Spatial Scale of Yosemite...

Spatial Scale: Yosemite National Park is located in the US, California; its landmass is 747,956 acres (or 1,169 square miles) that’s about the size of Rhode Island. The designated wilderness of the park is 704,624 acres (or 1,101 square miles), which is more than 94% of the park (National Park Services).Yosemite consists of 214 miles of paved roads, 68 miles of graded roads, 20 miles of paved walks and bicycle paths, and 800 miles of trails (includes Pacific Trail and John Muir Trail) (National Park Services).  Within the park, there is a diversity of rocks in Yosemite, which include:
Layers of Rock: There are cross-sections of large granite layers seemingly cut into the side of the road. Yosemite's granite continues to expand along joints or fractures in the rock due to internal pressure within the earth's crust. This process—known as exfoliation—causes slabs of granite to "peel" off, like layers of an onion. This natural process continues to shape the landscape of Yosemite and rockfalls are common in most areas of the park (ohRanger).
Hanging Valleys: The glaciers acted like giant bulldozers, plowing and plucking rocks from the surrounding cliff walls. Where streams once flowed into the Valley, the glaciers left behind dramatic precipices, known as "hanging valleys." This is particularly noticeable at Bridalveil Fall and Yosemite Falls in Yosemite Valley, and in Hetch Hetchy (ohRanger).



Roche MoutonnĂ©e (sheep rock): These asymmetrical outcroppings of rock resemble sheep feeding in a meadow. The gentle, sloping ridge follows the direction from which the glacier came. An example of this type of formation is Lembert Dome in Tuolumne Meadows (ohRanger).
Glacial Polish and Striations: The shiny, flat surface of some rocks is the handiwork of glaciers that polished them centuries ago. Sand and other small abrasives that pressed against the granite under the weight of the glaciers cut distinct striations, or scratch marks, on the rocks, which indicate the direction the glaciers were moving. Examples of glacial polish can be seen on the domes surrounding Tenaya Lake (ohRanger).
Dikes: Some rock faces show long white lines that are so neat and straight that they resemble street lines. These are rocks rich in feldspar and quartz, which, in their fluid state, oozed up through a crack in the rock and solidified millions of years ago (ohRanger).


Benefits people get from Yosemite: There were many early lodging establishments in Yosemite, like the Wawona Hotel; the hotel offered a more primitive setting for the Valley’s first tourists and today's visitors, and more elegant lodging. Other hotels, like The Ahwahnee was added to satisfy those looking for comfort (National Park Services). The Yosemite services benefits the people because different kind of hotel settings were created in order to fit with people’s tastes and cater to their experiences at Yosemite.

Protected Areas of Yosemite: The drive for federal protection of the Yosemite region began shortly after the first non-Indian settlers arrived and before conservationist John Muir first visited in 1868. Abraham Lincoln provided this protection when he signed the Yosemite Grant on June 30, 1864 (ohRanger).  This grant is considered the foundation upon which national and state parks were later established. As mentioned in the history, the Mariposa Grove and Yosemite became the first public preserved area in the country, but they were still under the control of the state of California (ohRanger). Finally, on October 1, 1890, the U.S. Congress set aside more than 1,500 square miles of "reserved forest lands" soon to be known as Yosemite National Park. It included the area surrounding Yosemite Valley and the Mariposa Grove of Giant Sequoias. These became protected areas of Yosemite (ohRanger). Finally, the Yosemite Valley and the Mariposa Grove ceded from the state of California's control and included with Yosemite National Park in 1906 (ohRanger). In early 20th century, “buffalo soldiers” were assigned to keep watch of the park (ohRanger).  Stories from those whole walked in Yosemite’s trails allows us to appreciate the place more and their lasting footprints led to conscious preservation (National Park Services).
Status of protected area: Yosemite’s resources fill a flourishing museum collection of more than 4 million items. The museum maintains a research library with some 10,000 books relevant to Yosemite, as well as photographs and articles (National Park Services).  Due to the booming amount of tourists and campers, "nature guides" were hired to help educate visitors about the park's special values and the Field School for Natural History was established to train future interpreters in the 1920s (ohRanger). This would create guidelines on how people should and should not treat Yosemite. For the status of preservation/protection of the park, today, the staff of the National Park Service—along with its park partners and legions of volunteers—continues to meet the challenge of protecting Yosemite's unique natural and cultural treasures for the benefit and enjoyment of future generations (ohRanger). Overall, it seems that the protection status of Yosemite National Park is going well for now.


How have the people impacted the Yosemite...


Throughout tens of thousands of years, humans have brought many changes upon Yosemite. Many people came to the Sierra to mine for gold; those mining sites are still there (National Park Services). Since Yosemite was such a beautiful and amazing place, the Europeans spread the word of it to everyone out there. Parts of the landscape were exploited, spurring conservationists to appeal for protections (National Park Services). Things got bad or ugly in 1889, as people began farming domestic animals in the area; there were flocks of domestic sheep were continuously consuming meadows and wildflowers, as well as destroyed the “soul of the land” (OhRanger). Allowing people to farm animals In Yosemite would have led to the consumption of the beautiful nature that Yosemite provides. Today, 3.5 million people enter the park’s gates to explore annually (National Park Services).



Although money and popularity of the park is brought in by visitors, humans are also responsible for impacting the ecosystem in a negative way. It is stated that vegetation, animals and environment suffer due to the effects of human presence within their habitat (Ournationalparks). Simple things like yelling or standing and walking on forbidden ground can deteriorate natural habitats and scare and harm animals (Ournationalparks). These threats can either be directly caused by humans, or indirectly sparked by the effects of human development and civilization. For instance, consequences might range from the disturbance and retreat of animals due to invasive visitors, to noise pollution due to nearby highways and airports (Ournationalparks). Roads, parking lots, hotels, airports, campgrounds and all the other infrastructure required to support human activity in a national park brings long-lasting impacts to the ecosystem (Ournationalparks). Wild animals are frequently hit and killed within park roads, due to the shock that vehicle lights and noises have over them. Impacts on Yosemite are more connected to the direct actions of visitors within the park as well. Some vehicles park along the roadways and slightly off the road, and what this does is that it encroaches on some of the nearby vegetation (Ournationalparks).  If this keeps happening day by day, then the local vegetation will face perpetual transformations. There are problems of trail cutting, in which people do not follow the marked trails and instead cut through the middle while stepping on vulnerable plants and grounds (Ournationalparks).  There also exists a problem of people petting or  feeding wild animals like deer or squirrels. Human interaction with wild animals can end in violence or else can disrupt the attitude and mood of the animals’ behavior (Ournationalparks).  A big problem that human poses for Yosemite is emissions from human activities; these emissions from human activities cause climate change, which in turn shifts biomes. This gradually leads to more fires, as it has been stated that wildfire frequency and duration have increased (Park Science).  Many numerous small mammals have also shifted upslope, as a result of the shift of climate change; they will continue to shift due to the climate change. Many vulnerable areas will be affected by the climate change and greenhouse gases (Park Science). In April 2009, the environmental protection agency outlined a report regarding the impact of human activity and human emissions, and to a certain extent climate change, to public health and welfare. It outlines that increased drought, more heavy downpours and flooding, more frequent and intense heat waves and wildfires, greater sea level rise, more intense storms, and harm to water resources, agriculture, wildlife and ecosystems will be the effect of human activity and climate change if the trend is not curbed. It is thus reasonable to conclude that broader and more general ecological footprints caused by human activity and emmissions will have a significant effect in the future of Yosemite and other national parks and forests. With this, one can arguably say that the human impact judging from this alone might be bad or ugly, especially in the near future (yosemite.epa.gov).



How Yosemite historically looked like ????


 
source1: http://www.americanindiansource.com/Muir/muir.html
source2: http://www.nps.gov/yose/historyculture/ansel-adams.htm





Human presence in Yosemite can be traced before the arrival of the Europeans. Way before Yosemite became a public attraction, a Native American group called the Ahwahneechee lived there for generations (National Park Services). Interestingly, the name “Yosemite” is borne out of the Native Americans who lived in and around the area. The name literally means “those who kill” denoting the bravery and aggressivenes of the Native Americans who lived in the area (Yosemite.ca.us). Then in the mid-1800s, Europeans arrived in Yosemite (National Park Services). The subsequent California Gold Rush, as well as the corresponding Indian Wars in California drove away the Ahwahnaeechee and the Yosemite Indians out of their homeland in and around the national park(Yosemite.ca.us). According to the information provided by National Park Services, Yosemite has been a rugged place for a long time, as the rugged terrain proved to be a challenge to many early travelers. Only about 650 travelers in the mid-1850s to mid-1860s made the journey to Yosemite Valley by horseback or stage (National Park Services). Construction of the Yosemite Valley Railroad (from Merced to El Porto) in the year 1907 made traveling to Yosemite easier; the construction of this railroad increased the amount of visitors. President Abraham Lincoln signed an 1864 bill granting Yosemite Valley and the Mariposa Grove to the State of California. John Muir helped spark the creation of Yosemite National Park in 1890 (National Park Services). Throughout history, glaciation was a major geological force that shaped the Yosemite landscape. This information below describes how Yosemite looked like throughout history and how it gradually formed or transformed:
500 to 200 million years ago
The Sierra Nevada region was once submerged beneath a sea. Sediments slowly accumulated on the ocean floor, growing thousands of feet thick and compressing the layers into sedimentary rock (ohRanger).
200 to 80 million years ago
A slab of the Earth's crust, called a plate, began to slide under the North American continent in a process called subduction. Deep within the earth, tremendous heat and pressure caused the downgoing plate to melt into magma. The magma rose toward the surface, where some of it erupted to form a mountain chain of volcanoes. Much of the magma cooled underground to become granite (ohRanger).
60 to 10 million years ago
After subduction ceased, prolonged erosion stripped away the overlying volcanic rocks and exposed the granite. The land destined to become Yosemite National Park was made up of low mountains with shallow river-cut canyons. Hardwood forest flourished (ohRanger).
10 million years ago
Over the next 5 million years, the Sierra Nevada, California's "backbone," rose. The Sierran block uplifted, tilting westward, increasing the Merced River began to carve a narrow canyon. Redwood forests flourished (ohRanger).
3 million years ago
The Merced River carved its canyon deeper, while its tributaries cut the land more slowly. Forests began to thin as the Ice Age approached (ohRanger).
1 to 2 million years ago
A series of large glaciers flowed from the crest of the mountain range into the river canyons. Glaciers repeatedly filled the "V"-shaped Yosemite Valley, widening, deepening and carving it into a "U" shape, forming hanging valleys from which waterfalls now cascade (ohRanger).
15,000 years ago
Temperatures warmed and the last glacier retreated from Yosemite Valley. Its terminal moraine (rock debris) dammed the Valley 14,000 to 15,000 years ago, creating a shallow lake. Sediment eventually filled the lake, which became the flat valley floor we see today (ohRanger).
Today
The same process of sedimentation continues at Mirror Lake, which is even smaller today than in this photo. Soon, sediment will completely fill in the lake, creating a meadow. Water and gravity continue to shape Yosemite's landscape. Events like the Middle Brother rockfall of 1987 and the flood of January 1997, were the most dramatic in the recorded history of the park. Be aware that rocks can fall at any time (ohRanger).




There were many things that were native to the Yosemite Valley, which included black oak acorns and some types of fish; they used those native items to trade for obsidian, rabbit skin, and pine nuts (ohRanger). Due to the discovery of gold in the Sierra Nevada foothills in 1848, many Native Americans were murdered and subjects of theft. Thousands of gold seekers were attracted to the Yosemite Valley and eventually it led to the Mariposa War in 1851. The Mariposa Battalion entered Yosemite and was the first non-Indians to be recorded as entering the Yosemite Valley (ohRanger). Historically, Yosemite has always been a beautiful place; word of Yosemite's beauty gradually spread, and in 1855, the first party of tourists arrived. Yosemite and the Mariposa Grove became the first public preserve in the United States due to Californians persuading Congress and President Lincoln in the 1860s (ohRanger).
Today, it is known as one of the “crown jewels” of the national park system, which arguably have impacted the way people and the government protect it (by giving more funds and added security to the areas) while also encouraging a lot of people to visit, thereby increasing the ecological footprint to the detriment of the living organisms in Yosemite (yosemitepark.com). At this point in history, the National Park vividly illustrates the effects of glacial erosion of granitic bedrock, creating geologic features that are unique in the world. Repeated glaciations over millions of years have resulted in a concentration of distinctive landscape features, including soaring cliffs, domes, and free-falling waterfalls. There is exceptional glaciated topography, including the spectacular Yosemite Valley, a 914-meter (1/2 mile) deep, glacier-carved cleft with massive sheer granite walls. These geologic features provide a scenic backdrop for mountain meadows and giant sequoia groves, resulting in a diverse landscape of exceptional natural and scenic beauty. From the UNESCO World Heritage site, Yosemite is known for:
  • exceptional natural beauty, including 5 of the world's highest waterfalls, a combination of granite domes and walls, deeply incised valleys, three groves of giant sequoia, numerous alpine meadows, lakes, diversity of life zones and variety of species.
  • Glacial action combined with the granitic bedrock has produced unique and pronounced landform features including distinctive polished dome structures, as well as hanging valleys, tarns, moraines and U-shaped valleys. Granitic landforms such as Half Dome and the vertical walls of El Capitan are classic distinctive reflections of geologic history. No other area portrays the effects of glaciation on underlying granitic domes as well as Yosemite does.

         (Source: Unesco World Heritage Site)