نتایج جستجو برای: evenness simpson
تعداد نتایج: 5643 فیلتر نتایج به سال:
This study was carried out to compare the biodiversity parameters of epigean insect species in 3 different regions with geographical conditions. Tefenni Plain, Beyköy (Abdülmelik) Plain and Çaylı Mountain Village, which are located at altitudes, were chosen as area. Pitfall traps placed agro-ecosystems anise fennel each region caught pitfall checked weekly. A total 2086 individuals belonging 11...
استفاده از اسکیدرهای چرخ لاستیکی، عملیاتی معمول برای خروج چوب از عرصه قطع است، هر چند گاهاً سبب بعضی مشکلات زیست محیطی می‌شود. هدف از این تحقیق بررسی تاثیر چوبکشی بر تنوع زیستی زادآوری درختی و پوشش علفی در اطراف مسیر چوبکشی بوده است. این پژوهش در پارسل 8 سری گردشی از جنگل‌های چوب و کاغذ مازندران به انجام رسید. دو پلات 400 متر مربعی در فواصل منظم در هر طرف مسیر چوبکشی در نظر گرفته شد که در این پ...
Silvicultural operation need to notice the plant species diversity in forest. To this study Gomarlang district in marivan region, northern zagros forest was selected. Selected 100 ha area because have similar physiography condition (north aspect and 1650 to 1800 m s.a.l. In study area 100 micro plots of 5m by 5 m (25 m2) including the species and the numbers of this species randomize...
Differences between plant biodiversity and grazing pastures grazed under improved management of rangeland habitat is of particular importance. The purpose of this study was to compare semi-steppe rangeland vegetation of Prdanan in the city of Piranshahr in the field under grazed and enclosed sites were considered. Sampled in both grazed and systematic random pastured five 40 meters trans...
Microzooplankton plays an important role in aquatic food web and they act as trophic intermediates between the phytoplankton and higher trophic levels. The purpose of this investigation was to study the ecological situation of bahmanshir base on biological indexes calculation. Biological indexes of zooplankton in coastal region of bahmanshir waters were investigated. Samples were collected usin...
Silvicultural operation need to notice the species diversity. To this study Gomarlang district in marivan region, northern zagros forest was selected. In this study 30 circle sample plots (500 m2) were collected by random method. In every sample plot the kind of species and number of trees and shrub were recorded. In the sample plots the micro plots of 5 m by 5 m (i.e. area of 25 m2) were desig...
To study the weed population indexes of onion (Allium cepa L.) monoculture systems in the Jiroft area, four onion continuous monocultures, including less 3 (S1), 3-5 (S2), 5-8 (S3), more than 8 (S4) years and long-term fallow (F) were sampled by systematic randomized method in three stages: before sowing, 60 days after planting and 30 days after harvest, during 2015-2016. Of the 28 weed species...
In this study, we evaluated the species diversity, density, cover, and size index of plant within outside 37 enclosures in South Sinai mountainous region (Egypt), which had been protected for six years (March 2012–March 2018) against over-grazing over-cutting medicinal fuel purposes. Within enclosures, were recorded, their density (individuals per 100 m2) cover (cm cm) estimated using line-inte...
To gain insight into the ecological processes driving community reassembly in disturbed ecosystems, we assessed the phylogenetic dispersion of earlyand late-successional tree species occurring in lowland forests of northeastern Costa Rica. Early-successional species were more closely related than expected by chance, whereas late-successional species tended to be less closely related than expect...
Biological indexes of zooplankton in coastal region of Bahrakan waters- Hendijan harbor were investigated. samples were collected using plankton net (45 cm and mesh size of 100 μm) during July, August, October of 2010 and December, February, April of 2011.Mean of Shannon diversity index was (1.95) over the year and the min of Margalef species richness was (0.98). The highest value of these inde...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید