The host specificity of a parasite is not merely a function of how many host species it can exploit, but also of how closely related these host species are to each other. Here, a new index of host specificity is proposed, one that takes into account the average taxonomic or phylogenetic distance between pairs of host species used by a parasite. The index is derived from measures of taxonomic di...

Post-fire survival, composition and regeneration of understory species in the boreal forest have shown to be affected by several factors, where consumption of the organic soil layer together with altered soil properties play important parts. There has however also been shown that the pre-fire site characteristics affect the post-fire understory vegetation. This study aimed to investigate the ef...

abstract seedless barberry (berberis vulgaris l. var. asperma) is one of the few crops that is cultured only in iran and southern parts of khorasan provinces. the origin of this variety is unknown and there has not been any study aiming to identify phylogenic relationships of this plant with other species existing in iran. in this study, aflp markers based on four primer combinations (ecori/tru...

the present study explores some physical and chemical parameters in the epilithic diatoms in the water samples obtained from two stations in koçan falls, erzincan from march to november 2014. over the course of the study, 19 taxa of epilithic diatoms were recorded. diatom genera which had the highest number of species in the study period were cymbella (4 species), navicula (4 species), and cycl...

in a faunistic survey conducted on auchenorrhyncha in sugar beet fields of mashhad and chenaran regions during 2008-2010, a total of 2741specimens belonging to 5 families were collected. as a result, 10 species were added to the fauna of the study area including: family cicadellidae: rhytidodus decimusquartus (schrank 1776), viridicerus malicola (dubovxdy 1966); handianus procerus (herrich-scha...

in this study an attempt has been made to empirically examine the relationship between biodiversity and economic growth using indicators of species diversity and income per capita as proxies for biodiversity and economic growth, respectively.also the effects of agricultural value added as a percentage of gdp, trade freedom index, exchange rate, population, percantage of land developed for agric...

In this research, biodiversity was investigated in the species diversity level. The objective of this research was to study of Norway Maple (Acer platanoides L.) dispersion and biodiversity of associated woody species in the Shafaroud forests, Gilan (IRAN). In this regard, a 0.5 ha lozenge sample plot was selected with considering presence of Norway Maple in each site. In each plot, geographic ...

Widespread concerns about global biodiversity loss have led to a growing demand for indices of biodiversity status. Today, climate change is among the most serious threats to global biodiversity. Although many studies have revealed phenological responses to climate change, no long-term community-level indices have been developed. We derived a 250-year index of first flowering dates for 405 plan...