The role of tree diversity in restored forests and its impact on key ecological processes like growth and resistance to herbivory has become increasingly important. We analyzed height growth and white-tailed deer Odocoileus virginianus browsing damage to saplings of 16 broadleaved tree species in a large-scale (13 ha) reforestation experiment in Maryland, USA, where we manipulated tree diversity in seventy 1200 m2 plots. After four growing seasons, higher plot-level tree richness led to increased deer browsing damage (i.e. associational susceptibility). Despite increased deer damage to saplings in mixed plots, tree richness had no overall effect on sapling height growth. However, diversity-height relationships were related to species functional traits. Light demanding species with large leaves and faster growth rates had reduced heights in mixtures, whereas shade-tolerant, slower-growing species generally had either increased or unchanged height growth in diverse tree communities, likely related to increased canopy closure in mixtures relative to monocultures. We show that tree diversity can improve growth of late successional species despite exacerbated mammalian herbivore damage. By facilitating the establishment of species with a range of life-history strategies, increased tree diversity may enhance ecosystem multi-functionality in the early stages of forest restoration.

中文翻译：

---

尽管恢复森林中的鹿损害增加，但树木多样性促进了晚期演替物种的生长

树木多样性在恢复森林中的作用及其对生长和对食草动物的抵抗力等关键生态过程的影响变得越来越重要。我们在美国马里兰州进行的大规模（13 公顷）重新造林实验中分析了高度增长和白尾鹿 Odocoileus virginianus 对 16 种阔叶树种树苗的破坏，我们在 70 个 1200 平方米的地块中操纵了树木多样性。在四个生长季节之后，较高的地块级别的树木丰富度导致鹿浏览损害（即关联易感性）增加。尽管在混合地块中鹿对树苗的伤害增加，但树木丰富度对树苗高度的增长没有总体影响。然而，多样性-高度关系与物种功能性状有关。具有大叶子和更快生长速度的光照要求物种在混合物中的高度降低，而耐阴、生长较慢的物种在不同的树群中通常具有增加或不变的高度增长，这可能与相对于单一栽培的混合物中冠层闭合增加有关。我们表明，尽管哺乳动物食草动物的损害加剧，但树木多样性可以改善晚期演替物种的生长。通过促进具有一系列生活史策略的物种的建立，增加树木多样性可以在森林恢复的早期阶段增强生态系统的多功能性。我们表明，尽管哺乳动物食草动物的损害加剧，但树木多样性可以改善晚期演替物种的生长。通过促进具有一系列生活史策略的物种的建立，增加树木多样性可以在森林恢复的早期阶段增强生态系统的多功能性。我们表明，尽管哺乳动物食草动物的损害加剧，但树木多样性可以改善晚期演替物种的生长。通过促进具有一系列生活史策略的物种的建立，增加树木多样性可以在森林恢复的早期阶段增强生态系统的多功能性。