Abstract: With hourly and high-resolution (0.0625°×0.0625°) temperature and precipitation data of CMA Land Data Assimilation System (CLDAS-V2.0), as well as groundbased observation data from 119 meteorological stations during 1981 to 2015, we determined the agricultural climatic division index of spring wheat planting distribution in Inner Mongolia by considering the agricultural climatic and productivity characters, according to climate suitability and key meteorological factors. The comprehensive division index of spring wheat was ranked. Raster calculating and multiple regression approaches were used to construct the refined agricultural climatic division maps of spring wheat planting distribution in Inner Mongolia. Our results showed that the CLDAS-based classification was generally consistent with that based on the data of the meteorological stations, with the former having more details regarding the spatial pattern. Furthermore, the comprehensive division index based on the data from meteorological stations was highly correlated with average yield at county level from 1987 to 2016 (R=0.70, P<0.01), indicating its suitability to predict the distribution of climate suitability of spring wheat in Inner Mongolia under climate warming. Seasonal drought and dry hot wind during filling stage largely constrained spring wheat production in Inner Mongolia. Good irrigation facilities in Hetao and West Liaohe Plain, as well as high precipitation along the Greater Khingan Range, made them ideal places for wheat production. Adequate water-heat conditions and low risk of dry hot wind in eastern Mt. Yinshan, the northern and southern foots of Greater Khingan Range were suitable for wheat production. The dry farming areas of the northern and southern foots of Mt. Yinshan, the foothills of Mt. Yanshan and West Liaohe Plain were sub-suitable for spring wheat planting, due to the potential drought damage in critical growth period. Strong water deficit and high risk of dry hot wind made western Inner Mongolia unsuitable for spring wheat planting. Our classifications provide basis for spring wheat production in Inner Mongolia.

Key words: community structure, species composition, target tree tending, natural secondary shrubs, species diversity, closed forest management.