Is spread of the neophyte Spartina anglica recently enhanced by increasing temperatures?

Abstract

The introduced cordgrass Spartina anglica, a fertile hybrid of S. maritima and S. alterniflora, grows as a pioneer plant in the upper intertidal zone and has invaded most sheltered shorelines of the Wadden Sea. After its introduction in 1927 S. anglica has spread vigorously along the mainland shore and on some of the more southern islands. In contrast, it has later established on Sylt and spread at a lower pace. On the island of Sylt it occurs near at its northern limit in Europe. Due to rising sea level and storm frequency a decrease or steady state of S. anglica was expected because its niche is narrowing rather than widening and plants are more frequently eroded. Contrary to that, many new sites were colonized and dense monotypic swards have formed after 1985. This new spread coincided with a shift in the local temperature regime around 1987. The monthly mean temperature from January to April has increased significantly after 1987. Furthermore, the important physiological thresholds of 4°C for germination and 7°C for photosynthesis were more often exceeded during spring after 1987 than before. We suggest that warmer spring seasons since 1988 could have promoted germination, growth and the recent accelerated spread of this neophyte.

Transitions in sandflat biota since the 1930s: effects of sea-level rise, eutrophication and biological globalization in the tidal bay Königshafen, northern Wadden Sea

“…2). This was already recorded by Loebl et al (2006) who propose that increasing summer temperature since the 1990s has facilitated the spread of S. anglica. We also found a single pioneer plant at Kersten Rimling (Fig.…”

“…Most changes in the Wadden Sea have been attributed to eutrophication (e.g. van Beusekom 2005), to the loss of apex predators (Lotze 2005), fisheries (Piersma et al 2001), artificial shores (Reise 2005), alien invaders (Buschbaum et al 2012) and to climate change (Beukema and Dekker 2005;Diederich et al 2005;Loebl et al 2006;Nehls et al 2006, Witte et al 2010. Here, we add a long-term study on sandflat benthos to further unravel small-scale responses to large-scale causes in a coastal ecosystem.…”

Associations between macrobenthos and invasive cordgrass, Spartina anglica, in the Danish Wadden Sea

“…Much work has been undertaken on the changes of invertebrate macrobenthic assemblages associated with Spartina saltmarshes in North America (Levin and Talley 2000;Neira et al 2005;Brusati and Grosholz 2006), while there is only limited information from northern Europe (Vinther et al 2001;Gribsholt and Kristensen 2003). The Wadden Sea is treasured by its special native biodiversity and is a stepping stone for a variety of migratory waterbirds (Vinther et al 2001;Loebl et al 2006). S. anglica was introduced in the Danish Wadden Sea around 1,940 where no native Spartina species were present (Nehring and Hesse 2008).…”

“…The expansion of S. anglica may even be accelerated in the future due to global warming (Gray and Mogg 2001;Loebl et al 2006). Danish Wadden Sea is a bird-protection area, and macroinfauna serve as important food for a variety of wading birds (Beukema et al 1993;Zwarts and Wanink 1993; Munch-Petersen and .…”

The significance and vulnerability of Australian saltmarshes: implications for management in a changing climate

“…The invasive saltmarsh plant Spartina spp. is currently restricted to small but dense patches in several Tasmanian and Victorian estuaries (Adam 2009;Williamson 1996), and higher temperatures may promote its further proliferation (Boon et al 2011), as has been observed in the Netherlands (Loebl et al 2006). Sea-level rise presents an opportunity and threat to coastal saltmarsh, depending on rates of sediment supply, local topographic conditions and barriers to transgression.…”