Wetlands, Marshes and Swamps

Ephemeral pondWeb
An ephemeral, or seasonal, pond in Devils Postpile


The Importance of Wetlands
Wetlands and meadows may not be the first thing on the must see vacation check list for many visitors, but the provide tremendous value to a diversity of plant and animal life as well as recreational opportunities for visitors. They are not, however, very common. In Devils Postpile they make up only 8.5% of the total area of the monument. In other Sierra Nevada parks such as Yosemite and Sequoia, that number is also less than 10%. So what is so special about these places? Read on to find out!

Habitat for Plants and Animals
Although we may think of wetlands and meadows as breeding grounds for mosquitoes in the summer, those mosquitoes are part of a complicated web of life that not only ends with top predators like black bears and mountain lions, but provides endless opportunities for wildlife watching. Meadows are some of the best places to view wildlife. The wetlands in Devils Postpile are home to over 100 species of insects. Most of these live in areas where there is flowing water, although many of them use more stagnant ephemeral, or temporary, ponds to breed. What is so great about bugs? They feed most other things in one way or another.

Eating those wetland and meadow insects are animals like the Belding ground squirrel and any one of ten species of bats found in Devils Postpile. Birds also rely heavily on healthy insect populations in wetland areas. Warblers and other migratory song birds use these meadow and wetland habitats as breeding grounds in the spring and migratory stopovers to refuel in both the spring and the fall. These habitats provide not only a valuable food source for these birds, but many of the willows and other low growing shrubs that depend on moist soil provide nesting locations and protection for breeding and migratory species. Aside from providing protection, meadow and wetland plants also provide food. Mule deer and ground squirrels feast on lush meadow grasses all summer long. Bears will also eat the roots of meadow plants as well as insects.

Many of these species in turn feed some of the larger carnivores that live in Devils Postpile. Meadows are great places for wildlife viewing because this is where animals come to drink and feed. The squirrels draw predators like the coyote and bobcat to Devils Postpile's meadows. Mule deer will draw larger predators such as the mountain lion. Even weasels have been known to come to the meadow to hunt ground squirrels from time to time.

Flood Control and Nutrient Cycling
Meadows and wetlands don't just provide places for plants and animals to live. One of the things that makes a wetland a wetland is the hydrology, or water characteristics, of the area. Not all meadows were once lakes that dried up, and not all wetlands have the same hydrology. Some of them are primarily fed by mineral springs, some by increased spring runoff, and some fueled by groundwater. Each one of these wetlands will be slightly different, but their benefits are similar. Wetlands are like giant sponges. During spring runoff and times of high water, they have the capacity to absorb much of the excess water. The plant species that make up the wetlands have adapted to survive floods and actually need the nutrients left behind by those floods to survive. The wetlands also act as filters. They filter out both sediments and pollutants, helping to provide clean, clear water to streams and rivers. This is vital to many riparian species. Because the wetlands absorb so much water, they also provide some flood control. This helps prevent excessive erosion downstream.

Wetland Monitoring
Because wetlands are relatively few in number and occupy a small area, yet provide so many vital benefits to plant and animal species, parks in the Sierra Nevada have been monitoring wetland health since 2007. Studies and restoration work was certainly completed before 2007, but an organized monitoring effort began in 2007. These studies will help scientists and resource managers understand the over all health of wetlands throughout the Sierra Nevada parks (Yosemite, Sequoia, Kings Canyon, and Devils Postpile), and make management decisions accordingly. These efforts continue today. For more information on wetland monitoring, check out this resource brief.

What Can You Do to Protect Wetlands?
You don't have to be a scientist or researcher to protect wetlands and meadows. Here are a few things that you can do during your visit and when you return home to help protect these ecosystems:

  • Conserve water. It may seem like there is an abundance of water in the monument, especially if you visit in late June or early July during peak runoff. Many of the wetlands, however, depend not only on spring melt water, but also on ground water. Both of these are affected by water use both in the monument and downstream. The water in the San Joaquin River is used for both agriculture and personal uses, such as dish washing, showers, and lawn watering. You can help by using only the water that you need during your visit. If you see leaking faucets or fountains, please notify park staff. At home, you can reduce water consumption by installing low flow faucets and shower heads, watering landscaping only during approved watering times, or by planting native plants, which will require less water to survive.
  • Stay on marked trails. A wide open meadow is a tempting place to explore, however, subalpine meadows like the ones found in Devils Postpile and the Reds Meadow Valley are sensitive environments. Due to a very short growing season and extremely moist soils, they recover from disturbance and trampling very slowly. Trails created by visitors cutting through meadows, often called social trails, aren't just an eyesore, but can alter the water flow through the meadow, causing increased erosion and sediment deposition into rivers and streams. You can help avoid this by staying on marked trails or traveling on durable surfaces such as exposed river banks.
  • Keep your pet leashed. Dogs are welcome on all trails in the monument, but they must stay on the trails and must be leashed. Many of the species that use the wetland and meadow environments are doing so during sensitive times of year. In the spring and early summer, animals are breeding or refueling during long migrations. In the late summer and fall, they are frantically storing fat for a long winter of hibernation, limited food availability, or migration. Dogs can startle these animals, causing them to use up valuable energy stores, which can cause unnecessary stress. Domestic dogs have also been know to catch and kill or injure small mammals and fawns or cubs. There are also dangers for your dog lurking in the meadows and wetlands. Coyotes have been know to lure off domestic dogs and kill or injure them. Ground squirrels may also carry the plague, which can be transmitted to domestic dogs and can be fatal. Small dogs are also easy prey for hawks and owls hunting ground squirrels and other small mammals in the meadows.

Last updated: February 28, 2015

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