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）为中国国家一级重点保护野生濒危植物。然而，由于过度采伐，目前该物种仅零散分布于长江流域的林下灌丛中。为优化该树种的保护管理策略，本研究采用结构指标，对通过迁地保护（ex situ conservation）建立的天然更新红豆杉种群的结构多样性展开了调查。研究结果显示，绝大多数红豆杉的邻株为非红豆杉树种，这些邻株的体量较参照树大30%至70%。总体而言，红豆杉与其最近3株邻树的平均间距较短（<3 m）。这一结果表明，红豆杉大概率面临邻株带来的强烈种间竞争压力。在这两个林分中，绝大多数小径阶红豆杉均生长于单株高大邻树（树高≥10 m）的冠下；且仅在单株邻树的庇佑下，其生长才会得到促进，而在有2株、3株邻树或无邻树的情况下生长未获提升。最后，本研究提出了可降低种间竞争的简易营林措施：具体为对大型邻树进行伐除或枝条修剪，并同步疏伐红豆杉植株周边的上层冠层林木。