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。然而由于过度开发利用，目前其种群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）形成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，多数南方红豆杉的邻株为非红豆杉类树木，其体量较目标红豆杉大30%~70%。整体而言，南方红豆杉与最近3株邻树的平均距离较短（小于3米），该结果表明其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，多数杆径级南方红豆杉仅生长在单株高邻树（树高≥10米）的冠幅下，且仅在单株邻树的生境下生长得到促进，而在两株、三株或无邻树的生境中生长未受显著促进。最后，本研究提出可通过简易营林措施缓解种间竞争：具体措施包括对大型邻树进行截干或修枝，同时对紧邻目标红豆杉植株的冠层树木进行疏伐。