Belowground Biomass ofPhragmites australisin Coastal Marshes

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

“…The roots of P. australis are dense and have very resilient rhizomes that stabilize soil and enhance gas diffusion into the rhizosphere (Bart and Hartman, 2003;Moore et al, 2012), and as described above, invasion tends to dry soils and infill open-water patches (Rooth et al, 2003;Windham and Lathrop, 1999). Within dense stands the accumulation of above-ground litter and below-ground material, driven by rhizomes mats, fills in creeks and standing water pools to the point where increases in marsh elevation make flooding rare .…”

“…While the above-ground biomass of P. australis can alter light availability to other marsh plants, the rhizomes and roots of P. australis also contribute to its invasive potential. Phragmites australis can alter below-ground competitive interactions by producing extensive root and rhizome networks which reach up to 1 m in depth, and are typically deeper than resident plants (Moore et al, 2012). This consistently deeper root profile may circumvent nutrient competition for P.…”

“…These hydrologic changes combine to increase the aeration of wetland soils, which can reduce the anoxia stress experienced by wetland plant roots (Moore et al, 2012), potentially altering competition dynamics in an environment where resident plant species are adapted to inundated soils. With shallower standing water (Rooth et al, 2003), elevated and smoothed topography, and reduced flooding and surface run-off (Weinstein and Balletro, 1999), portions of the marsh may more closely resemble the upland environment.…”

Greenhouse Gas Fluxes Vary Between Phragmites Australis and Native Vegetation Zones in Coastal Wetlands Along a Salinity Gradient

“…Generally, coastal wetlands emit minimal carbon dioxide (CO 2 ) and methane (CH 4 ) (Mitsch and Gosselink 2000;Poffenbarger et al 2011;Madigan 2012). Phragmites may increase marsh CO 2 uptake in the short term due to its greater productivity relative to smaller native species (Windham 1999).…”

Microbial response to salt marsh restoration

“…The restriction of tidal water slows marsh accretion while decomposition and compaction continue, altering the biogeochemistry of the sediments (Portnoy and Giblin 1997). With decreased salinity the native, salt-tolerant marsh grasses can be outcompeted by less salt water-tolerant species such as invasive Phragmites australis, with cascading effects on associated salt marsh ecosystem services (Able and Hagan 2003;Rickey and Anderson 2004;Meyerson et al 2010;Moore et al 2016). Restoring tidal flow to these previously restricted marshes is one common means of restoring salt marshes but the timeframe for the return of marsh ecosystem services remains unclear (Warren et al 2002;Roman and Burdick 2012).…”