Restoration on Private Lands: A Case Study Examining Vegetation Recruitment following Restoration Treatments in an Oak-pine Barrens Ecosystem in Western Michigan, USA

摘要

Oak-pine barrens ecosystems provide critical habitat for the federally endangered Earner blue butterfly (Lycaeides melissa samuelis). Wild lupine (Lupinus perennis), an herbaceous perennial in this ecosystem is the only food source for the butterfly's larvae. The range and quality of these ecosystems have declined significantly. Restoration in private lands can be key to expanding these habitats, but often there is limited or no follow-up to assess the recovery of the site following restoration treatments. We conducted a case study in a private property in Newaygo County, Michigan for which prescribed fire had been implemented every 2 y from 2007 through 2011 to promote recruitment of key understory vegetation, but there had been no follow-up recovery assessment. The burn treatment consisted of a section that was not burned, one that was burned twice, and one that was burned three times. We collected data on vegetation groups and site related factors along this fire gradient to examine differences as a function of fire frequency, as well as delineate factors driving patterns of understory plant recruitment. Results show little tree recruitment from seedlings, but high densities of tree saplings recruited via resprouting. Estimated cover of lupine was low across all treatments, whereas Pennsylvania sedge (Carex pensylvanica Lana) was highest among species in both cover and biomass. Lupine exhibited a negative relationship with Pennsylvania sedge, litter, and sprouted tree saplings, but a positive relationship with moss cover. We make recommendations for additional restoration interventions and highlight the need for continued support of private landowners as they engage in conservation of imperiled species.