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1.
Loss of water availability and stream biodiversity under land abandonment and climate change in a Mediterranean catchment (Olzinelles,NE Spain) 总被引:1,自引:0,他引:1
Iago Otero Martí Boada Anna Badia Eduard Pla Jordi Vayreda Santi Sabaté Carles A. Gracia Josep Peñuelas 《Land use policy》2011
In the north rim of the Mediterranean region, where forest cover is increasing as a result of land abandonment and temperatures are rising as a result of climate change, there is increasing interest for the effects of such changes on the runoff of water courses. This is a paramount issue for the conservation of many freshwater habitats and species. In this work we studied the effects of both an increase in forest cover after depopulation and land abandonment and an increase in temperature on the runoff of a Mediterranean catchment and on the aquatic and semi-aquatic fauna species of the stream (Olzinelles valley, NE Spain). Although in our simulation no decreasing trend in runoff is detected, the monthly runoff-rainfall ratio is now 15% lower than 30 years ago, a fact that may be attributed to a drier period rather than to the small afforestation experienced by the catchment in the last decades. Other factors such as increasing temperatures, changing rainfall patterns and increasing canopy cover are discussed. The observed decrease in the water flow has caused the disappearance of white-clawed crayfish (Austropotamobius pallipes), Mediterranean barbel (Barbus meridionalis), chub (Squalius cephalus), European eel (Anguilla anguilla), and southern water vole (Arvicola sapidus). Our results suggest that in a progressively warmer climate, and especially after land abandonment processes, management of Mediterranean mountain areas should be oriented towards an appropriate distribution of agrarian and forest land-covers in terms of water availability. Down to the stream scale, the pools that keep water throughout the year should be conserved and extended to enhance its potential to maintain aquatic and semi-aquatic species populations. 相似文献
2.
Scholars of environmental governance are increasingly intrigued by issues of scale. Efforts to institutionalise river basin management represent a pertinent exemplar, as they aspire to strengthen hydrological vis-à-vis political–administrative scales of governance. The EU Water Framework Directive (WFD) is one of the most ambitious policy initiatives worldwide to reconfigure water management planning around the hydrological scale of river basins. Whilst it is widely assumed that the WFD is rescaling water governance in Europe, few empirical studies have been conducted to ascertain how far this is the case, what scalar strategies and practices are emerging and to what effect. The paper addresses these open issues with a study analysing the multi-scalar actions of water authorities, water management organisations, local authorities and interest groups involved in implementing the WFD. It investigates how stakeholders are acting scalar from the local to the European scale and back to further their interests in the course of WFD implementation, focussing on the Wupper sub-basin in Germany. Drawing for conceptual insight on the human geography debate on the politics of scale and processes of rescaling, we demonstrate how all relevant stakeholders are increasingly working across scales to advance their interests but in very different ways, with different degrees of deliberation and to different effect. A typology of multi-scalar action is developed to interpret this diversity. The paper draws conclusions on how multi-scalar action is altering not only power relations between the actors but also the scalar configurations themselves. 相似文献
3.
《国际农业可持续发展杂志》2013,11(1):129-136
In response to the declining soil fertility in southern Africa and the negative effects that this leads to, such as food insecurity besides other developmental challenges, fertilizer tree systems (FTS) were developed as technological innovation to help smallholder farmers to build soil organic matter and fertility in a sustainable manner. In this paper, we trace the historical background and highlight the developmental phases and outcomes of the technology. The synthesis shows that FTS are inexpensive technologies that significantly raise crop yields, reduce food insecurity and enhance environmental services and resilience of agro-ecologies. Many of the achievements recorded with FTS can be traced to some key factors: the availability of a suite of technological options that are appropriate in a range of different household and ecological circumstances, partnership between multiple institutions and disciplines in the development of the technology, active encouragement of farmer innovations in the adaptation process and proactive engagement of several consortia of partner institutions to scale up the technology in farming communities. It is recommended that smallholder farmers would benefit if rural development planners emphasize the merits of different fertility replenishment approaches and taking advantage of the synergy between FTS and mineral fertilizers rather than focusing on ‘organic vs. inorganic’ debates. 相似文献
4.
At the beginning of the 21st century, the Netherlands and Flanders introduced a risk-based approach to flood risk management (FRM), labelled as multi-layer (water) safety. In contrast to a flood defence approach, risk-based management stresses the need to manage both the consequences and probability of a flood. The concept has developed differently in the two countries, as we conclude from a discursive-institutionalist research perspective. The Netherlands is characterised by a high institutionalization of the traditional flood defence discourse and a more closed policy arrangement, whereas in Flanders, the flood defence discourse is less institutionalized and the arrangement is more open. In both countries we see an opening of the arrangement preceding the establishment of multi-layer (water) safety, but at the same time, actors stress different aspects of the concept in order to increase its compatibility with the existing policy arrangement. In the Netherlands, the focus is on probability management, in Flanders on consequence management. In the Netherlands, multi-layer (water) safety as a concept could be established because it stabilises the system in the short-term by reinforcing the importance of flood defence, whereas in Flanders, policymakers were receptive to the concept because it supports a shift of responsibility towards actors outside traditional water management. 相似文献
5.
《国际农业可持续发展杂志》2013,11(3):183-194
The introduction of farmer participatory approaches over the past decades has to some extent improved the relevance and uptake of research results. While R&D prioritization increasingly involves more stakeholders, including the private sector, policymakers and civil society, building ecological literacy among all stakeholders is urgent, especially for sustainable agricultural development. A case study of an emerging fruit innovation system in Guinea, West Africa, highlights the challenges of supply- and demand-driven approaches to R&D prioritization. Shallow ecological knowledge and a blind faith in ‘modern’ technologies by scientists and farmers alike distort prioritization. Locally available, appropriate technologies are dismissed in favour of high technologies that are inaccessible to most smallholder growers. Strengthening the ecological literacy of all stakeholders may help to overcome this bias. On the other hand, building socio-technological literacy would allow innovation intermediaries, who typically act as brokers between the demand- and supply-side of technologies, to better understand the social and institutional contexts of technologies and how these affect potential uptake by poor farmers. Member centres of the Consultative Group on International Agricultural Research (CGIAR) could use the notion of ecological and socio-technological literacy to better understand supply and demand of technology and to work more effectively with their partners towards pro-poor and sustainable agricultural development. 相似文献