We sample the production of graminoid plants (sedges and grasses) and measure the impact of goose grazing in wetlands at 3 wetland sites on Bylot Island every year. At each site, 12 new exclosures (1 m x 1 m x 50 cm high) made of chicken wire are installed in late June. At the end of the growing season in mid-August, we sample plant biomass by removing 20x20 cm plots in ungrazed and grazed areas (i.e. inside and outside exclosures). All live above-ground biomass is cut, sorted out by species and weighed dry. Use of the area by geese is monitored by counting feces on 1 x 10 m transects located near each exclosure every 2 weeks during the summer. We monitor the phenology of graminoids inside exclosures by counting flower heads and recording their stage every 2 week since 2005. We monitor the long-term impact of herbivores in wetlands with 18 permanent exclosures installed in 1994. Each exclosure excludes geese over a 4 m x 4 m area enclosed with chicken wire, and also excludes lemmings over a 2 m x 2 m area of the larger exclosure enclosed with smaller mesh welded wire. Graminoids and mosses inside these long-term exclosures are sampled at 5 to 8-year intervals. From 2007 to 2009, we also sampled the production of plants (sedges, grasses and dicotyledons) and measure the impact of goose grazing in mesic communities following the same methods as in wetlands. ** Data from the IPY years 2007-2009 are available for download. If data are downloaded and used for analyses, it would greatly be appreciated that the principal investigator be informed.