Context dependent effect of an herbivorous subterranean rodent on vegetation in relation to primary productivity

Subterranean rodents could modify the environment becoming keystone species and/or ecosystem engineers. This role may be context dependent if the changes produced shift throughout the species range and are stronger under certain environmental conditions. Our objective was to analyze if the effect of Ctenomys mendocinus on vegetation cover is context dependent, specifically examining variations between areas with different levels of primary productivity. We compared the effect of C. mendocinus on plant cover among four contrasting environments and found that it depended on primary productivity in a predictable manner. In low productivity environments, the rodent significantly reduces vegetation cover, while it has no discernible effect in highly productive ones. These findings suggest that the effect of C. mendocinus on plant cover may be dependent on primary productivity level and highlights the importance of accounting for the underlying environmental factors that influence the intensity of C. mendocinus-plant interaction.地下啮齿类动物可通过改造生境成为关键物种（keystone species）和/或生态系统工程师（ecosystem engineers）。这类生态功能可能具有情境依赖性：即其介导的生境改变会随物种分布范围的差异而发生变化，且在特定环境条件下作用更为显著。本研究旨在分析门多萨栉鼠（Ctenomys mendocinus）对植被盖度的影响是否具有情境依赖性，重点考察不同初级生产力（primary productivity）水平区域间的差异。我们在四种生境差异显著的环境中比较了门多萨栉鼠对植物盖度的影响，结果发现其影响随初级生产力呈现出可预测的变化规律。在初级生产力较低的生境中，该啮齿类动物会显著降低植被盖度；而在生产力较高的生境中则未产生可观测到的影响。本研究结果表明，门多萨栉鼠对植被盖度的影响可能依赖于生境的初级生产力水平，同时也凸显了考量影响门多萨栉鼠与植物互作强度的潜在环境因子的重要性。