Questions Did high densities of wild ungulates cause a decline in plant species richness in a temperate oakwood? How did species composition change after nearly five decades? Did ungulates facilitate the spread of ruderal species and supress endangered species? Did dispersal strategies play a role in these processes? Location Krumlov Wood, SE Czech Republic. Methods In 2012, we resampled 58 quasi-permanent vegetation plots first surveyed in 1960s. Between the surveys, 36 plots were enclosed in a game preserve with artificially high density of ungulates (mostly deer, mouflon and wild boar; ca. 55 animals per square km). We analysed the differences in temporal changes between plots inside and outside the game preserve, focusing on species diversity and composition. We assessed species characteristics relevant to grazing to understand compositional changes. Results Ungulates significantly increased alpha and gamma diversity and caused significant vegetation homogenization inside the game preserve. Vegetation homogenization and the increase in species richness resulted from massive enrichment by ruderal species. However, richness of endangered species decreased. Species dispersed by animals internally (endozoochory) increased, while species dispersed externally (epizoochory) or by wind (anemochory) decreased. Conclusions Contrary to our expectations, our long-term data showed that artificially high ungulate densities substantially increased plant species richness. Apparently, the establishment of ruderal herbs was supported by frequent disturbances and ungulate-mediated dispersal. At the same time, species richness of non-ruderal plants did not change, probably because ungulates hindered the regeneration of woody species and maintained an open forest canopy. In conclusion, high ungulate density led to the spread of ruderal species, which in turn strongly contributed to the observed shift towards nutrient-richer conditions and taxonomically more homogenous communities.

中文翻译：

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长期有蹄类动物影响的悖论：温带森林植物物种丰富度的增加

问题 高密度的野生有蹄类动物是否会导致温带橡木的植物物种丰富度下降？近五年后物种组成发生了怎样的变化？有蹄类动物是否促进了粗野物种的传播并压制了濒危物种？分散策略在这些过程中发挥了作用吗？地点 Krumlov Wood, SE 捷克共和国。方法 2012 年，我们对 1960 年代首次调查的 58 个准永久性植被样地进行了重新采样。在两次调查之间，有 36 个地块被封闭在一个人工高密度有蹄类动物（主要是鹿、摩弗隆和野猪；每平方公里约 55 只动物）的野生动物保护区内。我们分析了游戏保护区内外地块的时间变化差异，重点关注物种多样性和组成。我们评估了与放牧相关的物种特征，以了解成分变化。结果 有蹄类动物显着增加了 alpha 和 gamma 多样性，并导致游戏保护区内的植被显着均质化。植被均匀化和物种丰富度的增加是由于粗野物种的大量富集所致。然而，濒危物种的丰富度有所下降。由动物内部（内生动物）散布的物种增加，而由外部（外生动物）或风（风散物）散布的物种减少。结论 与我们的预期相反，我们的长期数据表明，人为地提高有蹄类动物的密度大大增加了植物物种的丰富度。显然，粗制草药的建立得到了频繁的干扰和有蹄类动物介导的传播的支持。同时，非粗生植物的物种丰富度没有改变，可能是因为有蹄类动物阻碍了木本物种的再生并保持了开阔的森林树冠。总之，高有蹄类动物密度导致了粗野物种的传播，这反过来又强烈地促进了观察到的向营养更丰富的条件和分类学上更同质的群落的转变。