December 2, 2021—Ha-Shilth-Sa—Page 5
Clearcuts examined as B.C. struggles with floods The absence of large swaths of trees has had a role in November’s catastrophic landslides, according to studies By Melissa Renwick Local Journalism Initiative Reporter Thousands of British Columbians remain displaced following a series of devastating floods and landslides that have swallowed highway roads and entire cities in the southern part of the province. The floods prompted British Columbia to declare its third state of emergency this year on Nov. 17. The devastation was triggered by an atmospheric river that carried rainfall two times the average amount within a 72-hour period. As the severity and frequency of extreme weather events increases in B.C., researchers say the long-standing use of clearcut logging has exacerbated the probability of floods. But one of Vancouver Island’s largest forestry management companies disagrees, maintaining that it is an “effective” system that actually reduces the area of disturbance. A recent University of British Columbia (UBC) study by XuJian Joe Yu and Younes Alila found that logging can increase the frequency of large floods by up to four times. Alila is a UBC forestry professor who has been studying the relationship between the forest cover, logging, and hydrology for over 25 years. “What we are seeing now is just the tip of the iceberg,” he said. Aggressive forestry practices over the past several decades have resulted in cut rates of up to 60 per cent in some watersheds, said Alila. The way the province has been managing forests is not only “highly unsustainable,” but regulation and policies do not appreciate how sensitive the hydrology is to these “high cut levels,” he said. When a forest is removed from a watershed, its canopy is no longer there to intercept precipitation. “That means you have more rain directly hitting the ground,” said Alila. “And therefore, you have more moisture available for runoff.” The forest’s canopy also slows down snow melt because it acts like a barrier from the sun’s radiation. “If you remove the trees, the snowpack is receiving way more solar radiation,” he said. “So, you’ve got more snow on the ground, but also more energy to melt the snow.” The location of a cut-block can also greatly contribute to the disruption of hydrology within a watershed, Alila explained. South and west-facing aspects of mountains are more sensitive to logging than east and north-facing sides. Global warming only adds to the issue, he said. “The severity and the frequency of these atmospheric rivers in the fall has now increased as a result of global warming,” said Alila. “Even modest increases in the magnitude of these larger extreme events, like floods, can translate into surprisingly large changes in their frequency. The larger the event, the more frequent it becomes.” Clearcutting does not cause landslides, says Mosaic The Ministry of Forests said that harvesting can contribute to flooding because it creates soil conditions less conducive to absorbing water. “That’s why B.C. uses a science-based reforestation approach to reduce risk of flooding,” the ministry added. Under the province’s new vision for forests, the ministry said it’s working “to
Photo by Eric Plummer
Clearcuts are seen on a slope near Port Renfrew, just outside of the Fairy Creek valley in Pacheedaht territory. Researchers are linking the commonly used forestry practice to flooding events in British Columbia. Low land and flat areas in watersheds ensure our oldest and most ancient forests these sites. All these forest plants conare critical sponges, said Merkel, adding are protected, and Indigenous peoples are tribute to the soil structure and rooting that many have been cleared for roads, full partners in sustainable forest manage- systems in these areas.” houses, agriculture, forestry, and logging. Mosaic said a variety of factors influment.” “It’s not surprising that we’re having ence slope stability, including steepness, Nuu-chah-nulth Tribal Council Presisome of these problems because we’ve precipitation, the types of vegetation dent Judith Sayers said she has yet to see taken out those buffer areas of our landpresent, historic disturbance, as well this transition. There is recognition by scape,” he said. the government, she said, but there are no as man-made structures like roads and Since 2018, the Ministry of Forests said culverts. “concrete” actions yet. the province has planted over 1 billion “Because these factors, and many oth“UNDRIP [The United Nations Declaratrees in its reforestation efforts. tion on the Rights of Indigenous Peoples] ers, all come into a geotechnical engi“Replanting harvested areas and those talks about our ability to control, manage neer’s assessment of landslide risk, it areas ravaged by wildfire and pests is eswould be highly unlikely that any expert and use our own forests,” said Sayers. “And I don’t see that reflected in the new would categorically suggest that clearcuts sential to our fight against climate change and rebuilding forest health,” the ministry cause landslides,” said Mosaic. “Instead, forestry policies or law that [the governsaid. with today’s professional standards in ment] is proposing.” While clearcutting is “the most comMudslides are also triggered after heavy place and scientific knowledge and legmonly applied” harvesting practice over islative framework, it would be weather events like the one B.C. just the last 20 years, the Ministry of Forests more appropriate to say that profesexperienced, said Garry Merkel, B.C.’s noted that in recent years logging represional foresters assess landslide risk beold-growth strategic review panel expert sents less than a third of the disturbance fore proceeding with harvesting activiand a professional forester. caused by wildfires. ties.” Debris from clearcuts accumulates in “In general, any stand-replacing disturClearcutting is commonly used in forest and around creek channels, which evenbance, be it through harvesting, wildfires tually lets loose under heavy rain, he said. management for a number of reasons, or mountain pine beetle, can contribute to said Mosaic. Some of these include It tears creek banks, taking mud and all flooding because they create soil condimimicking fire and other types of natural the surrounding debris with it, he added. tions less conducive to absorbing water,” “You end up with very large landslides,” disturbances, providing safer working said the ministry. “In BC, over 16 million conditions, managing mature trees that Merkel said. hectares have been affected by the mouncontain forest health issues, as well as One of the 14 recommendations outlined in the Old Growth Strategic Review providing optimal growing conditions for tain pine beetle, and a record 2.7 million hectares have burned in wildfires over suggested developing alternative harvest- crops of trees that will be replanted, such the last 5 years. In comparison, 888,000 as the Douglas-fir. ing methods to clearcutting. hectares were harvested between 2016 But Alila maintained that the only way If forests were harvested delicately so and 2020.” forward is to rethink how we manage the ecosystem’s attributes, structure and In August, Environment and Climate function remained intact, Merkel said you forests “before it’s too late.” Change Canada announced an investment Governments also need to consider the can have very little effect on the ecosysof up to $340 million in new funding over impacts of climate change and land use tem. developments when designing infrastruc- the next five years to support Indigenous “But the standard systems that we use leadership in nature conservation. ture, such as bridges and culverts, said are primarily clearcut,” he said. “Indigenous peoples are key partners as Alila. Mosaic Forest Management is the man“We should not continue doing business we work to protect more nature, conserve ager for TimberWest and Island Timberbiodiversity, and combat the worst effects lands, which have been operating for over as usual without accounting for the fact of climate change,” Jonathan Wilkinson, that the flood regime has changed and is 100 years on B.C.’s coast. “It is a common misconception from the continuing to change,” he said. “The past minister of Environment and Climate Change, said in a release. does not represent the future anymore.” public that clearcutting causes landWhile Sayers said, “there’s never going slides,” a Mosaic spokesperson wrote in Floods are ‘not surprising’ to be enough money for the amount of an email. “The public has probably seen work that needs to be done,” she hopes old stumps that persist for decades and The Ministry of Transportation stated that the federal and provincial governmore – all still functioning to support “to ensure transportation infrastructure is ments show more of a willingness to sit stable slopes. Furthermore, other plants resilient and adapted to the effects of cliat the same table with First Nations. – both planted trees and other forest mate change, including extreme weather “I really would like to see the province shrubs and herbs – quickly re-establish events, we must look beyond historical working more closely with First Nations on these sites. Mosaic plants trees information to future trends and what [to] use our traditional ecological knowlon average within ten months of harthey might mean for British Columbia.” edge and Indigenous wisdom,” she said. vest. Native shrubs and herbs persist The province has undertaken initiatives “We can use our knowledge to restore or re-establish after harvesting, and seed- to evaluate and address potential climate these forests.” lings growing from seed dropped from change impacts on transportation infrathe original forest also re-establish on structure, the ministry wrote.
