西安和宝鸡木本植物花期物候变化及温度敏感度对比

植物物候是指示生态系统对气候变化响应的重要证据。已有研究多基于代表性站点的物候观测数据研究物候特征及其对气候变化的响应规律。同一气候区内,不同站点的物候变化及对温度变化响应的敏感度是否一致仍需深入探讨。本文选择同属于暖温带湿润区汾渭平原气候区的西安和宝鸡为研究区,利用"中国物候观测网"在两个站点21个共有物种的开花始期和开花末期数据,比较了1987—2016年两站点各植物花期物候变化特征及其对温度变化响应的敏感度差异。结果表明,西安和宝鸡各物种的开花始期和开花末期均以提前趋势为主。大部分物种开花始期在西安的提前趋势(平均趋势-0.57 d/a)明显强于在宝鸡的提前趋势(平均趋势-0.29 d/a),但开花末期趋势差异不显著。除紫薇和迎春的敏感度差异较大外,其他物种开花始期和开花末期的温度敏感度在两站点间非常接近,无显著差异。由此可见,在同一气候区的不同站点,因增温幅度不同,植物的始花期变化存在较大差异,不能用单站点的物候变化反映整个气候区的物候变化。但同一植物在单站点的温度敏感度可以较好的反映同一气候区其他站点的植物物候-气候关系。本文研究结果可为利用有限站点的物候观测数据分析区域物候...

Comparison of changes in flowering phenology of woody plants and temperature sensitivity between Xi'an and Baoji

Plant phenology is an important indicator of ecosystem response to climate change. Most of the previous studies used the phenological observation data from the representative sites to investigate the phenological characteristics and its responses to climate change. Whether the phenological changes and their sensitivity to temperature are consistent among different sites of the same climatic region needs further exploration. This study selects Xi''an and Baoji, which are distributed at the Fen-Wei Plains climatic region with a humid and temperate climate, as the study area. Using the data of the first flowering date (FFD) and end of flowering date (EFD) of 21 woody plants in Xi''an and Baoji from China Phenological Observation Network, the interannual change and temperature sensitivity of flowering phenology were compared at different sites during 1987-2016. The results showed that the FFD and EFD of most species advanced in Xi''an and Baoji over the past 30 years. For most species, the trend of FFD in Xi''an (mean: -0.57 days/year) was significantly stronger than that in Baoji (mean: -0.29 days/year), but there was little difference in the trend of EFD between the two sites. Except for Lagerstroemia indica and Jasminum nudiflorum, the temperature sensitivity of the FFD and EFD for other species presented no significant difference between the two sites. Thus, the phenological changes at a single site cannot reflect the phenological changes in the whole climatic region, because the changes in FFD always showed significant discrepancies among different sites due to divergent changes in temperature. However, the temperature sensitivity of FFD and EFD calculated at a single site could well reflect the plant phenology-climate relationship at other sites in the same climatic region. Our study could provide a scientific basis for the analysis of regional phenological changes and responses to climate change using phenological observation data from the limited sites.