Mostafa Jafari
Abstract
Environmental and climatic conditions influence growth of the trees as well as beech (Fagus orientalis Lipsky), a species which is widely spread in the Hyrcanian forests in northern region of Iran. However, in the northern border of the forests, Oak (Quercus macranthera) dominates. Despite the ...
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Environmental and climatic conditions influence growth of the trees as well as beech (Fagus orientalis Lipsky), a species which is widely spread in the Hyrcanian forests in northern region of Iran. However, in the northern border of the forests, Oak (Quercus macranthera) dominates. Despite the variation in the growth and environmental preferences of beech and oak trees, but experiencing similar climatic and environmental impacts. Therefore, the response of the species could be evaluated simulteneously in various watershed districts. Height and standing volume of Fagus orientalis Lipsky and Quercus castaneifolia as wood producing criteria in response to changes in precipitation, temperature, evaporation, longitude, latitude, elevation and ratio of forest cover to total watershed areas across Hyrcanian forest from Astara to Golidaghi-Golestan was investigated. Results showed, mean forest cover elevation increase significantly with increase in longitude but decreased as latitude increases. The ratio of forest covers to total watershed district areas decreased with increasing longitude and latitude. K-means Cluster Analysis for all variables has been done in 2, 3, 4, and 5 cluster groups using SPSS statistical software to produce cluster dendrograms. In all cluster groups, forests category groups were; height and volume of beech, height and volume of oak, precipitation, the ratio of forest cover area to total areas of watershed districts and temperature, The outcome of this research showed that, beech and oak wood production and growth are primarily affected by the precipitation, the ratio of forest cover to total watershed areas and the temperature, and in the secondary level by longitude, latitude and evaporation. Pearson Correlation at the significance levels of 0.01 and 0.05 are presented.
Asghar Falah; Shamsaldin Balapour; Mohssen Yekekhani; Hamid Jalilvand
Abstract
The objectives of research were to create tree ring chronology of juniper trees and investigation on the relationship between the growth rate of the tree and the climate. Juniper trees are naturally distributed in High Mountain with semi-arid and arctic climate condition of Iran. Samples were collected ...
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The objectives of research were to create tree ring chronology of juniper trees and investigation on the relationship between the growth rate of the tree and the climate. Juniper trees are naturally distributed in High Mountain with semi-arid and arctic climate condition of Iran. Samples were collected from 20 trees in Shah-Kouh Mountain with 54° 42´ 58˝ longitude and 36° 61´ 01˝ latitude coordinate. Increment core were prepared and analyzed. The time span for tree ring chronology was 271 year (1741-2012 AD). Tree ring chronology statistic for MS, EPS, SNR, were 5.6, 0.85, 0.29 respectively. Correlation between tree ring index and climate data showed that mean temperature in the previous growing season is an important factor for growth of juniper trees. The result of this research can help the development of climate data and is useful for the creation of weather atlas.
Mostafa Jafari
Abstract
Environmental and climatic conditions influence growth of the trees as well as beech (Fagus orientalis Lipsky), a species which is widely spread in the Hyrcanian forests in northern region of Iran. However, in the northern border of the forests, Oak (Quercus macranthera) dominates. Despite the ...
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Environmental and climatic conditions influence growth of the trees as well as beech (Fagus orientalis Lipsky), a species which is widely spread in the Hyrcanian forests in northern region of Iran. However, in the northern border of the forests, Oak (Quercus macranthera) dominates. Despite the variation in the growth and environmental preferences of beech and oak trees, but experiencing similar climatic and environmental impacts. Therefore, the response of the species could be evaluated simulteneously in various watershed districts. Height and standing volume of Fagus orientalis Lipsky and Quercus castaneifolia as wood producing criteria in response to changes in precipitation, temperature, evaporation, longitude, latitude, elevation and ratio of forest cover to total watershed areas across Hyrcanian forest from Astara to Golidaghi-Golestan was investigated. Results showed, mean forest cover elevation increase significantly with increase in longitude but decreased as latitude increases. The ratio of forest covers to total watershed district areas decreased with increasing longitude and latitude. K-means Cluster Analysis for all variables has been done in 2, 3, 4, and 5 cluster groups using SPSS statistical software to produce cluster dendrograms. In all cluster groups, forests category groups were; height and volume of beech, height and volume of oak, precipitation, the ratio of forest cover area to total areas of watershed districts and temperature, The outcome of this research showed that, beech and oak wood production and growth are primarily affected by the precipitation, the ratio of forest cover to total watershed areas and the temperature, and in the secondary level by longitude, latitude and evaporation. Pearson Correlation at the significance levels of 0.01 and 0.05 are presented.
Shamsaldin Balapoor; Mahmood Kazemi
Abstract
Plants such as tree species respond to their surrounding environmental variations over their biological life cycle. One of the techniques to study the tree response to environmental conditions is dendrochronolog. In this study, 20 samples were prepared from 10 Zelkova carpinifolia trees in Badleh-Sari ...
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Plants such as tree species respond to their surrounding environmental variations over their biological life cycle. One of the techniques to study the tree response to environmental conditions is dendrochronolog. In this study, 20 samples were prepared from 10 Zelkova carpinifolia trees in Badleh-Sari area. The effects of climate variables (precipitation and temperature) on annual rings of Zelkova carpinifolia trees were examined. Samples rings cross-date was determined using dendrochronological method. Also a chronology of 78 years period was made (1932-2012 AD). Mean Sensitivity (MS), mean correlation coefficient between the samples (trees), EPS and SNR, were determined as 20%, 0.5, 0.88 and 4.11 respectively. Analysis of the relationship between growth and climate over the period of 1951 – 2005, using response function (RF) showed that temperature did not significantly affect growth but total precipitation in February had positive effect (r = 0.45 p <0.001) on the growth of Zelkova carpinifolia. Analysis of trees growth response to precipitation in February showed that precipitation in the periods 1976–1994 had significant impact on the growth. However, in recent years (2011-2006) the rate of effectiveness of the precipitation on tree growth was decreased. Finally it could be mentioned that Zelkova can be a useful tree species for dendroclimatological purposes in terms of high rate of MS, EPS and SNR.
