نتایج جستجو برای: 2 population criteria population density and 3 ecological criteria patch richness
تعداد نتایج: 17539890 فیلتر نتایج به سال:
the methods which are used to analyze microstrip antennas, are divited into three categories: empirical methods, semi-empirical methods and full-wave analysis. empirical and semi-empirical methods are generally based on some fundamental simplifying assumptions about quality of surface current distribution and substrate thickness. thses simplificatioms cause low accuracy in field evaluation. ful...
The present study aimed to assess the spatio-temporal changes in the natural vegetation cover of Ahl Iman watershed, Ardabil province. For this purpose, land use maps of the three years (2000, 2010, and 2020) were extracted from Landsat satellite images. Then, seven landscape metrics (patch density, edge density, patch richness, splitting index, contagion index, Euclidean nearest neighbor dista...
یکی از مهم ترین عوامل موثر در وقوع آتش سوزی در مناطق خشک، پوشش گیاهی و شرایط آب و هوایی منطقه می باشد. منطقه حفاظت شده باغ شادی یکی از مناطق جنگلی استان یزد بوده که بیش ترین آتش سوزی های استان در آن رخ داده است. به منظور بررسی عوامل موثر بر وقوع آتش سوزی در این منطقه از روش تحلیل سلسله مراتبی (ahp) استفاده شد و معیارهای فیزیوگرافی شامل سه زیرمعیار ارتفاع، شیب و جهت شیب، اقلیم شامل دو زیرمعیار د...
Traditionally, to determine the possible evolutionary behaviour of an ecological system using adaptive dynamics, it is necessary to calculate the fitness and its derivatives at a singular point. We investigate the claim that the possible evolutionary behaviour can be predicted directly from the population dynamics, without the need for calculation, by applying three criteria - one based on the ...
The study of coherence of population dynamics is extremely important for predicting and evaluating the risk of global extinctions. The migration in a network of patch populations (metapopulation) inevitably involves various environmental noises or outside disturbances, which make the migration model time evolving and spatially extended. Thus time-invariant discrete ecological networks are often...
BACKGROUND Evolutionary change in individual species has been hypothesized to have far-reaching consequences for entire ecological communities, and such coupling of ecological and evolutionary dynamics ("eco-evolutionary dynamics") has been demonstrated for a variety systems. However, the general importance of evolutionary dynamics for ecological dynamics remains unclear. Here, we investigate h...
nowadays enhancing critical thinking in learners is considered one of the foreign language teachers’ tasks due to its high position in foreign language classrooms. when it comes to selecting materials for language classrooms, there are obviously some criteria that teachers should apply. the present study aimed at a critical thinking based analysis of ten picture story books and ten folktales th...
the purpose of this study was to investigate the relationship between teachers’ class management practices with students’ self- regulated learning and academic self-efficacy. in this study relating to the management class, three dimensions, (training management, people management and behavior management) and three style (interventionist, interactionist and non-interventionist) was considered. r...
E attributes such as population abundance and species richness depend not only on patch characteristics but also on the characteristics of the landscape surrounding the patch, known as patch context (Åberg et al. 1995, Gascon et al. 1999, Saab 1999, Szacki 1999, Fahrig 2001). Focal patch studies are one approach to studying the effects of patch context. In such studies, the data on species abun...
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