Wei Xiaoxing, Guo Zhenggang
The 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 730020, China.
Plants (Basel). 2022 Aug 31;11(17):2266. doi: 10.3390/plants11172266.
Disturbance by small burrowing herbivores often has an impact on plant aboveground biomass of grassland because it makes grasslands into a mosaic of discrete vegetated surfaces and bare soil patches. This study focuses on the plateau pika () to investigate the effect of the disturbance by a small burrowing herbivore on plant aboveground biomass through upscaling the quadrat scale to the plot scale across five sites. This study showed that the plateau pika disturbance reduced sedge biomass and increased forb biomass. In contrast, they did not affect plant community biomass, grass biomass and legume biomass at the quadrat scale across the five sites. At the plot scale, that is, when the bare soil patches with a lack of plants were considered, plateau pika disturbance induced lower aboveground biomass of the plant community, sedge and legumes, while it had no relationship with grass biomass and forb biomass. As the disturbance intensity increased, the aboveground biomass of the plant community and sedge decreased, whereas the grass biomass showed a hump-shaped trend. These results indicate that plateau pika disturbance might be not beneficial to alpine meadows given the aboveground biomass of the plant community at the plot scale. In contrast, the intermediate disturbance intensity improves the grazing quality of alpine meadows through the higher grass biomass. The findings of this study imply that the plot scale is better than the quadrat scale to investigate the influence of the disturbance by a small burrowing herbivore on the plant aboveground biomass, and that management of a small burrowing herbivore needs to consider its disturbance intensity.
小型穴居食草动物造成的干扰往往会对草原植物地上生物量产生影响，因为它会使草原形成由离散植被表面和裸土斑块组成的镶嵌体。本研究聚焦于高原鼠兔，通过将样方尺度扩大到五个地点的样地尺度，来探究小型穴居食草动物的干扰对植物地上生物量的影响。本研究表明，高原鼠兔的干扰降低了莎草生物量，增加了杂类草生物量。相比之下，在五个地点的样方尺度上，它们并未影响植物群落生物量、禾本科生物量和豆科生物量。在样地尺度上，即当考虑到缺乏植物的裸土斑块时，高原鼠兔的干扰导致植物群落、莎草和豆科植物的地上生物量降低，而它与禾本科生物量和杂类草生物量无关。随着干扰强度的增加，植物群落和莎草的地上生物量下降，而禾本科生物量呈驼峰状趋势。这些结果表明，考虑到样地尺度上植物群落的地上生物量，高原鼠兔的干扰可能对高寒草甸不利。相比之下，中等干扰强度通过较高的禾本科生物量提高了高寒草甸的放牧质量。本研究结果表明，在研究小型穴居食草动物的干扰对植物地上生物量的影响时，样地尺度比样方尺度更好，并且对小型穴居食草动物的管理需要考虑其干扰强度。
