Alpine plants with short-lived seeds have declined over the past two decades

The rate of temperature increase in alpine environments exceeds the global average, threatening alpine plant species. While some species benefit from changing conditions, others decline or risk extinction. Understanding the mechanisms that drive these divergent responses is crucial for biodiversity conservation. Although functional traits have been widely used to predict alpine plant responses to climate shifts, the role of seed traits remains largely overlooked. In this study, we tested the hypothesis that species decreasing in abundance produce shorter-lived seeds than those increasing. Seed longevity was estimated through accelerated ageing tests in 24 alpine and subalpine species from the Northern Apennines (Italy), estimating the time required for seed viability to decline to 50% (p50) using probit analysis. The relationship between species-specific p50 value and 21-year population dynamics, quantified via the Cliff ‘Delta’ Index, was tested using a linear model. The results support the hypothesis, revealing a positive correlation between seed longevity (p50) and species population trends, as measured by Cliff ‘Delta’ index. These findings highlight the potential role of seed longevity as a functional trait linked to plant population dynamics under environmental change. While vegetative traits have often been the focus of climate response studies, our results suggest that regenerative traits also warrant greater attention.