1987 SCHNOES AND HUMPHREY: TERRESTRIAL COMMUNITIES IN FLORIDA 75


 Figure 13.-Saddle Creek Park, >30 years with lakes, Unreclaimed Pits and Spoil
Piles, with an elm and several red maples on the left. The forest canopy completely shades
the water's edge.


characterized by Caesar weed, ferns, and panic grass. One site had little
herbaceous growth but an unusual abundance of grape vines. Shrubs
were similar in identity on the two treatments, but grape vines were
dominant, and young trees and shrubs were few on all of the sites with-
out lakes, giving the shrub layer an open appearance. The abundance of
vines may be underestimated, because much vine growth was high in
the forest canopy where our sampling technique was relatively ineffec-
tive. Unlike the with-lakes treatment, all sites without lakes were domi-
nated by a closed canopy of live and water oaks, with more biomass but
much less diversity. Relictual pioneers from earlier seral stages were scarce.
 To summarize the response of vegetation on unreclaimed pits and spoil
piles, we documented a primary successional process, with an oldfield
community developing in 0-5 years and peaking in 5-15 years, a shrub-
dominated community in 15-30 years, and a maturing, closed-canopy
hardwood forest at >30 years. Mean total basal area of trees steadily
increased with the age of the spoil piles (Fig. 5), as biomass accumulated
in the growing trees. Forest composition differed in old sites with and
without lakes. Presumably the more diverse forests on with-lakes sites
resulted from the gradients of groundwater and sunlight along lake edges,