نتایج جستجو برای: astara
تعداد نتایج: 93 فیلتر نتایج به سال:
climatological parameters are among the most important ecological capability evaluation criterias, on other hand, climate changes which has intensified in the past decades and has the consequences such as; increases in climatic threshold phenomena like occurrence of horrific floodings, destructive hurricanes, abnormal and sudden colds and heats, untimely rainfalls and heavy snows, widespread dr...
Due to variances in response of different tree species in different habitats to climate changes, further studies in this field is clearly required. On the other hand, the lack of studies on chronology to evaluate the effect of solar radiation on radial growth of tree species due to lack of long term data of an important climatic variable, new approaches to determine the effect of this parameter...
The purpose of this study is to determine the woody species diversity in Sweet chestnut tree, Hazel-tree and Italian cypress ecosystems in the Guilan forests. A lozeng 0.5 ha sample plot was selectively established on each site. In the Sweet chestnut ecosystems , 4 sites were classified, whereas 10 sites of Hazel tree and Italian cypress ecosystems were classified based on species composition. ...
The present study involves the flora of the Estil wetland and its surroundings in Astara, northwest Iran. During 2006-07, we examined the plant specimens collected in this area and determined that there are 247 vascular plant taxa (229 species, 11 subspecies, and seven varieties) in 170 genera and 60 families. The largest families are Poaceae (27 taxa), Asteraceae (26), and Brassicaceae (21). G...
introduction climate change happens due to abnormal changes of climate within the earth’s atmosphere and their consequences. one of the most significant effects of climate change is the irreversible damage to some floral species and forest ecosystems. tree species reflect the impact of climate changes on their ring width. generally, tree rings vary in size each year depending upon the environme...
Neogobius caspius is an endemic species of the Caspian Sea which plays an important role in food chain as a predatory fish. The main aim of this study was to investigate selected feeding characteristics of Neogobius caspius in the south west coasts of the Caspian Sea. Monthly sampling was carried out using a bottom trawler at three stations (Astara, Anzali and Chabuksar) in three depths (0-5,...
The aim of this study was to investigate vegetation composition in broadleaved and conifers plantations in 220 ha of Loblloly pine (Pinus taeda), alder (Alnus glutinosa( and poplar (Popolus deltoides) hardwood plantations and its comparison with natural forests in Bibiyanlu protected forest park, Astara. A total of 60 sampling plots of 1000 m2 were taken using randomly-systematic method with1...
The genetic variation and population structure of narrow-clawed crayfish (Astacus leptodactylus) was examined by means of polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) analysis of the cytochrome oxidase subunit I (COI) of mitochondrial DNA. A total of 194 adult specimens were collected from seven sample sites including, two in the south Caspian Sea and one each...
Abstract Long-term observational data are essential for detecting and understanding local, regional and global climate change. The goal of this paper is to consider climate data of west of the Caspian Sea for any trends in Annual means of 2m temperature and precipitation at the stations of Anzali, Rasht, Astara and Lahijan for 1956-2018 period. Some inconsistencies in the data were found. Our ...
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