A Journey Through the Magnificent Sequoias By: Amanda Stone*Photos of Sequoia National Park are from personal album
The Sierra NevadaPRESENT DAY mountain range is the longest in the United States (Geology Overview, 2006). The tallest mountain in the contiguous United States, Mt. Whitney, rises above these mountains at 14,491 feet above sea level (Geology Overview, 2006). This mountain range includes deep canyons, vast meadows and limestone caves.
HOW HAS IT CHANGED? Made up mostly of granitic (red) and metamorphic rock (blue), the Sierra Nevada formed mostly during the Mezozoic/Paleozoic, placing its origins around 500 to 65 million years old (Note 17, 2002) The uplift of the Sierra Nevada Mountains began relatively recently about 10 million years ago (Geology Overview, 2006). 150 million years ago the Nevadan mountains were the Western coast of the US and the seas only extended to the Eastern edges of the Central Valley (Williams, 2008). Powerful erosion forces for millions of years sent rich sediment into the valley, which is thousands of feet thick (Geology Overview, 2006).
These beautiful giants arePRESENT DAY between 1800 and 2700 years old and grow up to 26 stories tall (The Giant Sequoia, 2009). These giants are native to the western side of Calfornia’s Sierra Nevadas at around 5,000 to 7,000 feet elevation. The dry heat of the summer in this area is what allows the cones on these trees to open and release their seeds, which is the only way these trees can reproduce (Redwoods & Sequoias).
Gymnosperms, like the sequoias,HOW HAS IT CHANGED? were present during the Jurassic and Cretaceous (Levin, 2006). Evolutionary advantages in regard to reproduction and photosynthesis were important for the continued existence of these giants. Reproduction by seed gives plants like the giant sequoias an advantage because the seeds can wait until conditions are favorable before starting to develop (Knee, 2010). Like mentioned before how certain weather conditions cause the cones of the Sequoia to open. It has also been important for these trees to retain their needles through winter so they can begin photosynthesis immediately after spring returns (Plants, 2011).
Mule deer are found extensively throughoutPRESENT DAY the Sequoias. They are extremely adaptable and can survive in a variety of habitats, from wooded hills to deserts (Deer Facts, 2008). Most mule deer will live around 9-11 years in the wild (Deer Facts, 2008). They play a key part in the larger ecosystem: as prey to bigger predators and as managers of the plant species they use for food.
The first hooved animalsHOW HAS IT CHANGED? (ungulates) appeared in the fossil record about 50 mya and subsequently branched into two separate groups: even-toed and odd-toed (Baldwin, 2010). The first deer appeared on the scene about 25 million years after these first ungulates (Baldwin, 2010). Syndyoceras (shown left) is likely a precursor to modern deer and lived about 35 million years ago in North America, during the Miocene (Baldwin, 2010).
PRESENT DAY At least four different periods of glacial advance have covered these mountains. The movement of these glaciers is what has carved the valleys, craggy peaks and gigantic canyons (Geology Overview, 2006). These rocks contain quartz, feldspars and micas which give it a speckled appearance (Geology Overview, 2006). The steep nature of these mountains makes it easy to see how rain and snow quickly erode this landscape, sending the sediment into the valley (Geology Overview, 2006).
About 210 mya the NevadanHOW HAS IT CHANGED? Orogeny uplifted the ancient mountains generated enormous amounts of magma which formed these granite batholiths of igneous rock (Levin, 2006). The granite rocks that make up most of this area formed when molten rock cooled beneath the Earth as a result of subduction (Geology Overview, 2006). The forces pushing out these granitic rocks continued until about 90 million years ago (Williams, 2008). Interestingly, these mountains continue to grow today with each eastern earthquake (Geology Overview, 2006).
The Sequoia National ParkPRESENT DAY sees about 1 million visitors each year (Sequoia National Forest). Modern humans have impacted these forests negatively and protective measures must be taken to ensure the safety and health of plants and animals. Air pollution is the most powerful way that humans affect these mountains. The geography of this area and the neighboring valley create an air flow eddy that carries pollution into the parks (Environmental Factors, 2010).
The oldest Homo remains areHOW HAS IT CHANGED? almost 2.5 million years old. These early hominids continued evolving eventually to Homo erectus, Homo sapiens neandertalensis and Homo spaiens sapiens (Cro-Magnon Humans) (Levin, 2006). After spreading from Africa into Europe, evidence suggests that humans moved down into North America about 12,000 years ago, via land bridge (Levin, 2006). Humans have lived in the Sierras for some 6,000 to 7,000 years. The two main tribes of people here were the Monache and Yokuts (History & Culture, 2009). The Sequoias National Park contains around 265 Native American archeological sites (History & Culture, 2009).
Baldwin, M. (2010, April). Deer. Retrieved May 18, 2011, from http://www.wildlifeonline.me.uk/deer.html#evolution Deer Facts. (2008). Retrieved May 18, 2011 from http://www.desertmuseum.org/kids/oz/long-fact- sheets/Mule%20Deer.php Environmental Factors. (2010, August). Retrieved May 18, 2011, from The National Park Service Web site: http://www.nps.gov/seki/naturescience/environmentalfactors.htm Geology Overview. (2006, August). Retrieved May 18, 2011, from The National Park Service Web site: http://www.nps.gov/seki/naturescience/geology_overview.htm History and Culture. (2009, July). Retrieved May 18, 2011, from The National Park Service Web site: http://www.nps.gov/seki/historyculture/index.htm Knee, M. (2010, August). Gymosperms. Retrieved May 18, 2011, from Ohio State University Web site: http://hcs.osu.edu/hcs300/gymno.htm Levin, H. (2006). The Earth Through Time. Hoboken, NJ: John Wiley & Sons. Note 17. (2002, April). Generalized Geologic Map of California. Retrieved May 18, 2011, from California Department of Conservation Web site: http://www.consrv.ca.gov/cgs/Information/publications/ cgs_notes/note_17/note_17.pdf Plants. (2011, March). Retrieved May 18, 2011, from http://users.rcn.com/jkimball.ma.ultranet/ BiologyPages/P/Plants.html Redwoods and Sequoias. Retrieved May 18, 2011, from http://www.visitsequoia.com/redwoods-and- sequoias.aspx Sequoia National Forest. Retrieved May 18, 2011, from http://www.visitsequoia.com/sequoia-national- park.aspx The Giant Sequoia. (2009, June). Retrieved May 18, 2011, from The National Park Service Web site: http://www.nps.gov/seki/naturescience/bigtrees.htm Williams, M. (2008). California Geologic History. Retrieved May 18, 2011, from University of Colorado Web site: http://snobear.colorado.edu/Markw/Mountains/08/CaliforniaMtns/California_geologic_history.pdf