Forest Community Structure Differs, but Not Ecosystem Processes, 25 Years After Eastern Hemlock Removal in an Accidental Experiment

Abstract

Abstract The spread of Adelges tsugae (Hemlock Woolly Adelgid) directly threatens the survival of Tsuga canadensis (Eastern Hemlock) and has also triggered pre-emptive and salvage logging. In this study, we took advantage of a 25-year-old accidental experiment involving Eastern Hemlock removal by logging at Smith College's MacLeish Field Station, in western Massachusetts, to investigate how microclimate, ecosystem processes, and forest-floor animal communities might change in the decades following Eastern Hemlock loss. On average, mean understory light levels in summer were 68% higher under young Black Birch (Betula lenta) canopies as compared to adjacent mature Eastern Hemlock forest. Mean daily air temperature, relative humidity, soil temperature, and organic-layer moisture content were similar between young Black Birch and mature Eastern Hemlock plots, although some of these factors were significantly more variable in the former. The soil organic horizon was significantly thicker in Eastern Hemlock plo...