Friday, August 10, 2007 - 8:20 AMOOS 47-2: Patterns of rarity among the listed plants of Santa Cruz Island: Using the raw materials for recovery
Kathryn McEachern1, Katherine A. Chess2, and Ken G. Neissen1. (1) USGS-BRD-WERC, (2) Northern Arizona University and USGS-BRD-WERC
More than a century of intense grazing and herbivory has changed the ecological context within which the endemic plants of the Channel Islands evolved. Now, Santa Cruz Island is poised for rapid rebound since the removal of feral pigs in 2006-2007. There are 45 Channel Island endemic plants on the island, and nine are Federally listed as threatened or endangered. These nine species have diverse habitat affinities and span a range of life histories from tiny annuals seen only intermittently to long-lived clonal shrubs. They have all come through the ranching period with a few, disjunct populations that now provide the raw materials for population recovery. Surveys show that most of the populations that were known in the mid-1900s persist today. Repeat censuses and demographic data show that each faces unique challenges for recovery, resulting from such diverse mechanisms as loss of pollinators, altered habitats, and demographic instability in the face of variable weather patterns and altered microclimate regimes. While removal of ungulates is certainly good for the island ecosystems, the rapid change now facing some rare plants will present special autecological and management challenges.