This study focuses on the phenological changes of Stipa krylovii steppe in Inner Mongolia and their responses to the maximum and the minimum air temperature, based on MODIS NDVI data and corresponding ground-based phenological observations from 2000 to 2024. The HANTS method was employed to reconstruct NDVI time series, and the start of season (SOS) and the end of season (EOS) were obtained using a dynamic threshold method. The results showed that: (1) the thresholds of 50% for SOS and 65% for EOS resulted in the lowest extraction errors, with RMSE values of 8d and 11d, respectively; (2) from 2000to 2024, the SOS advanced at a rate of 0.32d/10a, while the EOS was delayed at a rate of 0.12d/10a, indicating a prolonged growing season; (3) the EOS was more sensitive to air temperature than the SOS, the daytime mean maximum temperature had a significantly stronger advancing effect on EOS than the nighttime mean minimum temperature. This study determined the remote sensing-based optimal thresholds of Stipa krylovii steppe phenology, revealed the effect of air temperature on phenological change, and provided a scientific basis for steppe management under 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 |