USA On a remote island located off the coast of British Columbia, new research has shown that indigenous populations likely had a profound effect on patterns of wildfires.
By combining tree ring evidence with climate data, researchers from two Pacific Northwest universities were able to track a pattern of fires over five centuries that weaved together El Nino events and human activity.
The new study adds to a growing body of evidence suggesting fires were more frequent in the Pacific Northwest prior to 1900, a pattern that can likely be explained by human factors.
Fire is historically important in the West, said Daniel G. Gavin, professor of Geography at the University of Oregon. There is a lot of evidence from fire scars throughout the Pacific Northwest, not just in the dry pine forests, that point to more frequent fires having occurred before 1900.
Gavin and his co-author, Kira M. Hoffman of the University of Victoria, focused on the isolated Hecate Island off British Columbia. Crucially, they found that the last forest fire on Hecate occurred in 1893, around the time the island was abandoned as the indigenous populations were relocated to permanent settlements on the North American mainland.
Hecate experiences more than 4,000 millimeters of rain annually and has a short dry season, perhaps making it an unlikely location to perform a study on forest fires. The island is located in a northern region where both lightning and human caused fires are considered to be a rarity. On the other hand, the island has hardly been affected by twentieth century land use or modern fire suppression methods, making it ideal for determining the human factors behind pre-twentieth century fires.
A former fire fighter, Hoffman chose the island after stumbling across a fire damaged tree there while working a project for her masters of science degree. Finding this fire evidence was an accident and I was really surprised because there had been no evidence of fire on the central coast of British Columbia, she said in a press release. The more I looked, the more I found. We know that the fires were smoldering ground fires because they didnt kill the trees that they scarred, and they didnt fully burn ground fuels.
Drawing data from around 3,000 trees at 30 plots within a 300 hectare area that included three archaeological sites where indigenous populations had lived, the team, which also included Brian M. Starzomski; a professor in UVics School of Environmental Studies, were able to correlate wild fire occurrences in respect to other fires, climate events and human activity. Over a 517-year period, from 1376 to 1893, 13 fire events occurring roughly every 39 years were documented. Significantly, these fires seemed to follow El Nino events by either six to nine, or thirteen to seventeen years.
By incorporating tree ring records into their research, Gavin, Hoffman and Starzomski found that wild fires were 25 times more likely than previous estimates based on intervals of over a thousand years had suggested. Interestingly, the team found little connection between drought and fire years.
It seems that fire events dont have a pattern if you look only at weather in any given year, Hoffman explained. When we pulled back and look at longer climate patterns, we began to see that fires were linked to prolonged periods of warm and dry conditions that build up over time.
The teams findings are the first in the region to tie forest fires to human activity. Evidence for fires became scarcer farther away from the areas of the island that had been populated. This, alongside the sudden lack of fires after 1893, leads the team to suggest the indigenous populations had used fire as a means to manage resources.
Its possible they would have relied heavily on burning forests and single trees to create dry firewood for cooking and heating, clothing, canoes, food and many other resources, Hoffman said.
Government has urged Malawi Defence Force (MDF) soldiers who are deployed to guard Viphya Plantation against destruction to be vigilant by dealing with the perpetrators accordingly.
Msaka (left) walking in the plantantion
Minister of Mines, Energy and Natural Resources, Bright Msaka, made the statement Tuesday after touring the plantation, especially areas under the jurisdiction of Total Land Care and Raiply Malawi Limited.
Incidences of fire destroying numerous hectares of trees every year have been a never-ending song for the Viphya Plantation for over a decade now. The plantation is shared by two districts of Mzimba andNkhata Bay.
However, the issue has raged on in spite of efforts by government and its stakeholders to plant trees and guard them against destruction. Reports have indicated that more often, the fires that destroy the plantation are deliberately set rather than accidental.
The minister said government is aware that some disgruntled workers and individuals whose licences were cancelled are the ones setting fires in the plantation.
People need to know that this is a national asset, so if the department of forestry has denied somebody a licence for the reasons best known by the department, they are supposed to understand instead of setting fires, he said.
To mitigate the challenge, Msaka said government deployed MDF soldiers in protected forests across the country as a way of scaring people from destroying the plantations.
In spite of the effort, some people are still setting parts of the Viphya Forest on fire, regardless of the size of trees.
We have directed the Malawi Defence Force solders to deal with anyone setting bush fires and operating in the forest without licences and that the law will take its course [against them], he warned.
However, Msaka commended Raiply Malawi Limited and Total Land Care for utilizing the forest sustainably and adding value to the trees from the forest.
In the past, we have been cutting trees or sawing and selling them abroad at a very cheap price. We behaved like a prodigal son who squandered all what his father gave him.
We need to be very careful and be proud of what we inherited so that we can benefit from it and pass on those benefits to the next generation, advised the minister.
Earlier, Chief Executive Officer of Raiply Malawi Limited, Thomas Oomen, cited bush fires and encroachment as major challenges facing his company.
This year alone, we have lost about 526 hectares [of trees] to bush fires, unfortunately, most of these trees are below 15 years old but they are supposed to be harvested at the age of 25. This is dooming our future, said Oomen.
Chikangawa Forest consists of seven plantations comprising 53,000 hectares.
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