Carson City Wetlands Earthcache
Wetlands are generally considered to be areas of land whose soils are saturated with moisture either permanently or seasonally. The official definition given by the United States Army Corps of Engineers (COE) and the U.S. Environmental Protection Agency (EPA) are ”those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil” (COE 1987). Wetlands generally include swamps, marshes, bogs and similar areas and can be created by fresh or salt water or any combination thereof. This discussion will mostly be limited to the freshwater type. Since the 18th century it is estimated that more than half of the original 220 million acres of wetlands in the US have been degraded or destroyed, for such purposes as conversion to agriculture, real estate development and flooding during reservoir construction (EPA 2004).
Geology and Wetland Landscapes
Wetlands can develop only in regions where water accumulates, meaning that the ground under the wetland must be impervious to water. Underlying geology provides the base on which wetlands can form. This includes the softer materials such as silt, clay, and charcoal that can be deposited over the parent rocks below. The form of the landscape also has an effect on wetland development. The illustration below shows how wetlands are most likely to be found in valleys or hollow spots in the general landscape.
The first kind (shown in the top illustration) is called topogenous. This kind depends on the shape and form of the landscape. This is the most abundant type. Especially found where precipitation is low and water gathers from a wider source.
The second type (shown in the middle) is called soligenous. It is close to the same type as the first, except that it is formed by ground water emerging from the ground through porous water-laden rocks till it meets impervious rocks below. The water then forms springs that feed the wetland. This type of wetland is only found where two very different types of rocks come together.
The third type (shown at the bottom) is a floodplain wetland. It is usually formed in the lower parts of river valleys where the river has often overflowed its banks. The waters from these floods spread out over the floodplain and form the wetlands. The sediments in the flood waters fertilize these regions and make them very fertile for farming.
Wetlands have three critical criteria, hydrology, soils, and hydrophytic vegetation. Without these the entire wetland ecosystem would collapse. Hydric soils are the building blocks for wetlands and are present in the landscape primarily due to the geology and hydrogeology of the region.and plays a
critical role in wetland dynamics (Warner 2004). Furthermore, wetlands are closely connected to their individual basins and to their watersheds. Soils that are saturated due to surface or groundwater (flooding, ponding or shallow groundwater) during the growing season develop anaerobic conditions (lacking oxygen) in the upper layer and support hydrophytic vegetation adapted for life in saturated soil conditions. Terrestrial plants, as opposed, to hydrophytic ones, require oxygen in the soil to grow.
Values and Functions of Wetlands
Wetlands are very valuable for the region and watershed in which they exist. A watershed is an area of land in which the surface water converges to a single point.
Wetlands do more than provide habitat for plants and animals. The following describes the various
functions of a wetland:
- Water Quality: As water flows through a wetland it flows more slowly and moves around and through the plants and has contact with the soil.. This has many benefits to the quality of the water. As the water slows sediment drops out and settles to the bottom. Nutrients such as nitrogen and phosphorus, that cause algae to grow downstream, are removed with the sediment, or absorbed by the plants and microorganisms in the soil. Wetlands are so efficient at this function that some municipalities are constructing artificial wetlands to treat wastewater and stormwater. Another way wetlands filter water is their capability to remove harmful bacteria. Invertebrates that live in the wetland, such as aquatic insects, feed on bacteria. One study showed that up to 90% of the bacteria entering a wetland were removed by the time the water left the wetlands (EPA 2010). Other studies have found that the oils and
heavy metals that drain off of streets with stormwater can also be treated by passing through a wetland.
- Water Storage: Wetlands act like natural sponges in that they absorb the water that enters and then gradually release it very slowly over an extended period of time. This process provides an important benefit during a flood, as the water is released from the wetland after the peak flood-flows have passed, thereby reducing the damaging effects of the flood . Flood control is a major issue in the Truckee Meadows at
the present time and millions of dollars will soon be spent in order to lessen the impact of these events that have been regularly occurring about every 10 years. Related to this function is a reduction of erosion which damages stream channels and increases sediment load. It also increases groundwater recharge and contributes to base flows, which is especially important during dry years.
- Habitat for fish and wildlife: Wetlands are considered to be one of the most biologically productive ecosystems in the world, comparable to tropical rainforests and coral reefs (EPA 2001).. They are home to one the largest collections of biodiversity to be found on the planet (www.articlemyriad.com), representing reptiles, amphibians, fish, birds and mammals. Large numbers of both terrestrial and aquatic organisms rely on wetlands for some phase of their life cycle. A large variety of migratory birds, breed, rest, and feed in these areas More than one-third of the threatened and endangered species in the US live only in wetlands, and nearly half use wetlands at some point in their lives (EPA 1995). Most commercial and gamefish breed and raise their young in coastal marshes and estuaries. Important species of fish you may have heard of that use wetlands include Menhaden, Flounder, Sea Trout, Spot, Croaker and Striped Bass. Likewise, shrimp, oysters, clams, and crab need these wetlands for food, shelter or breeding. Wetlands are so important that an international agreement was developed because some species of migratory birds are completely dependent on certain wetlands.
Carson City Wetlands
This wetland is different that other wetlands in the area. You can find floodplain wetlands all up an down the Carson River, just within a mile or two from this spot. This wetland's water comes from the Sierra Nevada, but at a slower pace from Governor's Creek.
Logging this cache
To log this cache, please let me know which type of wetland this is and why. Also include a photo of you (no faces are required) holding a piece of paper with your geocaching name and date you log the cache. I will only contact you if the logging requirements are incorrect Please do not include your answer in your log.