Qian Jianqiang, Wang Zhengwen, Klimešová Jitka, Lü Xiaotao, Kuang Wennong, Liu Zhimin, Han Xingguo
CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, P. R. China.
Department of Functional Ecology, Institute of Botany ASCR, CZ-379 82 Třeboň, Czech Republic.
Ann Bot. 2017 Nov 10;120(5):755-764. doi: 10.1093/aob/mcx072.
Understanding the changes in below-ground bud bank density and composition along a climatic gradient is essential for the exploration of species distribution pattern and vegetation composition in response to climatic changes. Nevertheless, investigations on bud banks along climatic gradients are still scarce. The below-ground bud bank is expected to be reduced in size in arid conditions, and costly, bud-bearing organs with long spacers would be replaced by more compact forms with buds that are better protected than those found in moist conditions.
How total bud density and composition (different bud bank types) change with aridity (calculated value 0·43-0·91), mean annual precipitation (MAP; 93-420 mm) and mean annual temperature (MAT; -1·51 to 6·93 °C) was tested at 21 sites along a 2500-km climatic gradient in the temperate steppe of northern China.
Belowground bud bank density decreases towards the dry, hot end of the climatic gradient. Based on the distribution of bud types along the climatic gradient, bulb buds and tiller buds of tussock grasses seem to be more resistant to environmental stress than rhizome buds. The dominance of annual species and smaller bud banks in arid region implies that plant reproductive strategies and vegetation composition will be shifted in scenarios of increased drought under future climate change.
了解地下芽库密度和组成沿气候梯度的变化，对于探索物种分布格局和植被组成对气候变化的响应至关重要。然而，关于沿气候梯度的芽库研究仍然匮乏。预计在干旱条件下地下芽库规模会减小，带有长间隔物的昂贵的芽器官将被更紧凑的形式所取代，这些芽比在湿润条件下的芽受到更好的保护。
在中国北方温带草原2500公里的气候梯度上的21个地点，测试了总芽密度和组成（不同芽库类型）如何随干旱度（计算值0·43 - 0·91）、年平均降水量（MAP；93 - 420毫米）和年平均温度（MAT；-1·51至6·93°C）而变化。
地下芽库密度朝着气候梯度干燥、炎热的一端降低。根据芽类型沿气候梯度的分布，丛生禾本科植物的鳞茎芽和分蘖芽似乎比根茎芽更能抵抗环境压力。干旱地区一年生植物的优势和较小的芽库意味着在未来气候变化下干旱加剧的情况下，植物繁殖策略和植被组成将会发生变化。
