典型区域的休耕面积,积极谨慎地评估主功能区调整形成的潜在资源消耗缓解与环境效益提升作用。提出:改变以牺牲耕地资源环境为代价换取粮食持续增长、建立以资源环境效应评估为平衡点的粮食供需模式的时机已成熟,粮食生产的耕地资源环境效应,应纳入国家粮食战略安全保障整体计划中。     

Adaptation to Climatic Variability and Change: Asian Perspectives on Agriculture and Food Security

The impacts of climate change on potential rice production in Asia are reviewed in the light of the adaptation to climatic variability and change. Collaborative studies carried out by IRRI and US-EPA reported that using process-based crop simulation models increasing temperature may decrease rice potential yield up to 7.4% per degree increment of temperature. When climate scenarios predicted by GCMs were applied it was demonstrated that rice production in Asia may decline by 3.8% under the climates of the next century. Moreover, changes in rainfall pattern and distribution were also found suggesting the possible shift of agricultural lands in the region. The studies however have not taken the impacts of climatic variability into account, which often produce extreme events like that caused by monsoons and El Niño. Shifts in rice-growing areas are likely to be constrained by land-use changes occurring for other developmental reasons, which may force greater cultivation of marginal lands and further deforestation. This should be taken into account and lead to more integrated assessment, especially in developing countries where land-use change is more a top-down policy rather than farmers' decision. A key question is: To what extent will improving the ability of societies to cope with current climatic variability through changing design of agricultural systems and practices help the same societies cope with the likely changes in climate?     

矿山废弃地的生态恢复

本文通过对矿山废弃地及其恢复情况调查,分析了我国矿山废弃地生态恢复的方向及蕴藏的产业机遇。     

Guidelines and Incentives for Conservation Development in Local Land‐Use Regulations

Effective conservation of biological diversity on private lands will require changes in land‐use policy and development practice. Conservation development (CD) is an alternative form of residential development in which homes are built on smaller lots and clustered together and the remainder of the property is permanently protected for conservation purposes. We assessed the degree to which CD is permitted and encouraged by local land‐use regulations in 414 counties in the western United States. Thirty‐two percent of local planning jurisdictions have adopted CD ordinances, mostly within the past 10 years. CD ordinances were adopted in counties with human population densities that were 3.0 times greater and in counties with 2.5 times more land use at urban, suburban, and exurban densities than counties without CD ordinances. Despite strong economic incentives for CD (e.g., density bonuses, which allow for a mean of 66% more homes to be built per subdivision area), several issues may limit the effectiveness of CD for biological diversity conservation. Although most CD ordinances required a greater proportion of the site area be protected than in a typical residential development, just 13% (n = 17) of the ordinances required an ecological site analysis to identify and map features that should be protected. Few CD ordinances provided guidelines regarding the design and configuration of the protected lands, including specifying a minimum size for protected land parcels or encouraging contiguity with other protected lands within or near to the site. Eight percent (n =11) of CD ordinances encouraged consultation with a biological expert or compliance with a conservation plan. We recommend that conservation scientists help to improve the effectiveness of CD by educating planning staff and government officials regarding biological diversity conservation, volunteering for their local planning boards, or consulting on development reviews. Guías e Incentivos para el Desarrollo de la Conservación en Regulaciones de Uso Local de Suelos     

行动者网络视角的生态退化区耕地休耕管护模式——以贵州省松桃县为例

近年来,中国将石漠化等生态退化区作为休耕的主要试点类型区之一,该区域人地矛盾突出,休耕试点中多以村委会为休耕管护主体。立足于探索在生态退化区以新型经营主体为休耕管护主体的不同休耕管护模式中遇到的主要问题及其适用的运行条件,运用行动者网络理论,以国家第一批休耕试点的松桃县为案例区,选择5个片区（7个村）为样本,围绕不同休耕试点阶段遇到的主要问题,解析不同休耕管护模式下行动者网络的稳定性以及不同休耕管护模式的特点及其适用性。结果表明：（1）松桃县休耕试点形成了四种休耕管护模式,即模式Ⅰ（种植大户管护）、模式Ⅱ（农民专业合作社管护）、模式Ⅲ（公司/企业管护）和模式Ⅳ（村集体经济合作社管护）;不同休耕管护模式下的行动者网络转译过程经历了两个阶段,并且遇到了9个方面的休耕问题,导致试行阶段的行动者网络不太稳定和调整阶段的行动者网络出现了分化,其中“休耕补助大幅减少和现行统一的休耕补助标准”是造成行动者网络分化的主要原因;应当制定有梯度、有弹性的休耕补助标准,加强休耕资金管理,创新投融资方式,加大机械化投入。 （2）休耕行动者网络中,人类行动者的理性行为是休耕试点顺利推进的关键因素,应当因地制宜地选择休耕管护模式及其策略。模式Ⅰ适合农业基础条件较好的坝区,但需要酌情提高现有补助标准;模式Ⅱ适合任何区域,但需要合理分配休耕补助和酌情提高现有补助标准,在做好风险防范措施的前提下,可以种植花生等利润相对较高的作物;模式Ⅲ适合石漠化程度较严重的区域,但需要资金雄厚和与休耕有产业上下游关联的公司/企业参与管护;模式Ⅳ适合土地流转费较低、村干部管理能力较强的偏远落后山区,但休耕区域必须符合休耕要求。（3）无论何种休耕管护模式,在生态严重退化区选取休耕区域,关键在于找准提升地力与农民增收的结合点,同时,严格筛选休耕片区和管控休耕时长,保障复耕后可持续利用休耕地以及做好休耕户转移劳动力就业工作。此外,应当完善乡镇政府、乡镇农业服务中心、村支两委和风险防范体系等休耕相关行动者,进一步提高休耕行动者网络的稳定性。