[Spatial and temporal variability of climatic potential productivity in Yunnan Province, China.] / 云南省气候生产潜力的时空变化.

We used the mean annual temperature and mean annual precipitation data during 1961 and 2017 of 101 national meteorological stations in Yunnan Province to calculate three climate-induced potential productivity in Yunnan Province by Miami model and the Thornthwaite Memorial model. The abrupt test was carried out by Mann-Kendell method. The spatial and temporal distribution characteristics and future trends of the three climate-induced potential productivities were analyzed. Results showed that the average values of the temperature potential productivity (Yt), precipitation potential productivity (Yr) and evapotranspiration potential productivity (Ye) during the study period was 1968, 1477 and 1434 g·m-2·a-1, respectively. The value of Yt was rising in Yunnan Province. For the value of Yr /Yt, there was a large difference in water-heat ratio among regions, as well as the binding conditions. There was an abrupt change in climate-induced potential productivity, with Yt began to abrupt change significantly in 2001. There was no abrupt change in Yr, but Ye had abrupt change in 2002-2004. The spatial distribution of climate production potential and climate tendency were uneven. The annual average value of Yt, Yr and Ye was 1030-2465, 927-2341 and 832-1995 g·m-2·a-1, respectively. The climate-induced potential productivity was the lowest in the northwestern and northeastern Yunnan and the highest in the southwestern and southern Yunnan. Most of the climatic propensity rates of Yt, Yr and Ye showed increase, decrease and increase trends respectively. Eight schemes simulating future climate change (i.e., temperature increased by 1 ℃, precipitation increased by 10%, temperature decreased by 1 ℃, precipitation decreased by 10%, temperature increased by 1 ℃ and precipitation decreased by 10%, temperature increased by 1 ℃ and precipitation increased by 10%, the temperature decrease by 1 ℃ and the precipitation increased by 10%, the temperature decrease by 1 ℃ and precipitation decreased by 10%) would lead to Ye changes of 6-45, 13-77.2, 15-67, -87 to -17, -74-46, 58-96, -54-57, -101 to -59 g·m-2·a-1, respectively. On the whole, if the climate tends to be "warm and wet" in the future, it will be beneficial for crop production. However, if it tends to be "cold and dry", it will be unfavorable to crop production in the study area.

[Effects of future climate change on climatic suitability of flue-cured tobacco plantation in Yunnan, China.] / 未来气候变化对云南烤烟种植气候适宜性的影响.

The climatic suitability distribution of flue-cured tobacco planting in Yunnan will be profoundly affected by climate change. According to three key factors influencing climatic suitability of flue-cured tobacco planting in Yunnan, namely, average temperature in July, sunshine duration from July to August, precipitation from April to September, the variations of climatic suitability distribution of flue-cured tobacco planting in Yunnan respectively in 1986-2005, 2021-2040 and 2041-2060 under RCP4.5 and RCP8.5 climate scenarios were investigated by using the climatic simulation data in 1981-2060 and the meteorological observation data during 1986-2005. The results showed that climatic suitability region would expand northward and eastward and plantable area of flue-cured tobacco would gradually increase. The increment of plantable area was more in 2041-2060 than in 2021-2040, and under RCP8.5 scenario than under RCP4.5 scenario. The optimum climatic area and sub-suitable climatic area were expanded considerably, while the suitable climatic area was not much changed. In the future, the north-central Yunnan such as Kunming, Qujing, Dali, Chuxiong, Lijiang would have a big increase in both the optimum climatic area and the cultivable area, meanwhile, the southern Yunnan including Wenshan, Honghe, Puer and Xishuangbanna would have a big decrease in both the optimum climatic area and the cultivable area.

[Simulation model of the development stages of flue-cured tobacco based on physiological development period and growing degree days].

Based on the 2010-2011 experimental data of planting flue-cured tobacco in its representative production counties of Yunnan Province, Southwest China, the models of the tobacco plant physiological development period and growing degree days were established, and validated by the observation data from local agro-meteorological stations. The two models had good performance at pre-transplanting stage, and the errors of the estimated dates were smaller. After transplanting stage, the errors of the estimated dates were larger, because of the disturbances from farming activities such as transplanting and topping. The simulated values based on the tobacco plant physiological development period had a higher coincidence with the observed values, especially at the pretransplanting stage, with the errors of the estimated dates being smaller than two days. As affected by the photoperiod effect, the model of tobacco plant physiological development period fitted better in high latitude regions than in low latitude regions.