drought stress is one of the most important dangers for increasing the yield and good production of crops in iran and the world. to evaluate the genetic diversity of rapeseed genotypes, identifying the drought resistance indices and drought tolerant genotypes, 16 genotypes were tested in a randomized complete block design (rcbd) with three replications and two different water regimes (irrigated...

Urbanization is rapidly enveloping isolated remnants of Sonoran Desert habitat in southern Arizona. Understanding the means by which herpetofaunal elements can persist in these habitats in the face of multiple impacts is vital to conservation efforts to retain intact biotic communities, especially those with a high diversity of reptile species. We surveyed twelve preserves in the Phoenix Metrop...

Functional trait databases are powerful tools in ecology, though most of them contain large amounts of missing values. The goal of this study was to test the effect of imputation methods on the evaluation of trait values at species level and on the subsequent calculation of functional diversity indices at community level using functional trait databases. Two simple imputation methods (average a...

abstract geopedology is a systematic approach of geomorphic analysis for soil mapping which focuses the field operation mainly on sample area. the purpose of this study is to determine the credibility of generalization of the results of geopedological approach for similar landforms in the borujen region, using diversity and similarity indices in a soil taxonomic hierarchical structure. after a ...

Whittaker (1960, 1972) first proposed the idea that species diversity has spatial components, with alpha diversity estimating diversity within individual stands (or communities) and beta diversity estimating the number of community types in an area (or in Whittaker’s terminology, ‘‘differentiation of communities along gradients’’). These two values combined make up gamma diversity. Beta diversi...