Loss of local biodiversity resulting from abrupt environmental change is a significant environmental problem throughout the world. Extinctions of plants are particularly important yet are often overlooked. Drawing from a case in Hawai‘i, a global hotspot for plant and other extinctions, we demonstrate an effort to better understand and determine priorities for the management of an endangered plant (‘Ihi makole or Portulaca sclerocarpa) in the face of rapid and extreme environmental change. Volcanic heat emissions and biological invasions have anecdotally been suggested as possible threats to the species. We integrated P. sclerocarpa outplanting with efforts to collect geological and ecological data to gauge the role of elevated soil temperatures and invasive grasses in driving P. sclerocarpa mortality and population decline. We measured soil temperature, soil depth, surrounding cover and P. sclerocarpa survivorship over three decades. The abundance of wild P. sclerocarpa decreased by 99.7% from the 1990s to 2021. Only 51% of outplantings persisted through 3–4 years. Binomial regression and structural equation modelling revealed that, among the variables we analysed, high soil temperatures were most strongly associated with population decline. Finding the niche where soil temperatures are low enough to allow P. sclerocarpa survival but high enough to limit other agents of P. sclerocarpa mortality may be necessary to increase population growth of this species.

突然的环境变化导致当地生物多样性的丧失是全世界的一个重大环境问题。植物灭绝尤为重要，但往往被忽视。借鉴全球植物和其他物种灭绝热点地区夏威夷的案例，我们展示了在面对快速和极端的情况下更好地理解和确定濒危植物（'Ihi makole 或Portulaca sclerocarpa）的管理优先级的努力环境变化。据传闻，火山热排放和生物入侵被认为是对该物种的可能威胁。我们将P. sclerocarpa外植与收集地质和生态数据的努力相结合，以衡量土壤温度升高和入侵草在驾驶中的作用P. sclerocarpa死亡率和种群下降。我们测量了土壤温度、土壤深度、周围覆盖物和P. sclerocarpa三个十年的存活率。从 1990 年代到 2021 年，野生P. sclerocarpa的丰度下降了 99.7%。只有 51% 的外植持续了 3-4 年。二项式回归和结构方程模型显示，在我们分析的变量中，高土壤温度与人口下降的相关性最强。找到土壤温度低到足以让P. sclerocarpa生存但又高到足以限制P. sclerocarpa死亡率的其他因素的生态位可能是增加该物种种群增长的必要条件。