نتایج جستجو برای: species changes and species
تعداد نتایج: 16982894 فیلتر نتایج به سال:
The effect of the paleoclimatic and paleoenvironmental changes on the structure of the bioticcommunities are stronger and better recorded in the shelf area than in the open sea. The present study isdevoted to impact of climatic events on some species of calcareous nannofossils. For this reason, 17samples of surface sediments of the Persian Gulf were studied. Preservation of calcareous nannofoss...
climate changes and global warming are considered as very important challenges of sustainable development. carbon sequestration is the easiest and cheapest way to reduce the greenhouse gases, especially carbon which constitutes the largest portion of them. in the present study, the potential of carbon sequestration in four plant species of atriplex canescens, haloxylon persicum, artemisia siebe...
background: the species of ectoparasites that live on a specific host in a geographical region form an ectoparasite community. species abundance distributions describe the number of individuals observed for each different species that is encountered within a community. based on properties of the species abundance distribution, the expected total number of species present in the community can be...
the evaluation of the edge effects of forest roads on ecosystem is very useful to understand changes from forest road. with this regard, in this research the effect of main forest road construction on regeneration and biodiversity of established trees in edge of forest road was investigated at 35 m distance into forest area. an existing 10 years old road segment, with same physiographic propert...
in this paper, the metazoan parasite community system of capoeta damascina in the tigris basin (mesopotamian region) in the middle-east is presented. overall, 54 species have been identified. between 2005 and 2008, iranian surveys of capoeta damascina found a total of 47 metazoan parasites species, most identified to species level. in addition, 6 parasite species from iraq and 1 species from oc...
road construction is one of the effective factors for ecological changes which affects diversity and species composition in forest roads edges. this research was performed in kheirud forest to evaluate herbaceous diversity and tree regeneration establishment in different distances from road edge. for this purpose, we sampled herbaceous and tree species regeneration in 0,5,10,25, 50 and 100 m di...
the “kuh-e-gorm” non-hunting area is located in the northwest of jahrom city, fars province, iran. since there is no adequate knowledge on fauna of this region, a survey was conducted on the vertebrate fauna of the region from april 2007 to april 2008. in total, 124 vertebrate species were identified including: 11 fishes (belong to 10 genera, four families and three orders), four amphibians (be...
this paper reviews the research on taxonomy of the trombidioidea in iran, with an updated checklist of 32 species (+5 undetermined species) belonging to five families and 22 genera. among them, 27 species (+1 undetermined species) are reported based on larvae only, three undetermined species based on adults only, and six species based on both larval and post-larval stages. also, 14 species (+3 ...
statistical studies on palynology contents of late cretaceous to paleocene age gurpi formation in a surface section in zagros basin,sw iran indicate changes in abundance, species diversity, ratio of spiniferites to cyclonephelium (s/c), palynological marine index(pmi) values and organic facies. these palynological variations clearly reflect fluctuations in relative sea-level and depositionalenv...
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