The effects of climate warming and urbanised areas on the future distribution of Cortaderia selloana, pampas grass, in France

Abstract

Summary The spread of many invasive plants could be facilitated by their presence in urban areas that may act as dispersal centres and by climate warming. Cortaderia selloana, pampas grass, is native to South America and raises considerable concern worldwide as an introduction. We used Maxent niche modelling, based on occurrence records and on a set of simulated occurrence points with high probability of presence in urbanised areas in France, where the species was introduced and is still planted. We calibrated the model with current climate data coupled with several habitat variables and used it to predict range shifts of C. selloana under four climate change scenarios (RCP) for 2060. The results were consistent with the known ecology of the species and showed that the most important variables that explain the current distribution in the introduced area were mean annual minimum temperatures, sandy habitats, disturbed habitats and urbanised areas. While the species already occupies large areas along the western and Mediterranean coasts, the models predicted an expansion northward and inland to the east under future climates. The area of suitable habitats could increase by up to 69% under the RCP 8.5 climate scenario in 2060 and by 116% with the extra occurrences in urban/suburban areas. This latter scenario suggests that areas like public and private gardens or urban parks, where the species is currently cultivated, could contribute to increase the invasion risk under climate warming. The results provide predictions of potential environments for the species, which can be helpful for anticipating its spread.

Considering urban uses at a fine spatial resolution to understand the distribution of invasive plant species in cities

“…For instance in western European cities, A. altissima and A. negundo have been planted since the end of the 18 th century along streets because of their fast growth and R. pseudoacacia because of its showy fragrant flowers. B. davidii and B. aquifolium have been planted in gardens for their abundant and colorful flowers and C. selloana has been planted on traffic roundabouts and urban parks for its large plumes (Sheppard et al 2006;Kowarik and Säumel 2007;Sladonja et al 2015;Straigytė et al 2015;Tarabon et al 2018). These species are easily identifiable in the field and are thus of interest in the study of IAP patterns at a city scale.…”

Modeling the geographic spread and proliferation of invasive alien plants (IAPs) into new ecosystems using multi-source data and multiple predictive models in the Heuningnes catchment, South Africa

“…The establishment and success of IAPs into new ecosystems is mainly caused by environmental changes because of anthropogenic influences and climate change (Buckley, Catford, and Gibson 2016). It is expected that the increase in temperatures may facilitate and accelerate the spread of IAPs while reducing the resilience of natural vegetation (Ncube et al 2020;Tarabon et al 2018). This will likely increase the areas at risk of invasion due to the increased competition, hence causing massive losses in biodiversity as a result of species range shifts or extinctions.…”

Considering Urban Social Functions at Fine Spatial Resolution to Understand the Distribution of Invasive Plant Species in Cities

“…& Schult.f., Asch. & Graebn., 1900) has been planted in tra c roundabouts and urban parks for its large plumes (Sheppard et al 2006;Kowarik and Säumel 2007;Sladonja et al 2015;Straigytė et al 2015;Tarabon et al 2018). After their introductions, expansion of IAS through cities relies on different vectors of the urban landscape.…”