Tropical alpine areas are some of the most vulnerable areas in the world to climate change. Their plant communities have narrow thermal niches and have limited geographic areas to expand. Here we examine changes in plant species' abundance and distribution in the Teleki Valley (3900–4500 m asl) of Mount Kenya using a spatially explicit vegetation survey from 1980. Vascular plant species were re-sampled in 35 plots across the valley, and additional size and density data were collected for the two Dendrosenecio species. Overall species richness and diversity were lower in 2021 than in 1980, and the abundance of dominant species had declined. Changes in elevation suggested both upward and downward shifts had occurred. Dendrosenecio keniodendron exhibited a shift towards the valley bottom as well as a change in population structure towards younger individuals. The dominant environmental factors affecting plant composition were similar in both 1980 and 2021, namely elevation, vegetation cover and the presence of D. keniodendron. This keystone species plays a significant role in shaping communities but is undergoing rapid demographic changes, which may have cascading implications on the ecology of the system.

中文翻译：

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40年后肯尼亚山不同植物物种对气候和环境变化的反应

热带高山地区是世界上最容易受到气候变化影响的地区之一。它们的植物群落具有狭窄的热生态位，并且可扩展的地理区域有限。在这里，我们利用 1980 年以来的空间明确植被调查，研究了肯尼亚山 Teleki 山谷（海拔 3900-4500 米）植物物种丰度和分布的变化。在整个山谷的 35 个地块中对维管束植物物种进行了重新采样，并附加了额外的样本。收集了两种Dendrosenecio物种的大小和密度数据。2021年总体物种丰富度和多样性低于1980年，优势物种丰度有所下降。海拔的变化表明发生了向上和向下的变化。Dendrosenecio keniodendron表现出向谷底的转变以及种群结构向年轻个体的变化。1980 年和 2021 年影响植物组成的主要环境因素相似，即海拔、植被覆盖和D. keniodendron的存在。这一关键物种在塑造群落方面发挥着重要作用，但正在经历快速的人口变化，这可能会对系统的生态产生连锁影响。