Forest Ecology

Lobaria Oregana Lichen, Vancouver Island, Pacific Northwest
Lobaria oregana Lichen, Vancouver Island, Pacific Northwest, Photo By Bud Logan

Awhile back, l took a group of people out for a walk on the canyon view trail that runs alongside the Campbell River. I was showing them different edible/medicinal plants, with information on how they could be harvested and used. I was also teaching about Forest Ecology. It was right after a heavy wind storm and there was lots of lichen on the ground, mostly lobaria oregana. Lobaria oregana lichen is also known as a lettuce lichen because of its lettuce-like leaf shape, it grows at the tops of coniferous trees, attaching itself to the bark. It looks just like the iceberg lettuce after it has wilted a bit.

This lichen is able to absorb nitrogen from the air. Most plants get nitrogen from the soil, Lobaria Oregana Lichen can’t reach the soil because it lives in the tops of the forest, so it fertilizes itself from the air. While the lichen is growing in the treetops, it is attached to the tree, tiny fir rootlets will form under the lichen and will draw nitrogen directly from it straight into the fir tree. Another way that the trees and other plants benefit from this lichen’s ability to absorb nitrogen from the air is when the winter storms blow parts of the lichen loose to fall to the forest floor where it breaks down and the nitrogen is released into the soil. Up to 30% of the trees lichen will fall during the winter months.

Fir Tree, Vancouver Island, Vancouver Island, BC
Fir Tree, Vancouver Island, Vancouver Island, BC, Photo By Bud Logan

This is pretty cool and as lobaria oregana can be as much as 3% of the total foliage weight, this can be quite a bounty to the nitrogen-poor forest floor. Once it is taken into the soil, it will find its way to the tree roots where are taken in as fertilizer by the plants and trees.

If you were to look under your feet in a forest, you would first find the roots of all the plants, then the mycelium fungal, and below this, the mineral horizons. These are the different parts of a system of roots, fungi, and mineral components that all work together to move the nitrogen and many other types of nutrients, plant medicines, and trace elements about to the various trees and plants, They operate almost as if they were part of one giant organism, one system you might say of transportation. There are even mother trees in this system that are able to send out food for their own offspring. The system of roots and fungal around these mother trees are much denser than in other areas of the forest.

Forest Systems, Vancouver Island, BC
Forest Systems, Vancouver Island, BC, Photo By Bud Logan

There are studies being done to learn more about these forest systems. One of the best studies is being conducted by Susanne Simard, it was started over 30 years ago and is still ongoing. She has broadened the knowledge base on the reproduction of forests after logging immensely.

As a young man, i was employed with the BC Forest Service and had the opportunity to work with a science officer as his assistant. We were studying what goes on underground in different conditions.  We did plots that involved recording everything from tree and plant species to how healthy their growth was. We also recorded the insects, roots, mycelium concentrations, soil conditions, and all microorganisms. Weather stations were put out to record rain volumes and frequency. We did plots in old-growth forests, second growth, newly logged clear cuts, and in various stages of regeneration. In the newly logged areas, the system was almost completely missing, but as we move up through the various stages of regeneration, you could see a return of most of the components. They did not come back to the same volumes as in the old-growth forests, but perhaps if the forest was allowed to become a true old-growth forest, they might.

Mother Tree, Vancouver Island, BC
Mother Tree, Vancouver Island, BC, Photo By Bud Logan

New studies are showing that if you leave some of the mother trees in place and log smaller cut blocks, the system has a much faster turnaround.

Before working with the forest service, I used to think of a forest as just a bunch of trees that only needed sunlight and water to grow, I was wrong. It is a very complex system. Its also absolutely fascinating. Next time you are in a forest, take a good look around, you should be amazed.

I like to walk the trails alongside the Campbell River where if you look, you can see the way the forest works, the system that is in place to move various nutrients and minerals, and the all-important nitrogen to feed the and grow the forest is quite fascinating. So take a hike and see for yourself.

2 thoughts on “Forest Ecology”

  1. Lung lichen came up just yesterday on a forum I participate in. How can you tell the difference between it (Lobaria pulmonaria) and Lobaria oregana? Is it mainly because the former prefers Big Leaf Maples and the latter, Douglas Firs?

    1. Lobaria pulmonaria mostly grows on softwoods like douglas firs. It can also grow on rocks, I see this on Vancouver Island quite often. When this lichen reaches around 25 years of age, it becomes capable of reproduction. In sexual reproduction, the species produces small reddish-brown discs known as apothecia containing asci, from which spores are forcibly released into the air.

      Lobaria Oregana mostly grows on hardwood bark in the pacific northwest but can also be found on various other trees. I have seen very little if any in the coastal second-growth forests. It needs big trees to exist. This lichen is a loosely attached leaf lichen. It is large, with broad lobes. Size ranges from 20mm to 35mm wide. Its upper surface is yellowish-green, and its lower surface is pale brown with fine hairs and scattered pale, yellowish, hair-free patches. It can turn white when it dries out. This lichen has strong and deeply indented ridges. It has no soredia or isidia. The lobe margins are frilly. The frills at the end of the lobes are small.

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