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作物生产不仅取决于单位面积产量，而且也依赖收获面积。关于作物单位面积产量对气候变化的反应已有广泛的研究，而作物土地利用对设想的气候变化的敏感性则缺乏直接的考查。为了估算作物面积指数（ＣＡＩ）——玉米、大豆、小麦和高粱生产的土地利用百分率，提出作物土地利用回归模式。模式的输入量包括土壤有效持水量，用于雨养农业的土地百分率，年降水量和年温度。ＣＡＩ模式解释的总方差为７８％（小麦）到８７％（高粱），标准差为１．７４％（高粱）到４．２４％（玉米）。模式引进其它气候变量后没能明显改善模式的性能。在目前气候条件和未来可能的气候变化情况下（温度和降水量分别变化－３℃—＋６℃，－２０％—＋２０％的各种组合），运用作物土地利用模式来预测美国每个作物公报地区的ＣＡＩ。按ＧＣＭ（ＧＩＳＳ和ＧＦＤＬ）提出的美国各地气候增暖的量值为３．５℃到５．９℃。在此增暖值情况下，模式揭示玉米和大豆生产面积可能减少，而小麦和高粱生产面积则可能扩大。如果增暖伴随年降水量减少１％到１０％，则玉米和大豆生产面积可能分别减少２０％和４０％。在这种条件下，高粱和小麦生产面积将分别增加８０％和７０％。确切的数值在很大程度上取决于降水量的变化。一般来说，温度?
Crop production depends not only on yield per unit area, but also on the area harvested. There has been extensive research on the response of crop yield per unit area to climate change and the lack of direct examination of the sensitivity of crop land use to envisaged climate change. In order to estimate the crop area index (CAI) - the percentages of land use for maize, soybean, wheat and sorghum production, a crop land use regression model was proposed. Inputs to the model include soil available water holding capacity, percentage of land used for rainfed agriculture, annual precipitation and annual temperature. The total variance explained by the CAI model was 78% (wheat) to 87% (sorghum) with a standard deviation of 1.74% (sorghum) to 4.24% (maize). The introduction of other climate variables did not significantly improve the performance of the model. Crop cropland use patterns are used to predict the status of each crop in the United States under current climatic conditions and possible future climate change (temperatures and precipitation varied by -3 ° C - + 6 ° C, -20% - + 20%, respectively) Regional CAI. According to GCM (GISS and GFDL) proposed the value of climate warming throughout the United States is 3.5 ℃ to 5.9 ℃. At this warming value, the pattern reveals that production of maize and soybeans may decrease while that of wheat and sorghum may expand. If warming is accompanied by a 1% to 10% decrease in annual precipitation, the maize and soybean production areas may be reduced by 20% and 40%, respectively. Under these conditions, sorghum and wheat production will increase by 80% and 70%, respectively. The exact value depends very much on the change in precipitation. In general, the temperature?