基于生态位和模糊数学的冬小麦适宜性评价

为定量评价气象、土壤等要素对作物生长的影响,利用江苏省及周边40个气象站1980—2010年日气象资料,选取影响冬小麦品种生长发育的主要气象(如气温、降水、日照时数等)和土壤(如土壤厚度、有机质和p H值等)生态因子,基于生态位理论和模糊数学的方法,依据冬小麦生长对生态各因子的响应关系建立各生态因子适宜度模型,借助GIS空间插值和空间分析,计算江苏省冬小麦品种的种植适宜度并进行等级划分。结果表明:从单要素看,研究区气温适宜度和日照时数适宜度都由北往南逐渐降低,降水适宜度由南往北逐渐降低;大部分地区土壤厚度和土壤有机质适宜,但大部分地区的p H值适宜度较低;从气候适宜度看,江苏省气候适宜度的范围为0.68—0.81,中北部大部分区域适宜度大于0.73,全省的气候适宜度均适合种植冬小麦,大体上呈现由北往南逐渐减小的变化;从土壤适宜度看,全省中部、南部与西北部大部分区域适宜度大于0.70,适合种植冬小麦。从综合适宜度看,全省大部分地区适宜度为0.50—0.86,适宜于冬小麦生长。综合考虑农业气候资源和土壤资源对江苏省冬小麦品种种植的综合适宜性进行评价,评价结果为充分利用江苏省农业生态资源、指导及科学制定冬小麦品种区域种植规划提供科学依据;按作物品种分生育期多角度的精细化研究方法和建立的各因子的适宜度模型可为今后作物区域适宜性评价提供一种新的思路,对同类研究具有一定的借鉴作用。

Assessment of ecological suitability of winter wheat in Jiangsu Province based on the niche-fitness theory and fuzzy mathematics

In order to quantitatively evaluate the influence of weather and soil on the growth of wheat crops, we use the day-to-day meteorological data from Jiangsu Province during 19802010, and develop an ecological suitability model of winter wheat on the basis of the niche suitability theory and fuzzy mathematics. The growth suitability of winter wheat in Jiangsu Province is evaluated and the regions in the province are delineated for different degrees of suitability with the aid of GIS spatial interpolation and analysis technologies; the different degrees of suitability assigned included the most suitable, more suitable, suitable, and not suitable. The major ecological factors affecting winter wheat growth such as temperature, precipitation, sunshine, soil depth, organic matter, and pH value were considered during the analysis. The analysis process includes four parts. First, the analysis was performed taking into account every growth period of winter wheat, to gain spatial distribution of meteorological stations during 19802010, using the most suitable method from the six spatial interpolation methods, including IDW, Kriging, and spline. Second, the analysis was conducted using the fuzzy mathematical models and considering the obtained ecoclimatic indices for the crop''s growth period, and the suitability of temperature, precipitation, and sunlight in different growth periods. Third, the weight of each meteorological factor at the different stages, the suitability of temperature, precipitation, and sunlight for the entire life period were calculated for analysis. Lastly, the comprehensive adaptability model for winter wheat was constructed using the relative weight method which determine the weight of all factors, each high suitability degree factor multiplied to reduce its weight while each weak factor multiplied to increase its weight. The integrated suitability values of winter wheat were calculated using this comprehensive adaptability model taking into consideration the previous results that took into account the temperature, precipitation, sunshine, soil thickness, soil pH, and soil organic matter concentration. The conclusions of our research are:1) The suitability of temperature and sunshine hours gradually decreases from north to south within the study area, while the suitability of rainfall gradually decreases from south to north. 2) The suitability of soil thickness and soil organic matter are higher for crop growth in most of the study area, while the suitability of the soil pH value is low. For climatic suitability, the suitability value of Jiangsu Province varied from 0.68 to 0.81, where the suitability in middle and north area exceeds 0.73. 3) The climate of Jiangsu Province is suitable for the growth of winter wheat, and the suitability value decreases from north to south. Considering soil suitability, the value for middle, south and northwest parts of study area are more than 0.7, which indicates that they are suitable for the growth of winter wheat. 4) The comprehensive suitability degree for most part of research area varies from 0.5 to 0.86, which is considered suitable for the growth of winter wheat. Our research can provide reasonable guidance to the scientific plans for the cultivation of winter wheat in Jiangsu Province. Furthermore, the developed suitability model that considers crop variety and its growth stages provides a new method to the crop ecological suitability evaluation, and can be used in similar researches.