华南地区龙眼种植的温度风险评估

建立了龙眼温度适宜度模型和风险动态评估模型,对华南地区龙眼温度适宜性和风险性及其时空差异进行了计算、评价和预测。首先,分析龙眼各生育期适宜度,结果表明:影响华南地区龙眼生产的关键问题不是冷害,而是冬春季节的热害;未来各生育期中除果实发育成熟期和抽梢期无明显变动外,其他生育期的温度适宜度都有下降趋势。其次,根据华南地区龙眼不同减产率的温度适宜度的概率分布,将华南地区龙眼温度风险大致划分高、中、低三个区,并对不同时段华南地区龙眼温度风险进行了对比分析,结果表明:在空间上,华南地区龙眼温度风险性的地域分异呈现纬度地带性规律;在时间上,其风险性随时间推移有增加的趋势。最后,分析了龙眼生育期温度风险对气候变暖的响应。

Assessing the temperature risk to longan planting in South China

Being an important subtropical fruit, the longan is very sensitive to climate change, especially temperature. Based on previous researches, selecting observed temperature data from 60 counties of South China from 1960 to 2005, the article established the longan temperature suitability model and the temperature risk dynamic assessment model to calculate the temperature suitability and risk of longan, to evaluate the temporal and spatial differences and also to predict the temperature suitability and risk of longan. Firstly, the article analyzes the temperature suitability of longan at different growth stages, and the result shows that temperature change has a great impact on the temperature suitability of dormancy stage, physiologic differentiation of flower bud stage and morphologic differentiation of flower bud stage. All these have low suitability and high variability, while the other three stages have high suitability and low variability. In addition, the inter-annual change of temperature suitability at different growth stages is analyzed, and the result shows all the growth stages except for fruit growth and maturity stage and treetop growth stage have a decreasing trend in the future. This is caused by the temperature differences between the different growth stages. Further study indicates that it is hot damage in winter and spring rather than cold damage that plays an important role in longan production in South China. Secondly, based on probability distributions of the longan temperature suitability degrees of different reduction rates of yield, the article divided South China into three regions: the low risk region, the medium risk region and the high risk region. At the same time, a comparative analysis was done on the longan temperature risk among different periods in South China. The result shows that there is difference in the changing trend of the longan temperature risk: in the aspect of spatial distribution, the temperature risk degree decreases with increasing latitude in South China; in the aspect of temporal distribution, the temperature risk of longan has a gradual increasing trend with the elapse of time. Finally, the responses of longan growth stages to climate warming in South China were analyzed.