| In my research the The Great Clay Belt of North Ontario which has a lot of fertile soil with frigid climate was studied under the background of global warming. Basing on meteorological datas of the Great Clay Belt from 1970 to 2000, daily temperature and monthly precipatition from 2015 to 2099 was predicted by SDSM downscaling models and multi-model ensemble method to determine the growing season of maize and analyse the climate resources in that peried.then the variety distribution of maize in 2020s,2050s and 2080s was talked about and the climate potential productivity of maize in the Great Clay Belt was calculated finally. The results show:(1) The variation of temperature and precipatition from 1970 to 2099 in the Great Clay Belt are as follows:(a) Temperature has an upward trend over time and the variation in scenario A2 is 1.6℃ higher than scenario B2 in 2080s.the change of daily mean temperature is higher than minimum,and maximum is the lowest. Smoky Fall in the north, Kapuskasing and Mattice in the middle have higher growth rate than the other ares. January and February has the fast growth rate which is 0.93℃/10a, following by May,June,July Augest and September.(b) The growth rate of precipitation is not significant in both scenario A2 and B2,which is1.3 mm/10a and 1.2 mm/10a respectively.The yearly precipitation is 800mm.the monthly precipitation of summer and autumn is beyond 70mm,bigger than spring’s and winter’s. the precipitation has downward trend over time from June to September, while the other months has upward trend, although the change is not obvious. Considering about spatial difference, the precipitation increases from northeast to southwest.(2) The influence of climate change to the climate resource of corn growing season in the Great Clay Belt are as follow:(a)Corn growing season from 2015 to 2099 is 20 days longer than before.Sowing time is advanced to the beginning of May.Frost free season is delayed to the beginning of Octomber.And corn heat unit increases by 550-1150℃. The increasing of corn heat unit and lengthen of growing season have the same trend in scenario A2 and B2. The growth rating in scenario A2 which is lower than B2 in 2020s,start to accelerate in 2050s and overtake in 2080s.(b)The preciaptation in growing season is beyond 400mm,which is sufficient for maize growth and change faintly over time. The precipitation of seeding, tasseling,maturation stage are 60mm,180mm,170mm respectively. Considering about spatial difference, the precipitation increases from southwest to northeast.(3) Considering about temperature,CHU and water in different stages of corn growing season to analysis corn variety distribution in the Great Clay Belt, In 2020s the climate resource of study area is not afford to plant corn. Part of the area is able to plant early maturing maize with 15 or 16 leaves in 2050s.The whole area is afford to plant corn and part of it is able to plant maturing maize with 18 or 19 leaves in 2080s. Seeding date can be advanced and maturation stage should be finished before the middle of September to make use of the heat in summer,avoid the low tempreture In October and ensure maturing rate and productivity.(4) Agroecological Zone Method is used to calculate climate potential productivity of maize in the Great Clay Belt. the results show:Conversion rate from Photosynthetic potential productivity to temperature potential productivity is between 48% to 65%. Conversion rate from temperature potential productivity to climate potential productivity is between 62% to 75%. Climate potential productivity is more than 8000 kg/hm2 in 2050s and beyond 11000 kg/hm2 in 2080s.Climate potential productivity in scenario A2 is bigger than scenario B2. The area with higher temperature, lower precipitation and planting corn with more leaves has higher climate potential productivity. |
PDF Full Text Request