372 Natural Resources Systems Copyright Goodheart-Willcox Co., Inc. The most distinctive characteristic of a poco- sin is its unique fl ora. Some pocosins are predom- inantly wooded with evergreen trees, such as the pond or loblolly pine, and are referred to as high or pond pine pocosins. High pocosin wetlands have trees that are over 20′ (6 m) tall and shallow peat soil with more nutritive value. Other poco- sins have short shrubs as the predominant plant material and are referred to as low pocosins or shrub bogs. Low pocosin wetlands have trees and shrubs less than 20′ (6 m) tall and deeper peat with fewer nutrients. The acidic soil is ideal for certain plants, such as marsh pines, red bay shrubs, evergreens, orchids, and a variety of car- nivorous plants, such as the Venus fl ytrap and yellow pitcher plant, Figure 15-19. Pocosins, like many other wetlands, are impor- tant to migratory birds as they travel southward. Pyrophytic Ecosystems Many years ago, we began controlling wildfires in the United States to prevent damage to homes, prairies, and forests. What we did not understand at the time is that wildfires are a necessary component of healthy prairies, forests, and wetlands. Another unknown was that some plants need fire to release seeds. In a pyrophytic ecosystem, fire is needed for the future generations of plants to be able to grow and develop. These ecosystems contain plants that have become fire-adapted and annual fires are needed to clear undergrowth and thin out shrubs or trees so new plants can take root. In a pyrophytic Serotinous Plants ecosystem, fire suppression reduces the health of the area by allowing the build-up of undergrowth that prevents seeds from taking root and becomes excess fuel for wildfires. The excess fuel causes fires to burn so intensely that the ground will burn and very little of the natural flora will survive. Many of the plants living in pocosin wetlands are serotinous. A serotinous plant relies on an environmental change to release a seed for reproduction. Some serotinous plants possess fire-activated seeds, cones, or sprouting mechanisms with a thermal insulation that will not open without being exposed to the heat of a wildfire. Fire also clears away other plant materials that would compete with the new seedling for space. By waiting for the fire, serotinous plants give themselves the best chances for growth and future reproduction. Consider This 1. Not all serotinous plants rely on fire for reproduction. Research the Ponderosa pine for an example of another accommodation that plants have developed to survive in fire-prone areas. 2. Controlled fires are very important for forest preservation. Research the 2018 Camp Fire and discuss with classmates the pros and cons of major forest fires. How do they impact people, animals, and plants? How could such a fire have been prevented or lessened in strength? Tom Grundy/Shutterstock.com Lodgepole pine Victoria Field/Shutterstock.com South African aloe Photo by Susan Berescik Figure 15-19. A—The Venus flytrap is another carnivorous plant that is native to many pocosins in North Carolina. B—The yellow pitcher plant uses nectar at its neck to lure insects. The nectar contains fluids and enzymes that dissolve the captured prey. AlessandroZocc/Shutterstock.com A B