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1.
The study of successional gradients may help to understand the relative influence of habitat structure and competition on territory characteristics. Here, we evaluate the effects of vegetation cover, conspecific and heterospecific densities, and distance to the nearest neighbor on territory size, shape, and overlap in insectivorous birds. We studied these effects along a gradient of postfire habitat regeneration in which foliage cover and densities of focal species varied several-fold. We delineate 197 territories (minimum convex polygons) of the shrub-dwelling Dartford warbler (Sylvia undata) and 255 of the syntopic Sardinian (Sylvia melanocephala), subalpine (Sylvia cantillans) and melodious (Hippolais polyglotta) warblers at three plots in NE Catalonia (Spain and France) in 1987–2005. After accounting for the effect of the number of locations used to delineate polygons, generalized linear mixed models (GLMM) showed a reduction in territory area of the Dartford warbler as conspecific density increased and distance to nearest neighbor decreased, in accordance with the contender pressure hypothesis for territory size regulation. Heterospecific density was not included in the final model of territory size and the effect of habitat structure was marginal. Territory roundness was positively correlated with its size and with conspecific density, probably in relation to energetic constraints, and negatively with heterospecific density. Territorial exclusion was almost complete among Dartford warblers, whereas interspecific territory overlap was extensive and tended to increase with heterospecific density and with structural diversity along the gradient. Our results support the hypothesis that Mediterranean warbler coexistence derives from ecological segregation and not from interspecific territoriality.  相似文献   
2.
Throughout Europe, the role of farming as the private provider of public goods and services increasingly valuated by society is today generally acknowledged. Furthermore, in the turn towards rural development concerns, multifunctionality as an attribute of rural space has emerged, justifying the territorial approach of farming. The situation facing the multifunctionality demand is nevertheless not the same in all European regions, which by all means is getting strengthened in the transition towards post-productivism. In some regions, there is a productivist orientation and production has a dominant economic role, while others will need to be supported on other functions to survive economically and socially, or may be best suited to environmental functions alone. The vocation of the rural territories is different, and thus also the functions they are able to support. This paper discusses the concept of multifunctionality of the rural areas, and defines a possible methodological approach towards the identification of the different types of rural areas in Europe, based on the identification of ideal types, through the analysis of selected indicators. The empirical application has been developed for the Portuguese Ministry of Agriculture, aiming at assessing the differentiated characteristics and dynamics of the Portuguese rural territory. Analyzing data from 1990 and 2000, at municipal level, three dimensions have been considered: the land cover, the agricultural sector and the rural community. Combining the three analyses, it was possible to identify different vocations of the rural space, and the role that farming could have in the future for the multifunctionality of the territory. Accordingly, the municipalities have been grouped in types, pre-defined as ideal types. This was a first attempt to understand the differentiation of the rural territory in Portugal. For decision-making it should be further developed. It nevertheless shows that there is clear differentiation concerning the possible landscape functions to be developed between regions and a possible way to assess. It also shows that a territorial approach to agriculture may be the key for the maintenance of the sector in many areas where production by itself, as it has been know until now, may be severely threatened.  相似文献   
3.
Climate change is one of the main factors that will affect biodiversity in the future and may even cause species extinctions. We suggest a methodology to derive a general relationship between biodiversity change and global warming. In conjunction with other pressure relationships, our relationship can help to assess the combined effect of different pressures to overall biodiversity change and indicate areas that are most at risk. We use a combination of an integrated environmental model (IMAGE) and climate envelope models for European plant species for several climate change scenarios to estimate changes in mean stable area of species and species turnover. We show that if global temperature increases, then both species turnover will increase, and mean stable area of species will decrease in all biomes. The most dramatic changes will occur in Northern Europe, where more than 35% of the species composition in 2100 will be new for that region, and in Southern Europe, where up to 25% of the species now present will have disappeared under the climatic circumstances forecasted for 2100. In Mediterranean scrubland and natural grassland/steppe systems, arctic and tundra systems species turnover is high, indicating major changes in species composition in these ecosystems. The mean stable area of species decreases mostly in Mediterranean scrubland, grassland/steppe systems and warm mixed forests.  相似文献   
4.
Network‐bound systems such as water and energy systems are increasingly confronted with environmental problems that cannot be solved without changing their modes of provision. More than any other flow provided through a network‐bound system, the waste water flow comes very close to intimate personal and social life, complicating the introduction of environmental innovations in this sector. Using the concepts of trust and identity, questions concerning changing consumer roles in two cases of Decentralised Sanitation and Reuse Systems in the Netherlands are addressed. In both cases the building of trust within provider networks and between consumers and providers, as well as the possibility for consumers and providers to identify themselves with the aims of the project were key factors determining the success or failure of environmental innovations in waste water flows.  相似文献   
5.
In the process of implementing EU policy, Member States sometimes introduce new policy instruments in cases where this is not obligatory. To better understand this phenomenon, this paper reviews three cases in which new instruments emerged and develops a methodology to trace back the influence of EU Directives on instrument choice. The method is illustrated by a narrative of the emergence of new management planning instruments during the implementation of the EU Habitats Directive in three EU Member States: Finland, Hungary and the Netherlands. Three key features of a policy instrument are defined, namely, its authoritative force, action content and governance design. These are used to measure the contribution of the Habitats Directive compared to other potential explanatory causes for the emergence of the new policy instrument. In all three reviewed countries a nested causal relationship between the Habitats Directive and the introduction of the new policy instrument is identified. Based on the relative contribution of the Habitats Directive to the emergence of the new instrument a distinction is made whether the Directive acted as a cause, catalyst or if conjunction occurred.  相似文献   
6.
Bas Kolen  Ira Helsloot 《Disasters》2014,38(3):610-635
A traditional view of decision‐making for evacuation planning is that, given an uncertain threat, there is a deterministic way of defining the best decision. In other words, there is a linear relation between threat, decision, and execution consequences. Alternatives and the impact of uncertainties are not taken into account. This study considers the ‘top strategic decision‐making’ for mass evacuation owing to flooding in the Netherlands. It reveals that the top strategic decision‐making process itself is probabilistic because of the decision‐makers involved and their crisis managers (as advisers). The paper concludes that deterministic planning is not sufficient, and it recommends probabilistic planning that considers uncertainties in the decision‐making process itself as well as other uncertainties, such as forecasts, citizens responses, and the capacity of infrastructure. This results in less optimistic, but more realistic, strategies and a need to pay attention to alternative strategies.  相似文献   
7.
Kolen B  Helsloot I 《Disasters》2012,36(4):700-722
On 30 May 2008, the Government of the Netherlands informed the national parliament about the effectiveness of preventive evacuation of coastal and river areas in case of flooding. Analysis of a case study showed that it is impossible to evacuate coastal areas preventively within a 48-hour time span preceding a worst credible scenario flood caused by a storm surge. This fact illustrates the need for alternative evacuation strategies, such as vertical evacuation (evacuating to safe havens, inside the flood zone) or shelter-in-place (hiding), to reduce loss of life and the impact of the evacuation. This paper defines these strategies and demonstrates, by returning to the case study used by the Dutch government, that they require different measures, methods of approach, and crisis management processes. In addition, it addresses the need for flexible and scalable preparation so that after detecting and understanding the threat, authorities and citizens can make decisions about different evacuation strategies.  相似文献   
8.
This paper investigated the effect of goal and mindset specificity on goal-related behavior in the environmental domain. Two studies demonstrated that goal-related behavior was maximized when participants focused on an abstract goal in combination with a specific mindset, or when they focused on a specific goal in combination with an abstract mindset. When goals and mindsets instead matched in terms of abstractness, goal-related behavior was reduced. Study 2 demonstrated that the effect of goal specificity on behavior was mediated by different processes in each of the mindset conditions. When mindsets were abstract, self-efficacy mediated the positive effect of specific goals on behavior; when mindsets were specific, the value of collective environmental action mediated the positive effect of abstract goals on behavior. The results are discussed in the framework of a complementarity approach. It is argued that complementarity of levels of specificity of goals and mindsets may affect behavior particularly strongly in domains where the discrepancy between the abstract and the specific is large (e.g. the environmental domain).  相似文献   
9.
Prenatal diagnosis for infantile osteopetrosis was attempted during the third pregnancy of a first-cousin marriage whose family history revealed an affected previous child. At the 25th week of pregnancy, fetal X-ray evaluation revealed marked sclerosis of osteopetrotic bone and metaphyseal splaying and clubbing of both femurs. The pregnancy was terminated and repeated X-rays and histopathological examination of fetal bone (femur) confirmed the diagnosis.  相似文献   
10.
The habit discontinuity hypothesis states that when a context change disrupts individuals’ habits, a window opens in which behavior is more likely to be deliberately considered. The self-activation hypothesis states that when values incorporated in the self-concept are activated, these are more likely to guide behavior. Combining these two hypotheses, it was predicted that context change enhances the likelihood that important values are considered and guide behavior. This prediction was tested in the domain of travel mode choices among university employees who had recently moved versus had not recently moved residence. As was anticipated, participants who had recently moved and were environmentally concerned used the car less frequently for commuting to work. This was found not only when compared to those who were low on environmental concern (which would be a trivial finding), but also to those who were environmentally concerned but had not recently moved. The effects were controlled for a range of background variables. The results support the notion that context change can activate important values that guide the process of negotiating sustainable behaviors.  相似文献   
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