February 13, 2013
The Sierra Snowpack: Losing Snow, Losing Species
The Sierra Nevada Mountains, a spectacular mountain range located in California and Nevada, is not only a major source of California’s water supply, but is also home to hundreds of endemic species. During the fall and winter, a snowpack accumulates on the mountaintops and naturally melts during the spring, providing plants, animals, and people with a fresh source of water. In the past, the annual snowpack was enough to support these species as well as California’s water supply, however due to climate change and anthropogenic causes, precipitation has decreased and the snowpack is not able to accumulate the proper amount of snow like it has in past years. While the Sierra snowpack provides the majority of California’s water supply, it also is vital to the survival of the plants and animals in the Sierras. The snowmelt that supports these now endangered and at risk species are suffering. Higher temperatures, invasive species, and human influence are some of the causes that pose major threats to this ecosystem.
Some of these species include the bighorn sheep, yellow-legged frog, American pika, and Delta smelt. The bighorn sheep are one species who are severely impacted from the loss of snowpack because their natural habitat is being depleted. The bighorn, who has already had to recover from the brink of extinction in the 20th century, is an animal that utilizes the elevation to escape from predators. The warming temperatures has allowed the tree lines to move to higher elevations which encroaches on the bighorn’s living space and makes it more difficult for the bighorns to evade predators. The yellow-legged frog is also affected by the lack of snow because it depends on the snowpack to melt during certain times of the year to assure proper living conditions (doesn’t freeze in the winter, but has enough water in the summer to lay eggs). Additionally, they are at risk because of the numerous invasive species that are preying on the frogs during their tadpole stages. Another species that has been severely impacted by the decline of snowpack is the American pika. The pika is a small hamster-like creature that has a minuscule temperature window and relies on the snowpack for insulation in the winter and moderate temperatures in the summer. In response to the unbearable temperatures, the pika have been forced to move upslope, an unsafe habitat for the vulnerable animal, which has already become extinct in some low-lying areas. Lastly, the Delta smelt, like salmon, is an upstream swimming species of fish that is reliant on the cold downstream that the snowmelt usually provides. “As the headwaters decrease and temperatures rise, endangered fish species such as the Delta smelt will suffer.” (Merry) Not only are animals suffering as a result of decreased snowpack and higher temperatures, but plants are also feeling the effects.
Conifer trees are surprising less resistant to the hotter temperatures and decrease in precipitation. The trees are dying much more often than in previous years because of warmer temperatures and evaporated moisture in the soil. In addition, the conifers are also being infested by fungi and insects that thrive in the warmer climates. Both drier conditions and increased temperatures have led to an increase in wildfires. A positive feedback loop is created when trees that catch fire release carbon dioxide stored in their trunks, which is in turn absorbed into the atmosphere, further advancing global climate change.
The Sierra snowpack is a crucial part of this environment that requires mitigation in order to protect the vulnerable species that rely on its abundance. The Sierra Club proposes a great strategy as to how to protect these animals and is a decent step towards finding a solution that solves the issue at hand. They propose that a core area and a buffer zone are necessary so that species are able to withstand the changes that are occurring within their habitats. Although some steps that will help alleviate the issue are in action, state legislature would be a strong supplement that may drastically increase the revitalization of species in the Sierra Nevada ecosystem.
This post was authored by Dana Handy, a sophomore majoring in Environmental Studies, and Angel Marquez, a sophomore double majoring in Economics/ Mathematics, and Business Administration.
Works Cited:
http://blog.stopextinction.org/2011/02/sierra-nevadas-strained-by-changing.html
http://www.sierraclub.org/habitat/ecosystems/sierra-nevada.aspx
September 12, 2011
Slippery Slope on the Sierras: California’s Water Crisis Continues
The Sierra Nevada Snowpack is one of California’s most important natural water reservoirs. The snowpack is formed during the fall and winter and as it melts in the spring and summer (the two seasons when California’s water demand is greatest), slowly releases about 15 million acre-feet of water. Because of its role in the water supply within California, changes in its formation and melting cycles can play a major role in the economy, infrastructure, and land development of the state overall.
The 2011 snowpack made headlines for its large size; over the winter it developed to 165% its average size, momentarily putting Californians at ease about their water demands being met. This good news comes after years of smaller snowpacks and subsequent droughts. Yet even in a year when the snowpack is projected to meet California’s water needs, there is still cause for concern.
Though it is well known that the size of the snow pack varies, recently there have also been changes in the pack’s melting cycle. Research published in 2008 suggests that the rate at which the snowpack melts has been increasing annually. So much so, scientists predict that by 2100 the snowpack will melt completely a full two months earlier than it does now. Current infrastructure, dams and other water storage and transportation facilities, have been built to best deal with the previous predictable cycle of snow melt. As the climate changes and temperatures in the area increase, the sudden burst of water earlier than expected and larger than these structures were built for threatens to overwhelm the storage facilities and threatens to increase the risk of both floods and waters shortages. Uncontrolled floods and the inability to properly store water from a mass runoff endangers development and the economy in that it threatens to damage development, which render the dams and other storage facilities useless, and after the runoff has ended suddenly there is little water left over for the seasons in which it is most desperately needed.
Land in the Sierras has long been considered prime for development. Since 1973, some 800,000 acres of woodland have been converted to new land uses. It has been projected that by 2040 almost 20% of private forests in the area will be affected or altered by even more development. More development would add more greenhouse gas emissions and increase erosion and runoff, all changing the behavior of the snowpack further. Development and industry could also introduce pollutants to the snowpack, as they have in the past.
The ecosystem accounts for approximately $2.2 billion of commodities and services annually. In 2005, agriculture production in California counties using Sierra Nevada water was valued at more than $18 billion. Any change or damage to the Sierra Nevada ecosystem has dramatic repercussions for tourism /recreation, agriculture and resource extraction opportunities. The water resources themselves contribute more than 60% and yield 65% of the developed urban and rural water supplies for California. In addition, the Sierra is also home to one of the greatest areas of biodiversity, and many rare organisms.
The main strategies for preserving the Sierra snowpack recently have been greenhouse gas emission reduction and water conservation and recycling. The fact remains, however, that the population of California continues to grow while their main water supply source does not. The steps proposed by the California Department of Water Resources can only counteract the observed changes in the snowpack’s melting cycle, but even a healthy snowpack will reach a point where it cannot meet California’s growing needs.
About the authors: Makena Crowe and Minda Monteagudo are working towards their bachelor’s degrees in Environmental Studies and Political Science, respectively, in the USC Dana and David Dornsife College of Letters, Arts and Sciences.