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51.
The machair sand dune systems of the Outer Hebrides of Scotland are a unique habitat, which is rare within both a global and
European context. Unusually, the machair habitat also represents an agricultural resource that is very important to the Hebridean
people, having been subject to both grazing and cultivation throughout the historical period. Following designation as an
Environmentally Sensitive Area (ESA) in 1988, the machairs of South Uist have been studied with the aim of understanding the
links between agricultural practice and their plant community and ecosystem dynamics. This research focused primarily on the
effects of cultivation practices and their role in maintaining plant species richness and community and ecosystem stability.
Within two carefully selected areas, the successional plant communities of machair at different stages of recovery following
ploughing and cultivation of cereals and potato patches or ‘lazy beds’ were identified at both a macro- and micro-level. Investigations
of the vegetation recovery processes on turves taken from newly ploughed land indicated that the initial stages of recolonization
are characterized primarily by rapid vegetative reproduction and growth, although re-vegetation by seeds is also an important
factor. The implications of these findings for the long-term management of machair plant communities are discussed and in
particular the need to maintain old cultivation practices such as shallow ploughing. The need for more detailed research into
both seed banks and seed rain and into processes of vegetative reproduction is stressed.
Nomenclature: Clapham et al. (1981) and Stace (1991, 1997) for vascular plants; Hubbard (1984) for grasses; Pankhurst & Mullin (1991) for
the regional flora; Dobson (1992) for lichens; Watson (1981) for mosses and liverworts. 相似文献
52.
The use of quantitative data for constructing prognostic maps of the dynamics of ecosystem degradation and restoration by
nonlinear simulation methods is a topical field of landscape ecology. This method of dynamic cartography is based on fiberwise
comparison of data on the state of Chernye Zemli (the Kalmyk Republic, Russia) in different years and the detailed analysis
of the period on which the prognosis was based. For this purpose, materials of repeated aerial and satellite photography obtained
during a long period (1954–1993) were used. Comparison of maps characterizing the dynamics of Chernye Zemli between 1958 and
1993 allows prognostic electronic maps for the next 10–15 years (with a five-year interval) to be drawn and land prognosis
for the next 20–30 years (1998–2023) to be obtained.
Deceased 相似文献
53.
Michael Duijn Arwin van Buuren Magnus Sparrevik Adriaan Slob Gerald Jan Ellen Amy Oen 《Journal of Environmental Planning and Management》2016,59(5):927-947
This study aims at describing, analyzing and evaluating the relation between management styles and process dynamics of a complex planning process confronted with unexpected dynamics. The development of an aquatic disposal site for dredged contaminated sediments in Oslo was managed by a project management style focused on timely and cost-effective implementation. Coupling the remediation project with another infrastructural project and the actual construction of the site led to unexpected dynamics in terms of resistance and controversy. Project management had difficulties in adjusting its style accordingly, resulting in even more delay and resistance. Managing complex planning projects requires a style suitable to the characteristics of the project and the capability of adjusting it to changing circumstances. The paper concludes with some explanations why it is difficult to change management styles in complex planning and implementation processes and complexity-embracing approaches to deal with this. 相似文献
54.
采用固相烧结法制备了NaCo_2O_4催化剂,构建了NaCo_2O_4-H_2O_2热催化体系降解亚甲基蓝(MB)。XRD和SEM表征结果显示,合成的NaCo_2O_4催化剂具有良好的稳定性。NaCo_2O_4对H_2O_2具有良好的热催化性能,反应温度越高,反应速率常数k越大,该催化反应符合一级动力学方程。NaCo_2O_4-H_2O_2体系对MB具有较好的降解效果,在反应温度为50℃、NaCo_2O_4加入量为50 mg、MB溶液加入量为100 mL、MB初始质量浓度为30 mg/L、H_2O_2加入量为1.00 mL的最优条件下,反应340 min时,MB降解率达87.00%;催化剂重复使用三次,MB降解率仍可达85%以上;经捕获剂效果对比实验发现,催化反应体系中存在h~+、·OH等催化活性物种。 相似文献
55.
Regime shifts and resilience in China’s coastal ecosystems 总被引:1,自引:0,他引:1
Regime shift often results in large, abrupt, and persistent changes in the provision of ecosystem services and can therefore have significant impacts on human wellbeing. Understanding regime shifts has profound implications for ecosystem recovery and management. China’s coastal ecosystems have experienced substantial deterioration within the past decades, at a scale and speed the world has never seen before. Yet, information about this coastal ecosystem change from a dynamics perspective is quite limited. In this review, I synthesize existing information on coastal ecosystem regime shifts in China and discuss their interactions and cascading effects. The accumulation of regime shifts in China’s coastal ecosystems suggests that the desired system resilience has been profoundly eroded, increasing the potential of abrupt shifts to undesirable states at a larger scale, especially given multiple escalating pressures. Policy and management strategies need to incorporate resilience approaches in order to cope with future challenges and avoid major losses in China’s coastal ecosystem services.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-015-0692-2) contains supplementary material, which is available to authorized users. 相似文献56.
近年来,长三角地区灰霾天气持续增多,空气细颗粒物污染问题日益突出。基于2013年1月至2015年5月长三角地区及周边缓冲区内共214个空气质量监测站点PM2.5逐时监测数据,运用普通克里金插值方法,从年、季、月尺度上分析了PM2.5的空间分布格局和时间动态变化。结果表明:(1)2 a来,长三角地区PM2.5浓度空间分布明显呈现整体北部高南部低,局部地区略有突出的分布特征;长三角地区PM2.5浓度年均值为57.08μg/m3;其中,江苏省PM2.5的年均值为三省市最高,为65.84μg/m3;其次为上海市,年均值为53.87μg/m3;浙江省PM2.5的年均值较小,为51.53μg/m3。(2)从季节尺度分析,长三角地区PM2.5浓度变化表现出冬春季高,夏秋季低的变化趋势;这与区域内冬季风向来源、降水稀少、气象扩散条件差有着密切的关系; (3)长三角地区月浓度变化大致呈U形分布; 12月份PM2.5浓度最高; 3月份以后, PM2.5浓度开始呈逐步下降趋势;在5~9月份,区域PM2.5处于"U"字的谷底,其中6月份夏收时期秸秆焚烧、气象等因素导致PM2.5浓度有略微升高;进入10月份后迅速攀升,且11、12月份呈现持续升高态势。 相似文献
57.
Both the ‘cascade model’ of ecosystem service provision and the Driver-Pressure-State-Impact-Response framework individually contribute to the understanding of human–nature interactions in social–ecological systems (SES). Yet, as several points of criticism show, they are limited analytical tools when it comes to reproducing complex cause–effect relationships in such systems. However, in this paper, we point out that by merging the two models, they can mutually enhance their comprehensiveness and overcome their individual conceptual deficits. Therefore we closed a cycle of ecosystem service provision and societal feedback by rethinking and reassembling the core elements of both models. That way, we established a causal sequence apt to describe the causes of change to SES, their effects and their consequences. Finally, to illustrate its functioning we exemplified and discussed our approach based on a case study conducted in the Alpujarra de la Sierra in southern Spain.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-015-0651-y) contains supplementary material, which is available to authorized users. 相似文献58.
Elena N. Bukvareva Karsten Grunewald Sergey N. Bobylev Dimitry G. Zamolodchikov Alexey V. Zimenko Olaf Bastian 《Ambio》2015,44(6):491-507
This paper focusses on a conceptual overview of ways to address a comprehensive analysis of ecosystem services (ES) in a country as large and heterogeneous as Russia. As a first step, a methodology for assessing the services for the federal subjects of Russia was chosen, i.e., its constituent provinces and similar entities, in physical terms. Russia harbors a great diversity of natural conditions and ecosystems which are suppliers of ES, and likewise a variety of the socio-economic conditions that shape the demand for these services and their consumption. The methodological approach described permits several important tasks to be addressed: the evaluation of the degree of satisfaction of people’s needs for ES, the identification of ecological donor and acceptor regions, and zoning of the country’s territory for ES assessment. The next step is to prepare a prototype of a National Report on ES in Russia, for which we are presenting the planned structure. 相似文献
59.
Urban ecologists have demonstrated that cities are functioning ecosystems. It follows then that species living in these contexts should participate in and experience the same suite of biological processes, including evolution, that have occupied scientists for centuries in more “natural” contexts. In fact, urban ecosystems with myriad novel contexts, pressures, and species rosters provide unprecedentedly potent evolutionary stimuli. Here, we present the case for studying adaptive evolution in urban settings. We then review and synthesize techniques into a coherent approach for studying adaptive evolution in urban settings that combines observations of phenotypic divergence, measurements of fitness benefits of novel genetically based phenotypes, and experimental manipulations of potential drivers of adaptation. We believe that studying evolution in urban contexts can provide insights into fundamental evolutionary biology questions on rate, direction, and repeatability of evolution, and may inform species and ecosystem service conservation efforts. 相似文献
60.
Svetlana V. Degteva Vasily I. Ponomarev Sasha W. Eisenman Vyacheslav Dushenkov 《Ambio》2015,44(6):473-490
Increasing anthropogenic pressure on the largest remaining tracts of old-growth boreal forest in Europe necessitates additional conservation of ecosystems and biodiversity in northeastern European Russia. In a regional network comprising 8 % of the Nenets Autonomous District and 13.5 % of the Komi Republic, 248 areas have varying protected statuses as state nature reserves (zapovedniks), national parks, reserves/sanctuaries (zakazniks), or natural monuments. Due to increased natural resource extraction in this relatively pristine area, designation of additional protected areas is critical for the protection of key ecological sites. The history of ecological preservation in these regions is herein described, and recent recommendations for incorporating additional ecologically representative areas into the regional network are presented. If the protected area network can be expanded, the overall environmental stability in these globally significant ecosystems may remain intact, and can help Russia meet the 2020 Aichi conservation targets, as set forth by the Convention of Biological Diversity. 相似文献