Invasiveness of Campylopus introflexus in drift sands depends on nitrogen deposition and soil organic matter

Abstract

Question: Does the neophyte moss Campylopus introflexus invade more often in drift sand pioneer vegetations under high nitrogen (N) deposition? Location: Fourteen inland dune reserves in The Netherlands over a gradient of atmospheric N deposition. Methods: A transect study, dispersal experiment and culture experiment were carried out. In the transect study, the establishment of C. introflexus and lichens was measured in pure mats of Polytrichum piliferum, an early succession stage. The overall presence of C. introflexus in the area was also estimated. In the dispersal experiment, fragments of C. introflexus and lichen species were sown in P. piliferum mats at two sites with high and low N deposition. In the culture experiment C. introflexus fragments were grown on soil with different carbon (C) content and N dose. Results: The Campylopus:lichen ratio was positively correlated (r2=0.61) with the atmospheric ammonia concentration. Campylopus began to dominate at an ammonia air concentration of 7 μg m−3, correlated with the overall presence of the species in the sites investigated. Survival of sown Campylopus fragments was significantly higher and the endangered lichen Cladonia strepsilis significantly lower in the site with a high ammonia concentration. Survival of Cladonia coccifera and Cladonia portentosa was high at both sites. Experimental growing of C. introflexus showed significant responses to both C content and N, although C content showed the strongest effect. Conclusions: Growth of C. introflexus is affected by soil C content and N deposition. Inland dune reserves under high N deposition risk loss of lichen‐dominated vegetations because of moss encroachment.

Ecological niche comparison and molecular phylogeny segregate the invasive moss species Campylopus introflexus (Leucobryaceae, Bryophyta) from its closest relatives

“…We selected environmental data regarding eco-physiological constraints of the target taxa according to recent literature on habitat preferences (Frahm & Stech, 2006;Klinck, 2010;Spagnuolo et al, 2014;Sparrius & Kooijman, 2011;Sparrius, Sevink, & Kooijman, 2012). The selected 10 environmental variables were obtained from WorldClim (www.worldclim.org) and are of high spatial and temporal resolution.…”

“…Besides Europe, C. introflexus was introduced in North America (Carter, 2014). Its negative impact on the biodiversity of natural habitats such as coastal and inland dunes, especially lichen-rich gray dunes (Essl et al, 2014;Klinck, 2010;Sparrius & Kooijman, 2011), should have brought attention to its troublesome delimitation from closely related species, especially Campylopus pilifer Brid. (Frahm, 1974;Frahm & Stech, 2006;Gradstein & Sipman, 1978).…”

Effect of geomorphology and nitrogen deposition on rate of vegetation succession in inland drift sands

“…Nitrogen deposition was found to cause faster growth and early settlement of thick mats of the invasive bryophyte Campylopus introflexus , leaving less space for lichen vegetation (Sparrius & Kooijman ); that study includes several sites for which results are reported here. We indeed observed that the relative cover of the Campylopus vegetation class is much higher in regions with high N deposition in both active and more stabilized drift sand.…”

Response of inland dune vegetation to increased nitrogen and phosphorus levels

“…In both sites, plots were selected in three different vegetation types, which can be compared with those of Hasse (): (1) Polytrichum piliferum mats that had recently developed on bare sand with a minimum of 90% moss cover and a maximum of 10% grasses (mostly tussocks of Corynephorus canescens ) on a 2–3‐cm thick A h horizon; (2) Campylopus introflexus ‐dominated vegetation with over 90% moss cover and sparse presence of grasses and lichens on a 3–4‐cm thick A h horizon, which usually develops on older Polytrichum piliferum mats and may be interpreted as an alternative stable state for young lichen vegetation under high N deposition or after disturbance (Sparrius & Kooijman ); and (3) species‐rich Cladonia ‐dominated vegetation (mainly Cladonia portentosa, C. cervicornis, C. gracilis and C. furcata ) with over 30% lichen cover on a 6–7‐cm thick A h horizon, which may develop from Campylopus mats and vegetation with small lichen species. This last vegetation type also develops on Polytrichum piliferum mats, but is generally older than the Campylopus type, which is reflected in the thicker A h horizon.…”

“…). In the 1960s, introduction of the invasive bryophyte Campylopus introflexus (Hassel & Söderström ) added a new threat to the lichen‐dominated grassland communities of the inland dunes, as this species partially replaced vegetation dominated by smaller lichens (Ketner‐Oostra & Sýkora ), especially in areas with high N deposition (Sparrius & Kooijman ). Further successional stages, i.e.…”