نتایج جستجو برای: rare species

تعداد نتایج: 777083  

2016
T. Edward Roberts Thomas C. Bridge M. Julian Caley Andrew H. Baird

Understanding patterns in species richness and diversity over environmental gradients (such as altitude and depth) is an enduring component of ecology. As most biological communities feature few common and many rare species, quantifying the presence and abundance of rare species is a crucial requirement for analysis of these patterns. Coral reefs present specific challenges for data collection,...

2013
Stephen P Hubbell

Data from a global network of large, permanent plots in lowland tropical forests demonstrate (1) that the phenomenon of tropical tree rarity is real and (2) that almost all the species diversity in such forests is due to rare species. Theoretical and empirically based reasoning suggests that many of these rare species are not as geographically widespread as previously thought. These findings su...

Journal: :journal of arthropod-borne diseases 0
xian guo guo vector laboratory, institute of pathogens and vectors, dali university (branch of yunnan provincial key laboratory for zoonosis control and prevention), dali, yunnan, china wen ge dong vector laboratory, institute of pathogens and vectors, dali university (branch of yunnan provincial key laboratory for zoonosis control and prevention), dali, yunnan, china xing yuan men institute of plant protection, shandong academy of agricultural sciences, jinan, china ti jun qian vector laboratory, institute of pathogens and vectors, dali university (branch of yunnan provincial key laboratory for zoonosis control and prevention), dali, yunnan, china dian wu vector laboratory, institute of pathogens and vectors, dali university (branch of yunnan provincial key laboratory for zoonosis control and prevention), dali, yunnan, china tian guang ren vector laboratory, institute of pathogens and vectors, dali university (branch of yunnan provincial key laboratory for zoonosis control and prevention), dali, yunnan, china

background: the species of ectoparasites that live on a specific host in a geographical region form an ectoparasite community. species abundance distributions describe the number of individuals observed for each different species that is encountered within a community. based on properties of the species abundance distribution, the expected total number of species present in the community can be...

Understanding distributions of wildlife species is a key step towards identifying biodiversity hotspots and designing effective conservation strategies. In this paper, the spatial pattern of diversity of birds in Golestan Province, Iran was estimated. Ecological niche modeling was used to determine distributions of 144 bird species across the province using a maximum entropy algorithm. Richness...

2009
Carolyn Hull Sieg

In virtually all ecological communities around the world, most species are represented by few individuals, and most individuals come from only a few of the most common species. Why this distribution of species abundances is so regularly observed among different taxonomic sets in geographically diverse systems is a question that has received considerable theoretical and empirical investigation (...

One of the effective steps for the sustainable forest development is the recognition of habitat condition and silvicultural characteristics of the rare species. Accordingly, this study investigated the aut ecology of Sorbus lorestanica as a rare species of Zagros. For this purpose, the exclusive natural habitat of Sorbus lorestanica in Lorestan province (Gahar rood protected area) was selected ...

Journal: :Ecology 2011
Jimena Dorado Diego P Vázquez Erica L Stevani Natacha P Chacoff

Most rare species appear to be specialists in plant-pollinator networks. This observation could result either from real ecological processes or from sampling artifacts. Several methods have been proposed to overcome these artifacts, but they have the limitation of being based on visitation data, causing interactions involving rare visitor species to remain undersampled. We propose the analysis ...

Journal: :journal of herbal drugs (an international journal on medicinal herbs) 2011
hamzeh ali shirmardi asghar shahrokhi hossain mohammadi najaf-abadi mahmood talebi

background & aim: the present study was to identify the medicinal plant species and introduced as one of the key priority areas for conservation and determination of endangered species were done. experimental: the method of plant collection in this region was classical method of regional plant taxonomic studies. collected plants were recognized and determined families, genera and species o...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید