|The Catalina mahogany (Cercocarpus traskiae) is thought to be one of the rarest shrubs in the continental United States. It grows naturally only in one gully system on the south side of the Island. Early monitoring revealed that this plant was not successfully reproducing, and several individuals were fenced to exclude browsing animals. This resulted in improved regeneration for these individuals. In 1999, the entire gully was fenced against all non-native herbivores, enclosing 112 acres.
To increase the total number of Catalina mahogany trees within Wild Boar Gully from a current total of 12 adults (7 pure individuals, 5 hybrids with C. betuloides) by at least 2 individuals of sapling size or greater every five years starting in the year 2001. Towards this goal, the entire gully supporting this species has been fenced against all non-native animals to eliminate browsing pressures.
Each mahogany individual is visited during the time of fruiting and such variables as basal diameter, percent of deadwood, fruit production, canopy dimensions, overall health, and associated species are recorded. A search is conducted in the vicinity of each tree for new seedlings. All seedlings and saplings are marked and tracked by recording height and vigor.