As spatially fine-scale foraging decisions are intrinsic to browsing herbivores such as deer, the search and selection of individual plants may be shaped by the density of neighbouring plants. However, how such neighbourhood effects may modify herbivore foraging decisions at different spatial scales is largely unexplored. Our main goal was to examine deer foraging preferences for tree species and seedling sizes, and to ask whether the spatial relationship of unbrowsed and browsed seedlings was indicative of different neighbourhood effects at the spatial scale of seedling neighbourhoods. We used two data sets from an old-growth temperate forest: (1) a seedling inventory and (2) fully mapped transect data, and applied a generalized linear mixed model and spatial point pattern analyses, respectively. We found that neighbourhood effects modified deer foraging behaviour depending on the proximity, density and species identity of neighbours, which, in turn, determined the strength and spatial extent of browsing impacts on tree seedlings. While sycamore maple seedlings experienced the highest levels of deer selectivity, deer were selective for European beech seedlings only within short distances. Beyond these distances, beech seedlings were browsed only opportunistically, as conspecific neighbours ceased to modify deer selectivity. Beech seedlings were also more susceptible to browsing within short distances from silver fir seedlings, indicating an associational susceptibility. As fir seedlings experienced strong and extensive density-dependent deer selectivity both near conspecific and beech neighbours, using such neighbourhood effects may not be a promising tool to prevent deer browsing on tree seedlings at the spatial scale of seedling neighbourhoods.

中文翻译：

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邻里效应改变了鹿对树苗的食草行为

由于空间精细的觅食决定是食草动物（如鹿）所固有的，因此对单个植物的搜索和选择可能受邻近植物的密度影响。然而，这种邻域效应如何在不同空间尺度上改变食草动物的觅食决策，在很大程度上尚未得到探索。我们的主要目标是检查鹿对树种和幼苗大小的觅食偏好，并询问未浏览和浏览的幼苗的空间关系是否表明幼苗邻域空间尺度上的不同邻域效应。我们使用了来自古老温带森林的两个数据集：(1) 幼苗清单和 (2) 完全映射的样带数据，并分别应用了广义线性混合模型和空间点模式分析。我们发现，邻里效应根据邻里的接近度、密度和物种身份改变了鹿的觅食行为，这反过来又决定了浏览对树苗影响的强度和空间范围。虽然美国梧桐枫树幼苗经历了最高水平的鹿选择性，但鹿仅在短距离内对欧洲山毛榉幼苗具有选择性。超出这些距离，山毛榉幼苗只是机会性地被浏览，因为同种邻居不再改变鹿的选择性。山毛榉幼苗也更容易在距银杉幼苗的短距离内浏览，表明关联易感性。由于冷杉幼苗在同种和山毛榉邻居附近都经历了强烈而广泛的密度依赖性鹿选择性，