The Ecology of Tidal Freshwater Marshes of the - USGS National ...

progresses, some pl ants wi 11 be overtopaedby other species commonly inhabiting thelow intertidal zone such as arrow-arum,pickerelweed, and wild rice.2) Arrow-arum1Pickerelweed CommunityType - Arrow-arum is an extremely cosmopoli tan species growing throughout theintertidal zone of many marshes. Thisspecies forms its purest stands in the lowintertidal portions of the marsh in springor early summer. Pickerelweed, a commonassociate, is equally as likely to dominateor codominate this lower marsh zone(Figure S), although its distribution isusual ly more cl unped than arrow-arum.Both species tolerate long periods of inundation.Other species associated withthis community type, especially in moreelevated sections of the marsh, includeburrnarigolds and wild rice, and less frequently,arrowhead, sweetfl ag, and smartweeds.3) Wild Rice Community Type - Wild rice isconspicuous and widly distributed throughoutthe Atlantic Coastal Dlain. This annualgrass can completely dominate a givenmarsh, producing plants which attainheights in excess of 4 m (13 ft) in Augustand September (Figure 7). Wild rice isnot noticable until midsummer when itbegins to overtop a discontinuous canopygeneral ly composed of arrow-arum,pickerelweed , spatterdock, arrowhead,smartweed, and burnarigolds.4) Cattail Community Type - Cattails areamong the most ubiquitous of wetlandplants and are princioal components ofmany tidal freshwater marshes. The cattailcommunity type (Fiqure 8), whichincludes several species of Typha in themid-Atlantic region, is qostly confined tothe upper intertidal zone of the marsh.Cattails are usually found with one ormore common associates---arrow-arum, rosema11 ow, snartweeds, jewelweed, and arrowhead---butwill a1 so form dense inonospecific stands. Cattail communities area1 so prevalent in disturbed areas, wherethey often are associated with commonreed.5) Giant Cutgrass Community T.yne - Giantcutgrass, also known as southern wildrice, is an aggressive perenni a1 confined~redorilinantlv to wetlands south of Virqin-Fi gure 5. Spatterdock cornrnuii ty type. i a and l4aryl and. This species dominated19