نتایج جستجو برای: extinction of rare species
تعداد نتایج: 21217683 فیلتر نتایج به سال:
There now appears to be a plausible pathway for reviving species that have been extinct for several decades, centuries, or even millennia. I conducted an ethical analysis of de-extinction of long extinct species. I assessed several possible ethical considerations in favor of pursuing de-extinction: that it is a matter of justice; that it would reestablish lost value; that it would create new va...
The maintenance of species diversity is a central focus in ecology. It is not rare to observe more species than the number of limiting resources, especially in plankton communities. However, such high species diversity is hard to achieve in theory under the competitive exclusion principles, known as the plankton paradox. Previous studies often focus on the coexistence of predefined species and ...
Habitat destruction, often caused by anthropogenic disturbance, can lead to the extinction of species at an unprecedented rate. It is important, therefore, to consider habitat destruction when assessing population viability. Another factor often ignored in population viability analysis, is the Allee effect that adds to the risk of populations already on the verge of extinction. Understanding th...
BACKGROUND Predicting which species are likely to go extinct is perhaps one of the most fundamental yet challenging tasks for conservation biologists. This is particularly relevant for freshwater ecosystems which tend to have the highest proportion of species threatened with extinction. According to metapopulation theories, local extinction and colonization rates of freshwater subpopulations ca...
Following habitat fragmentation individual habitat patches may lose species over time as they pay off their "extinction debt." Species with relatively low rates of population extinction and colonization ("slow" species) may maintain extinction debts for particularly prolonged periods, but few data are available to test this prediction. We analyzed two unusually detailed data sets on forest plan...
august wilson is undoubtedly one of the rare black playwrights whose works have attracted streams of attention and worldwide audience. the present study aims at analyzing fences and piano lesson which are two of the most successful plays in his pittsburgh cycle from the perspective of michel foucault’s theories and ideas. studying these two plays from foucault’s perspective opens new windows in...
The present study aimed to update the categorization of extinction risk Discocactus bahiensis Britton & Rose and zehntneri Rose, endemic Cactaceae species from Northeastern Brazil. georeferenced occurrence points were obtained online databases speciesLink Global Biodiversity Information Facility (GBIF). Polygons traced using these points, being gridded with 4 km² cells virtually divided in ...
With regard to retrogression trend of rangelands in central Zagross, many native plant species are expected to be increasingly on the verge of extinction. Therefore, for proper rangeland management the optimum harvest intensity of important plant species is an essential factor for rehabilitation and recovery of native rangeland species. This research was aimed to study the response of four rang...
The quantification of tropical tree biodiversity worldwide remains an open and challenging problem. More than two-fifths of the number of worldwide trees can be found either in tropical or in subtropical forests, but only ≈0.000067% of species identities are known. We introduce an analytical framework that provides robust and accurate estimates of species richness and abundances in biodiversity...
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