The issue of tree poaching may be a familiar story to people in British Columbia but, as writer Lyndsie Bourgon explores in her new book, the reasons why some choose to steal old-growth trees is more complicated than she initially thought.

Speaking to CTV's Your Morning on Thursday, Bourgon, author of "Tree Thieves: Crime and Survival in North America's Woods," said the timber black market costs B.C. an estimated $20 million each year.

In the United States, tree poaching can be worth up to $100 million annually and up to $1 billion across North America.

"It looks a little bit different depending on the species that's being taken, but it's essentially just chopping down a tree," said Bourgon, who is based in B.C. and Scotland.

In researching for her book, the 2018 National Geographic Explorer — individuals whose work is supported by the National Geographic Society — spoke to poachers themselves, as well as law enforcement, residents of former logging towns, and others to get a broader understanding of why people enter the illegal market.

She found that the problem is more systemic than she realized, with poverty in a number of former logging communities in the Pacific Northwest being a factor for some.

"As I began researching the book and doing interviews in some of the towns where poaching is really common, a lot of people started telling me about how there's not a lot of work in the towns," she said.

"There are a lot of people that are from these areas and don't want to move and they feel very comfortable working in logging, and tree poaching is one way of keeping that work going," she said.

Watch the full interview with Lyndsie Bourgon at the top of the article. With files from CTV News.