August 9, 2012
Trailblazers: Rudimentary Soil Survey of the Deer Valley Trail
By Will Getz
The Deer Valley trail, recently completed by USC ENST faculty and students[i] provides great insight into the Mediterranean climate and chaparral biome that characterizes southern California. Dry and warm with low precipitation, this climate still supports a variety of grasses, plants and tree species.[ii] Located a few hundred meters from the Wrigley Center, Deer Valley serves as part of the greater watershed that terminates into the Marine Protected Area (MPA) of Fisherman’s Cove. This course’s weekly fieldwork has been dedicated to analyzing soils along the Deer Valley trail and their possible role in the larger watershed dynamic as well as the other environmental issues associated with them.
The surface soil quality along the trail seems fairly uniform up the valley supporting large populations of the native Coastal Sage, Coastal Prickly Pear Cactus, and Toyon bush, and other scrub. However, the climate has brought on the prolific invasive Mediterranean Fennel, which has outcompeted native scrub. Fennel removal is one of the new projects of the Wrigley Center, and this class has aided in that effort. The prolific and virulent Fennel are persistent and can survive in a wide variety of soils and variable climate conditions. Controlling the already prevalent Fennel is a challenging task, and is the subject of future work by the ENST program. About a half kilometer into the trail there is a section of soil, which has undergone great degradation where the organic layer and topsoil were removed for road development and subsequently eroded via water and wind. This area is a site of restoration, with the goal to regenerate the top layers of soil and seed native scrub. Preventing large-scale loss of soil quantity and quality such as occurred in is important to maintain health of the watershed.
In our elementary survey of the surface layer soils on the trail (most likely the O and A Horizons), we sampled ten different sites and took one sample at the beachfront adjacent to Fisherman’s cove to analyze particle size and soil porosity as well as pH. Due to material and time constraints, we were only able to analyze six of the samples collected. Presently, the soil texture analyses have not yielded any conclusive results. However, from the raw pH data collected, one interesting trend that emerged was an increasing basicity of soils moving down the watershed from the top of the trail towards the trail entrance at Little Fisherman’s Cove road. The pH of the soil at the top of the trail is 6.0. This value gradually increased moving up the trail to the trail entrance where the pH value is 7.0-7.5. The pH of the soil at the beachfront was measured to be 6.5. In viewing a soil survey of Catalina conducted by the US Department of Agriculture, most soils at comparable altitudes with similar vegetation had pH within the neutral pH range observed 6.0-7.0.[iii] According to the survey, most surface soils on Catalina are slightly acidic, with some being more acidic such as Dewpoint having a pH of 5.5 and Luff a pH of 5.3 at the time of the survey in 2008.
It is premature to make any conclusions from this rough survey of the soils. We certainly did not perform a comprehensive survey of the trail given a number of details: The sample size was not large enough and we did not collect enough replicates of soil samples to reanalyze in order to remove probability that observed results were due to error or random chance. We also only analyzed soils that were in relative proximity to the trail, and not those of a significant distance from the trail path. However, these interesting preliminary results are motivation for extensive future study. The variation of pH we observed was not drastic, moving from slightly acidic to slightly alkaline down the trail. If this trend is accurate, it may reveal that soils near the bottom of the trail have a better buffering capacity or have greater interaction with basic minerals, which can affect what flora are capable of growing which can change watershed dynamic. These initial tests hold great promise for future soil surveys of the Deer Valley trail looking into how the soils might play a role in the watershed function and proliferation of invasive species.
About the Author: Will Getz is a junior working toward dual degrees, a BS in Chemistry, and a BA in East Asian Languages in Cultures with a minor in Environmental Studies in the USC Dana and David Dornsife School of Letters, Arts, and Sciences.
[i] Hoops, R. (2011, July 15). A Trail-Blazing Summer Internship USC Dana and David Dornsife College of Letters, Arts and Sciences. Retrieved August 7, 2012, from http://dornsife.usc.edu/news/stories/980/a-trail-blazing-summer-internship/
[ii] Regional Climate Center. (2012, June 30). SANTA CATALINA WB AIRPO, CALIFORNIA – Climate Summary . Western Regional Climate Center. Retrieved August 9, 2012, from http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?ca7910
[iii] United States Department of Agriculture. (2008). Soil Survey of Santa Catalina Island, California (Part of the Soil Survey Area of the Channel Islands (CA688)) Washington, DC: Natural Resources Conservation Service. Retrieved August 7, 2012, from http://soils.usda.gov/survey/online_surveys/california/catalina/Catalina_CA.pdf
[i] Hoops, R. (2011, July 15). A Trail-Blazing Summer Internship USC Dana and David Dornsife College of Letters, Arts and Sciences. Retrieved August 7, 2012, from http://dornsife.usc.edu/news/stories/980/a-trail-blazing-summer-internship/
[ii] Regional Climate Center. (2012, June 30). SANTA CATALINA WB AIRPO, CALIFORNIA – Climate Summary . Western Regional Climate Center. Retrieved August 9, 2012, from http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?ca7910
[iii] United States Department of Agriculture. (2008). Soil Survey of Santa Catalina Island, California (Part of the Soil Survey Area of the Channel Islands (CA688)) Washington, DC: Natural Resources Conservation Service. Retrieved August 7, 2012, from http://soils.usda.gov/survey/online_surveys/california/catalina/Catalina_CA.pdf
Protect Our Oceans
By: Jordan Smith-Newman
In the many environmental studies courses I have been required to take as part of my major, I have learned the huge range of threats to which marine habitats are exposed. From unsustainable and destructive fishing to heavy-footed coral trampling, from runoff of land-based agriculture to the threats of global warming, ocean acidification, and bleaching, numerous factors are placing stress on our oceans.
These same oceans provide us with beauty and are home to thousands of flora and fauna species. They supply millions of people with their primary protein and absorb much of the problematic atmospheric carbon dioxide. Because these resources are so valuable international agencies have recently taken action to protect and preserve such striking ecosystems.
Despite its reputation for not having reached significant outcomes, the 2002 Earth Summit on Sustainable Development held in Johannesburg, South Africa has succeeded in calling for the establishment of marine protected areas. The National Oceanic and Atmospheric Administration (NOAA) defines the general function of Marine Protected Areas as a place to help protect resources within the marine environment for the benefit of present and future generations.
One such Marine Protected Area is Big Fisherman’s Cove, right off of the USC Wrigley Institute for Environmental Studies on Catalina Island. The land was formally owned by the Wrigley family, the founders of the chewing gum company, with the ultimate goal of preservation. The kelp beds are some of the largest in the world, reason alone to protect the area. The kelp and cove also shelter the California garibaldi, leopard sharks, white sea bass and lobsters, to name a few fish species. Big Fisherman’s Cove falls into the 5% designated Marine Protected Areas of Southern California that are fully protected no-take areas. The commitment and relationship between the Wrigley family and USC has been crucial in keeping the cove pristine.
A similar marine protected area is Ngederrak Reef in the Republic of Palau. The vulnerability of the coral reef ecosystems has led to its recognition as a Special Management Area by the Koror State Government Department of Conservation and Law Enforcement. Unless conducting research with permission and a permit from the State, no one can enter the area because Ngederrak Reef goes beyond a no-take zone and is a no-entry zone. Continual surveying of the reef has been effective for the conservation and preservation of species biodiversity.
While protection of marine ecosystems is imperative, practical and effective means of enforcement have proven to be challenging. There must be continued and additional work by respective governments to further protect both official Marine Protected Areas as well as the general marine habitat.
About the author: Jordan forgot to submit her author bio….
Wildflowers or weeds: the answer is all in your shoes
By Connie Ge
“Wildflowers and weeds are the same thing; it’s a matter of perception in our mind” said Kate Cruikshank, a former associate professor of education at Indiana University, in regards to the increased use of pesticides on “weeds” from ancient times to the development of chemical warfare since World War II.
“We have to start back 200 million years ago, when there was no barrier to movement of animals and plants. (Weeds) first became a problem when we evolved from a hunter/gatherer lifestyle towards industrial forms of agriculture,” she said. “We stopped coexisting with weeds. Fifteenth and 16th century European exploration mixed plants and animals, spreading them ahead of immigration.”
One thought that has crossed my mind since starting ENST courses is the subjectivity of how knowledge is accumulated and passed on from generation to generation. The Catalina Island Conservancy, founded in 1972 attempts to monitor and curb the growth of invasive species introduced when Europeans and their descendants invaded the formerly native Pimungan-occupied island. These invasive species include fennel, which obstructs hawks and eagles from seeing smaller birds, as well as rats, mule deer, bison, bullfrog, and the feral cat. To me the story of human invasion, or migration on Catalina is enough to question present human-plant and human-animal relations.
“Pimu” is the last known name which Tongva, Pimungans, or Pimuvit people called the island upon European arrival in the 1500’s[1]. Various groups of Native American people before the Pimuvit are thought to have inhibited the island over the course of hundreds of years, at least 7,000 years ago. Still in search of Asia 50 years after Columbus’ arrival in the Bahamas, the Viceroy of New Spain (Mexico) sponsored an expedition up the coast of California.
“Santa Catalina” was the second name the island was dubbed by a Spanish explorer. The Pimuvit are said to have been dismayed when Spanish sailors shot ravens, which held a place in native folklore. They were hit hard by microbes brought by the Spanish and those that survived and abandoned the island in the early 1800’s were known in southern California as Gabrielinos. Today there are people descended from Gabrielinos.
Some animals that lived alongside the Pumuvit may have included the small endemic fox, quail, bald eagles, and raven, which were said to be a part of native folklore[2]. There are 76 invasive plants identified by the Conservancy that, “left unmanaged, these invaders would overtake native habitats, potentially dooming some to extinction.” While non-native plants compete for resources with native plants, what makes humans today think they have control over an ecosystem?
These questions pressed me while the class and I sweated hacking away at the roots of fennel, which were well suited for the dry, rocky soil of the desert island. Fennel is abundant not but twenty miles away on the coast of southern California – that it arrived and thrived should be an indicator of the limitations and transience of efforts by one species to alter the entire balance of an ecosystem.
Are (essentially “invasive” species ourselves) humans inserting themselves into a foreign ecosystem and assigning themselves the role of keystone species through science? If a weed is an organism that proliferates rapidly, homo sapiens is a weed in the world – why don’t we focus on controlling our own population? I’m supportive of natural research, but pondering the practicality of long-term conservation and value of accepting change as it naturally comes, due to its inevitability, just like an ocean wave.
Institutionalized science is shaped by cultural conjecture. Wildflowers or weeds? Pimu, Santa Catalina, or Catalina? The answer depends on whom you are talking to. Fennel is frivolous to homo sapiens, but food for mule deer. So the answer is all in your shoes. Or watch – either way, keep looking.
Sources:
1. Catalina Island History.” Catalina Island Chamber of Commerce & Visitor’s Bureau. http://www.catalinachamber.
2. “Professor pleads for weeds: Address urges appreciation of simpler ways of life.” David A. Nosko. September 27, 2004. Indiana Daily Student.
3. Catalina Island Conservancy website
About the author: Connie Ge is a sophomore at the University of Southern California from Boulder, Colorado. She is working to complete a Bachelor of Science in Earth Sciences.