黄土高原半干旱区物候变化特征及其对气候变暖的响应

利用黄土高原半干旱区1994-2014年典型植物物候和气温资料,通过相关分析等方法分析典型植物展叶始期、展叶盛期、开花始期、开花盛期等春季物候期和叶初变期、叶全变期、落叶始期、落叶末期等秋季物候期的变化特征,以揭示黄土高原典型植物物候期对气候变暖的响应规律。结果表明:(1)在展叶期,草本植物历史最早和最晚出现日期相差20~36d,木本植物为20~38d;(2)草本植物春季物候期表现为明显的提前趋势,木本植物物候期的变化趋势差异较大,牡丹、旱柳展叶始期提前趋势明显;草本植物叶变色始期、黄枯始期以及木本植物落叶始期等秋季物候期的推迟趋势明显;(3)研究期内牡丹生长季的变化趋势不明显,其余典型植物生长季均一致表现为显著延长趋势(P0.05);(4)典型植物开花始期对前1月、前第3月(车前草为当月)以及春季(3-5月)气温的响应明显,春季气温每升高1℃,植物开花始期提前5~8d。研究结果表明黄土高原草本植物对气候变暖的响应比木本植物更明显,因此,在黄土高原生态脆弱区,选用对气候变化反应较为迟钝的杏树、榆树等乔木进行地区生态恢复重建较适宜。

Phenological Variation and Its Response to Climate Warming in Semi-Arid Region of Loess Plateau

To reveal the response characteristics of typical plant phenology to climate warming in semi-arid region of the Loss plateau,the variation characters of phenophases for typical plant during spring and autumn was investigated by using correlation methods,based on phonological and temperature data from 1994 to 2014.The results showed that the day difference of leaf-expansion stage for herbaceous plant between earliest date and latest date ranged from 20-36d in historical record,and 20-38d for woody pant.The phenology for herbaceous plant in spring showed an advanced trend,and there was a large difference of phenology for woody plants.The leaf-expansion stage of Peony (Paeonia suffruticoss) and Hankow willow (Salix matsudana) showed an obviously advanced trend.Meanwhile,there was a delay trend in discoloration beginning period and withered beginning period of herbaceous plant,as same as for woody plant,withered the deciduous beginning period in autumn.There was no obviously variation for growing season of Peony,but the growing season of other typical plant increased significantly.The beginning flowering stage was sensitive to temperature in past one month and three months,and temperature from March to May.The beginning flowering stage advanced 5-8d when the temperature increased 1℃.We concluded that the phenology of herbaceous plant in Loss plateau was more sensitive to climate warming than woody plant.For the purpose of ecological restoration,we suggested that choosing insensitive trees to climate warming,including Almond (Prunus armeniaca) and Elm (Ulmus pumila),in vulnerable region of Loss plateau was the best choice.