Invasive Plants, Pacific Northwest
Invasive plant species are considered to be one of the greatest threats to biodiversity not just on the BC coast, but worldwide, second only to loss of habitat, the BC coast is being attacked by many invasive species of plants.
The coast has very diverse and rare ecosystems that support many rare and endangered species that depend on these habitats for their survival, Invasive plants can take over and force the native plants out. The closer you come to communities, the more you see, spread by dumping garden debris in the forest. Some Plants like English Holly are mostly distributed by birds, the seeds will go right through them and then be delivered along with a good fertilizer. I have seen these trees a very long way from any road.
Invasive plants are brought to the BC coast, either accidentally or intentionally, and include species like purple loosestrife, scotch broom and japanese knotweed. These are just a few of the plant species that are threatening our indigenous plant species on our coast.
These invasive plants can get established easily and because they may have no natural predators, they can quickly take over an area and force out native species and this can also have an adverse effect on our native wildlife. As the animals usually do not eat the invasive plants and as these plants take over areas, it forces the wildlife to look further for food.
Some of these plants can have a direct negative effect on humans as well, some can have huge economic impacts by competing with agricultural plantings and forest harvesting areas. They can also pose significant threats to humans by causing skin irritation, burns and poisonings.
BC has a real problem with these plants, everyone who lives on the coast, especially on Vancouver Island, has seen the advance of plants like Scotch Broom. When I was a young man, you hardly ever saw this plant on the Island, now its everywhere you look. I was hiking up a mountain in the Kelsey Bay area this year and near the top, almost out of the tree line, there it was, scotch broom. This really upset me.