Orange-colored deposits often occur around roots growing within hydric soils. Plants that are able to grow and reproduce in wetlands do so because of special adaptations which allow them to survive in a waterlogged environment. Many wetland plants have very spongy roots. These roots have air spaces, which are believed to allow the movement of oxygen from the leaves to the roots, thereby allowing the plant to thrive despite the anaerobic conditions present in the soil. The type and abundance of vegetation is an important factor in determining what types of animal species use the wetland.
Many wetlands have very high primary productivity rates.
This means that the plants growing in the wetland are very efficient at converting sunlight, water, and soil nutrients into plant tissue. Typically, the most productive wetlands are coastal wetlands and wetlands located adjacent to rivers or streams. The reason that many of these areas are so productive is related to the hydrology or movement of water which occurs within many wetlands. Coastal wetlands flood regularly due to tidal water movement. Tidal flooding flushes the soils of coastal wetlands, removing toxins and wastes which may make the soils inhospitable to plants or burrowing animals.