نتایج جستجو برای: ecological factors

تعداد نتایج: 1163995  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز - دانشکده کشاورزی 1394

with the increasing population and the need for more food, as well as with the development of science and technology, human approach to unnatural and often chemical inputs to increase agricultural production has been a great expansion and problems such as increased cancers, chronic diseases has created environmental pollution. implementation of organic organic is a solution to these problems . ...

Journal: Addiction and Health 2016
Ali Akbar Haghdoost Farin Kamangar Hamideh Rashidian Kazem Zendehdel Reza Malekzadeh

Background: Cancer is the second leading cause of death after cardiovascular disease. In recent years it has been hypothesized that opiate use could be a risk factor for cancer. This study aimed to evaluate a possible association between opiate use and common cancers using ecological statistics from around the world.Methods: To investigate the association we used ordinary linear regression mode...

2008
Suzanne V. Olyarnik Matthew E.S. Bracken Jarrett E. Byrnes A. Randall Hughes Kristin M. Hultgren John J. Stachowicz

What makes a community invasible? For over a century ecologists have sought to understand the relative importance of biotic and abiotic factors that determine community composition. The fact that we are still exploring this topic today hints at both its importance and complexity. As the impacts from harmful non-native species accumulate, it has become increasingly urgent to find answers to the ...

Journal: :journal of rangeland science 2012
saed shahrokhi sarduo reza bagheri hamzeh ahmadi fatemeh mahdavi

awareness of the effects of fire on various aspects of an ecosystem after the fire,is important for range management. changes in soil physical and chemical propertiescaused by fire can be the cause of changes in the vegetation. in this study, effects of fire onphysical and chemical characteristics of soil were investigated. this research was carriedout in a randomized block design method in the...

رحیمی, وریا, عادل, محمد نقی, پوربابائی, حسن,

The aim of this study was to investigate the relationship between physical and chemical properties of soils with vegetation distribution in Divan-Darre rangeland as one of the most important rangelands in Kurdistan province. For this purpose, a random systematic 150 m × 200 m gird sampling plan was used to establish 90 sampling plots. In each plot, soil factors and percent cover of each plant s...

Journal: رستنیها 2014
Fereshteh Sheikh Hasan Shahriar Saeidi Mehrvarz, Younes Asri,

The Oak genus (Quercus L.) is one of the most important genera of beach family (Fagaceae) that has ecological and economical importance. Chestnutleaf oak (Quercus castaneifolia C.A. Mey.) is native to Iran and distributed in Hyrcanian forests. Pure and mixed stands of this taxon have covered about 6.5 % of Hyrcanian forests. This study was undertaken to evaluate the effects of ecological factor...

Journal: :رستنیها 0
فرشته شیخ حسن دانشجوی کارشناسی ارشد، گروه زیست شناسی، دانشکده علوم پایه، دانشگاه گیلان، رشت شهریار سعیدی مهرورز دانشیار گروه زیست شناسی، دانشکده علوم پایه، دانشگاه گیلان، رشت([email protected]) یونس عصری دانشیار پژوهش بخش تحقیقات گیاه شناسی، موسسه تحقیقات جنگل ها و مراتع کشور، تهران

the oak genus (quercus l.) is one of the most important genera of beach family (fagaceae) that has ecological and economical importance. chestnutleaf oak (quercus castaneifolia c.a. mey.) is native to iran and distributed in hyrcanian forests. pure and mixed stands of this taxon have covered about 6.5 % of hyrcanian forests. this study was undertaken to evaluate the effects of ecological factor...

2002
Pierre P. Duez Kim J. Vicente

can be found at: Proceedings of the Human Factors and Ergonomics Society Annual Meeting Additional services and information for http://pro.sagepub.com/cgi/alerts Email Alerts: http://pro.sagepub.com/subscriptions Subscriptions: http://www.sagepub.com/journalsReprints.nav Reprints: http://www.sagepub.com/journalsPermissions.nav Permissions: http://pro.sagepub.com/content/47/3/572.refs.html Cita...

Journal: :Human Factors 1996
Klaus Christoffersen Christopher N. Hunter Kim J. Vicente

can be found at: Human Factors: The Journal of the Human Factors and Ergonomics Society Additional services and information for http://hfs.sagepub.com/cgi/alerts Email Alerts: http://hfs.sagepub.com/subscriptions Subscriptions: http://www.sagepub.com/journalsReprints.nav Reprints: http://www.sagepub.com/journalsPermissions.nav Permissions: http://hfs.sagepub.com/content/38/3/523.refs.html Cita...

The study of plant under environmental conditions leads to an appreciation of their physical and chemical requirements for growth and reproduction. It contributes to increase the knowledge of where the plants grow. This study was conducted to determine the main autecological characteristics of Salvia hydrangea L. which is an endemic plant distributed in Mazanadarn province, Iran. The habitats o...

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