Guo Fenghui, Li Xiliang, Jimoh Saheed Olaide, Ding Yong, Zhang Yong, Shi Shangli, Hou Xiangyang
Pratacultural College, Gansu Agricultural University, Lan Zhou, Gan Su Province, China.
Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Hohhot, Inner Mongolia, China.
PeerJ. 2020 Oct 8;8:e10116. doi: 10.7717/peerj.10116. eCollection 2020.
There is growing evidence that herbivory-induced legacy effects permit plants to cope with herbivory. However, herbivory-induced defense strategies in plants against grazing mammals have received little attention. To further understand the grazing-induced legacy effects on plants, we conducted a greenhouse experiment with experiencing different grazing histories. We focused on grazing-induced legacy effects on above-ground spatial avoidance and below-ground biomass allocation. Our results showed that collected from the continuous overgrazing plot (OG) exhibited higher performance under simulated grazing in terms of growth, cloning and colonizing ability than those collected from the 35-year no-grazing plot (NG). The enhanced adaptability of OG was attributed to increased above-ground spatial avoidance, which was mediated by larger leaf angle and shorter height (reduced vertical height and increased leaf angle contributed to the above-ground spatial avoidance at a lower herbivory stubble height, while reduced tiller natural height contributed to above-ground spatial avoidance at a higher herbivory stubble height). Contrary to our prediction, OG pre-allocated less biomass to the rhizome, which does not benefit the herbivory tolerance and avoidance of ; however, this also may reflect a tolerance strategy where reduced allocation to rhizomes is associated with increased production of ramets.
越来越多的证据表明,食草动物诱导的遗留效应使植物能够应对食草行为。然而,植物针对放牧哺乳动物的食草动物诱导防御策略却很少受到关注。为了进一步了解放牧对植物的遗留效应,我们进行了一项温室实验,使用经历了不同放牧历史的植物。我们重点研究了放牧对地上空间回避和地下生物量分配的遗留效应。我们的结果表明,从持续过度放牧地块(OG)采集的植物在模拟放牧条件下,在生长、克隆和定殖能力方面比从35年未放牧地块(NG)采集的植物表现更好。OG适应性增强归因于地上空间回避增加,这是由更大的叶角和更短的高度介导的(在较低的食草残茬高度下,叶角增大和垂直高度降低有助于地上空间回避,而在较高的食草残茬高度下,分蘖自然高度降低有助于地上空间回避)。与我们的预测相反,OG对根状茎的生物量预分配较少,这对食草耐受性和回避没有好处;然而,这也可能反映了一种耐受策略,即减少对根状茎的分配与分株产量增加有关。