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重点保护野生濒危植物。然而，由于过度开发利用，如今该物种仅零散分布于长江流域的林下层中。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，多数红豆杉的邻体均为非红豆杉类树木，其体量较目标样树大30%至70%。总体而言，红豆杉与最近3株邻体树木的平均间距较短，不足3米。该结果表明，红豆杉大概率面临来自邻体植物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在单株高大邻体树木（树高≥10米）的冠幅之下；且仅在单株邻体树木的遮蔽下，红豆杉的生长才会得到促进，而在双株、三株或无邻体树木的生境中则无此增益效果。最后，本研究提出了可降低种间竞争的简易营林措施：具体包括对大型邻体树木的枝干进行截除或修枝，并同步疏伐紧邻红豆杉母株的冠层树木。