长期施肥对农牧交错带旱地土壤微生物多样性及群落结构的影响

为探讨长期不同施肥模式对农牧交错带旱地土壤微生物多样性和群落结构的影响,以农业农村部内蒙古耕地保育科学观测试验站的长期定位施肥试验为研究对象,选取不施肥(CK)、单施氮肥(NF)、单施化肥(CF)和有机肥+化肥配施(CFM)这4个处理,于试验开展16 a后(2019年)的马铃薯成熟期分取各处理0～10 cm和10～20 cm土层土壤,利用高通量测序技术对土壤细菌和真菌群落进行测定,以期从微生物学的角度探究农田不同施肥措施对土壤质量的影响,并通过偏最小二乘路径模型(PLS-PM)揭示了施肥模式转变中旱地土壤微生物群落演替和作物产量提升的关键环境驱动因子.结果表明：(1)CF和CFM处理均改善了土壤肥力,但后者效果明显优于前者,CFM处理土壤碱解氮、有效磷和速效钾分别提高131.9%～174.7%、 216.9%～283.3%和103.3%～109.3%,有机质和全氮也显著增加;CF处理仍保持了较高的土壤pH,而NF处理土壤pH显著降低,对土壤肥力的提升效果微弱.(2)与CK相比,NF处理显著降低了土壤细菌的Chao1和Shannon指数,CFM处理显著增加了细菌的物种丰富度、 Chao1...     

Ageing processes and soil microbial community effects on the biodegradation of soil C-2,4-D nonextractable residues

The biodegradation of nonextractable residues (NER) of pesticides in soil is still poorly understood. The aim of this study was to evaluate the influence of NER ageing and fresh soil addition on the microbial communities responsible for their mineralisation. Soil containing either 15 or 90-day-old NER of ¹³C-2,4-D (NER15 and NER90, respectively) was incubated for 90 days with or without fresh soil. The addition of fresh soil had no effect on the mineralisation of NER90 or of SOM, but increased the extent and rate of NER15 mineralisation. The analyses of ¹³C-enriched FAME (fatty acids methyl esters) profiles showed that the fresh soil amendment only influenced the amount and structure of microbial populations responsible for the biodegradation of NER15. By coupling biological and chemical analyses, we gained some insight into the nature and the biodegradability of pesticide NER.     

Environmental, cultural, economic and socio-community sustainability: a framework for sustainable tourism in resort destinations

This paper utilizes an inclusive community based sustainability framework with a focus on a resort destination in providing a potential model for more inclusive long-range destination planning and implementation. Four diverse, but interrelated areas of sustainable tourism were specified in this framework for a more comprehensive process including ecological, cultural, economic and socio-community sustainability. In addition a strategic community driven structure, which provides direction, information and practices, serves the purpose of integrating and implementing the framework. The unique tourism destination, Noosa in Australia is used as an example of embracing sustainable tourism as a community and as part of a larger focus on the four key components of sustainability. By viewing sustainable community attributes as assets, all of which are important to manage, enhance and/or conserve, it is expected that the resort community will continue to attract visitors to feel connected and committed to experiencing its lifestyle, sense-of-community and natural features while also contributing to community sustainable stewardship and a strong tourism economy. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. Dr. Richins is Chair of the Graduate Program within the School of Travel Industry Management at University of Hawaii. He holds a Ph.D. from James Cook University in Australia and a B.S. and M.S. from University of Oregon. Previously he held leadership positions for over 15 years in Australian and New Zealand including Waikato University, University of Newcastle and University of the Sunshine Coast. He was also Chair of the Resort Management program at Sierra Nevada College in Nevada.     

Collective action in water-point management: The case of pastoral and agropastoral communities in eastern Ethiopia

This paper explores collective activities in water-point management by pastoral and agropastoral herders. It examines conditions that strengthen or weaken cooperative behaviour. By employing a comparative case study approach, the paper covers three types of water-points: ponds, cisterns and water wells. Results show that factors beyond the expectation of economic benefits influence the development of cooperative behaviour, including embedded social relationships, which provide a basis for sanctions. However, the absence of clear allocation rules and of secure property rights discourages sustained contribution of inputs. The study also finds that the contribution, and the ultimate benefits gained, by the members of the group are dependent on limited technological options and other attributes of the water-points they manage. Interestingly, divergence of interests (between economic elites and poor herders) in institutional change precluding the establishment of cisterns negatively affects the livelihoods of the poor (agro) pastoralists. Where internal capacity is limited, assisted collective action that builds on diverse local interests could contribute to sustainable management of collectively used water-points. The study concludes that both economic incentives and socio-cultural norms affect collective action in a more complex way than the theory of determinants of collective action predicts.     

Ecosystem responses to reduced and oxidised nitrogen inputs in European terrestrial habitats

While it is well established that ecosystems display strong responses to elevated nitrogen deposition, the importance of the ratio between the dominant forms of deposited nitrogen (NH_x and NO_y) in determining ecosystem response is poorly understood. As large changes in the ratio of oxidised and reduced nitrogen inputs are occurring, this oversight requires attention. One reason for this knowledge gap is that plants experience a different NH_x:NO_y ratio in soil to that seen in atmospheric deposits because atmospheric inputs are modified by soil transformations, mediated by soil pH. Consequently species of neutral and alkaline habitats are less likely to encounter high NH₄⁺ concentrations than species from acid soils. We suggest that the response of vascular plant species to changing ratios of NH_x:NO_y deposits will be driven primarily by a combination of soil pH and nitrification rates. Testing this hypothesis requires a combination of experimental and survey work in a range of systems.     

Operationalising just sustainability: towards a model for place-based governance

As the concept of sustainability broadens to include social aspects, sustainability organisations must embrace strategies that allow them to more effectively address community issues and procedural concerns. Biosphere reserves (BRs) and model forests (MFs) advocate strongly for community engagement to achieve place-based sustainability; in practice, however, these organisations have had variable success in effectively engaging community residents and addressing their needs and interests. In this paper, we offer a framework for place-based governance for sustainability that is used to compare strategies used in BRs and MFs operating in the Maritime Provinces of Canada with the operations of Vibrant Communities, an anti-poverty organisation that operates locally in Saint John, New Brunswick. We draw attention to three imperatives: comprehensive understanding, community empowerment, and community-based outcomes, and five procedural drivers: local leadership, strong networks, diverse community engagement, learning together, and information sharing. Based on our results, we provide greater clarity on processes that address the imperatives and mobilise the drivers of effective place-based governance for sustainability. Our results suggest that there is a need for theory and practice to advance beyond current understandings of sustainability governance to enhance the capacity of organisations seeking to implement community-based sustainability strategies.     

Visions for the North Sea: The Societal Dilemma Behind Specifying Good Environmental Status

We augment discussions about the Good Environmental Status of the North Sea by developing two extreme visions and assessing their societal benefits. One vision (‘Then’) assumes restoration of benthic functioning; we contend that trawling had already degraded the southern North Sea a century ago. Available information is used to speculate about benthic functioning in a relatively undisturbed southern North Sea. The second vision (‘Now’) draws on recent benthic functioning. The supply of five ecosystem services, supported by benthic functioning, is discussed. ‘Then’ offers confidence in the sustainable supply of diverse services but restoration of past function is uncertain and likely to be paired with costs, notably trawling restraints. ‘Now’ delivers known and valued services but sustained delivery is threatened by, for example, climate change. We do not advocate either vision. Our purpose is to stimulate debate about what society wants, and might receive, from the future southern North Sea.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-014-0536-5) contains supplementary material, which is available to authorized users.     

PCR技术在水体微生物检测中的应用

聚合酶链式反应(PCR)技术因其特异性强、灵敏度高以及快速简便等优点广泛应用于水体微生物的检测。综述了PCR技术的原理、方法及其在水体微生物检测中的研究进展。主要介绍了该技术应用于水环境中微生物病原体的检测、污水生物处理过程的监测与评价中的重要意义以及本实验室在该领域的研究进展。PCR技术为在分子水平上进行环境微生物的结构、多样性分析提供了有力的实验手段,有着广泛的应用前景。     

Sediment quality triad assessment of an industrialized estuary of the northeastern USA

The lower Passaic River in northern New Jersey (USA) has been heavily industrialized since the mid-nineteenth century and its shoreline and aquatic habitats degraded or destroyed. Similar to other urban systems, Passaic River sediments, both surface and buried, historically have contained elevated levels of numerous contaminants that may pose risks to ecological receptors and humans. Sediments from 15 stations in the lower Passaic River and 3 reference stations in the Mullica River in southern New Jersey were sampled in 1999 and characterized for chemical contamination, toxicity, and impairment of the benthic community. The objective of this study was to determine the incidence, degree, and nature of degraded surficial sediments in the area to support subsequent plans for restoration of the system. Results demonstrated that Passaic River sediments had concentrations of many organic and inorganic contaminants at levels significantly greater than the reference area and effect-based guidelines. Sediments were toxic to marine amphipods at 11 stations and the benthic assemblages were impaired relative to the reference area at all stations. The weight-of-evidence of this sediment quality triad (SQT) assessment indicates that impacts from multiple contaminants are occurring throughout the lower Passaic River and, that these impacts must be evaluated further and addressed as part of ongoing restoration initiatives for the river.