Map of Yosemite
Image obtained from http://www.nps.gov/yose/planyourvisit/upload/YOSEmap1.pdf
Yosemite, Past and Present
Yosemite Valley
1864
Image obtained from http://www.sothebys.com/en/auctions/ecatalogue/2012/photographs-n08885/lot.25.html
2014
Hetch Hetchy Valley
1908
Historical State
Before Yosemite was established as a National Park on Oct 1 1890, it suffered great damage as an ecosystem due to commercial exploitation and tourism. The gold rush of 1849 attracted thousands of miners and settlers into the Sierra Nevada Mountain Range, which encompasses the Yosemite Valley.
In 1889, John Muir, a famous and influential naturalist and conservationist and Robert Underwood Johnson had concerns about the negative effects of grazing in Yosemite. They later launched a successful campaign and persuaded congress to establish this area as a National Park in 1890. Ever since, the human impact of the system has be largely contained and minimized.
An exception was the Hetch Hetchy Valley. Hetch Hetchy Valley is part of Yosemite National Park and was once a beautiful glacier carved valley with cliffs, waterfalls and trees. Up to the 1850s, it was inhabited by Native Americans who used the valley as a means of subsistence through hunting and agriculture. In 1890, it was to arranged to be protected as part of Yosemite National Park. However, this was overturned when President Woodrow Wilson signed the Raker Act on December 19, 1913, which permitted the building of O’Shaughnessy Dam and flooding of the valley.This dam served as a water source for San Francisco and the Bay Area. Although John Muir led the naturalists to oppose this legislation, this Act was still pushed through Congress by San Francisco lobbyists.
Current Animal and Plant species
Animal
Species
Yosemite
National Park supports more than 400 species of vertebrates including fish,
amphibians, reptiles, birds, and mammals. The high diversity of species is the
result of diverse habitats in Yosemite that are largely intact.
Examples
of Habitats and Animals that reside there:
a)
Yosemite Valley – Mule deer and Black bear (animals that depend on meadow
habitats)
Mule Deer
Black
Bear
Image
from http://dliq60eur0hds.cloudfront.net/wp-content/uploads/2011/12/yosemite-bears-wildlife.jpg
b)
Coniferous forests - bobcat, gray fox, mountain kingsnake, Gilbert's skink,
white-headed woodpecker, brown creeper, spotted owl, and a wide variety of bat
species
Bobcat
c) At
higher elevations, fewer wildlife species are found - golden-mantled
ground squirrel, chickaree, marten, Steller's jay, hermit thrush, and northern
goshawk. Reptiles are not common but include rubber boa, western fence
lizard, and alligator lizard.
Golden-mantled
ground squirrel
Chickaree
Image
from http://www.seeyosemite.com/images/funny-squirrel-pictures-yosemite-wildlife-chickaree-squirrel.jpg
d) Above
treeline, it is a harsher climate. Species such as pika, yellow-bellied marmot,
white-tailed hare, Clark's nutcracker, and rosy finch are adapted to these
conditions
Pika
e)
Other species- Sierra Nevada bighorn
sheep are found in the Yosemite area only
Image from http://www.nps.gov/yose/naturescience/images/bighorn-3-vert-ron-wolf-web_1.jpg
Plant
Species
The
combination of climate, topography, moisture, and soils influence the
distribution of plant communities across an elevation gradient from 1,800 feet
to over 13,000 feet
a)
Foothill-woodland zone (lowest elevation), 1800 ft. - chamise, ceanothus,
manzanita, blue oak, interior live oak, and gray pine. These plant communities
can also be found near Hetch Hetchy reservoir.
b) Lower
Montane Forest, 3000 ft. (Mediterranean Climate- hot dry summers and cool
moist winters) - California black oak, ponderosa pine, incense-cedar, and
white fir. , sequoia groves
c) Upper
Montane Forest, 6000 ft. (short, moist cool summers and cold wet winters)
- Red Fir, Lodgepole Pine, Jeffrey Pine, Wildflowers
d) Subalpine
Forest, 8000 ft. - cool climate, cold and snowy winters. -western white pine,
mountain hemlock, and lodgepole pine
e) Alpine
Zone (highest elevation), 9500 ft., no trees grow here due to harsh
conditions, limited vegetation (Short cool summers with long cold snowy
winters) - Herbs, flowering plants
Current
vegetation map
Yosemite
shelters 37 species of native trees and hundreds of species of native wildflowers, many of which can be found only in the park. Forests fires put
these plants and trees at risk of dying and being extinct.
Image from http://www.nps.gov/yose/naturescience/vegetation-map.htm
Current Human Impacts
Direct
Impacts
Visitor
Use
Today, Yosemite is known as one of the most beautiful
national parks in the united states and attracts over 3.5 million visitors a
year. Most of them spent their time in Yosemite Valley.
Year - Visitor Population figures
2003
|
3,378,664
|
2004
|
3,280,911
|
2005
|
3,304,144
|
2006
|
3,242,644
|
2007
|
3,503,428
|
2008
|
3,431,514
|
2009
|
3,737,472
|
2010
|
3,901,408
|
2011
|
3,951,393
|
2012
|
3,853,404
|
2013
|
3,691,191
|
This offers a fundamental challenge for the park - balancing
providing enjoyment for visitors and protection. Direct human impact on
Yosemite, primarily through visitor use, is rather limited due to its
designation as a National Park. Nearly 95% of the park is congressionally
classified as wilderness areas as well, the highest level of conservation
protection for federal lands. Federal laws and regulations established by the
National Park Service and 1964 Wilderness Act, ranging from the prohibition of
motorized vehicles on park trails to the requirement of permits for commercial
activities, ensure that park property and natural resources are protected and
undisturbed. On top of that, Yosemite National Park has a visitor use and social
science branch that conducts visitor use research, impact surveillance and
planning-related projects. This ensures that actual visitor behavior is
actively monitored and unhealthy conduct is appropriately addressed.
Indirect
Impacts
a) Climate
Change
-Animal
and agricultural species loss
Higher
temperatures in spring and summer has caused some plant and animals species to
become restricted in their needs for habitats. This has led to some plants and
animals being at risk of extinction. For example, the pika population in
yosemite is in danger of becoming extinct as temperatures rise on the
mountainsides. As they reside in cool habitats, they have to shift their homes
further upslope and eventually if this continues, they may have nowhere higher
to go. Cold-water fish species like trout might also decline because they are
unable to adapt to warm waters.
Image from http://images.sciencedaily.com/2004/12/041219160938.jpg
Image from http://dliq60eur0hds.cloudfront.net/wp-content/uploads/2011/11/yosemite-trout.jpg
Image from http://images.sciencedaily.com/2004/12/041219160938.jpg
Image from http://dliq60eur0hds.cloudfront.net/wp-content/uploads/2011/11/yosemite-trout.jpg
Forest Fires, which leads to loss of habitat and species
Climate
change has also been found to result in hotter weather and hence the thinning
of snow packs in recent years, contributing to an increase in frequency and
duration of wildland fires in Yosemite. This often leads to a loss of habitat
and species.
For
example, one of the fires known as the Rim Fire which started on August 2013 in
Stanislaus National forest burned approximately 250,000 acres of land , with
about 77,000 of those acres within Yosemite National Park.
b) Air
Pollution
Research
has revealed that Airborne pollutants are a major reason for the degradation of
Yosemite National Park resources. In particular, the burning of fossil fuels
and agricultural emission from sources west of Yosemite cause most of the
pollution. When fossil fuels are burned, nitric oxide, phosphates and other
impurities released into the atmosphere. These contribute to smog, acid rain
and pH imbalances that harm plant and animal communities. In California’s Central
Valley, pesticides and Nitrogen-based fertilizers are used extensively in
agriculture, and unfortunately, westerly winds blow these harmful substances
into Yosemite on a regular basis, especially during the summer. Contaminating
water bodies with toxins and raising soil nitrogen levels which result in the
invasion of foreign plant species respectively, pesticides and nitrogen-based
fertilizers have a devastating impact on the habitats in Yosemite.
Future Prospects
As long as funding is not drastically cut from the national park system, habitat upkeep and park services will mostly be fine. That, combined with the fact that people are generally much more respectful to national parks than they are to the environment outside of national parks, will help keep direct human impact to a minimum. However, climate change and air pollution will only further change and damage the ecosystems inside Yosemite if we do not mitigate the process. While humans may not be cause direct destruction of habitats, the changing climate is disturbing the habitats of many animals. For example, The alpine chipmunk is sensitive to temperature. As temperature has risen in the last 100 years, the chipmunk has been forced to seek higher ground, where the temperature is cooler than on lower ground. As a result, there is less suitable land for the chipmunk and its habitats have become fragmented. This fragmentation has also led to a loss of species diversity and smaller population size, which lowers ability to adapt and increases the threat of extinction.
As long as funding is not drastically cut from the national park system, habitat upkeep and park services will mostly be fine. That, combined with the fact that people are generally much more respectful to national parks than they are to the environment outside of national parks, will help keep direct human impact to a minimum. However, climate change and air pollution will only further change and damage the ecosystems inside Yosemite if we do not mitigate the process. While humans may not be cause direct destruction of habitats, the changing climate is disturbing the habitats of many animals. For example, The alpine chipmunk is sensitive to temperature. As temperature has risen in the last 100 years, the chipmunk has been forced to seek higher ground, where the temperature is cooler than on lower ground. As a result, there is less suitable land for the chipmunk and its habitats have become fragmented. This fragmentation has also led to a loss of species diversity and smaller population size, which lowers ability to adapt and increases the threat of extinction.
What can be done
Much of the air pollution is inorganic blowoff from agriculture in the Central Valley. We can reduce the damage from this by switching to organic pesticides and insecticides. Another major factor of air pollution is the carbon emissions from factories and vehicles. By switching to renewable sources of energy and low or zero-emission vehicles, we can stop this damage. This is also the number one way we can combat climate change.
Much of the air pollution is inorganic blowoff from agriculture in the Central Valley. We can reduce the damage from this by switching to organic pesticides and insecticides. Another major factor of air pollution is the carbon emissions from factories and vehicles. By switching to renewable sources of energy and low or zero-emission vehicles, we can stop this damage. This is also the number one way we can combat climate change.
Data Table
Reference List
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