Climate change and loss of saltmarshes: consequences for birds

Abstract

Saltmarshes are areas of vegetation subject to tidal inundation and are important to birds for several reasons. Saltmarshes are areas of high primary productivity and their greatest significance for coastal birds is probably as the base of estuarine food webs, because saltmarshes export considerable amounts of organic carbon to adjacent habitats, particularly to the invertebrates of mudflats. In addition, saltmarshes are of direct importance to birds by providing sites for feeding, nesting and roosting. Climate change can affect saltmarshes in a number of ways, including through sea‐level rise. When sea‐level rises the marsh vegetation moves upward and inland but sea walls that prevent this are said to lead to coastal squeeze and loss of marsh area. However, evidence from southeast England, and elsewhere, indicates that sea‐level rise does not necessarily lead to loss of marsh area because marshes accrete vertically and maintain their elevation with respect to sea‐level where the supply of sediment is sufficient. Organogenic marshes and those in areas where sediment may be more limiting (e.g. some west coast areas) may be more susceptible to coastal squeeze, as may other marshes, if some extreme predictions of accelerated rates of sea‐level rise are realized.

The impact of tidal inundation on salt marsh vegetation after de-embankment on Langeoog Island, Germany—six years time series of permanent plots

“…However, most (over 90%) parts of these areas are embanked or are still in anthropogenic use (Reise 2005). More than that, salt marshes along the North Sea are mostly narrow areas which in many regions of the coastal mainland eroding because of the coastal squeeze (Adam 2002;Doody 2004;Hughes 2004;Wolters et al 2005c). In the future it might be necessary to breach more of the existing seawalls to allow development of potentially natural salt marshes.…”

Comparison of Biomass and Nutrient Dynamics Between an Invasive and a Native Species in a Mediterranean Saltmarsh

“…Tidal saltmarshes are critical transition zones that perform an essential function in maintaining the health and ecology of estuaries (Teal and Howes 2000;Hughes 2004; Rosso et al 2006). Normal saltmarsh functioning, especially throughout the vegetation component, is closely related to a series of natural factors such as competition, salinity, degree of waterlogging, and nutrient status.…”

Avian communities inSpartina maritimarestored and non-restored salt marshes

“…Salt marsh habitats are recognized for their importance for many bird species, both migratory and resident, as habitats for feeding, resting and breeding (Howe 1987, Ferns 1992, Hughes 2004, Laegdsaard 2006. For example, many shorebird species, with extremely high energy requirements and very high feeding rates (Nagy 2001), feed on invertebrates living in sediments that, in turn, feed on detritus produced by marsh vegetation (Chung 1993, Rowcliffe et al 1995, Brown & Atkinson 1996.…”