Three years of manual removal of invasive Typha in a Lake Ontario shoreline plain fen

Session: Wetland Restoration in the Great Lakes Basin: Research and Innovation (1)

C. Eric Hellquist, State University of New York Oswego, [email protected]
Faith Page, SUNY Oswego, [email protected]
Ampalavanar Nanthakumar, State University of New York Oswego, [email protected]

Abstract

Endangered bog buckmoth (Hemileuca sp.1: Saturniidae) populations have decreased precipitously along the Lake Ontario shoreline plain.  At one of the few remaining bog buckmoth sites, expansion by cattail (Typha angustifolia and T. x glauca) is altering the habitat of the bog buckmoth’s primary food source, bog buckbean (Menyanthes trifoliata). Since 2016, we have been manually removing Typha by cutting stems below the water line in the spring and fall.  In 2018, there were 3x fewer cattails in cut plots than in uncut control plots. Living biomass was ca. 4 gm^-2 in spring harvest plots and ca. 8-16 gm^-2 in fall harvest plots.  In spring harvest plots, stem counts decreased 3-4x compared to control plots. In fall harvests, Typha stems decreased 2-3x compared to control plots.  There has been an insignificant decreasing trend in living biomass in the fall.  Thatch decreased ~8x in the spring harvest plots and has been essentially eliminated in fall harvest plots.  When faced with Typha colonization, manual removal of thatch in experimental plots has maintained conditions that will support the growth of native plant community structure, including microhabitats critical for bog buckbean.