Mahmood Kazemi; Hamideh Asadpoor; Shamsaldin Balapoor
Abstract
During 2008, a severe deluge in Sari caused huge damages and Cupressus sempervirens l. var. horizantalis trees in botany garden of Natural Sciences College were also fallen by the overflow. To perform the study the fallen trees disks and cores of standing trees were prepared. Using Lintab Measurement ...
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During 2008, a severe deluge in Sari caused huge damages and Cupressus sempervirens l. var. horizantalis trees in botany garden of Natural Sciences College were also fallen by the overflow. To perform the study the fallen trees disks and cores of standing trees were prepared. Using Lintab Measurement Table, the width of each growth ring per year and their average were calculated. The raw data related to rings growth were standardized by method of ARSTAN and index average of growth rings was recorded. To study the relationship between climatic variables and C. sempervirens rings growth, data of Babolsar and Tajan synoptic stations were found. The observation results of fallen trees in flat sites showed that C. sempervirens is not resistant against deluge and in the places which ground water table is raised; C. sempervirens is not suggested for planting. Numerical results also indicated that the mean growth ring is about 3.62 mm per year. Taking into account the bark width, the average of trunk diameter after 40 years was about 30 cm. Temperature increase during the Past years had caused the trend of growth width to reduce. Also the relation of index average of growth with rainfall showed that precipitation is an effective factor on C. sempervirens growth and as a result, the average of rainfall in April had a positive and significance effect on C. sempervirens growth (R= 0.61 and P<0.01).
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.
