气候变化背景下青藏高原东部猪毛蒿物候的变化规律和影响因素

近几十年来青藏高原正经历着广泛而深远的气候变化，这种变化对当地物种的物候及分布格局产生了显著影响。猪毛蒿作为干旱半干旱地区的优势物种和影响群落稳定性的关键物种，青藏高原东缘是其重要的分布区域之一，然而其物候将如何应对气候变化目前我们尚不清楚。为此，基于青海省东部连续20年的气象数据和原位物候观测实验，探讨猪毛蒿物候的变化规律及量化不同气候因子的相对贡献率。结果表明：1)过去20年间年均温和年均每日日照时长分别呈现出显著的上升和下降趋势，而年降水和年均每日最大风速没有显著的变化；2)20年间猪毛蒿返青-开花的时间间隔和开花-结果的时间间隔并未表现出显著的变化趋势，结果-枯黄的时间间隔显著缩短；3)所有气候因子均对猪毛蒿不同物候的时间间隔有显著影响，其中最大风速是影响猪毛蒿物候时间间隔最重要的气候因子。这一研究发现可以为气候变化情景下青藏高原高寒植物的保护和利用提供理论依据。

Drivers in shaping the phenological dynamics of Artemisia scoparia on the eastern Qinghai-Tibetan Plateau under climate change

In recent decades, the Qinghai-Tibetan Plateau (QTP) has been experiencing extensive and profound climate change, which would significantly affect phenology and distribution pattern of local species. Artemisia scoparia is a dominant species and key species affecting community stability in arid and semi-arid areas. The eastern edge of QTP is one of its important distribution areas. How the phenology of Artemisia scoparia responds to climate change is still an unsettled question. Therefore, the meteorological data and in-situ phenological observation experiments of 20 consecutive years on the eastern QTP were conducted to explore the dynamics of phenology of Artemisia selengensis and quantify the relative importance of different climatic factors. The results showed that: 1) In the past 20 years, the average annual temperature and average annual daily sunshine duration presented significantly upward and downward trends respectively, while annual precipitation and average annual daily maximum wind speed did not change significantly; 2) The intervals from greening-up to flowering and from flowering to fruiting of Artemisia selengensis did not show any significant trends in the past 20 years, while the interval from fruiting to withering was significantly shortened; 3) All climatic factors had significant effects on the intervals of different phenology of Artemisia selengensis, and the maximum wind speed was the most important climatic factor affecting the phenology of Artemisia selengensis. The study could provide a theoretical basis for the protection and utilization of alpine plants on the QTP under climate change.