Based on the data of rice growth period in Dongfang and Ledong, main producers for rice seed reproduction in Hainan, and the meteorological data from 1971 to 2020, the Penman-Monteith formula and crop coefficient method and the method recommended by the Soil Conservation Service of the United States Department of Agriculture were used to obtain the water requirement (ETc), effective precipitation (Pe) and water deficit (Dw) of rice seed reproduction in field period and early, middle and late stage of field period. The change characteristics of water supply and demand of rice seed reproduction in the two regions were then analyzed. The 50-year average value of ETc in field period of rice seed reproduction in Dongfang and Ledong was 400.2 mm and 322.3 mm, respectively, the mean value of Pe was 45.7 mm and 84.3 mm, respectively, and the mean value of Dw was 354.5 mm and 238.0 mm, respectively. The ETc and Dw in field period of rice seed reproduction were mainly distributed in the middle and early stages, accounting for 72.4% to 85.2% of ETc and Dw during the field period. The Pe in field period of rice seed reproduction was mainly distributed in the late and middle stages, accounting for 78.2% and 85.6% of Pe during the field period, respectively. In the past 50 years, the ETc and Dw of rice seed reproduction in field period and all growth stages of field period in Dongfang showed an increasing trend (the increase in field period was significant), while the Pe showed a decreasing trend. The variation trend of ETc, Pe and Dw of rice seed reproduction with time in Ledong was roughly opposite to that in Dongfang. In the past 50 years, the water shortage situation of rice seed reproduction in Dongfang was significantly worsening, while the water shortage situation in Ledong was easing to some extent but remained severe. Effective measures should be taken to mitigate the impact of climate change on the rice seed reproduction. In the past 50 years, the main reasons for the increase of ETc and Dw during most growth stages of rice seed reproduction in Dongfang were the insignificant increase in high temperature and extremely significant increase in low temperature, or the insignificant increase in high temperature and sunshine hours. The main reasons for the decrease of ETc and Dw during most growth stages of rice seed reproduction in Ledong were the insignificant decrease in sunshine hours, extremely significant decrease in average wind speed, or insignificant decrease in sunshine hours and insignificant increase in precipitation. The results of this study provide strong support for rational water use and scientific irrigation scheme for rice seed reproduction in Hainan province under the background of climate change.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |