Relationships between resprouting ability, species traits and resource allocation patterns in woody species in a temperate forest

Summary Many woody plants resprout to restore above-ground biomass after disturbances or to survive in stressful environments. Resprouting requires carbohydrate storage, but the general relationship between resource allocation patterns and resprouting ability remains unclear because it can be influenced by the disturbance regime to which species have adapted. We studied deciduous broadleaved trees that coexist in a Japanese cool-temperate forest to investigate the relationships among the biomass and total non-structural carbohydrate (TNC) allocation patterns of saplings, resprouting ability and functional traits. The study species comprised 16 single-stemmed species that only resprout when above-ground biomass loss occurs and eight multi-stemmed species that resprout regardless of whether above-ground damage occurs or not. Single-stemmed species with better juvenile resprouting ability had larger roots, whereas multi-stemmed species with better juvenile resprouting ability did not necessarily depend on below-ground reserves. Species that retain their ability to resprout until a larger size had a higher root TNC content as saplings, suggesting that they can survive major disturbances such as fire and coppicing by resprouting supported by TNC stored in their roots. Species with shade-tolerant traits (i.e. low foliar nitrogen indicating low photosynthetic capacity, high wood density indicating high defensive investment) had small below-ground TNC reserves irrespective of resprouting types. On the other hand, multi-stemmed species with high wood density and high LMA (indicating high photosynthetic capacity) had small above-ground TNC reserves. Contrary to our hypothesis, a species’ maximum size did not relate to the size of its below-ground reserves. By considering the differences in resprouting types, we suggest more complex control of resprouting than was formerly proposed. Variation in the resprouting ability of single-stemmed species was based on a trade-off between below-ground reserves for resprouting and shade-tolerant traits. However, multi-stemmed species can vigorously resprout irrespective of the size of its below-ground reserves. Their multi-stemmed architecture, well-defended wood, high photosynthetic capacity or large above-ground carbohydrate reserves seem to respectively contribute to their persistence. Such variation in the resprouting strategy based on a trade-off between shade tolerance and resource storage would promote species coexistence under a range of disturbance regimes and light environments.