نتایج جستجو برای: habitat patches
تعداد نتایج: 75719 فیلتر نتایج به سال:
Many populations in nature are fragmented: they consist of local populations occupying separate patches. A local population is prone to extinction due to the shot noise of birth and death processes. A migrating population from another patch can dramatically delay the extinction. What is the optimal migration rate that minimizes the extinction risk of the whole population? Here, we answer this q...
Many ecologists believe that fragmenting habitats into discontinuous patches disrupts the reproduction, survivorship and movement of animals. It has seldom, however, been possible to measure all these processes in one study. Recent work by Lesley and Michael Brooker on an Australian songbird, the blue-breasted fairy wren Malurus pulcherrimus, has achieved this elusive goal. Their new paper in W...
Reducing fragmentation and increasing interior area of habitat patches are major goals of restoration programs. Most strategies to correct these issues are qualitative based on visual interpretation, rather than quantitative based on the spatial characteristics of patches. To circumvent this, we developed an approach that integrates domain knowledge into an objective and geometric analysis of t...
Hanski’s incidence function model is one of the most widely used metapopulation models in ecology. It models the presence/absence of a species at spatially distinct habitat patches as a discrete-time Markov chain whose transition probabilities are determined by the physical landscape. In this analysis, the limiting behaviour of the model is studied as the number of patches increases and the siz...
The dynamic nature of habitat patches in rivers is driven primarily by flow regime. Altered hydrology, through river regulation, can limit the size and distribution of slackwater patches; important areas for the development of young fish and for shrimp in lowland rivers. Between late October 2002 and late January 2003, we investigated responses of fish, shrimp and their potential prey to the ex...
reserches show that relationship between human and residential places is based upo both emotional and identity structures. in other words, habitat place is not only the creator of a part of humanistic identity but also form a kind of sentimental and emotional bond that may result in tendency to maintain closeness to a specific place. therefor, formaton of emotional and identity relationship wit...
The diversity, expressed as species richness in equal-sized samples, of wood-living beetles in successional stages of deciduous forest after forest fires approximately 100 years ago did not differ between patch sizes in this study. Thus, the crucial question for conservation is whether the lack of reduction in diversity in small patches means that a number of small patches can elevate the regio...
Metrics that quantify habitat connectivity and fragmentation in landscape ecology are examined, as well as the relations between them and their interpretation. The radius of gyration, defined here as the root-mean-square distance of habitat patches from the center of the habitat, has special significance from an ecological point of view that other metrics lack. This metric has been incorrectly ...
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