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141.
A rapid ecological network assessment tool and its use in locating habitat extension areas in a changing landscape 总被引:1,自引:0,他引:1
An understanding of the ecological systems which dictate landscape form and function must be achieved in order to objectively view development led landscape ecological change. Habitat fragmentation, loss and isolation of habitat patches and reduced connectivity are having a significant detrimental effect on the way our landscapes function. A conservation planning tool which considers these issues in tandem with planned landscape level change, whilst incorporating species and habitat specific details, is necessary if we are to ameliorate the ecological impact of built development.A landscape scale modelling approach was developed for a case study area in the South Midlands of the UK to investigate spatial targeting of habitat extension areas. Habitat extension opportunities currently arise as a consequence of existing planning regulations and conditions and are likely to increase as the concept of habitat “banking” is embraced. Ecological networks and ecoprofiles were employed to guide the location of these extension areas via an examination of the landscape ecology effects of area composition, size and location. The ability of extension areas to contribute to landscape functionality was determined spatially. Habitat extension areas identified by the approach increased the existing ecological network size by a factor of over 2.7:1 and were able to deliver the majority of habitat creation targets set out in regional Biodiversity Action Plans (BAPs). 100% of wetland, unimproved grassland and broadleaf and mixed woodland creation targets were met, whilst 75% of the lowland heath target could be achieved. Semi-natural habitat mosaic areas of over 3700 ha which incorporated habitat of more than one type were identified, with such areas determined to be of importance in achieving landscape improvements for a wide range of species. We conclude that rapid assessment tools such as that employed in this research will have increased utility in conservation planning as the British landscape continues to experience both sustained and elevated levels of built development pressure. 相似文献
142.
邓超代志刚张红 《现代生物医学进展》2011,11(2):387-389
适宜的麻醉深度是保证患者的生命安全和创造良好手术条件的关键。脑电双频指数(bispectralindex,BIS)是用于监测镇静程度的一种新方法,自从临床应用以来它已得到多方面关注和研究,本文就其概念、原理及临床应用等方面进行综述。 相似文献
143.
ANTONIO MARTURANO 《Bioethics》2009,23(7):385-393
In this paper I analyse the ethical implications of the two main competing methodologies in genomic research. I do not aim to provide another contribution from the mainstream legal and public policy perspective; rather I offer a novel approach in which I analyse and describe the patent-and-publish regime (the proprietary regime) led by biologist J. Craig Venter and the 'open-source' methodologies led by biotechnology Nobel laureate John Sulston. The 'open-source methodologies' arose in biotechnology as an alternative to the patent-and-publish regime in the wake of the explosion in computer technology. Indeed, the tremendous increase in computer technology has generated a corresponding increase in the pace of genomics research. I conclude this paper by arguing that while the patent-and-publish method is a transactional method based on the exchange of extrinsic goods (patents in exchange for research funds), the free and open-source methodology (FLOSS) 1 is a transformational method based on a visionary ideal of science, which leads to prioritizing intrinsic goods in scientific research over extrinsic goods. 相似文献
144.
We used laboratory experiments with ten Daphnia taxa to test for links between Daphnia P-content, growth rate and habitat preference. The taxa represent a wide range of body sizes and most show distinct preferences for one of three habitats: shallow lakes, deep, stratified lakes or fishless ponds. Previous studies show that taxa from shallow lakes and fishless ponds experience high predation risk and rich food resources, whereas taxa from deep lakes experience low predation risk, strong food limitation and potentially P-deficient resources. Thus, we predicted higher P-content and higher maximal growth rates in taxa from ponds and shallow lakes and lower P-content, lower maximal growth but reduced sensitivity to P-limitation in taxa preferring stratified lakes. In each of 25 experiments, a clonal Daphnia cohort was cultured for 4 days on a P-sufficient (molar C:P ratio 70) or a P-deficient (C:P 1,000) diet of a green alga at a high concentration (1 mg C l–1). The P-content of adult Daphnia fed the P-sufficient diet ranged from 1.52 to 1.22% mass. Small-bodied taxa from shallow lakes had higher P-content than larger-bodied taxa from deep lakes or fishless ponds. However, we found a nonsignificant negative correlation between P-content and growth on the P-sufficient diet, rather than the positive relationship predicted by the growth rate hypothesis. The P-deficient diet resulted in declines in both growth rate and P-content compared with the P-sufficient controls and the extent of the declines differed between taxa. Taxa from ponds showed a marginally greater decline in growth with the P-deficient diet compared with taxa from shallow or deep lakes. However, contrary to stoichiometric theory, no relationship was found between a species P-content and growth depression on the P-deficient diet. Although we found evidence for habitat adaptations, our results show that factors other than Daphnia P-content are important in determining differences between Daphnia species in both maximal growth rate and sensitivity to P-limited growth. 相似文献
145.
The loss of urban green space as a result of urbanization threatens the overall biodiversity of urban areas, and prompts us to consider the importance of existing urban nature more carefully. Because urban ecological systems are in intense interaction with human-social systems, it is fruitful to create an interdisciplinary research and planning framework to ensure the maintenance of biodiversity in urban areas. For this purpose, we adapted a suitable theoretical and conceptual scheme for the setting of Finnish urban development, which provides an example of a situation where a lot of nature has so far remained inside and around urban area. The adapted scheme focuses on the land use change as a result of urban land use planning and development, and may provide a way to address the important variables and feedback mechanisms between information flowing from ecological systems and drivers from the social system. Furthermore, we outlined a more specific framework around the Finnish urban detailed planning process in order to study the interactions between these systems further. After addressing ecology-oriented questions of quantity, quality and needs of urban nature, and human-oriented drivers, such as flow and incorporation of information, knowledge, values and institutions, we identified several challenges in integrating the components of ecological and social systems. Creating common conceptual ground for different actors and disciplines, improving communication in the process, matching contradictory values and perceptions, and improving stakeholder participation would be in the best interest of nature and people of urban areas. 相似文献
146.
Herizo T.?AndrianandrasanaEmail author Jonah?Randriamahefasoa Joanna?Durbin Richard E.?Lewis Jonah H.?Ratsimbazafy 《Biodiversity and Conservation》2005,14(11):2757-2774
Participatory ecological monitoring is a realistic and effective approach in wetlands such as Alaotra, Madagascar, where important
biodiversity is found in an area with high human population density. Since 2001, Durrell Wildlife Conservation Trust, government
technical services, regional non-governmental organisations and local communities have collected data on key species, such
as waterbirds, a locally endemic lemur and useful natural resources. The monitoring was linked with environmental quizzes
and an inter-village competition, which helped raise interest in the monitoring and publicise results. The monitoring has
assisted wetland management by guiding amendments to and increasing respect for the regional fishing convention, raising awareness,
catalysing marsh management transfer to communities and stimulating collaboration and good governance. The sustainability
of the monitoring scheme and the usefulness of the data for detecting trends and guiding local managements are discussed. 相似文献
147.
148.
Perspective: Reproductive isolation caused by natural selection against immigrants from divergent habitats 总被引:7,自引:0,他引:7
The classification of reproductive isolating barriers laid out by Dobzhansky and Mayr has motivated and structured decades of research on speciation. We argue, however, that this classification is incomplete and that the unique contributions of a major source of reproductive isolation have often been overlooked. Here, we describe reproductive barriers that derive from the reduced survival of immigrants upon reaching foreign habitats that are ecologically divergent from their native habitat. This selection against immigrants reduces encounters and thus mating opportunities between individuals from divergently adapted populations. It also reduces the likelihood that successfully mated immigrant females will survive long enough to produce their hybrid offspring. Thus, natural selection against immigrants results in distinctive elements of premating and postmating reproductive isolation that we hereby dub "immigrant inviability." We quantify the contributions of immigrant inviability to total reproductive isolation by examining study systems where multiple components of reproductive isolation have been measured and demonstrate that these contributions are frequently greater than those of traditionally recognized reproductive barriers. The relevance of immigrant inviability is further illustrated by a consideration of population-genetic theory, a review of selection against immigrant alleles in hybrid zone studies, and an examination of its participation in feedback loops that influence the evolution of additional reproductive barriers. Because some degree of immigrant inviability will commonly exist between populations that exhibit adaptive ecological divergence, we emphasize that these barriers play critical roles in ecological modes of speciation. We hope that the formal recognition of immigrant inviability and our demonstration of its evolutionary importance will stimulate more explicit empirical studies of its contributions to speciation. 相似文献
149.
J.?M.?De.?MiguelEmail author L.?Ramírez-Sanz I.?Castro M.?Costa-Tenorio M.?A.?Casado F.?D.?Pineda 《Plant Ecology》2005,176(2):185-194
The relationship between plant species richness and the space organization of the community at different small scales was studied. The study was based on 51 sites distributed along a belt from Central Spain to Portugal. Each site was analyzed with a transect cutting across the boundary between two neighboring patches of shrubland and grassland. Local spatial organization of vegetation was analyzed at different levels of detail and each transect was divided into successively smaller portions. The first division coincides with a physiognomic perception of the site in two patches (shrubland and grassland). The average spatial niche width of the species was used to calculate the spatial organization of the vegetation of each division in each site. The correlation between species richness and spatial organization depended on the block size under consideration. A physiognomic criterion, sectorizing the sites into patches of shrubland and grassland, determines noteworthy floristic changes but does not enable us to express satisfactorily the variability in plant richness. In order to account for this variation, other factors must be taken into account which act at a more detailed small-scale and which determine the internal variability of these patches. In the case studied, the species richness of the sites increases along with an increase in the percentage of species whose occupation of the space is relatively restricted within the site. Many of these species are, however, frequent within the whole of the territory studied. The results highlight the importance of the level of local scale at which the factors influencing occupation of the space, and consequentially, plant richness, preferentially act. This circumstance ought to be taken into consideration in strategies for the conservation of biological diversity, and based on the delimitation of protected spaces with criteria frequently linked to the physiognomy of the vegetation.Nomenclature: Follows T.G. Tutin et al. 1964-1980. Flora Europaea. Cambridge University Press, Cambridge 相似文献
150.