the study was performed for assess the environmental factors affecting weed species diversity and composition of wheat (triticum aestivum l.) fields in jajarm, north-khorasan of iran, in 2009. the crop management (herbicide, amount of nitrogen applied and preceding crop type) and edaphic factors (ph, texture and content of phosphorus) of 16 fields were collected. shannon’s diversity index, spec...

Background and Objectives: This study was undertaken to determine the relationship between food security and individual dietary diversity score (IDDS). Materials and Methods: This population-based cross-sectional study was conducted on 200 non-diabetic individuals aged ≥40 years, selected randomly from the Tehran Lipid and Glucose Study. Household food security was measured using a validated U...

in order to study genetic diversity of aegilops tauschii populations, 188 populations of national plant gene bank collection of iran were evaluated for morphological traits according to ipgri descriptors in research station of national plant gene bank. moreover, 100 out of 188 populations were evaluated in research station of seed and plant improvement institute for resistance to yellow rust, p...

The tree species diversity in mixed stands of beech and valuable broadleaves was researched in the area of the National Park `Djerdap` on fifteen sample plots (total study area of about 5 ha). For this purpose, the following diversity measures were applied: (1) Shannon`s index H', (2) Simpson`s index (Simpson 1949), (3) McIntosh`s diversity index D' (McIntosh 1967), (4) Hill’s N1 diversity numb...

Anostracan bioregions were identified for Australia. These regions were quantitatively defined using species distributions compared through Jaccard's Coefficient of Community Similarity, and qualitatively defined using regional soils data. Community assemblages are quantified using Fager's Index of Recurring Species Groups. Substrate geochemistry was used to investigate additional relationships...

our planet is threatened by nuclear wars, climate change and degradation of biodiversity. the first two dangers are relatively focused on, but biodiversity degradation is not properly considered yet. species diversity is mostly composed of biodiversity and is considered an index of changes in ecosystems. many of researchers think of higher species diversity as an index of bio-system’s stability...

The dilemma which remained unsolved using Rao-Stirling diversity, namely of how variety and balance can be combined into “dual concept diversity” (Stirling, 1998, pp. 48f.) can be clarified by using Nijssen et al.’s (1998) argument that the Gini coefficient is a perfect indicator of balance. However, the Gini coefficient is not an indicator of variety; this latter term can be operationalized in...

Genetic variation in 150 trees of A. spinosa was estimated using inter-simple sequence repeat (ISSR). The plant material used in this study were originated from five provenances belonging to the principal provinces of argan ecosystem in southwest of Morocco. Based on the nine ISSR primers, 86 loci were scored. At the population level, percentage of polymorphic bands (PPB) was ranged from 75.58 ...