نتایج جستجو برای: species diversity index
تعداد نتایج: 1072319 فیلتر نتایج به سال:
This study aimed to investigate the diversity and types of arbuscular mycorrhizal fungi (AMF) associated with the wild service tree, Sorbus torminalis (L.) Crantz in spring and autumn followed by identifying similarities among the different study sites. Three different sites were selected including Kheiroud, Lalis, and Tarkin, in the Hyrcanian forests, north of Iran. Five rhizosphere soil sampl...
Variation in the diversity of ichthyoplankton was analyzed from samples collected during threeyear cycle in Boka Kotorska Bay. Samples were collected using Calvet (modified PairOVET) plankton net at 18 stations, from July 2006 through January 2009. Families with most numerous species were Engraulidae, Sparidae and Labridae. Investigation shows dominance of anchovy (Engraulis encrasicolus), Medi...
this study investigated the genetic diversity of morchella species using randomly amplified polymorphic dna markers. morchella species are an important group of edible mushrooms belonging to the family helveliaceae with medicinal and economical significance. in this study we have developed an efficient method of genomic dna isolation which was amplified by eight rapd primers to test the polymor...
Drought and grazing rangelands play an important role in changing the structure of vegetation and losing the biodiversity of natural ecosystems. In this research, in order to determine the effects of drought and livestock grazing on the vegetation structure of rangelands located in the Nakhab Forest of South Khorasan Province, species abundance, biodiversity, and range condition and trend were ...
Recent attitude of vegetation assessors is using of new ecologic approaches to evaluate and analyse the complex rangeland ecosystems. Plant diversity is the most important indices to assess the ecological changes of rangelands. In order to survey of plant indices of rangelands, two exclosure areas (long-term and mid-term) and a grazing area in rangelands of Javaherdeh (Ramsar, Iran) were select...
Due to the difficulties of field-based species data collection at wide spatial scales, remotely sensed spectral diversity has been advocated as one of the most effective proxies of ecosystem and species diversity. It is widely accepted that the relationship between species and spectral diversity is scale dependent. However, few studies have evaluated the impacts of scale on species diversity es...
It is important to investigate the genetic diversity and evaluate symbiotic effectiveness of the indigenous rhizobial population. It helps understand the responses of indigenous isolates to different rhizobial inoculants. In spite of the importance of bacterial diversity, there are a few scientific reports about it in Iranian soils. Genetic diversity of 150 isolates of Sinorhizobium isolated ...
Phytoplankton is one of the main components of wetlands, which plays a vital role in providing nutrients, oxygen for other organisms, stabilizing nitrogen and carbon dioxide. In the meantime, the current status of Lake Urmia highlights the need to conserve and protect wetlands related to these ecosystems and their living and non-living components. Therefore, this study was conducted to assist i...
The regeneration is one of the most important phenomena in forest ecosystems and the most important factor of development and sustainability of forests. Assessment of the regeneration is one of the best criteria for monitoring forest function stability. The aim of this study was to investigate the spatial variability of regeneration diversity and its relationship with tree species diversity in ...
the tomato leafminer, tuta absoluta (meyrick), is one of the most important pests of tomato, solanum lycopersicum l., in iran. in this research, natural enemies diversity of t. absoluta and proportion of predators or parasitoids density to moth eggs or larvae density on five tomato cultivars including super strain b, super chief, mobil, korral, and early urbana y were studied in an experimental...
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