Geocarpon minimum, listed by the U.S. Fish & Wildlife Service as threatened, was monitored at Warren Prairie Natural Area, Bradley County, Arkansas, 1986-90. Selected environmental variables were compared with Geocarpon productivity plot by plot. Principal components (PC) analysis generated two eigenvectors that jointly accounted for 30% of the variation among plots. PC-l describes an exposure gradient; high-productivity plots had less litter and grass cover, more cryptogamic lip, and more iron nodules lying on the surface than most other plots. PC-II was more useful for separating highly productive plots from all other plots; the highly productive plots lay in close proximity to slicks and remote from low spots where shallow water stands after a rain. Geocarpon productivity at Warren Prairie Natural Area peaked in 1987 and has declined steeply and steadily in the following years. Recommendations for further study are offered
Shepherd, William M.; Preston, Charles R.; and Steinauer, Robert
"Five-Year Study of Geocarpon minimum at Warren Prairie Natural Area Bradley County, Arkansas,"
Journal of the Arkansas Academy of Science: Vol. 45
, Article 31.
Available at: http://scholarworks.uark.edu/jaas/vol45/iss1/31