Early response of herbaceous vegetation toRhododendron ponticumsubsp.baeticuminvasion in European Atlantic forests

• DOI: 10.1111/avsc.12734
• Publication Date: 2023-06-27T04:34:05Z
• Authors: Marion Casati; Fabien Spicher; Thomas Kichey; Guillaume Decocq

Abstract Questions Rhododendron ponticum subsp. baeticum is an invasive shrub of growing concern in continental Europe, but little known about its impact on native plant communities. Here we ask: do environmental conditions differ between forest stands invaded by it and uninvaded stands? Do these differences correlate with R. 's cover? Are associated taxonomic functional diversity vascular species the herb layer? Can vegetation changes be explained sorting certain life‐history traits ‐induced changes? Location Several forests French Atlantic domain. Methods We recorded composition a number variables 400‐m 2 plots that were established 64 paired (32 vs 32 uninvaded). compiled from existing databases. computed several metrics diversity. compared stands. used correlation regression analyses to relate them cover. ran RLQ fourth‐corner explore relationships invasion, variables, traits, composition. Results Independent abundance, invasion was lower light arrival at floor increased litter thickness. Concomitantly, richness trait reduced. The major driver assemblages soil pH, which strongly interacted gradient. did not sort according shade tolerance thick‐litter tolerance. However, tree saplings more abundant than stands, expense graminoid fern species. Conclusions As becomes dominant shrub, exerts new selection forces extant species, mostly via reduced availability, thickness, physical competition, thereby reducing layer, without impeding self‐regeneration, least short term.