Quantitative monitoring of fen vegetation and hydrology at North Star Nature
Preserve was conducted in 2022, two years after installation of the drainage ditch plug
in late summer of 2020 which was designed to restore the hydrology of the fen. The
data presented in this report show there has been a slight decline in the cover of reed
canarygrass (Phalaris arundinacea), a non-native invasive grass, and an increase in the
wetland hydrology of the fen compared to pre-restoration conditions. By the end of
July 2022, the saturated area of the fen was about 27 percent greater than in July 2018,
and in August 2022 it was about 70 percent greater than in August 2018. Per the
requirements set forth in the U.S. Army Corps of Engineers (USACE) Permit received
for this project, monitoring of the fen hydrology and vegetation is required for three
years, commencing two years after construction. This report represents Year 1 of the
3 years of required USACE monitoring.