Plant community persistence strategy is elevation-specific

Abstract

Aims: Persistence plays a key role in both plant population and community dynamics as it allows withstanding temporarily habitat conditions unsuitable for growth and reproduction. Plants can exploit three different strategies to persist in situ (building soil seed banks, increasing adult longevity and/or clonal reproduction), the dominance of which in a community might vary along environmental gradients. Yet, their relative role in plant persistence has never been investigated. Location: The Bavarian Alps, Germany. Methods: We collected data on seed soil persistence, adult longevity and clonality for 290 species occurring in 18 grasslands located along an elevational gradient of 1,000 metres and examined their contribution to persistence in a community. Linear models were used to estimate the relationship between elevation and these persistence strategies. Results: We found that dominance of a certain persistence strategy varied depending on environmental variability. Specifically, persistence in lowlands was mainly achieved by persistent and dense soil seed banks along with extended clonal growth (larger spread distances and higher number of offspring). Contrastingly, the main persistence strategy in the alpine communities was increased adult longevity. Conclusions: The changes in relative contribution of each strategy to community persistence along the elevational gradient are interrelated suggesting a trade-off among them. We conclude that this trade-off plays an important role in species co-existence and community assembly, and might be useful to understand vegetation dynamics under ongoing climate change and improve restoration efforts of upland ecosystems.