PARENT SESSION
Poster Session 13: Landscape Ecology / Geomorphology
Tuesday, August 9, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Community decline and population success: A recent history of Eastern Red Cedar in southern Wisconsin.

Mills, Jason^*,1, Allen , T¹, ¹ University of Wisconsin- Madison, Madison, WI

ABSTRACT- According to statewide surveys conducted by the General Land Office in the mid-nineteenth century, Eastern red cedar (Juniperus virginiana L.), a fire-sensitive conifer, rarely occurred on the Southern Wisconsin landscape since frequent fire constrained red cedar to bluffs and ridges. The communities on these sites were most likely savannas, composed of dry prairie herbs and red cedar trees limited in density by infrequent fire and very dry, nutrient-poor soils. Fifty years ago, John T. Curtis sampled seven of these communities as part of his effort to reconstruct the pre-settlement vegetation of Wisconsin. My re-sampling of these sites in 2004 shows that red cedar has formed closed-canopy stands, eliminating prairie species and significantly changing the community structure. Rather than fire, agricultural abandonment or over-grazing now maintains openness in the landscape. Since red cedar can quickly colonize open and degraded sites, it has expanded its range in many Midwestern states. Analysis of aerial and landscape photographs and the application of an occurrence model suggest the wide distribution of red cedar on the modern landscape of Southern Wisconsin. Ironically, fire suppression and agriculture have led to the destruction of the community that included red cedar while creating ideal conditions elsewhere for the success of the population.

Key words: Juniperus virginiana, vegetation change, fire suppression