Forest ecology - much more than trees

When we think of forests, we often think only of the trees that grow there. And while many tree species are impressive - such as the 82m (274 ft) California Sequoia that is the earth's largest living thing or Methuselah, a California Bristlecone Pine that dates almost 4,770 years  - trees represent only a tiny percentage of life in the forests. Part of what makes forests so amazing are the complex relationships between flora and fauna - like the incredible salmon forest story.

 

Critters like insects, slugs, voles, and shrews are perhaps not as majestic as ancient trees, but they are as important to the health and longevity of a forest. Mosses and lichens are also essential elements of a forest, and if any of these pieces of the puzzle go missing, the entire forest can be critically impaired, especially in the long- term.

These often-considered lesser species can have the same function as a canary in a coal mine, warning us when human activities are undermining the forest ecosystem. And in order to protect valuable species - like spotted owls or marbled murrelets - we must protect their forest habitat.

The lowly mushroom is an excellent example of how a visually small part of the forest is actually a significant element of the forest ecology.

The mushroom that we see is merely the fruiting body of a much larger fungal web that can spread far and deep into the earth. Different types of mushroom provide different functions in the forest, and because they lack chlorophyll - the green pigment that plants use to absorb energy from sunlight in order to make food - most forest mushrooms obtain their food energy in one of two ways.

Saprophytic mushrooms obtain nutrients through the decomposition of dead wood and other plant material on the forest floor. This assists in recycling critically limited nutrients back into the soil. While others, like mycorrhizal mushrooms, absorb nutrients from living plants though a network of fibres that link with the root systems of host trees and vegetation.

This relationship is mutually beneficial for both the mushroom and its plant host. For example, the massive underground networks of mycorrhizal fibres extend the area from which trees can obtain much-needed nutrients from the soil. And, the mycorrhizal mushroom can also act as a protective, absorptive or disease-repelling agent for its tree host. Given the intimate relationship between mycorrhizal mushrooms and their hosts, many tree species can thrive only through their symbiotic relationship with specific mycorrhizal species.

Despite the ecological importance of mushrooms, industrial logging methods like clear-cutting are extremely damaging to them. Research shows that certain mushrooms are restricted to old-growth forests and others to mature forests. This underscores the importance of forest management and logging methods that maintain a wide range of forest types and ages.

Just as we must protect our own lungs in order to live, our forests - the lungs of the earth - require great care and conservation for the future health of the planet and generations to come.

Look into the forest
View a short film of the rainforest, featuring an interview with:

 

 David Suzuki