What is the significance of old growth?

Question

I know it looks cool, but how is it better for the environment to have old growth stands?

I am a hunter and a conservationsist. Probably in a different camp than some of the tree huggers, but we probably have a few things in common.

Anyway, I have seen forests clear cut and within five years the new scrubby brush is teeming with wildlife. Yes, the habitat is different and will support different species than it did before, but those trees mature.

By the time the stand is about 15 years old, what is the difference? It seems like the same animals can live there.

Answer 1

The main concern with cutting old growth is the loss of biodiversity and the loss of a carbon sink.

Certain animals that thrive in old growth such as owls that are on the endangered list occupy only old growth.

Also old growth has stored large amounts of carbon dioxide over the hundreds of years it has been alive. When they are harvested carbon dioxide is released through decomposition (debris from logging), leftovers at mills are burned to run mill, and eventually the wood made out of them is decomposed and released back into the atmosphere.

It is true that new growth takes in carbon dioxide at a faster rate than old growth but it does not compensate for the amount released.

Also degradation of soils from logging can lead to loss of nutrients, less water holding capacity, and less water infiltration.

Answer 2

there is something deeper here... literally.

cutting down trees is not the biggest problem when it comes to deforestation. underneath the trees is something called a mychorrizal network which is essentially underground fungal growth. mychorrizal mats underneath the forests are essential to sustainable growth. they aid in floral respiration, moisture uptake and nutrient intake.

what happens when trees are cut down in small numbers? not really much. you are right about that. a small clear cut area will usually rebound relatively quickly. however, the danger lies in farming the area afterwards. nitrogen fertilizers destroy mychorrizal growth and if this network is damaged, it can take several decades to have any significant sustainable growth.

and furthermore, most of the moisture taken in by mychorrizal fungi comes from groundwater. the connection between logging and paper mills cannot be overlooked in this case as the sulfide and sulfate chemicals used in the wood pulp refining process get into the ground water far too easily. due to the proximity of pulp mills to the logging areas, it can have a compounded effect on the logged region.

Answer 3

1.  Certain species (plants and animals) truly only survive in the nooks and crannies of very old trees.  That doesn't mean 15 years later.  Where do they go for those fifteen years?

2.  Old growth is important for tourism. Also, I for one would never want to see trees that were hundreds of years old be cut down for recreational use!  It is a tragedy.  

3.  When clear cut, old growth forests release a significant amount of greenhouse gases.