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Zhang R.,Desert Research Institute | Zhang R.,Lanzhou University | Yuan Y.,Desert Research Institute | Gou X.,Lanzhou University | And 8 more authors.
Dendrochronologia | Year: 2016

Schrenk spruce (Picea schrenkiana Fisch. et Mey.) is widely distributed in the Tianshan Mountains. In this study, four Schrenk spruce trees were continuously monitored with dendrometers from 27 April to 30 September 2014 on the northern slopes of the Tianshan Mountains in northwest China. The goal of this monitoring study was to determine the main growing season of Schrenk spruce and to analyze intra-annual radial growth variability and its relation to daily meteorological factors. Our studies have shown that the critical growing season of Schrenk spruce is from late May to late July and that the rapid growth stage is from mid-June to early July. Meanwhile, in the growing season, changes in the radial growth of Schrenk spruce were negatively correlated with daily temperature, evaporation, sunshine hours and vapor pressure deficit (VPD), and were positively correlated with precipitation and relative humidity (RH). The correlation coefficient between radial growth and RH can be as high as 0.750 (Pearson, p < 0.0001, n = 60). Dates in which precipitation occurred corresponded to periods of rapid growth. The results of the climate-growth analysis show that changes in radial growth reflect the effect of water stress on tree growth, whether or not the changes are positively or negatively correlated with the above climatic factors. This indicates that moisture plays a major role in the growth of Schrenk spruce. We suggest that precipitation between late May to late June is a limiting factor for radial growth of Schrenk spruce on the northern slopes of the Tianshan Mountains. © 2016 Elsevier GmbH.


Zhi J.,Xinjiang Agricultural University | Zhang S.-Q.,Xinjiang Agro meteorological Observatory | Xu W.-X.,Xinjiang Agricultural University | Tian Y.-J.,Xinjiang Agricultural University | And 2 more authors.
Chinese Journal of Applied Ecology | Year: 2015

Based on the meteorological date acquired from 11 meteorological stations in Northern Slope Economic Zone of Tianshan Mountain during 1971-2010 and by using the methods of linear regression, t-test technique and IDW interpolation, this paper analyzed the spatial distribution of each ten-day average temperature from late March to late April and beginning date of ≥12℃ to understand the effect of climate change on the cotton seeding date. Results showed that each ten-day average temperature from late March to late April increased by 0.8, 0.5, 0.1 and 0.5℃·(10 a)-1, but the beginning date of ≥12℃ advanced by 0.5 d·(10 a)-1 during 1971-2010. All meteorological elements in this research ascended abruptly in the 1990s. The abrupt climate change made each ten-day average temperature increasing by 2.5, 1.9, 1.1 and 1.5℃, to 7.2, 10.0, 13.2 and 15.6℃, respectively from late March to late April. The high values of each ten-day average temperature from late March to late April expanded the scope of main cotton producing areas in Northern Slope Economic Zone of Tianshan Mountain, such as Wusu, Sawan and Manasi, and the low values were observed in Urmuqi. The spatial distribution of the beginning day of ≥12℃ was significant different in different regions. During this study period, the early beginning dates of ≥12℃ expanded the scope of Jinghe and Manasi as cotton producing areas, and the late beginning dates of ≥12℃ narrowed to areas around Urumqi. With the advance of the beginning day of ≥12℃, the seeding date of cotton could start from 22nd to 28th April in most of the counties, and mulch cover could bring forward the suitable sowing date to 15th through 21st April. ©, 2015, Editorial Board of Chinese Journal of Applied Ecology. All right reserved.

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