Say it ain't so, St. Joe. Saying "St. Joe Co." and "Florida's largest private landowner" used to go hand in hand. No more. Florida Trend, a sister publication to the St. Petersburg Times, reports that land sales by St. Joe have diminished its acreage. The state's new No. 1 is Plum Creek Timber Co., a Seattle real estate investment trust whose primary business is to grow, harvest and sell timber. It owns just over 600,000 acres in 22 Florida counties, with concentrations in St. Johns Forest, Gulf Hammock Forest, Lake Butler Forest and the Wire Grass Forest in Northwest Florida. St. Joe, based in Jacksonville and whose land holdings are concentrated in the Florida Panhandle area, says it's down to 585,000 acres statewide, according to its first-quarter earnings report.