Before this century, fires burned vast areas. The only barriers were natural waterways—sloughs, lakes and ponds, and estuaries—which retained some water during the rainless season when the rest of the glades and pinelands dried up. Old-timers say that sometimes a fire would travel all the way from Lake Okeechobee to the coastal prairie of Cape Sable (_see_ page 2). In the pine forest, any area bypassed by these fires for a lengthy period developed into a junglelike island of hardwoods. We call such stands “hammocks,” whether they develop in the pine forest or in the open glades. On the limestone ridge, the hammocks support a community of plants and animals strikingly different from the surrounding pine forests. [Illustration: PINE AND HAMMOCK RIDGE (_elevation: 3 to 7 feet above sea level_)] SAWGRASS GLADES PINELAND HARDWOOD HAMMOCK PINELAND 1 SOUTH FLORIDA SLASH PINE 2 SAW-PALMETTO 3 COONTIE 4 SAW-PALMETTO AFTER FIRE With the opening up of south Florida for farming and industry, man’s works—particularly roads and canals—soon crisscrossed the region, forming barriers to the spread of the fires. Suppression of fire by farmers, lumbermen, and park managers also lessened their effect. Thus the hardwoods, which previously had been held back by fire, tended to replace the pines. And although the park was established to preserve a patch of primitive subtropical America as it was in earlier centuries, the landscape began to change. Continued protection of the park from fire would in time eliminate the pineland—a plant community that has little chance to survive elsewhere. So, in Everglades National Park, Smokey Bear must take a back seat: park rangers deliberately set fires to help nature maintain the natural scene. Thus, as you drive down the road to Flamingo, do not be shocked to discover park rangers burning the vegetation. The fires are controlled, of course, and the existing hammocks are not destroyed. When you visit the park take a close look at the pinelands community. Notice, as you walk on the manmade trail through the pine forest, that the ground on either side of you is extremely rough. The limestone bedrock is visible everywhere; what soil there is has accumulated in the pits and potholes that riddle the bedrock. The trees, shrubs, grasses, and other plants are rooted in these pockets of soil. The limestone looks rather hazardous to walk on—and it is. You must be careful not to break through a thin shell of rock covering a cavity. This pitted, honeycombed condition is due to the fact that the limestone is easily dissolved by acids. Decaying pine needles, palmetto leaves, and other dead plant materials produce weak acids that continually eat away at the rock.