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3.0 Module Learning Objectives
3.0 Module Learning Objectives
After completion of this module, you will be able to:
Describe the importance and characteristics of the different ecosystems in northern California.
Understand how climate change will effect California ecosystems.
Explain how biodiversity is being impacted by human activities.
Acknowledge that we can all learn how to be better stewards of our land from the Native people who have done so for thousands of years.
3.1 Ecosystems in Northern California
3.1 Ecosystems in Northern California
The Bay is home to several interconnected ecosystems that are fundamental to life in the area. The expansive estuary with its maze of bays, rich delta, and associated rivers and streams are vital to supporting the Bay’s nearly 500 species of fish, birds, mammals, amphibians, and invertebrates. These ecosystems are also essential to human civilization in the Bay, as they provide our food and water, supply us with wood, paper and minerals, and regulate our climate.
Image 3.1 The San Francisco Bay estuary.
San Francisco’s estuary, one of the largest in North America, is an ecological mixing bowl where Pacific saltwater meets the freshwater runoff that flows from the Sierra Nevada through the Sacramento and San Joaquin rivers into San Francisco Bay and on to the ocean. The blending of these waters produces rich habitat for salmon, smelt, shrimp, crabs, pelicans, cormorants, ducks, whales, seals, and humans.
Image 3.2 Wetlands in the area produce oxygen, filter chemicals, reduce flooding and erosion, recharge groundwater, and provide critical habitat.
Image 3.3 Remnants of grasslands in Northern California support a wide array of wildlife.
Image 3.4 Oak woodlands store carbon, and harbor insects, birds and mammals.
Image 3.5 Coastal scrub habitats are found throughout much of the Bay, and support a unique array of plants and animals.
Image 3.6 Ancient redwood forests along the coast store more carbon per acre than any other forest type in the world. Before 1849, there were two million acres of old-growth redwoods in California. Because of deforestation, only 5 percent of old-growth redwood forests remain, and only 23 percent are protected.
Image 3.7 To the west of San Francisco along the coast lie the Greater Farallones National Marine Sanctuary and the Cordell Bank National Marine Sanctuary. These sanctuaries create some of the most biodiverse marine ecosystems on the planet, housing whales, sharks, deep sea corals, sponges and much more.
3.2 Effects of Climate Change on Northern California Ecosystems
3.2 Effects of Climate Change on Northern California Ecosystems
The impacts of climate change are already being felt in the San Francisco Bay Area and Northern California. Nearly every aspect of northern California’s ecosystems will be affected by climate change as a result of warming temperatures, rising sea levels, ocean acidification, increase in wildfires, drought, and air pollution.
Increase in Temperature
Increase in Temperature
Image 3.8
Overall, the Bay Area’s average annual maximum temperature increased by 1.7°F (0.95 °C) from 1950-2005.
If we continue the rate at which we release harmful greenhouse gasses into the atmosphere, the average annual maximum daily temperature in California is projected to increase by 5.6 degrees to 8.8 degrees by 2100. This would result in the collapse of the interconnected ecosystems in the Bay area.
Warmer temperatures have dried out vegetation and soils, making wildfires more intense and more common.
Ocean Acidification
Ocean Acidification
Just as the atmosphere has absorbed vast amounts of carbon dioxide, so too have the oceans. Scientists have observed that ocean water is becoming more acidic because of this. Ocean acidification has chemically changed the properties of ocean water, which is harmful for marine plants and animals
Sea Level Rise
Sea Level Rise
Sea level in the Bay Area has risen over 8 inches in the last 100 years.
Scientific evidence shows that sea levels in the Bay area could rise another 6 inches by 2030 and up to seven feet by 2100.
Four feet of higher water levels would cause daily flooding for nearly 28,000 socially vulnerable residents in the Bay Area.
Rising water levels in the Bay will make the water saltier and deeper, create stronger tide currents and more erosion along the banks. These changes in water conditions will devastate the Bay’s mosaic of marine habitats, wetlands, marshes, and mudflats.
Image 3.9 Saltwater inundation and flooding from sea level rise will expose marsh plants throughout the Bay to more saltwater, which could change the makeup of the habitat drastically. Flooding caused by sea level rise could wash toxic contaminants from 1,100 contaminated sites into the Bay. PCBs, selenium, mercury, arsenic, and other heavy metals and pollutants will contaminate the water and will have catastrophic consequences to the Bay Area’s flora and fauna.
Drought
Drought
Image 3.10 As of January 2022, all of San Francisco County, San Mateo County Marin County, Santa Clara County, Alameda County and Contra Costa County are considered to be in severe drought.
From July 1, 2020 to June 30, 2021, the Bay Area received only 40% of the amount of rainfall it normally gets. As temperatures continue to increase, it is likely that the amount of rainfall the Area receives will decrease.
Because of decreased rainfall, plants on the Bay shoreline may produce less flowers, seeds, and leaves. This could mean less food for insects, birds, and mice and in turn less food for wildlife that are higher up the food chain.
Wetland plants along rivers and creeks may die if they don’t get enough freshwater. Because wetland plants filter pollutants that run through the Bay, their loss would be detrimental.
Fish that need freshwater habitat may not be able to spawn if less rainfall flows into the Bay’s tributaries.
You can click on this link to the National Integrated Drought Information System to monitor current drought conditions in your County.
Air pollution
Air pollution
Air pollution can damage ecosystems in the Bay Area in a variety of ways. Air pollution can reduce growth and survivability of tree seedlings and increase plant susceptibility to disease, pests, and severe weather.
Animals can experience health problems if they are exposed to air pollutants over time. Air pollutants cause birth defects, reproductive failure, and disease in animals.
Image 3.11
Wildfire
Wildfire
A warmer, drier climate will also lead to increased intensity and frequency of wildfires. These could harm populations of upland birds, mammals, amphibians, and reptiles, especially those persisting in remnants of old growth forest vegetation.
If greenhouse gas emissions continue to rise, one study found that the frequency of extreme wildfires would increase, and the average area burned statewide would increase by 77%.
Image 3.12 The Dixie fire burned over 963,000 acres in Northern California in 2021. The fire was exacerbated by drought, hot weather, and exceptionally dry vegetation.
Image 3.13 Wildfire is a natural part of many ecosystems in California, but excessive wildfire can permanently alter these ecosystems. Ecosystems can naturally slow climate change by storing carbon, but recent wildfires have made California ecosystems and Southwest forests net carbon emitters (they are releasing more carbon to the atmosphere than they are storing). Wildfire has also exacerbated the spread of invasive plant species and damaged habitat. As shown in the graph above, it is estimated that the area burned by wildfire in the southwest United States from 1984 to 2015 was twice what would have burned without climate change.
3.3 Decreases in Biodiversity
3.3 Decreases in Biodiversity
A report by the United Nations found that around 1 million animal and plant species are now threatened with extinction, many within decades, more than ever before in human history. Biologists are becoming more and more concerned that global climate change will drastically reduce biodiversity. Some biologists estimate that 35% of animals and plants could become extinct in the wild by 2050 due to global climate change.
The most threatening effect of climate change to Bay Area wildlife is the impact of rising sea levels on wetland. Less rainfall, more summer heat, and increased drought will have negative impacts on amphibians and reptiles, while heat and wildfires may negatively affect upland birds, mammals, amphibians, and reptiles. Some wildlife species may need to shift locations as the vegetation they inhabit shifts with a changing climate. Relocating will be a challenge to many of these species due to urbanization of the Bay Area. Here is a link to the list of species that may disappear in California because of climate change, according to the Center for Biological Diversity.
Coastal Redwoods
Coastal Redwoods
Image 3.14 Coastal redwoods are powerful allies in meeting the threat of climate change because they are huge carbon sinks. Redwood forests store more carbon than any other forest ecosystem. They provide a safe haven for endangered birds like Northern spotted owls and homes for animals like black bears. Redwoods filter and shade rivers, providing clean drinking water for people and cool streams that native salmon require. With rising temperatures, coastal redwoods may receive less coastal fog, which they rely on for moisture and nutrients. Wildfires, flooding and an increase in pathogens will all threaten coastal redwoods.
Chinook Salmon
Chinook Salmon
Chinook salmon are considered a keystone species in the Bay area ecosystem. A keystone species is an organism that is vital to the ecosystems they inhabit. Without keystone species, an ecosystem can collapse because other organisms depend on their survival. Salmon are sources of food for many species, including orcas and sea birds.
Image 3.15 When salmon die at the end of their life cycle, the carcasses provide essential nutrients to streams and rivers, and these nutrients are then transported to all levels of the food chain.
Image 3.16 Winter-run Chinook salmon once came in droves each year from the Pacific Ocean, swimming through San Francisco Bay and up through the Central Valley. The man made dams, reservoirs and canals that were built to supply water to the Bay Area have cut off Chinook salmon from more than 90 percent of their ancient spawning grounds. Because of this, Chinook salmon populations have drastically decreased and now only a few hundred to a few thousand return to spawn beneath a giant dam on the Sacramento River.
Chinook salmon also require cold water temperatures throughout their life cycles to survive. With temperatures rising, the survival of Chinook salmon has decreased. If climate change continues to significantly alter the Bay estuary, the general economic and environmental stability of Northern California could go with it.
The decline of Chinook salmon has resulted in the collapse of the orca populations that depend on this keystone species for their survival. The population of orcas is now at a 30-year low.
3.4 Remothering the Land
3.4 Remothering the Land
The original peoples who inhabited the Northern California Coast are the Ohlone, who have an intimate connection with the land that they have lived on and stewarded for generations. The Ohlone lived for millennia without burning fossil fuels or destroying valuable ecosystems Before the Spanish colonized the area, around fifty separate Ohlone tribes in the San Francisco Bay region were living sustainably off of the land.
Despite over two centuries of genocide and colonization, Ohlone communities persist today and are active in efforts to preserve and revive their culture. The Lisjan Ohlone people have lived on the land that is now known today as the East Bay. Today, they continue to inhabit and care for their ancestral homeland and cultivate relationships with their native ecosystems. Organizations like the Sogorea Te' Land Trust work to revitalize the Ohlone culture and restore and rematriate the land.
Indigenous peoples sustainably managed their land for thousands of years without the use of fossil fuels and destructive land practices. By using regenerative land practices, they were and still are connected to their land in a way that those who are not of native heritage are not. Rematriation, or remothering the land, is a practice perfected by Indigenous and Black farmers, and involves restoring, healing, and rejuvenating the land to support natural ecosystems. By supporting your local Indigenous-led work, those who are not of native heritage can learn sustainable ways that they managed, and continue to manage, their land.
3.5 What is CLPCCD doing?
3.5 What is CLPCCD doing?
Las Positas has a Native Plant Trail on its campus that is available for students and faculty to enjoy.
Chabot College acknowledges that it sits on Ohlone Land.
3.6 Calls to Action
3.6 Calls to Action
What can you do?
What can you do?
Plant easy-to-grow plants in your yard and windows that are native to the East Bay.
Learn more about the Muwekma Ohlone Tribe of the San Francisco Bay Area.
Donate to the Rematriate the Land Fund.
Read the Rematriation Resource Guide to learn more about rematriation.
Use the resources below to educate yourself on the climate crisis.
Read
Read
Regeneration: Ending the Climate Crisis in One Generation by Paul Hawken
The Hidden Life of Trees by Peter Wohlleben
The Sixth Extinction by Elizabeth Kolbert
Decolonization is Not a Metaphor by Eve Tuck and K. Wayne Yang
3.7 Quiz
3.7 Quiz
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