Wang Hongying, Wang Bo, Chen Wenwen
School of Resources and Environmental Engineering, Anhui University, Hefei, China.
Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, Anhui University, Hefei, China.
Integr Zool. 2025 Jan;20(1):135-143. doi: 10.1111/1749-4877.12831. Epub 2024 May 2.
Scatter-hoarding rodents play important roles in plant regeneration and species coexistence in many forest ecosystems. Cache pilferage, the behavior of rodents seeking or relocating seeds cached by other individuals, is ubiquitous during the scatter-hoarding process. The effects of canopy openness on cache pilferage have received considerable attention, most of which have focused on the comparison between full canopy cover and completely open areas, such as forest gaps. However, little attention has been given to whether the subtle variation in forest canopy openness affects cache pilferage, although subtle variation in light environments exists in many forests, especially tropical and subtropical forests, where the overall canopy is large and the forest window is relatively small. Here, we directly tested these questions by simulating 400 artificial caches, each containing one seed from four selected tree species, in a subtropical forest in southwestern China. The overall canopy openness of the forest was relatively small (with a mean value of 11.1%), but subtle spatial variation still existed (ranging from 5.7% to 19.5%). Overall, caches with lower canopy openness were more likely to be pilfered and removed faster, although not all species showed the same pattern. Our study highlights that subtle variation in forest canopy openness, even in a closed primary forest, has significant effects on cache pilferage by rodents, which may influence the following seed germination and forest regeneration processes. Additionally, seedling species composition may further be altered because the canopy effects on cache pilferage are species-specific.
分散贮藏的啮齿动物在许多森林生态系统的植物更新和物种共存中发挥着重要作用。贮藏物盗窃行为，即啮齿动物寻找或重新安置其他个体贮藏的种子的行为，在分散贮藏过程中普遍存在。林冠开阔度对贮藏物盗窃行为的影响受到了相当多的关注，其中大部分研究集中在全林冠覆盖区域和完全开阔区域（如林窗）之间的比较。然而，尽管在许多森林中，特别是热带和亚热带森林中，光照环境存在细微变化，整体林冠较大而林窗相对较小，但对于森林林冠开阔度的细微变化是否会影响贮藏物盗窃行为却很少有人关注。在此，我们通过在中国西南部的一片亚热带森林中模拟400个人工贮藏点，每个贮藏点包含来自四种选定树种的一粒种子，直接测试了这些问题。这片森林的整体林冠开阔度相对较小（平均值为11.1%），但仍存在细微的空间变化（范围从5.7%到19.5%）。总体而言，林冠开阔度较低的贮藏点更有可能被盗窃且被移除的速度更快，尽管并非所有树种都呈现相同的模式。我们的研究强调，即使在封闭的原始森林中，森林林冠开阔度的细微变化对啮齿动物的贮藏物盗窃行为也有显著影响，这可能会影响后续的种子萌发和森林更新过程。此外，由于林冠对贮藏物盗窃行为的影响具有物种特异性，幼苗物种组成可能会进一步改变。
