Land Use History of Ventura, CA
My hometown of Newbury Park, California is quite diverse ecologically, containing mountainous chaparral. Geologically, the Santa Monica mountains overlooking Newbury Park were formed by the subduction of tectonic plates on the ocean floor over 20 million years ago, creating the volcanos that are now these mountains (1). The Santa Monica Mountains contain canyons that have been carved out by rivers; these river beds are now dry due to drought. Newbury Park is also a town at risk of burning in annual wildfires, which are growing larger each year partly due to the effects of climate change. I can remember every year growing up being evacuated or watching the flames burn over the mountains while sitting on the roof of my house.
Image Source: Visit California
Before European colonization, Newbury Park was primarily inhabited by people of the Chumash tribe. The Chumash lived in a hunter-gatherer society, hunting rabbits and quails from the chaparral and gathering acorns and chia seeds for consumption, and using oak wood and reeds to construct tools or lodging (2). Prior to colonization by the Spanish, the Chumash did not apply agricultural techniques to the land that is now Newbury Park.
Just down the grade from my hometown lies Ventura, California. A Spanish mission was established in Ventura and completed by 1805 (3). The Spanish enslaved the local Chumash and also shaped the ecology of the land. Lands in the plains of Ventura were cultivated and Ventura (and the surrounding areas) became an agricultural powerhouse in Southern California. In Ventura County (the county harboring Newbury Park), agriculture is the dominant industry. Oxnard, CA (the town in between Newbury Park and Ventura is currently one of the top producers of strawberries in the country.
In Newbury Park specifically, suburban development has been the driving force shaping the lands within the city limits. Many homes and paved roads now occupy what was once the ecologically diverse Conejo Valley overlooked by the Santa Monica mountains. A large biotechnology company, Amgen, is located in Newbury Park, which employs a lot of people in the town and is a major driver for immigration into the area (4); this influx of people has caused the land to be destroyed in order to build new homes for new residents.
Image Source: Google Maps
One major ecological issue in Newbury Park is the introduction of the invasive species, Black Mustard, into the area (5). This mustard plant was introduced into the area by the Spanish and has thrived ever since. I can remember as a kid hiking in Satwiwa (a portion of the Santa Monica Mountains National Recreation Area) and seeing miles upon miles of this yellow flower throughout the hills. This yellow flower was indeed Black Mustard and has outcompeted many endemic species of grasses. Once these plants dry out, they serve as tinder for the annual wildfires in the area. Wildfires now become a nearly uncontrollable blaze in the area due to this, so habitats for local animals and plants are often decimated in the area. Growing up, I can remember the mountains appearing barren and black as a result of these fires for a good portion of my childhood.
Image Source: All Trails
Image Source: Business Insider
References:
1. https://www.nps.gov/samo/learn/nature/volcanoes.htm
2. https://www.nps.gov/chis/learn/upload/CHIS-Plant-Usage-Garden-Guide-2017.pdf
3. https://www.sanbuenaventuramission.org/history
4. https://web.archive.org/web/20160121041755/http://www.toaks.org/civica/filebank/blobdload.asp?BlobID=29651 (page 151)
5. https://www.nps.gov/samo/learn/news/a-superbloom-impersonator-invasive-weeds-cover-hillsides-in-fields-of-green-yellow.htm
Hi Alexander! It seems like a lot of the class grew up in the Midwest (myself included) and so our hometowns have very similar ecological histories, so it was interesting to read about someplace so different in both its ecological history and current environmental threats. Wildfires aren't much of a risk here and it feels like we almost have the opposite problem, with fire suppression resulting in the loss of our prairies and oak savannas. Do you know what the history of wildfires in the area was like before European settlement? Did they play an ecological role like they do here or were they pretty much nonexistent before humans got involved?
ReplyDeleteHey Alexander,
ReplyDeleteAs Gabrielle noted above, it was really interesting reading about the land history of a coast rather than the midwest again. Particularly learning about California is interesting, as I know much less about their history than the east coast for example. I also really like how you drew on personal experience from the wildfires but also connected that with broader research about the land. The Business Insider photo you included helps actualize the fires, and that looks terrifying. The issue with yellow mustard reminded me of an issue with buckthorn in my hometown. It seems like a consistent theme with successional settlement was the introduction of invasive species that now dominate the landscape.
Really neat post, Alexander! I like the anecdote that you remember the mountains being barren and blackened throughout your childhood. It really helped me understand how these wildfires really dominated the landscapes - I could have never imagined they were so common! I felt similarly with your description of the "miles and miles" of Black Mustard - very good imagery! You mentioned the Chumash people being hunter-gatherers and thus not applying any agricultural techniques to the landscape. Did they manage the landscape in other ways and for other purposes? I know some tribes commonly burned sections of forest for clearing out wildlife or just maintaining habitat. Are you aware of any efforts by the Chumash tribe to maintain the chaparral or did the wildfire regimes of that time generally suffice? Also, do these wildfires aid or mitigate the spread of Black Mustard? The fact that Black Mustard seems to assist in starting these fires makes me suspect that they are especially adapted to frequent fires, but I would like to know if you found any information on this. Maybe the greater frequency of fires allows them to better outcompete native species?
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