Natural History and Population Status of a Rare Shrub, the Miccosukee Gooseberry, on Private Land in North Florida
R. Todd Engstrom, Tall Timbers Research Station and Land Conservancy
The Miccosukee gooseberry (Ribes echinellum) was discovered in on private land in Jefferson County, Florida, in 1924. A second population was located in McCormick County, South Carolina, in 1957, but this is a study of the Florida population only. The species was classified as federally threatened in 1985. A portion of the Florida population was monitored from 1992 to 2001 by The Nature Conservancy and intermittently from 2010 to 2016 for the USFWS. Florida Natural Areas Inventory ecologists mapped the general distribution of Ribes in Jefferson County in 1985. A resurvey of the same area in 2016 determined that gooseberry still occurs to the same extent 31 years later. Ribes appears to thrive in tree fall gaps. Some of the most productive plants, in terms of the number of fruit produced, and some of the densest patches of gooseberry occurred along trunks of large fallen trees. Fruit production in the gooseberry is rare (median number of clumps with fruiting stems was 1.4% for the two subpopulations from 1992-2001), but the species is still common in the small area where it was first described. In 2010 I estimated that there were 8600 gooseberry clumps in the two largest subpopulations, but how clumps relate to genets is unknown. The population trend of gooseberry in one of the two largest subpopulations indicated by transects declined by 14.2% from 2011 to 2013, and nearly every transect in the subpopulation declined from the 10-year average collected from 1992 to 2001. Recent genetic studies revealed low genetic variation suggesting an increased risk of extinction or population decline, and another recent study indicates that seed predation by a mouse could have a significant negative effect on seed dispersal. One hypothesis for local declines of Ribes is rapid growth of extremely dense stands of laurel cherry (Prunus caroliniana).