Author:

Keywords:

American black cherry, Biological invasion, biogeochemical cycles, canopy foliar nutrients, carbon mineralization, heterotrophic respiration, exotic species, invasive species, Ecosystem functioning, Fagus sylvatica, Quercus robur, Quercus petraea, Carpinus betulus, Pinus sylvestris, Science & Technology, Life Sciences & Biomedicine, Plant Sciences, biological invasion, litter, BLACK-CHERRY, LITTER DECOMPOSITION, SOIL RESPIRATION, EUROPEAN FORESTS, LEAF-LITTER, PLANTS, UNDERSTOREY, COMMUNITIES, DIVERSITY, BELGIUM, 0607 Plant Biology, 3004 Crop and pasture production, 3108 Plant biology

Abstract:

Alien invasive species can affect large areas, often with wide-ranging impacts on ecosystem structure, function and services. Prunus serotina is a widespread invader of European temperate forests, where it tends to form homogeneous stands and limits recruitment of indigenous trees. We hypotesized that invasion by P. serotina would be reflected in the nutrient contents of the native species’ leaves and in the respiration of invaded plots as efficient resource uptake and changes in nutrient cycling by P. serotina probably underly its aggressive invasiveness. We combined data from 48 field plots in the forest of Compiègne, France, and data from an experiment using 96 microcosms derived from those field plots. We used general linear models to separate effects of invasion by P. serotina on heterotrophic soil and litter respiration rates and on canopy foliar nutrient content from effects of soil chemical properties, litter quantity, litter species composition and tree species composition. In invaded stands, average respiration rates were 5.6% higher for soil (without litter) and 32% higher for soil and litter combined. Compared to indigenous tree species, P. serotina exhibited higher foliar N (+24.0%), foliar P (+50.7%) and lower foliar C:N (−22.4%) and N:P (−10.1%) ratios. Prunus serotina affected foliar nutrient contents of co-occuring indigenous tree species leading to decreased foliar N (−8.7 %) and increased C:N ratio (+9.5%) in Fagus sylvatica, decreased foliar N:P ratio in Carpinus betulus (−13.5%) and F. sylvatica (−11.8%), and increased foliar P in Pinus sylvestris (+12.3%) in invaded vs. uninvaded stands. Our results suggest that P. serotina is changing nitrogen, phosphorus and carbon cycles to its own advantage, hereby increasing carbon turnover via labile litter, affecting the relative nutrient contents in the overstory leaves, and potentially altering the photosynthetic capacity of the long-lived indigenous broadleaved species. Uncontrolled invasion of European temperate forests by P. serotina may affect the climate change mitigation potential of these forests in the long term, through additive effects on local nutrient cycles.