关键词: 辣木, 辣木, 营养元素, 缺素症, 幼苗生长

Abstract: Based on daily maximum temperature data of 18 meteorological stations in Hainan island during 1966-2015, the temporal and spatial distribution characteristics of high temperature days, frequency and intensity of heatwaves in Hainan island were analyzed. The results showed that: (1) for spatial distribution of annual high temperature days, frequency of different-class heatwaves and heatwaves intensity, there were higher in the northwest than in the southeast, that was, the high-value regions concentrated in the northwest, while the lower regions distributed in coastal areas, thereinto, annual high temperature days in Changjiang was the most, heatwaves frequency ties was the most, heatwaves intensity was the strongest; there was almost no heatwaves in Dongfang and Sanya; (2) in the last 50 years, light heatwaves with 3-4 days duration was the main type in Hainan island, and average high temperature days, total heatwaves frequency showed an overall increasing trend, thereinto, frequency of light and moderate heatwaves showed a slow increasing trend, variation of severe heatwaves frequency was not obvious; except severe heatwaves, high temperature days and frequency of other class heatwaves were more in most years after 2003; the increase trend of heatwaves intensity was non-significant, but it had increased obviously after 2000; (3) regional variation characteristics presented the non-uniform distribution, the annual high temperature days, frequency of annual heatwaves and light heatwaves in most areas had significant increasing trend, however, trends of annual heatwaves intensity, moderate and severe heatwaves frequency presented the non-uniform distribution and were non-significant in most areas.