- A new episode of “Mongabay Explains” delves into the biodiversity crisis in California, which is known to be one of the most biodiverse states in the U.S., hosting about 6,500 animal species, subspecies and plants.
- California has been bearing the brunt of climate change in recent years as wildfires and drought transform the land.
- The film focuses on three species that are being negatively affected by the climate crisis: California tiger salamanders, acorn woodpeckers, and monarch butterflies.
- The filmmaker says California is the “poster child of what’s happening to our ecosystems around the world.”
Taiwanese filmmaker Chris Chang moved to Berkeley, California, in August 2021, when the state was already experiencing a deep environmental crisis. In 2020, thousands of wildfires in California burnt through an estimated 4.2 million acres (1.7 million hectares), the most significant fire season in the state’s history. While the following two years have seen fewer fires, research suggests that climate change will increase the fire risk in California in the years to come. The state also experienced its driest year in 2021 after undergoing a drought for at least two decades, and 2022 is proving to be a drought-ridden year as well.
Experts say ongoing fire and drought propelled by climate change will take a considerable toll on much of the state’s biodiversity — and California has a lot to lose. Considered to be one of the most biodiverse states in the U.S., California hosts about 6,500 animal species, subspecies and plants.
Chang, a video journalist and animator currently studying at the University of California, Berkeley, Graduate School of Journalism, decided that California was the ideal location to create a film about the global biodiversity crisis, which Mongabay released as part of its Mongabay Explains series.
“[California] is the poster child of what’s happening to our ecosystems around the world,” Chang told Mongabay. “There might be more wildfires or more extreme weather conditions in California, but … we observe [similar events] in different parts of the world, and I think the basic principle is the same: you lose biodiversity, and the ecosystem will be tilted, and then we have all kinds of consequences.”
California also provides a suitable place to study climate and its biodiversity impacts due to the large number of academic institutions located there, some rated among the best in the world for environmental science. The large numbers of researchers in the state mean that multiple studies can often be compared and contrasted to tease out subtle interactions between climate and a host of species.
Chang focused his film on three species found in California that are particularly susceptible to the impacts of climate change: California tiger salamanders (Ambystoma californiense), acorn woodpeckers (Melanerpes formicivorus), and monarch butterflies (Danaus plexippus).
As the name suggests, the California tiger salamander is only found in California. The species is already vulnerable to extinction due to urban development, agriculture and the introduction of invasive species, but climate change could pose additional challenges. While California tiger salamanders are known to adapt to unpredictable environmental conditions quickly, there are concerns the species will not be able to adapt fast enough to increasingly erratic weather patterns due to human-driven climate change, according to a 2017 U.S. Fish and Wildlife report.
If California tiger salamanders decline, local ecosystems could lose vital plant matter that sequesters carbon, said Michelle Koo, the associate director of UC Berkeley’s Amphibia Web, who Chang interviewed for his video.
“In places where you remove the salamanders, the invertebrate populations increase, then your accumulated plant matter sort of disappears, and that means that there’s not as much carbon being sequestered in a system,” Koo said. “Without salamanders, we’re going to probably see an increase in greenhouse gases that are causing climate change.”
Similar complex influences of climate change on interspecies relationships, especially between animals and plants, have been detected around the world.
As carbon dioxide builds up in the atmosphere, climate change will accelerate, leading to more extreme weather causing wildfires like those annually ripping through California’s forests and grasslands. The video describes how acorn woodpeckers collect acorns from oak trees and then store them by drilling little holes in trees. But a wildfire can wipe out the birds’ food supplies, as it did when a fire burned the Hastings Natural History Reservation, which hosts a well-studied population of acorn woodpeckers, in 2020.
“This is a tremendous hit on an acorn woodpecker,” said Eric Walters, an acorn woodpecker expert at Old Dominion University, who was interviewed for the video. “There’s no resources left. There’s nothing for them to survive [on], and they’ll likely have to abandon the area.”
Climate change also appears to be impacting monarch butterflies, which spend the winter months in California. In 2020, experts didn’t observe any monarch butterflies at a famous overwintering site at Pacific Grove. Yet, 2,600 appeared there the following year.
This year, the IUCN, the global wildlife conservation authority, declared monarch butterflies to be officially endangered with extinction, with their potential loss impacting ecosystems not only in California, but in the monarchs’ wintering ground in Mexico.
While California is being hammered with climate change impacts like wildfires and droughts, every part of the world is experiencing environmental change threatening global biodiversity. In a 2021 report, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) estimated that humans have already altered about 77% of land and 87% of the ocean, which has led to the loss of half of the world’s plant biomass and 83% of the wild mammal biomass. As climate change accelerates, this outlook is expected to worsen, taking a toll on human health and well-being.
“We sometimes underestimate the roles that different species play in an ecosystem and how different ecosystems are interconnected,” Chang said. “If there’s one big takeaway, I want people to know that … the food we eat, the air, the clean water, it all depends on high levels of biodiversity.”
Dong, C., Williams, A. P., Abatzoglou, J. T., Lin, K., Okin, G. S., Gillespie, T. W., … MacDonald, G. M. (2022). The season for large fires in Southern California is projected to lengthen in a changing climate. Communications Earth & Environment, 3(1). doi:10.1038/s43247-022-00344-6
Pörtner, H. O., Scholes, R. J., Agard, J., Archer, E., Arneth, A., Bai, X., … Ngo, H. T. (2021). IPBES-IPCC co-sponsored workshop report on biodiversity and climate change. IPBES and IPCC. doi:10.5281/zenodo.4782538