introduction kermanshah province, iran, comprises an area, of 24640 km2 and is located between 33°37′-35°17′n and 45°20′-48°1′e. the average annual precipitation is 450 mm. most of the fields surveyed in this study lie between 542 and 1554 m a.s.l. among the factors decreasing the wheat yields, weeds have an important role. the results of some researches show that the weeds flora depends on cli...

In temperate forests, herbs comprise up to 90% of species richness yet received less attention, and their community structure, diversity patterns, driving mechanisms still remain understudied. We provide a phytosociological overview herb stratum develop vegetation model characterize designate groups interpret distribution patterns. Multivariate analyses – classification (TWINSPAN) ordination (i...

Soil properties are important drivers of species distribution and community structure in grassland. This study was undertaken to assess the influence soil on woody plant around six selected communally managed rangelands District. At each communal rangeland, a total 25 plots 20 × m were surveyed record density, frequency, composition species. samples collected for thirteen variables. A Tukey HSD...

Abstract An oasis is a unique natural landscape in arid and semi-arid areas, significant for regulating regional microclimates hydrological processes deserts. However, little known regarding the response of plants communities to various environmental factors. Nineteen sample plots (50 m × 50 m) were selected Daliyabuyi Oasis Taklimakan Desert hinterland based on location groundwater monitoring ...

the purpose of this study was to evaluate the species-environment relationships in arid and semi-arid rangelandsof nodushan, yazd. the plant species cover and the environmental variables were measured at 9 sites. soil sampleswere taken for measurement of 12 attributes in 0-10 cm and 10-80 cm layers. vegetation was classified using twowayindicator species analysis (twinspan). data was analyzed u...

The influence of environmental variables and the potential as bioindicators larval stages species Trichoptera were evaluated in a small stream northern Thailand from January to November 2017. A total 1,191 individual caddisfly larvae belonging 7 families 13 genus found. family Glossosomatidae most abundant, followed by Hydropsychidae Calamoceratidae. Glossosoma, Hydromanicusand Hydropsyche abun...

Intersite relationships among nematode communities of 18 Indiana mixed hardwood stands of varying composition, soils, physiography and past management practices were determined by community ordination techniques. All sites were sampled in April, July and October of 1968 and 1969, and ordinations were based on the number of individuals of each nematode species at each site at each sampling perio...

the current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. for this purpose, the study was conducted in nir rangelands of yazd province and topography, climate, soil and grazing intensity data of the region were determined. sampling method was randomized–systematic and within each sampling unit ...

Establishment of exotic plantations is one the most effective ways to induce natural regeneration for restoration degraded lands, as it has potential improve soil properties and creates favorable microclimates. This study aims determine effects stand structure composition well environmental factors under canopies three in northeastern Thailand on native species. For each plantation, we conducte...

Stephen B. Reilly Southwest Fisheries Science Center. National Marine Fisheries Service. NOM P. O. Box 27'. La Jolla. CA 92038 Interannual variability of dolphin habitats in the eastern tropical Pacific. II: Effects on abundances estimated from tuna vessel sightings, 1975-1990 Abstract.-The results of a canonical correspondence analysis (CCA) of data from research vessel surveys of the eastern ...