The Sensitivity of Green-Up Dates to Different Temperature Parameters in the Mongolian Plateau Grasslands

The rise in global average surface temperature has promoted the advancement of spring vegetation phenology. However, the response of spring vegetation phenology to different temperature parameters varies. The Mongolian Plateau, one of the largest grasslands in the world, has green-up dates (GUDs) with unclear sensitivity to different temperature parameters. To address this issue, we investigated the responses of GUDs to different temperature parameters in the Mongolian Plateau grasslands. The results show that GUDs responded significantly differently to changes in near-surface temperature (TMP), near-surface temperature maximum (TMX), near-surface temperature minimum (TMN), and diurnal temperature range (DTR). GUDs advanced as TMP, TMX, and TMN increased, with TMN having a more significant effect, whereas increases in DTR inhibited the advancement of GUDs. GUDs were more sensitive to TMX and TMN than to TMP. The sensitivity of GUDs to DTR showed an increasing trend from 1982 to 2015 and showed this parameter's great importance to GUDs. Our results also show that the spatial and temporal distributions of temperature sensitivity are only related to temperature conditions in climatic zones instead of whether they are arid.

Automated summary

The increase in global average surface temperature has led to advancements in spring vegetation phenology, but the response to different temperature parameters varies. The sensitivity of green-up dates (GUDs) in the Mongolian Plateau grasslands to various temperature parameters was investigated. The results showed that GUDs responded differently to near-surface temperature, near-surface temperature maximum, near-surface temperature minimum, and diurnal temperature range. GUDs advanced with increasing temperature, particularly minimum temperature, while an increase in diurnal temperature range inhibited the advancement of GUDs. The sensitivity of GUDs to temperature maximum and minimum was higher than to near-surface temperature. The sensitivity of GUDs to diurnal temperature range increased over time and was found to be of great importance. The spatial and temporal distribution of temperature sensitivity was related to climatic zones rather than aridity.