BC scientists are seeing a recovery, but fear that more heat domes could change the ecosystem forever

VANCOUVER — Dozens in British Columbia A year after the heat dome event that killed billions of flora and fauna, scientists say the ecosystem is recovering, but it can change forever as such events become more frequent.

Cold-water marine species can replace hot-water organisms and cause chained effects throughout the environment, says Christopher Harley, a professor of zoology at the University of British Columbia. increase.

"If another heat wave hits this summer, that would be a problem," he said. "Ecosystems may be able to cope with large heat waves once every few decades. There is plenty of time to recover, but once they start to occur every four to five years, the species we are accustomed to. Can no longer survive. "

Dozens of temperature records were set during the heat dome. The high-pressure system settled in western Canada, acting like a lid, trapping a layer of hot air that gradually heats up for about a week. Three consecutive records in Canada have been set in the town of Lytton. There, temperatures peaked at 49.6 ° C on June 30, the day before the fire destroyed most of the village.

The heat killed more than 600 BC. Coroner service reported. It also led to mass mortality of marine life, reduced crop yields, contributed to wildfires and later caused catastrophic landslides last fall.

Diane Sri Bastava, director of the Canadian Institute for Ecosystem Evolution, has organized a group of scientists currently working to understand the impact of heat dome on species and ecosystems. She said some were "immediate and obvious," but "getting a complete picture of the long-term effects" requires years of data. Harley, a member of the

group, said the heat wave had surprised researchers and they are now struggling to "understand what it means for marine ecosystems." I have. "

"It didn't happen to us asking what would happen if it got hot enough, so it's not that we don't know (ecological consequences). It's a little embarrassing, killing billions of marine animals, "he said. "The heat dome was far beyond what everyone expected."

Scientists initially estimate that more than a billion marine animals have died on the Pacific coast. was doing. Harley, who has been studying the West Coast coastline since 1995, said this was an underestimate.

"Billions of animals died easily," he said. "It was a perfect storm of several different things. Obviously much hotter than usual, their high temperatures were very consistent with low tide."

The mobile species is in shallow water. He explained that he had a higher survival rate than the species fixed to the rock.

"The mussels haven't returned yet, and some of the common seaweeds haven't, but the barnacle babies are spending their time in life. By the way, the first step in recovery is (when) they come, "he said. "This laid the foundation."

Adam Ford, assistant professor of wildlife restoration ecology at the University of British Columbia and chair of the Canadian Research Committee, said that the large mammals he is studying are marine life. Said that the effect of heat is much less than.

"There was several years of data under our belt, during which there was no increase in mortality, etc."

This is because large mammals are homeothermic. He said it was because he was able to regulate his body temperature and move to a cooler place to avoid direct heat.

Karen Hodges, a professor of conservation ecology at the University of British Columbia, said that most mobile animals and animals that sneak into the soil during the wildfire that followed the heat dome. He said it was likely to work better. A person who cannot escape immediately. She said it is difficult to estimate total mortality because "many assumptions about animal density" are required before the fire.

How quickly an ecosystem in a region recovers depends on environmental aspects such as soil moisture, but it depends on the practice of fire management and the response to climate change, Hodges said. Says.

"The answer to what comes back is the question of what humans do to these landscapes for the next 10 years, or 20 years if you want to be generous, a small fire. , Or you can set conditions that allow for the repetition of these large-scale fires, "she said. "This is a crucial time."

Ford reiterated his call for better wildfire practices to mitigate the effects of the heat wave.

"We already know that over the last 50 to 70 years, inadequate management practices such as climate change and fire extinguishing have really worsened the health of our forests. Therefore, the combination of these two results in a recipe for catastrophic failure that has permeated all kinds of areas of society, including biodiversity, "he said.

"We need to understand how to bring fire back to the landscape with the amount and intensity to restore wildlife and people's habitats."

Wilderness fires are forests A natural part of the ecosystem and important for maintaining the health and diversity of the forest, Natural Resources Canada says on its website.

"Open burning provides a valuable resource management tool to improve the condition of the ecosystem and eliminate excess fuel buildup," the website said. increase.

For decades, British Columbia scientists have called for the use of less severe fires to "maintain" forest health by creating firebreaks. According to Hodges, fire extinguishing efforts to protect the community have eliminated many of these natural breaks and made it easier for fires to spread.

She said the turning point was that a state report following the historic 2003 wildfire in British Columbia forced the evacuation of more than 45,000 people from within the state. Said.

"The report is full of all sorts of advice that the state doesn't basically do, such as how to burn a fire, the FireSmart community, and open burning, but that advice is at least that report," she said. Said.

According to Hodges, large-scale fires can also exacerbate climate change-related weather events, such as the catastrophic floods that occurred in British Columbia. last fall. She said a fire that kills thousands of trees affects soil composition and can make it hydrophobic, which repels water. After that, when it rains heavily, water is not absorbed by the soil and landslides occur.

"This is much more common after these big, hot and deadly fires than after the little ordinary fires that happened in our history." She said.

In a statement, the Ministry of Forests said, "One of several fuel management tools and techniques that can help reduce the intensity of naturally occurring wildfires while returning essential processes to the ecosystem." He said he was using open burning.

Rachel White, lead author of a report on the widespread ecological effects of heat waves in 2021 currently under peer review, said the lack of synthetic data is significant for scientists. Said it was a barrier.

"We have more frequent and hotter heat waves, which will affect all ecosystems. We need data to monitor them," she said. rice field.

"We need that data to really understand what the impact is. If we know how the system is responding now, how the system will be in the future if the climate continues. More information is available to show how to respond. To warm up through human behavior. "

Harley, a professor of zoology, and his team said that the ecosystem is in the heat wave. We are working to better understand why we are more or less sensitive to it.

"There may be minor changes we can make so that the ecosystem is more resistant to things like big heat waves and big droughts. No, "he said.

Srivastava stated that the Institute for Ecology and Evolution is advocating a state biodiversity monitoring network.

"This kind of event indicates that a biodiversity monitoring network needs to be in place already, which allows for long-term monitoring of large populations. "She said. "Instead, all we have to do is collect data from many different sources to see immediate and then long-term effects."

She said. He said the development of the network was the "subject of recent ongoing conversations" with the state and federal governments.

B. C. The Ministry of the Environment has confirmed that it is working on the integration of ecology research and data on climate change as part of new climate measures and adaptation strategies.

She states in a statement, "Understanding how climate change affects ecosystems is essential to responding to climate change.""The state has set up an ecosystem prediction center within the Ministry of Forests to help build the expertise and resources to transform technical climate change predictions into British Columbia's ecosystem change predictions.