نتایج جستجو برای: species changes and species
تعداد نتایج: 16982894 فیلتر نتایج به سال:
zygophyllum atriplicoides is one of the important species of iran rangelands that has special importance owing to some properties like high distribution rate, coverage percentage, density, and plant biomass that make it possible to supply a part of forage needed by livestock during spring and winter as well as to avoid soil degradation against water and wind erosions. this research tries to stu...
this checklist aims to reviews and summarize the results of the systematic and zoogeographical research on the iranian inland ichthyofauna that has been carried out for more than 200 years. since the work of j.j. heckel (1846-1849), the number of valid species has increased significantly and the systematic status of many of the species has changed, and reorganization and updating of the publish...
Species richness is a simple and interpretable indicator of biodiversity and is one of the most important and and practical measurements in the rangeland ecosystems. Experimental models of richness are used to determine the points of richness of suitable and unsuitable species, and the factors affecting it. The aim of this study is to compare two methods of modeling species richness S-SDM and M...
Rangeland ecosystems in arid and semiarid regions strongly were influenced by climatic factors and their kind of exploitation of management. These changes usually occur in combination and structure of vegetation over time. Because understanding the dynamics of pasture can choose the appropriate management practices and proper help, The changes of vegetation in desert ecosystem of Jajarm area, b...
Population dynamics indices of parasites infected on cultured ornamental fishes according to the climatic changes in kurunagala district,Sri Lanka were estimated.Sample of gold fishes and koi carps which were harvested from mud ponds in ornamental fish breeding and traning center was examined for ecto parasites. Four population indices were calculated for each abundant parasite species and dive...
rivers and runoff have always been of interest to human beings. in order to make use of the proper water resources, human societies, industrial and agricultural centers, etc. have usually been established near rivers. as the time goes on, these societies developed, and therefore water resources were extracted more and more. consequently, conditions of water quality of the rivers experienced rap...
piptatherum denaense به عنوان گونه ای جدید از کوه دنا در جنوب غرب ایران شرح داده می شود. این گونه با داشتن پوشینه بدون کرک در بخش تحتانی و انتهایی، بساک بدون کرک و برگ های رویشی باریک از گونه نزدیک به آن، p. laterale، تفاوت دارد. p. holciforme subsp. holciforme var. glabrum به عنوان یک واریته مشخص مورد تایید قرار نمی گیرد. p. sphacelatum که قبلا با گونه p. molinioides مترداف شده بود با ...
Colletotrichum species are associated with citrus plants as pathogens, saprobes and endophytes. According to the most recent multigene phylogenetic analysis, a lot of changes were happened in the taxonomy and species delimitation in the genus Colletotrichum. In this investigation, 292 Colletotrichum isolates were obtained from leaves, fruits and stems of Citrus species at Golestan, Mazandaran, ...
Using a semi-balloon otter trawl, crab fisheries in the main bays of Guangdong Province, China, were carried out seasonally . A total of 70 species were found, all belonging to the South China Sea Faunal sub region in the tropical India-West-Pacific Faunal Region. The clustering and nMDS ordination analysis revealed the existence of three groups. Group 1 included Hailing Bay and four bays to ...
Using a semi-balloon otter trawl, crab fisheries in the main bays of Guangdong Province, China, were carried out seasonally . A total of 70 species were found, all belonging to the South China Sea Faunal sub region in the tropical India-West-Pacific Faunal Region. The clustering and nMDS ordination analysis revealed the existence of three groups. Group 1 included Hailing Bay and four bays to ...
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