Effect of climate change on the phenological phase of herbs in meadow grassland of Tongliao City, Inner Mongolia

Plant phenology can directly reflect the effects of climate change, and it has become the focus of global climate change research. We compiled the meteorological data from 1981 to 2016 and the observational data of phenophases of four main herbs, Leymus chinensis, Agropyron cristatum, Potentilla chinensis, and Plantago asiatica from the Enkhbayar animal husbandry meteorological experiment station of Tongliao City, Inner Mongolia. The purpose of this research is to elucidate the effects of climate change on germination stage, withering stage, and the growing-season length for herbs. The results showed that the average air temperature had increased 0.35 ℃·10 a-1 (P<0.01) and precipitation had decreased 22.73 mm·10 a-1, and the climate was getting warmer and drier. The herb germination stage had been postponed 1.16~7.60 d·10 a-1, but the reasons were different with different herbs. The germination stages of L. chinensis and P. asiatica were mainly affected by the cumulative precipitation reduction from February to March, and the germination stages of A. cristatum and P. chinensis were affected by the cumulative precipitation reduction from February to April and March to April, respectively. The withering stage of herbs had different trends. The delay of the withering stage of L. chinensis and A. cristatum were mainly affected by precipitation in summer and early autumn. The advance in the withering stage of P. chinensis was mainly affected by precipitation and sunshine in summer and early autumn. The withering stage of P. asiatica was delayed mainly by average temperatures in summer and early autumn. The length of the growing season was mainly influenced by air temperature and precipitation. Our research demonstrated that the coming climate change will shorten the growing season of L. chinensis, A. cristatum and P. chinensis, due to the air temperature significantly increasing and precipitation decreasing in summer and the growing season; however, the increasing air temperature will extend the growing season of P. asiatica, due to its sensitively to temperature.