Ferrari Giulia, Devineau Olivier, Tagliapietra Valentina, Johnsen Kaja, Ossi Federico, Cagnacci Francesca
Inland Norway University of Applied Sciences, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology Koppang Norway.
Fondazione Edmund Mach Research and Innovation Centre San Michele all'Adige (Trento) - Italy.
Ecol Evol. 2025 Jun 2;15(6):e71466. doi: 10.1002/ece3.71466. eCollection 2025 Jun.
Climate change effects on primary productivity are especially evident along altitudinal and latitudinal gradients. Some of the species with a fast reproductive cycle strategy and relying on primary productivity may rapidly respond to such changes with alterations to demographic parameters. However, how these bottom-up effects may emerge in systems with different population dynamics has not been elucidated. We aimed to assess the role of food availability on rodent demography in populations characterised by different dynamics, that is multiannual cycles in Northern European populations and mast-driven outbreaks in Southern European populations, both driven by intrinsic and extrinsic factors. We live-trapped woodland rodents at these latitudinal extremes in two study systems (Norway, Italy) while deploying control/treatment designs of food manipulation providing ad libitum trophic resource availability, albeit not reflecting the natural resource fluctuations. We applied a multistate open robust design model to estimate population patterns and survival rates while controlling for seasonal variation, intrinsic traits, and co-occurrence of sympatric species. Yellow-necked and wood mouse ( spp.) were sympatric with bank vole () in Italy, while only the latter was trapped in Norway. Food provisioning increased both survival and population size of bank vole in Norway, where temperatures are harsher and snow cover persists in winter. In milder Italian habitats, the wood mouse abundance was boosted by food availability, increasing also survival rates (but only in females), whereas the bank vole showed a decrease in both parameters across sexes. We speculate that overabundant food resources may trigger some forms of competition between sympatric wood mouse and bank vole, although other types of interactions, such as predation and parasitism, may also contribute. By manipulating food availability in two systems where rodents have different population dynamics, we showed how resource availability exerted bottom-up effects on rodent demography, especially in the context of climate change, although being mediated by other intrinsic and extrinsic factors.
气候变化对初级生产力的影响在海拔和纬度梯度上尤为明显。一些具有快速繁殖周期策略并依赖初级生产力的物种可能会通过改变人口统计学参数来迅速应对此类变化。然而，这些自下而上的影响在具有不同种群动态的系统中如何出现尚未得到阐明。我们旨在评估食物可获得性在具有不同动态特征的种群（即北欧种群的多年周期和南欧种群由果实大年驱动的爆发，两者均由内在和外在因素驱动）中对啮齿动物种群统计学的作用。我们在两个研究系统（挪威、意大利）的这些纬度极端地区对林地啮齿动物进行活体诱捕，同时采用食物操纵的对照/处理设计，提供充足的营养资源，尽管这并未反映自然资源的波动。我们应用多状态开放稳健设计模型来估计种群模式和存活率，同时控制季节变化、内在特征以及同域物种的共存情况。在意大利，黄颈鼠和林姬鼠（ spp.）与棕背䶄（）同域分布，而在挪威只捕获到了后者。在挪威，由于冬季气温更严酷且积雪持续存在，提供食物提高了棕背䶄的存活率和种群数量。在气候较温和的意大利栖息地，食物可获得性提高了林姬鼠的数量，也提高了存活率（但仅在雌性中），而棕背䶄在两性中的这两个参数均有所下降。我们推测，食物资源过剩可能引发同域分布的林姬鼠和棕背䶄之间的某种形式的竞争，尽管其他类型的相互作用，如捕食和寄生，也可能起作用。通过在两个啮齿动物具有不同种群动态的系统中操纵食物可获得性，我们展示了资源可获得性如何对啮齿动物种群统计学产生自下而上的影响，尤其是在气候变化的背景下，尽管这种影响是由其他内在和外在因素介导的。
