Variations and Trends of Onset, Cessation and Length of Climatic Growing Season over Xinjiang

In the past decades, a warming trend has been occurring in Xinjiang. In the recent 50 years, increasing in air temperature with a linear tendency of 0.2°C/10a has been observed in this region. Studies using Regional Climate Models have shown that this warming trend will continue in the future, and compared with that in the 1990s, the mean temperature in 2050 will be warmer by 1.9–2.3°C. Under current global warming trends, it is unsure of the extent to which temperature variability may affect the agriculture, forestry, and animal husbandry in the Xinjiang region.

Therefore, researchers from Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences estimated spatial patterns of variations and trends of onset, cessation, and length of growing season using mean air temperature data recorded at 51 stations in Xinjiang over the period 1959–2008. Rank-based Mann–Kendall trend test and linear regression method are used to detect the significance and the magnitude of growing season change, respectively. Regionally, the average onset of the growing season has shifts 5.3 days earlier while the average ending date has moved 7.1 days later, increasing the length of the growing season by an average of 12.6 days. This study reveals a quite different result from previous studies. While the lengthening of the growing season in Xinjiang in the past 50 years is similar to that of previous studies, they find that the lengthening can be mainly attributed to delay of cessation in autumn rather than advance of onset in spring. The extended growing season will have strong implications in regional agricultural production of Xinjiang. The findings of this research should be scientifically important to agricultural and animal husbandry management and for protection of ecological environment in Xinjiang.

The work was financially supported by the Chinese National Basic Research Key Project and National Scientific and Technological Support Program of China.

The result has been published on Theoretical and Applied Climatology, 2011, 106(3-4): 449-458. This paper is also archived at http://www.springerlink.com/content/c723176372l4r170/.