Studies On Impacts Of Climate Change On Winter Wheat Growth And Development In Henan Province

Based on the records of growth stages of winter wheat from 1979 to 2007 and daily weather data, including daily precipitation, daily mean temperature and daily sunhour, from 1957 to 2007 of 30 weather stations in Henan Province,the linear changing tendency of duration of each growth stage and climate factor at each station as well as provincial averages were calculated. Provincial tendency distribution maps of each growth stage and climate factors during the same period were made using the spline method in Arcgis. Effects of changes of climate factors on growth stages were analyzed accordingly. In accordance with the climatic regionalization of winter wheat, Henan Province was divided into five climatic zones. Influences of climate changes on growth and development of winter wheat were analyzed in each zone by SPSS. Climate factors which closely related to growth and development of winter wheat were selected to establish the relation model between growth period and climate factors. The model was used to simulate and predict growth and development of winter wheat under future climate secnrios. Following main results and conclusions were obtained:1. In the global climate change context, whole growth duration of winter wheat in Henan Province presented the decreasing trend, but there were differences among different growth stages.Durations before overwintering and of heading - maturity stage were extended, while durations of overwintering stage,reviving - elongation stage and elongation - heading stage were shortened.2. At all growth stages, precipitation and sunshine hours showed a decreasing trend, but the accumulated temperature above 0℃increased. Precipitation and sunshine hour in the south part had higher linear changing tendency compared with other areas, while in the west ares with shallow hills, the precipitation, the sunshine hours and accumulated temperature above 0℃had more significant changes than other areas at the stage of heading to maturity.3. At the stages of before overwintering, overwintering and elongation to heading, changes of duration were similar at a high degree to the accumulated temperature above 0℃, indicating the relations between effective accumulated temperature and changes of growth duration. At overwintering and reviving - elongation stages, the trends of sunshine hours have a higher degree of similarity with the trend of duration changes, indicating that sunshine hour may have impact on the winter wheat growth. The trends of precipitation had a lower degree of similarity with growth duration, meaning that precipitation have little influences on growth duration of winter wheat.4. Analysis between growth duration and temperature and sunshine hours at the same periods indicated that sunshine and temperature had large effects on growth of winter wheat. At stage of sowing to elongation, sunshine had more effects than temperature and it was most significant at the stag of overwintering to elongation, afterwards, temperature had more effects. During the whole growint season, temperature had the most significant effects than other factors.5. Based on the WDSM, adjustment was made according to the specific conditions of winter wheat in Henan Province to obtain the phonological model driven mainly by temperature. The model was used to simulate growth of winer wheat under future climate change scenarios. When annual average temperature increases by 0.5℃, duration of whole growing season would be shorten by 2 to 4 days with mean value of 3 days. When annual average temperature increases by 1℃and 2℃, duration of whole growing season would be shorten by 5 to 7 days and 12 to 15 days, with a mean value of 6 and13.2 days, respectively.The methods as change sowing date and varieties to reduce the impacts of climate change on winter wheat growth and development in Henan Province in the future.