Ozark Highlands Cluster, Fire Ecology Annual Report: Calendar Year 2010
Author unknown. Ozark Highlands Cluster, Fire Ecology Annual Report: Calendar Year 2010
A summary of fire ecology activities and program information for the Park/network including fire effects plot workload, staffing, management objectives and monitoring results, and planning, fire monitoring, communications, and research. Also included are staff accomplishments/areas of focus, future program direction and other optional information (e.g. data analysis graphics or presentations, annual highlights, publications, program challenges, unique solutions to problems, collaboration, photographs of monitoring/fire activities, and suggestions on FFI). The highlight of the 2010 field season was Erin Yeoman’s discovery of a large population of Newton’s larkspur (alias Moore’s larkspur, Delphinium newtonianium) in the Point Peter/Robinson Hill prescribed burn unit at Buffalo National River (BUFF). The 1,116 plants make this a significant population for this nationally rare wildflower. Newton’s larkspur is ranked globally vulnerable to extirpation in the wild by The Nature Conservancy. Newton’s larkspur is only recorded from 7 counties in Arkansas and nowhere else in the world. According to my conversations with Dr. Edith Hardcastle, Theo Whitsell, and other experts on the species there is virtually no information on the fire ecology of this rare plant. My anecdotal observations of the Yeoman population at BUFF suggests that these plants benefitted from the canopy thinning that occurred from the Feb. 2009 ice storm. The ice storm was especially hard on the cedar trees in this area. I believe that the understory thinning and nutrient release from the March 2010 prescribed burn also benefitted this population. Interestingly, 99.5% of the larkspurs in this population were reproductive. I believe that this high percentage indicates that the population is getting the right balance of sun, shade, moisture, nutrients, and other variables needed for reproduction. We also found a population of 174 plants along the Ben Branch intermittent drainage about 3/4 mile due east of the Yeoman population, 90.6% were reproductive. We inventoried another population of 472 plants recently discovered by CD Scott in the Sod Collier prescribed burn unit near the Tyler Bend area, 99.4% were reproductive. This population was on a south facing toe-slope adjoining a county road. It went upslope about 70 feet. To me, these observations suggest that Newton’s larkspur is a disturbance dependent species that may specialize in using mesic woodlands as opposed to true forests. Mesic woodlands are the first natural community to be degraded by succession to fire-intolerant species due to the absence of the historic fire regime. Of the 1,780 Newton’s larkspurs that we inventoried, only 2 were basal rosettes (possibly seedlings), and another 25 plants only had leaves on the stalk with no sign of making flower buds. According to Dr. Hardcastle, no longevity or demographic studies exists for D. 2 newtonianum, a critical missing link in understanding this species. My ultimate goal is to understand (with certainty) how we can sustain seedling recruitment in these wild populations.