A recent study from the University of California, Davis revealed that up to 70% of California was covered by wildfire smoke during parts of 2020 and 2021. The research, published in the journal Communications: Earth & Environment, utilized lake-based sensors and satellite imagery to determine that the maximum smoke cover has increased by around 116,000 square miles since 2006. The study focused on the impact of wildfire smoke on lake ecosystems in California, which has seen a significant increase in wildfire extent over the years.
The study measured lake responses to wildfire smoke during the three largest fire seasons on record in California in 2018, 2020, and 2021. It found that the lakes were exposed to an average of 33 days of high-density smoke between July and October, with August and September experiencing the highest number of smoky days. Despite the alarming increase in wildfire activity in the state, there is limited knowledge about the effects of smoke on lake ecosystems, prompting the researchers to delve deeper into this aspect and its implications for aquatic systems.
Professor Steven Sadro, the senior author of the study, emphasized the need to address the long-term impact of smoke on the landscape for the next century or more. The researchers highlighted the importance of understanding the ecological consequences of smoke on lakes and how it may alter fundamental ecological processes. By monitoring scientific instruments in 10 lakes across various landscapes in California, the study aimed to measure the effects of wildfire smoke on factors such as temperature, light, and oxygen in the water that contribute to lake productivity and health.
Lead author Adrianne Smits, a research scientist at UC Davis, explained that the study sought to determine how wildfire smoke and ash affect the rates of photosynthesis and respiration of plant and aquatic life in lakes. While the research confirmed that wildfire smoke can alter light, water temperature, and oxygen levels in lakes, the changes varied among the different lakes studied. The study found that factors such as lake size, depth, smoke cover, and nutrient levels influence how a lake responds to these changes, impacting crucial processes like photosynthesis and respiration rates that drive ecosystem health.
The researchers stressed the need for further research to comprehend the impact of recent and future wildfires on lake ecosystems. They emphasized that wildfire smoke should be viewed not just as a temporary event but as a seasonal weather phenomenon that can have lasting effects on ecosystem health. Co-authored by institutions such as the UC Davis Tahoe Environmental Research Center and the University of Nevada-Reno, the study was funded by a grant for Rapid Response Research from the National Science Foundation. The findings underscore the urgency of studying the effects of wildfire smoke on lakes to ensure the preservation and resilience of these crucial aquatic ecosystems in the face of escalating wildfire activity in California.