Data from: Structural diversity of naturally regenerating Chinese yew (Taxus wallichiana var. mairei) populations in an ex situ conservation

The Chinese yew (Taxus wallichiana var. mairei) is ranked among the first class of important wild endangered plants in China. However, due to its overexploitation, it now occurs scattered in the forest undergrowth along the Yangtze River Valley. To improve this tree’s conservation management, we used structural indices to investigate the structural diversity of naturally regenerating yew populations that have established via ex situ conservation. The results show that most yews had larger non-yew tree neighbors; these were 30–70% larger than their reference trees. Collectively, the average distances between the yews and the three nearest-neighboring trees were short (<3 m). This result suggests that the yews likely face strong interspecific competition from neighbors. In these two forest stands, most of the pole-sized yews are found beneath a single tall neighboring tree (height ≥10 m), and their growth was enhanced under a single neighboring tree but not under two, three or zero neighboring trees. Finally, we recommend simple silvicultural treatments to reduce interspecific competition; specifically, the cutting or pruning of branches of large neighboring trees in tandem with the thinning of canopy trees growing next to the mother yews.南方红豆杉（Taxus wallichiana var. mairei）被列为中国国家一级保护野生濒危植物。然而，由于过度开发利用，目前该物种仅零散分布于长江流域沿线的林下生境中。为优化该树种的保护管理方案，本研究采用结构指标，对通过迁地保护（ex situ conservation）定植的天然更新红豆杉种群的结构多样性展开调查。研究结果显示，多数红豆杉的邻株为非红豆杉类树木，其体量较参照树高出30%至70%；整体而言，红豆杉与其最近三株邻树的平均距离较近（不足3米），这表明红豆杉大概率面临来自邻株的强烈种间竞争压力。在这两个林分中，多数杆材级红豆杉均生长于单株高邻树（树高≥10米）的冠下环境；单株邻树可促进红豆杉生长，但在两株、三株或零株邻树的情况下则无此增益效果。最后，本研究提出简化营林措施以缓解种间竞争：具体包括砍伐或修剪大型邻树的枝条，同时对红豆杉母株周边的冠层树木进行疏伐。