Whether environmental conditions under exotic tree plantations abandoned in the Western Ghats of India can facilitate the natural regeneration of tropical montane forest (Shola forest) tree species is being debated. In many cases, the exotic tree plantations are being cleared to allow for the restoration of native ecosystems. In this paper, we examined whether exotic tree plantations have indeed a negative effect on the regeneration of Shola forest tree species. For this, we assessed the abundance, diversity, and composition of the regeneration of Shola forest tree species in plantations, each with different dominant tree species (Acacia mearnsii, Pinus sp., and Eucalyptus sp.). We tested the abundance of regenerating native tree species against the main plantation canopy species (plantation type) as well as other environmental factors (aspect, distance to nearest Shola forest, structural diversity, slope, elevation, presence of herbivores, and canopy closure). We found that the number of native tree species regenerating in all plantation types was at an acceptable level: 1960, 1773, and 462 individuals ha−1 for Acacia, Eucalyptus, and Pinus plantations, respectively. A rare fraction analysis showed that the highest number of Shola tree species were regenerating under Acacia mearnsii (25) followed by Eucalyptus (19) and Pinus (8) plantations. The density and diversity of regenerating Shola trees was greatest under Acacia plantations and northern aspects but declined with increasing elevation. The presence of herbivores also reduced the density and diversity of Shola tree regeneration. We concluded that the restoration of Shola forest in the Western Ghats is possible in existing stands of exotic tree species and this process can be accelerated with appropriate silvicultural methods. We additionally recommend that studies involving long-term exclosures can provide valuable insights into the effects of browsing on regeneration and species composition.

中文翻译：

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热带山地森林（Shola）树种可以在印度西高止山脉废弃的外来树木种植园下再生

印度西高止山脉废弃的外来树木种植园的环境条件是否可以促进热带山地森林（绍拉森林）树种的自然更新，目前仍在争论中。在许多情况下，外来树木种植园正在被清除，以恢复本地生态系统。在本文中，我们研究了外来人工林是否确实对绍拉森林树种的再生产生负面影响。为此，我们评估了人工林中绍拉森林树种再生的丰富度、多样性和组成，每个人工林都有不同的优势树种（金合欢、松树和桉树）。我们根据主要种植园树冠物种（种植园类型）以及其他环境因素（坡向、到最近的绍拉森林的距离、结构多样性、坡度、海拔、食草动物的存在和树冠封闭）测试了再生本地树种的丰度。我们发现，所有人工林类型中本地树种的再生数量都处于可接受的水平：金合欢、桉树和松树人工林分别为 1960、1773 和 462 个 ha−1 个体。稀有分数分析显示，在金合欢 (25) 人工林下再生的绍拉树种数量最多，其次是桉树 (19) 和松树 (8)。再生绍拉树的密度和多样性在金合欢种植园和北部地区最大，但随着海拔的增加而下降。食草动物的存在也降低了绍拉树再生的密度和多样性。我们的结论是，在现有的外来树种中恢复西高止山脉肖拉森林是可能的，并且可以通过适当的造林方法加速这一过程。我们还建议，涉及长期保护区的研究可以为浏览对再生和物种组成的影响提供有价值的见解。