The shrubby layer is poorly developed unless fire has been excluded for some length of time. Many of the herbaceous species are unique to bog habitats and under natural conditions will grow nowhere else. Species diversity of carnivorous plants is perhaps the highest in the world. Over half of the 45 North American species occur along the Gulf Coast with as many as 13 species found in a single bog. Anaerobic soil conditions resulting from frequent saturation favors growth of water tolerant species.
Bogs are a fire subclimax community that succeed to other vegetation types when fire is eliminated.
The season during which fire occurs may influence the floristic composition of the bogs. Natural fires are ignited by dry lightening strikes and are most frequent in late spring and early summer. Frequency of fires at a particular site is greater than every 10 years. Without periodic fire, bogs are invaded by a variety of woody species that change the light regime and result in increased transpiration which lowers the water table and provides for further species invasions. The Gulf Coast Pitcher Plant Bogs.