Contrasting traits, contrasting environments, and considerations on population dynamics under a changing climate: an ecophysiological field study of two co-dominant tree species

摘要: The increase in light availability resulting from canopy changes or opening is not always beneficial and can inhibit photosynthesis of tree seedlings already under other environmental stress. Tree seedlings' responses to compounded abiotic stress depend on their life-history traits, understanding the variations such important for population dynamics a changing climate. In this study we investigate how juveniles two species with different Abies sachalinensis Betula ermanii, differs contrasting sites at sub-boreal forest northern Japan—one deciduous (Closed site) wide (Open site). Seedlings Open site had low Fv/Fm (quantum yield photosystem II) longer period than those Closed site. showed lower spring site, but recovered after canopy's new leaves flushed, indicating its acclimation shaded condition. Mean Pmax (light-saturated photosynthetic rate ambient CO2 levels) A. sachalinensis was affected by air temperature, while B. ermanii were also precipitation. Only B. ermanii's presented growth studied, spite observed mid-day drops attributed water-deficit-related photoprotection. Results suggest that climate change predicted Hokkaido area may competitive advantage broad-leaved species, as B. ermanii, relation evergreen conifers like A. sachalinensis.