Freshwater wetlands: fertile grounds for the invasive Phragmites australis in a climate change context

Ecology and Evolution

Marie-Andrée Tougas-Tellier¹  Jean Morin³  Daniel Hatin² 

[1] École supérieure d'aménagement du territoire et de développement régional and Centre de la science de la biodiversité du Québec, Université Laval, Québec City, Québec, Canada;Ministère des Forêts, de la Faune et des Parcs du Québec, Direction de la gestion de la faune de l'Estriea de Montréal, de la Montérégie et de Laval, Longueuil, Québec, Canada;Service météorologique du Canada, Section Hydrologie et Écohydraulique, Environnement Canada, Québec City, Québec, Canada

关键词: Climate change;    common reed;    Phragmites australis;    St. Lawrence River;    water level;    wetland;   

DOI  :  10.1002/ece3.1576

来源: Wiley

【 摘 要 】

Abstract

Climate change will likely affect flooding regimes, which have a large influence on the functioning of freshwater riparian wetlands. Low water levels predicted for several fluvial systems make wetlands especially vulnerable to the spread of invaders, such as the common reed (Phragmites australis), one of the most invasive species in North America. We developed a model to map the distribution of potential germination grounds of the common reed in freshwater wetlands of the St. Lawrence River (Québec, Canada) under current climate conditions and used this model to predict their future distribution under two climate change scenarios simulated for 2050. We gathered historical and recent (remote sensing) data on the distribution of common reed stands for model calibration and validation purposes, then determined the parameters controlling the species establishment by seed. A two-dimensional model and the identified parameters were used to simulate the current (2010) and future (2050) distribution of germination grounds. Common reed stands are not widespread along the St. Lawrence River (212 ha), but our model suggests that current climate conditions are already conducive to considerable further expansion (>16,000 ha). Climate change may also exacerbate the expansion, particularly if river water levels drop, which will expose large bare areas propitious to seed germination. This phenomenon may be particularly important in one sector of the river, where existing common reed stands could increase their areas by a factor of 100, potentially creating the most extensive reedbed complex in North America. After colonizing salt and brackishwater marshes, the common reed could considerably expand into the freshwater marshes of North America which cover several million hectares. The effects of common reed expansion on biodiversity are difficult to predict, but likely to be highly deleterious given the competitiveness of the invader and the biological richness of freshwater wetlands.

【 授权许可】

CC BY   
© 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.