Demography of Echinecea laevigata populations in southwest Virginia: The endangered flagship of rare forest glade habitats
Echinecea laevigata (smooth coneflower) is a federally listed endangered species found in forest glade habitats in the southeastern USA. In Virginia, these glades are small, historically open areas with basic soils embedded in forested landscapes of primarily acidic soils. Humans have reduced glade habitats through altered land-use and disturbance regimes. E. laevigatawas federally listed as endangered in 1992. Population monitoring has continued in some populations but a detailed study of population dynamics is largely lacking. Our goals were to assess changes in population size and examine demographic patterns. In 2014, we censused three populations and measured plant area, reproductive status, and herbivory level of 1,000 plants that we tagged. In 2015, we recensused these plants in order to complete a demographic analysis.
Large and small populations differed in size-class distribution and flowering-plant size. Large populations had more small plants (< 150cm2) and flowering plants were primarily from smaller size classes. Small populations had more even size-class distributions and flowering plants tended to be larger. Most plants had insect damage (> 50% of plants) but the amount of damage on plants was small (<25% of plant area). White-tailed deer herbivory was primarily present in populations that occupied deer right a ways (i.e., old roads and power lines). These results suggest that small and large populations are experiencing different demographic dynamics. The next step is to identify the ecological drivers causing the dichotomous demographic patterns, which could elucidated effective management strategies. Preserving a flagship species of rare forest glades has the potential of promoting population of other endemic glade species.