Climate change in alpine habitats has a direct impact on vascular plant species, and is leading to changes in species abundance and distribution. Alpine plant communities are expected to experience a turnover of species over time, due to the loss of cold-adapted specialists and the upslope migration of more thermophilic taxa. Therefore, assessments of single species changes are important for research and conservation. Here, we propose a new analysis protocol for the GLORIA (GLobal Observation Research Initiative in Alpine environments) network, and potentially, for other monitoring programmes capable of defining winning and losing plant species. The proposed approach involves the non-parametric Cliff's ‘Delta’ measure of ‘effect size’, which provides a measure of the intensity of species abundance changes over time and is applicable for vegetation data collected using both re-visitation and long-term monitoring approaches. Compared to other methods, Cliff's ‘Delta’ was more conservative and efficient in detecting winning/losing taxa, as well as being suitable to analyse data of rare species with few records. To test the effectivity of the Cliff ‘Delta’ method, we analysed the vegetation data from three Italian GLORIA sites. We investigated 413 vascular plant species and found a total of 41 winning and 24 losing species. Moreover, we used Cliff ‘Delta’ to assess whether plant assemblages are responding differently among sites and plant growth forms. Our findings showed that alpine plant communities are changing faster on Apennines sites and that growth form types respond differently across the study sites.

高山栖息地的气候变化对维管植物物种有直接影响，并导致物种丰度和分布的变化。由于适应寒冷的专家的流失和更多嗜热类群的上坡迁移，随着时间的推移，高山植物群落预计将经历物种更替。因此，评估单个物种的变化对于研究和保护非常重要。在这里，我们为 GLORIA（高山环境全球观测研究计划）网络提出了一种新的分析协议，也可能为其他能够定义获胜和失败植物物种的监测项目提出一种新的分析协议。所提出的方法涉及非参数 Cliff 的“效应大小”“Delta”测量，它提供了物种丰度随时间变化的强度的测量，并且适用于使用重访和长期监测方法收集的植被数据。与其他方法相比，Cliff 的“Delta”在检测获胜/失败类群方面更加保守和高效，并且适合分析记录较少的稀有物种的数据。为了测试悬崖“Delta”方法的有效性，我们分析了意大利 GLORIA 三个地点的植被数据。我们调查了 413 种维管植物，共发现 41 种获胜物种和 24 种失败物种。此外，我们使用 Cliff 'Delta' 来评估植物组合在不同地点和植物生长形式之间是否有不同的反应。我们的研究结果表明，亚平宁山脉地区的高山植物群落变化更快，并且不同研究地点的生长形式类型的反应不同。