نتایج جستجو برای: trophic evaluation

تعداد نتایج: 839178  

Journal: :Brazilian journal of biology = Revista brasleira de biologia 2001
M Callisto P Moreno F A Barbosa

The assessment of the diversity of habitats and the characterisation of the functional trophic groups of benthic macroinvertebrate communities of some rivers of Serra do Cipó (MG) were the main objectives of this study. The available trophic resources and the types of substrata were characterised along with the structure and composition of their using functional trophic groups. Serra do Cipó is...

2016
Sirpa Lehtinen Sanna Suikkanen Heidi Hällfors Pirkko Kauppila Maiju Lehtiniemi Jarno Tuimala Laura Uusitalo Harri Kuosa

Combining the existing knowledge on links between functional characteristics of phytoplankton taxa and food web functioning with the methods from long-term data analysis, we present an approach for using phytoplankton monitoring data to draw conclusions on potential effects of phytoplankton taxonomic composition on the next trophic level. This information can be used as a part of marine food we...

2003
Martial Depczynski David R. Bellwood

An examination of the trophic status of a cryptobenthic reef fish community from the central Great Barrier Reef was carried out to evaluate the potential role of cryptobenthic fishes in coral reef ecosystems. Using frequency of occurrence data, dietary analyses revealed a diverse range of trophic groups, although detritivory (in 10 out of 16 species and 39.3% of individuals) and carnivory (5 of...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده ادبیات و علوم انسانی دکتر علی شریعتی 1393

the purpose of the present study was to investigate the relationship between fear of negative evaluation (fne) and communication strategies (css) among iranian efl learners. it was aimed to examine the differences in the use of communication strategies between speakers with high or low degree of fear of negative evaluation. the current study was a case study consisting of 10 english learners at...

ژورنال: بوم شناسی آبزیان 2017

The estimation of fish potential production and trophic status are two important and necessary parts of fisheries management in lakes. This study was conducted to determinate the trophic status and fish production potential of Golbolagh Lake, for one year from October 2013 to September 2014. Physicochemical parameters and other necessary data such as chlorophyll a, phytoplankton phylum dominanc...

The aim of this study is to assess the eutrophication and trophic status based on different indices and also reference threshold values in the Iranian coastal waters of the southern Caspian Sea (ICWSCS). The water samples (three replicates) were collected along four transects (off the coast from Anzali, Tonekabon, Nowshahr and Amirabad) between spring 2013 and winter 2014. The results show mark...

ژورنال: سلامت و محیط زیست 2011
اکبرزاده, عباس, جعفری, فاطمه, فرمن اصغرزاده, دیانا, نوری, روح‌اله,

Backgrounds and Objectives: The Atrak River is an important water supply resource in the Razavi Khorasan, Northern Khorasan and Golestan provinces. This river is the line border of Iran and Turkistan countries. Unfortunately, lack of water quality and quantity data due to nonexistence of a proper surface water quality monitoring station network is one of the main problems for water quality eval...

Journal: :International Journal of Science and Engineering 2013

Journal: :international journal of environmental research 2014
f. abdolahpur monikh m. hosseini j. kazemzadeh khoei a.f. ghasemi

in this study, three stations of the north persian gulf were analyzed in order to determinethe effect of trophic levels on the concentration of harmful pahs in fish and sediment. in all cases,similar distributions were observed in which benzo(a)pyrene largely predominated andbenzo(b)fluoranthene and pyrene were the second major compounds in fish tissues. the predominantcomponents of pahs in sed...

Journal: :Philosophical transactions of the Royal Society of London. Series B, Biological sciences 2013
Caolan Kovach-Orr Gregor F Fussmann

Under changing environmental conditions, intraspecific variation can potentially rescue populations from extinction. There are two principal sources of variation that may ultimately lead to population rescue: genetic diversity and phenotypic plasticity. We compared the potential for evolutionary rescue (through genetic diversity) and plastic rescue (through phenotypic plasticity) by analysing t...

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