Plant competition dominates grass species interactions in a migrating marsh-forest ecotone

Ecotone communities are areas of high species turnover and steep environmental gradients. We investigated how environmental gradients shape species interactions between upland and tidal wetland grass species to shed light on zonation in these species’ distribution patterns, in the context of underst...

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Detalles Bibliográficos
Autores: Gedan, Keryn B., Hoot, Whitney C., Fernández-Pascual, Eduardo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/389024
Acceso en línea:http://hdl.handle.net/10261/389024
https://api.elsevier.com/content/abstract/scopus_id/105001547219
Access Level:acceso abierto
Palabra clave:Distichlis spicata
Facilitation
Panicum virgatum
Relative interaction index
Saltwater intrusion
Sea level rise
Spartina alterniflora
Spartina patens
Transgression
Descripción
Sumario:Ecotone communities are areas of high species turnover and steep environmental gradients. We investigated how environmental gradients shape species interactions between upland and tidal wetland grass species to shed light on zonation in these species’ distribution patterns, in the context of understanding how their distributions may change with sea level rise and forest dieback. Across the coastal marsh-forest ecotone, there are stark shifts in two vital conditions for plants: salinity and light availability. We measured these abiotic conditions and plant productivity at sites spanning the ecotone and within a forest clear-cut, where canopy shading had been experimentally removed. In a greenhouse manipulation of plant species neighbor, salinity, and light availability, we hypothesized that plant interactions would become more facilitative in stressful conditions and that more salt tolerant species would also be more light-demanding. Species salt tolerance followed an expected ranking based on species zonation in the field, but all species responded similarly to reductions in light. Plant interactions in all treatments were negative or neutral, never facilitative. Despite low resource availability of light and elevated levels of salinity within the marsh-forest ecotone, plant interactions there reflect a benign stress environment, in which competition is predominant and where resource limitation, stress, and competition have additive, negative effects on plant performance.