Mechanisms of dominance by the invasive hybrid cattail Typha × glauca

Abstract

The mechanisms by which invasive plants displace native species are often not well elucidated, limiting knowledge of invasion dynamics and the scientific basis for management responses. Typha 9 glauca Godr. invades wetlands throughout much of North America. Like other problematic wetland invaders, Typha is large, grows densely, and leaves behind copious litter. It thus has the potential to impact wetlands both in life and after death. We assessed patterns in field settings and used simulated wetland-plant communities to experimentally test abiotic and community responses to live Typha, Typha litter, and water-level differences (confounded in the field) using a full-factorial design. In general, litter was a stronger driver of change than live Typha. The greatest impacts were seen where, as in nature, live and dead Typha co-occurred. Live-Typha treatments did not differ from controls in light or temperature conditions but did reduce community biomass and alter community composition. Litter strongly affected light, temperature and its variability, community and species-level plant biomass, and community composition. Interactions between live Typha and litter affected aspects of plant-community composition. Advantageously for Typha, interspecific litter effects were not mirrored by intraspecific suppression of live Typha. These findings clarify how Typha is such an effective invader. Similar mechanisms are likely involved in invasions by other plant species, particularly in wetlands. Managers should respond quickly to new Typha invasions and, when dealing with established stands, remove litter in addition to eradicating live plants.

Herbicide management of invasive cattail (Typha × glauca) increases porewater nutrient concentrations

“…The experiment was conducted at the University of Michigan Biological Station (Pellston, Michigan, USA) during June-August in 2013 and 2014, using 16 experimental mesocosms that were initiated in 2002 (see Larkin et al 2012a for further details of experimental setup). Each mesocosm was a box frame measuring 1-m wide, 2-m long, and 1-m deep, lined with rubber pond liners (1-mm thick), counter-sunk into the ground, and filled with hydric soils from a nearby wetland and mixed with 20 % Rubicon sand.…”

“…Each were planted with 11 native species from a nearby marsh in 2003, and subsequently invaded in 2004 with Typha 9 glauca planted at a density of 16 stems/m 2 . The mesocosms have been subjected to different water levels and Typha litter addition in the past decade to investigate the effect these factors have on the vegetation community, Typha dominance, and nutrient cycling (Larkin et al 2012a;Lawrence et al unpublished data).…”

“…Dense litter accumulates in Typha-invaded wetlands (Mitchell et al 2011;Vaccaro et al 2009), promoting positive feedbacks that sustain the invaded state (Zedler 2009). Typha litter reduces sunlight penetration, moderates soil temperatures, and reduces native seed germination (Farrer and Goldberg 2009;Larkin et al 2012a;Vaccaro et al 2009). Larkin et al (2012b) found that Typha litter enriches its soils, generating plant-soil feedbacks that promote its dominance, suggesting that removal of Typha litter may facilitate the transition to a more desirable uninvaded state.…”

Leopold’s Arboretum Needs Upstream Water Treatment to Restore Wetlands Downstream

“…Once aggressive invaders are established, they persist indefinitely. Cattail perpetuates itself in part by garnering and holding onto nitrogen more effectively than competitors [37,38] and by producing high levels of biomass aboveground, where the thick litter displaces all but its own vegetative sprouts [39]. Similarly, reed canary grass self-perpetuates by accumulating thick litter that other species are less able to penetrate than its own sprouts [40][41][42].…”

Typha glauca Godron and its parental plants in Poland: taxonomic characteristics

“…(Smith, 1967). In North America, all three species and, in particular, Typha glauca, are regarded as expansive weeds that have altered wetland ecosystems (Grace & Harrison, 1986;Galatowitsch et al, 1999;Zedler & Kercher, 2004;Angeloni et al, 2006;Shih & Finkelstein, 2008;Tuchman et al, 2009;Lishawa et al, 2010;Travis et al, 2011;Larkin et al, 2012). Reports of spontaneous hybrid occurrence in Europe are comparatively much less frequent.…”