Liu Yongjie, Li Zhenqing
State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
Front Plant Sci. 2020 Nov 16;11:555743. doi: 10.3389/fpls.2020.555743. eCollection 2020.
Extreme events such as extreme drought and precipitation are expected to increase in intensity and/or duration in the face of climate change. Such changes significantly affect plant productivity and the biomass allocation between reproductive and vegetation organs (i.e., reproductive allocation). Our aims are to test the effects of water addition on the trade-offs in allocation of plant biomass and whether such effects are modified by species. A manipulative experiment was conducted from May 2000 to October 2001, where four dominant plant species (i.e., , , , and ) in the Inner Mongolia steppe in China were treated with 8 levels of water addition. Results demonstrated that water addition significantly affected the reproductive allocation of plants, and such effects were modified by species. Specifically, with increasing water availability, was not impacted, while allocated more biomass to reproductive organs than to vegetative organs, while such allocation in and first decreased, and then increased after reaching a peak. Our results indicated that plant species can adjust their reproductive allocation patterns to deal with water availability gradients. Climatic factors such as rainfall and temperature usually co-appearing, thus future research should explore the joint effects of several climate change factors on grasslands in order to maintain the health and sustainability of grasslands.
面对气候变化，诸如极端干旱和降水等极端事件的强度和/或持续时间预计将会增加。此类变化会显著影响植物生产力以及生殖器官与营养器官之间的生物量分配（即生殖分配）。我们的目标是测试水分添加对植物生物量分配权衡的影响，以及此类影响是否因物种而异。于2000年5月至2001年10月开展了一项控制性实验，对中国内蒙古草原的四种优势植物物种（即 、 、 和 ）进行了8个水分添加水平的处理。结果表明，水分添加显著影响了植物的生殖分配，且此类影响因物种而异。具体而言，随着水分可利用性的增加， 未受影响，而 分配到生殖器官的生物量多于营养器官，而 在 和 中的此类分配先下降，在达到峰值后又增加。我们的结果表明，植物物种能够调整其生殖分配模式以应对水分可利用性梯度。降雨和温度等气候因素通常同时出现，因此未来的研究应探索多种气候变化因素对草原的综合影响，以维持草原的健康与可持续性。
