population density and spatial distribution of thrips tabaci lindeman on seven soybean varieties (williams, tellar, sahar, dpx, l17, sari and zane) and one genotype (ks3494) were studied in tehran region, during 2007. the highest population density of the thrips per leaf was recorded on dpx and on ks3494 (0.810.05 and 0.800.05, respectively). the lowest population density was observed on l17 ...

One of the major issues examined in the quantitative ecology is the spatial distribution pattern of plant species. Knowledge of the spatial distribution patterns is essential to measure the level of uniformity in the surrounding environment, plant reproduction, and distribution of the seedlings, plant behavioral patterns, coexistence, allelopathic relations, and competition. Therefore, the aim ...

sustainable management of limited land and water resources is urgently needed to meet the increasing demand for food and to protect the environment. land suitability analysis is a prerequisite in assessing and proposing sustainable land use alternatives for an area. soil data are usually available at different levels of detail and stored in various forms, usually soil maps and/or soil observati...

the present study was carried out to evaluate three interpolation methods including weighted moving average (wma) with the power of 2 and 3, kriging and cokriging methods. data of 23 wells in mazandaran province were collected in fall and spring 2006. seven parameters including electrical conductivity (ec), ph, total dissolved solids (tds), sodium adsorption ratio (sar), total hardness (th), ch...

background: national institute of environmental health sciences (niehs) scientists shows that long-term exposure to air pollutants increases the risk of respiratory diseases such as allergies, asthma, chronic obstructive pulmonary disease, and lung cancer. children and the elderly are particularly vulnerable to the health effects of ozone, fine particles, and other airborne toxicants. air pollu...