نتایج جستجو برای: use change has strong effects on ecosystem properties

تعداد نتایج: 10675689  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زیست شناسی 1388

126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...

2009
Risto Seppälä Erkki Oksanen

Climate is a critical factor affecting forest ecosystems and their capacity to produce goods and services. This chapter reviews published studies of climate-forest relationships with emphasis on indications and mechanisms of change during recent decades. Effects of climate change on forests depend on ecosystem-specific factors including human activities, natural processes, and several dimension...

Journal: :Ecology 2011
F Tomas J M Abbott C Steinberg M Balk S L Williams J J Stachowicz

Genetic variation within and among key species can have significant ecological consequences at the population, community, and ecosystem levels. In order to understand ecological properties of systems based on habitat-forming clonal plants, it is crucial to clarify which traits vary among plant genotypes and how they influence ecological processes, and to assess their relative contribution to ec...

خانی‌زاده‌امیری, مجتبی, صامتی, مجید, مردیها, سارا, معینی, شهرام,

  Determining the real value of natural ecosystems, due to their significant function and ecosystem services and necessity of the best management for make use of them, has a great importance. Recently, natural resource economists have studied ecosystem value of natural resources and its role in human welfare. These studies have made a considerable progress in valuation of environmental as well ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1389

after the soviet union dissolution, a chaotic period was begun in the russia. russia lost its glory and felt disgrace. the first group of elites came to power under yeltsin; they tried to re-define russia’s identity as a european country and build a foreign policy on this baseline. therefore russia tried to become closer with the west especially with the u.s. according to their view the sovie...

BACKGROUND: The use of agricultural waste as organic fertilizers is important for soil fertility and plants health production. OBJECTIVES: The aims of this study were to examine the effects of different types and rates of vermicompost on physiological and morphological properties of lettuce. METHODS: Present study was conducted acco...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده فنی 1391

the study of air infiltration into the buildings is important from several perspectives that may be noted to energy and design of hvac systems, indoor air quality and thermal comfort and design of smoke control systems. given the importance of this issue, an experimental and numerical study of air infiltration through conventional doors and windows has been explored in iran. to this end, at fir...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان همدان - دانشکده ادبیات و علوم انسانی 1390

abstract this study is an attempt to determine the effect of nano- technology education on science lesson for fifth grade in primary school in the city of kermanshah. this research is experimental and is conducted in the from of pre-test and post- test for the control group. an achievement test was administered to determine the rate of learning in the students. the research is an applied one. ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده حقوق 1389

if the precise implementation of the principle of proportion and:balance between the violation and the penalty as well as the other dimensions could be considered as a stick yard for the imptementation of justice any lack of preciseness in carrying out such principle would not indeed be much too far from injustice . naturally ,if it would be imagined that the objective of balance between...

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