气候变化对通辽草甸草原草本植物物候期的影响

植物物候期的变化直接反映气候变化,并成为全球变化研究的重点。基于通辽市巴雅尔吐胡硕牧业气象试验站1981-2016年主要植物羊草(Leymus chinensis)、冰草(Agropyron cristatum)、委陵菜(Potentilla chinensis)、车前(Plantago asiatica)物候观测数据和同期气象观测数据,研究了气候变化对草本植物返青期、黄枯期和生长季的影响,结果表明:1)研究区近36年来年均气温上升0.35℃·10 a-1(P0.01),年均降水量减少22.73 mm·10 a-1,气候暖干化特征明显。2)草本植物返青期呈一致性延迟趋势,平均每10年延迟1.16~7.60 d。羊草、车前返青推迟主要受2-3月累计降水量减少的影响,冰草、委陵菜返青推迟主要受2-4月、3-4月累计降水量减少的影响。3)草本植物黄枯期变化趋势不同,羊草、冰草黄枯期延迟主要受夏季、初秋累计降水量影响,委陵菜黄枯期提前主要受夏季、初秋的累计降水量和日照时数共同影响,车前草黄枯期延迟主要受夏季、初秋平均气温影响。4)草本植物生长季长度主要受气温和降水量影响。气候变暖后,研究区夏季、生长季平均气温显著上升,降水量逐渐减少,导致羊草、冰草、委陵菜生长季缩短;而车前对气温反应比较敏感,气温升高有利于车前生长季延长。

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.