| 青藏高原草地植被秋季物候动态及其对极端降水的敏感性分析 |
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| 引用本文： | 刘 敏,,厉 悦,何 冰,赵文文.青藏高原草地植被秋季物候动态及其对极端降水的敏感性分析[J].水土保持研究,2023,30(3):353-363,372. |
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| 作者姓名： | 刘 敏 厉 悦 何 冰 赵文文 |
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| 作者单位： | (1.湖南城市学院, 湖南 益阳413000; 2.数字化城乡空间规划关键技术湖南省重点实验室, 湖南 益阳413000; 3.北京师范大学 水科学研究院, 北京100875) |
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| 摘 要： | 目的]草地植物物候是陆地生态系统对气候变化响应的最显著和最敏感的指标,研究其变化对于理解和预测陆地生态系统的显著变化非常重要。方法]基于1986—2015年的GIMMS NDVI提取了草地生长季末期(end of growing season,EOS),探究了30年间青藏高原草地EOS时空动态及其对不同极端降水指标的敏感性情况。结果]近30年青藏高原西北边缘草地EOS集中在9月底,西南边缘和东南边缘集中在11月上旬。喜马拉雅山脉和横断山脉是整个区域EOS最晚地区,昆仑山脉以北和柴达木盆地及周围地区是EOS最早区域。EOS以推迟趋势为主,推迟速率集中在0～1.5 d/a。EOS变化相对稳定,但在唐都拉山脉以东、横断山脉和喜马拉雅山脉东部地区波动性相对较大。未来一段时间内草地EOS变化趋势与过去30年变化趋势相反。降雨强度(SDII)对高山亚高山草甸植被EOS负影响最大,低强度降雨天数(R10MM)对其正影响最大。高山亚高山草原EOS主要受到SDII、中度强度降雨天数(R20MM)的负影响和最长连续湿润天数(CWD)的正影响。荒漠草原植被主要受到CWD的正影响和R20 MM,SDII的负影响。平地草原EOS对SDII的负敏感性较高。山地草甸EOS对最大1 d降雨量(RX1DAY)正敏感性最高。结论] 青藏高原不同草地植被秋季物候对不同极端降水事件变化的响应呈显著的空间异质性,如较高海拔的高山亚高山草甸和高山亚高山草原的EOS受SDII和R20MM的负影响较大,而干旱区域的荒漠草原与SDII和R20MM呈正相关。研究提供了植物秋季物候如何在未来气候变暖的情况下,极端降水事件增加的情况下青藏高原草地植被秋季物候可能会呈何种变化,可为青藏高原植被草地生长监测、应对气候异常保护策略制定和构建稳定生态屏障提供指导意义。
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| 关 键 词： | EOS 草地 极端降水 青藏高原 |
Spatiotemporal Dynamics of Grassland Phenology and Sensitivity to Extreme Precipitation in Autumn in Qinghai-Tibetan Plateau |
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| LIU Min,,LI Yue,HE Bing,ZHAO Wenwen.Spatiotemporal Dynamics of Grassland Phenology and Sensitivity to Extreme Precipitation in Autumn in Qinghai-Tibetan Plateau[J].Research of Soil and Water Conservation,2023,30(3):353-363,372. |
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| Authors: | LIU Min LI Yue HE Bing ZHAO Wenwen |
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| Institution: | (1.Hunan City University, Yiyang, Hunan 413000, China; 2.Key Laboratory of Key Technologies of Digital Urban-Rural Spatial Planning of Hunan Province, Yiyang, Hunan 413000, China; 3.College of Water Sciences, Beijing Normal University, Beijing 100875, China) |
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| Abstract: | Objective]Plant phenology is the most salient and sensitive indicator of the response of terrestrial ecosystem to climate change. Research for the change of plant phenology is of great significance for understanding and predicting the change of terrestrial ecosystem. Methods]The interference mechanism of extreme precipitation on vegetation phenology for coping with extreme precipitation events was exploreed in the future. Based on the GIMMS NDVI from 1986 to 2015, the end of growing season(EOS)of grassland was extracted, and the temporal and spatial dynamics of EOS and its response to different extreme precipitation indicators on the Qinghai Tibet Plateau in the past 30 years were explored. Results](1)In the past 30 years, in the Qinghai Tibet Plateau, the EOS of the northwest edge basically concentrated at the end of September, and that of the southwest and Southeast edges concentrated in the first ten days of November. The Himalayas and Handgun Mountains were the latest EOS regions in the whole region, and the north of Kunlun Mountains, Qaida Basin and surrounding areas were the earliest EOS regions.(2)EOS was mainly delayed, and the delay rate concentrated at 0～1.5 d/a. The change of EOS was relatively stable, but the fluctuations were relatively large in the east of Tangdula Mountains, Handgun Mountains and the east of Himalayas. The change trend of grassland EOS in the future is opposite to that in the past 30 years.(3)Rainfall intensity(SDII)had the greatest negative impact on EOS of alpine and subalpine meadow vegetation, and low intensity rainfall days(r10 mm)had the greatest positive impact on EOS. The EOS of alpine and subalpine grassland was mainly negatively affected by SDII, the days of moderate intensity rainfall(R20MM)and the longest continuous wet days(CWD). Desert steppe vegetation was mainly positively affected by CWD and negatively affected by R20MM and SDII. The negative sensitivity of EOS of mountain grassland vegetation to SDII was higher. EOS of mountain grassland vegetation was the most sensitive to the maximum one-day rainfall(RX1DAY). Conclusion] The response of autumn phenology of different grassland vegetation on the Qinghai-Tibetan Plateau to different extreme precipitation events showed significant spatial heterogeneity. For example, the EOS of alpine subalpine meadows and alpine subalpine grasslands at higher altitudes were negatively affected by SDII and R20MM, while the desert grasslands in arid regions were positively correlated with SDII and R20MM. This research can provide information on how the autumn phenology of plants may change in the case of future climate warming and the increase of extreme precipitation events, which can provide guidance for the monitoring of vegetation and grassland growth on the Qinghai Tibet Plateau, the formulation of protection strategies against climate anomalies, and the construction of a stable ecological barrier. |
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| Keywords: | phenology grassland extreme precipitation Qinghai-Tibetan Plateau |
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