It has been documented that there are 432 lichen species within one square kilometer at the Fakahatchee Strand Preserve State Park in southwestern Florida.
Only eight other parks in the United States have a higher number of lichen species. But in those eight other parks, the areas were much larger. The lichen found in the Fakahatchee Strand Preserve had more biodiversity in a relatively small space than anywhere else in North America. It is also thought that new species of lichen will be found in the park.
Lichen consists of two organisms in one living symbiotically. One part is fungus and the other is a photosynthetic companion. They have green algae, but some do have cyanobacteria (once known as blue-green algae). There are a few that have both green algae and cyanobacteria. They obtain water from the atmosphere through rain, fog, and dew and minerals from airborne dust. Green algae create simple sugars via photosynthesis, food for itself and its fungus companion. The fungus protects its photosynthetic partner and retains water for later use. Some fungi are able to extract minerals from what it is growing on, such as stone or bark. If cyanobacteria are present, they convert atmospheric nitrogen into ammonia for use by both the fungus and bacteria.
They have different morphologies with some looking like they were painted on a surface. Other have hair-like filaments, also known as “leafy” growths or branches. They get their nutrients from the air. Consequently, some lichens accumulate pollutants in their tissues making them useful biomonitors of environmental conditions. In some parts of the world, lichens are still used for food and medicine and dyes.
A lichen can thrive in a wide range of environments, including, frigid polar regions, rocky coastlines, and dry deserts. The highest diversity is found in tropical rainforests. Fakahatchee Strand Preserve has been regarded as the “Amazon of North America” due to its rich diversity of tropical plants.