نتایج جستجو برای: extinction of rare species

تعداد نتایج: 21217683  

Journal: :Biology letters 2008
Ralf Ohlemüller Barbara J Anderson Miguel B Araújo Stuart H M Butchart Otakar Kudrna Robert S Ridgely Chris D Thomas

Why do areas with high numbers of small-range species occur where they do? We found that, for butterfly and plant species in Europe, and for bird species in the Western Hemisphere, such areas coincide with regions that have rare climates, and are higher and colder areas than surrounding regions. Species with small range sizes also tend to occur in climatically diverse regions, where species are...

Climate change has a great impact on the species distribution range and many endangered plant species. Fritillaria imperialis as a species that is native to Central Zagros, Iran is a medicinal plant with great ecological and commercial profits. Its population has decreased considerably and the species would be endangered in later decades. Understanding the habitat needs of this species, evaluat...

Journal: :New Phytologist 2021

Although often not collected specifically for the purposes of conservation, herbarium specimens offer sufficient information to reconstruct parameters that are needed designate a species as ‘at-risk’ extinction. While such designations should prompt quick and efficient legal action towards recovery, lags far behind is mired in bureaucratic procedure. The increase online digitization natural his...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده کشاورزی 1394

with the increasing population and the need for more food, as well as with the development of science and technology, human approach to unnatural and often chemical inputs to increase agricultural production has been a great expansion and problems such as increased cancers, chronic diseases has created environmental pollution. implementation of organic organic is a solution to these problems . ...

Journal: :Current Biology 2007
Michael Hofreiter

For many years, the megafaunal extinctions at the end of the Pleistocene have been assumed to have affected only those species that became extinct. However, recent analyses show that the surviving species may also have experienced losses in terms of genetic and ecological diversity.

Journal: :Journal of theoretical biology 2014
Leithen K M'Gonigle Philip B Greenspoon

Explaining patterns of diversity has long been a central focus in ecology. One of the most challenging problems has been to understand how species occupying similar ecological niches can co-exist because, with limited resources, demographic stochasticity is expected to lead to the eventual extinction of all but one of them. The Allee effect has been widely studied for its impact on the extincti...

2009
Saskya van Nouhuys

A metapopulation is a spatially structured population that persists over time as a set of local populations in balance between local extinction and colonization. Starting in 1969, and accelerating since the early 1990s, mathematical models of metapopulations have shown the importance of landscape connectivity and dispersal for persistence of a species or of interacting species. Some metapopulat...

2015
Anastasia Stefanaki Aphrodite Kantsa Thomas Tscheulin Martha Charitonidou Theodora Petanidou Jeff Ollerton

The architectural complexity of flower structures (hereafter referred to as floral complexity) may be linked to pollination by specialized pollinators that can increase the probability of successful seed set. As plant-pollinator systems become fragile, a loss of such specialized pollinators could presumably result in an increased likelihood of pollination failure. This is an issue likely to be ...

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