Ecological Survey of a Florida Scrub

Abstract

Botanically, the Florida scrub is one of the most interesting and weird of plant associations. Economically, the plants, as well as the soil, have almost no importance. The nearly pure white sand of the ground surface, when viewed from a short distance, gives the impression of a thin rift of wind-driven snow. The vegetation is mostly dwarfed, gnarled and crooked, and presents a tangled, scraggly aspect. It appears to desire to display the result of the misery through which it has passed and is passing in its solution of life's grim riddle. Here live the rosemary (Ceratiola ericoides),1 spruce pine (Pinl is claui-sa), poor grub (Xolisata fci-rruginea) and their associates rooted in a bed of silica, to which the term soil is but remotely applicable. Here the sun sheds its glare and takes its toll of the unfit. In connection with the campaign against the Mediterranean fruit fly in Florida, 1929-30, a great many ecological plant surveys were made in various parts of the state by O'Neill and his associates; the work here reported was an intensive study of a small section of the broad field somewhat hastily covered by them. Three types of plant associations were considered in the study, but results secured on the scrub only are given here. The scrub association was recognized as a distinct type of vegetation in the early floristic and soil studies of Florida, and was probably first described by Vignoles (I823). It was, however, overlooked by Williams (1827) and Smith (i884) in their discussions of the soils and vegetation of the state. Nash (i895) distinguished 5 floral areas (high pine) land, scrub, low pine land, bayheads, and hammocks), and described in some detail the vegetation of each. He concluded that a definite antagonism existed between the plants on the scrub and the adjacent high pine, and called attention to the fact that there is no intermingling of the species peculiar to the two associations. He lists a few of the more abundant forms on the scrub, and notes the complete absence of grasses. Nash made the very interesting observation that scrub vegetation has no special provision for the prevention of death by fire. The high pine plants generally have some means of avoiding such a fate. \Vhitney (i898) briefly compares the high pine vegetation with that of the scrub, enmphasizing the sudden transition from one to the other, and states that fromn chemical and physical analyses there is no manifest reason for the difference observed. The topography is likewise dismissed as a factor.