DoesPhragmites expansion alter the structure and function of marsh landscapes? Patterns and processes revisited

Long-term effects of a Phragmites australis invasion on birds in a Lake Erie coastal marsh

“…This study (Anas discors), and terns (Laridae). The potential for P. australis to reduce the size of these areas or fill them entirely (Lathrop et al, 2003;Windham and Lathrop, 1999) is a threat to this open-water bird community.…”

“…Phragmites australis can spread by colonization, linear clonal growth, or circular clonal growth of patches, and within invaded wetlands patch numbers increase over time before decreasing as large patches integrate with one another (Lathrop et al, 2003). Lateral expansion of patches is enhanced by stolons, which can arise from fallen stems or horizontal rhizomes (Appendix 1c) (Brisson et al, 2010).…”

“…The wide range of disturbances and environmental variables that P. australis can tolerate, coupled with its morphological characteristics, contribute to P. australis having a competitive advantage over many resident wetland plant species. In brackish tidal marshes P. australis spreads rapidly until it reaches an equilibrium point that consists of 50-80% occupation of the marsh surface (Lathrop et al, 2003).…”

“…It has been argued that the density of stands and rigidity of stems can make the habitat impenetrable to large-bodied waterbirds (Benoit and Askins, 1999;Kessler et al, 2011). Further, the increased above-ground biomass couples with high litter accumulation (Rooth et al, 2003;Windham, 2001) to smooth microtopography, raise soil and reduce standing water levels (Lathrop et al, 2003;Weinstein and Balletro, 1999;Windham and Lathrop, 1999), eliminating open-water pools and creeks . Standing water and open-water pools are essential habitat for waterbirds and shorebirds, contributing to the overall heterogeneity of marshes and correlating with an increase in bird species richness, especially in meadows (Benoit and Askins, 1999;Riffell et al, 2001).…”

Restoration of invaded Cape Floristic Region riparian systems leads to a recovery in foliage-active arthropod alpha- and beta-diversity

“…The reason for this is unclear, but may be due to changes in plant characteristics (e.g. physical structure, leaf chemistry, and host abundance) associated with plant invasion (for example see Lathrop et al 2003). It is possible that M. angustifolia characteristics that may alter quality of habitats for arthropods for did not change in the presence of IAPs, hence arthropods were quick to recolonise M. angustifolia individuals after removal of IAPs.…”