Study area The Catoctin Mountains study area is approximately 485 km2 (301 mi2). Located in Frederick Co., Maryland and comprises the easternmost ridge of the Blue Ridge Mountains (Fig. 1; Schmidt 1993). The Catoctin Mountains are oriented in a northeast/southwest direction and stretch approximately 80 km from their origin at South Mountain near Emmitsburg, MD, to the south just

past Leesburg, VA, where they become undifferentiated into the Piedmont Physiographic Province (Schmidt 1993). The point VX-680 in vitro of greatest elevation is just southwest of Cunningham Falls State Park at 538 m (1,765 ft). The Catoctin Mountains are located in the transition between two of Köppen’s climatic types; the Cfa, of Humid Subtropical climates, and Dfa, of Humid Continental climates (Markus et al. 2006). Average weather conditions at Catoctin Mountain Park, located near Thurmont, MD, indicate that the climate is cool-temperate Selleckchem PRI-724 with a mean annual temperature of 12.0 °C (53.6 °F) and a mean annual precipitation of 115.2 cm (45.3) in (NOAA 2013). Fig. 1 Map of the Catoctin Mountains study area with State of Maryland depicted to the left. Circles locations of a survey site Floristically, the Catoctin Mountains are

dominated by deciduous forests comprised primarily of oak (Quercus L. spp.). NatureServe (2011) documents six forested systems present within the study area: Appalachian Hemlock (Tsuga Canadensis (L.))-Northern Hardwood Forest, Central Appalachian dry oak-pine (Pinus L. spp.) forests, Central Appalachian pine-oak PJ34 HCl rocky woodlands, central Appalachian steam and riparian forests, North-Central Appalachian acidic cliff and talus, and northeastern interior dry-mesic oak forests. The study area is located within the Catoctin-South Mountain

Region of the Blue Ridge and is underlain by Catoctin metabasalt greenstone (Schmidt 1993; Reger and Cleaves 2008). The area contains a number of large protected lands including Catoctin Mountain Park, Cunningham Falls State Park, Frederick Municipal Forest, Gambrill State Park, and Camp David, the Presidential retreat. Culling of the deer herd was not SB-715992 price allowed on Catoctin Mountain Park until 2010 (Loncosky personal communication). Materials and methods Twenty-one species of orchids were inventoried annually at 167 sites, during various times of year beginning in 1968 and ending in 2008 using traditional Natural Heritage Program inventory methods, namely the Observational Data Standard (Fig. 1; NatureServe 2006). The surveys were conducted by the second author or, occasionally, with assistance of other knowledgeable individuals. This reduced the likelihood that a site would not be thoroughly explored and helped limit issues with varying survey efforts among distinct surveyors over the years of the survey.