Wildfires Can Be Prevented By Old Forest...

Wildfires Can Be Prevented By Old Forest…

Almost everyone in the eastern United States has been delivered a strong reminder of the complicated implications of climate change as wildfires burn throughout Canada, causing dangerous air quality and apocalyptic orange sky thousands of miles away.

The Bald Mountain Wildfire burns in the Grande Prairie Forest Area on Friday, May 12, 2023

The effects of smoke on human health are obvious, but the hazy sky also draw attention to something else: the importance of forests in sustaining the health of our world.

Most people recognize that trees and forests play a vital part in minimizing climate change; nevertheless, many people are unaware that not all forests are alike, and that managing our forests to reduce climate change is far more complicated than just planting more trees.

It turns out that the age and composition of forests have a significant impact on their ability to prevent wildfires and store carbon. The best for both is old growth forest, but there is very little of it remaining in either the western or eastern United States.

However, a major portion of the forest on public lands is what foresters refer to as “mature” forest, which is nearly as excellent as old growth and is on the verge of becoming old growth. These older woods will help us prevent future forest fires and will do the most to minimize climate change, and so we must conserve them at all costs.

In a mature stage, the dark understory of the forest keeps things damp, and much of the debris consists of bigger logs that are not easily lit, thus the “dead stuff” is less likely to serve as fire fuel.

This mature forest contains fewer but larger trees, and its ecology grows more complicated, resulting in an increase in the number of plant and animal species. Because of the size and moisture content of the dead wood, forests become more resistant to flames as they age.

Old-growth forests can represent a wide diversity of structures, composition, and dynamics at the local and circumboreal scales. a Balsam fir (Abies balsamifera) forest in eastern Canada that was severely disturbed 40 years ago by a spruce budworm outbreak. This disturbance produced a stand having a relatively simple diameter structure despite a multicohort age structure and a large deadwood volume; b a large white spruce (Picea glauca) surrounded by smaller balsam fir trees in eastern Canada; c a mixed Siberian larch (Larix sibirica), Scots pine (Pinus sylvestris), and Norway spruce (Picea abies) forest in western Russia; d a primeval northern boreal Scots pine forest driven by periodic surface fires; e a Norway spruce forest in eastern Russia recently disturbed by moderate-severity windthrows, creating a diversity of soil microhabitats; f a dense black spruce (Picea mariana)–balsam fir forest in eastern Canada driven by low-severity disturbances; g a paludified black spruce forest in eastern Canada. Trees are generally small, but their age can often exceed 250 years; h buried deadwood pieces at various stages of decay in a black spruce forest in eastern Canada. A very large portion of deadwood in boreal old-growth forests can be hidden in the soil organic layer; i a large Siberian pine (Pinus sibirica) log in eastern Russia. These stems may require more than 1,000 years to decompose, sequestering carbon and nutrients and providing a habitat for many wood-inhabiting species; j a white spruce with a large wound exposing sapwood in eastern Canada. The disturbance dynamics and the presence of trees from all ages and sizes in old-growth forests favor the development of tree-related microhabitats, necessary for many species. Photo credits a b f–h j Maxence Martin, c–e i Ekaterina Shorohova

Woods may absorb carbon from the atmosphere again after a fire, but it takes a long time – many decades. Meanwhile, such a cycle would almost likely result in more wildfires, which may be exacerbated by more deforestation and poor forest management, so instead of planting new trees as a substitute for chopping down old ones, we should aim to avoid the cutting down of old mature trees. This way we will both mitigate and adapt to climate change.

Reference- National Geographic, Wikipedia, Duke University Nicholas School of the Environment, Reuters, University of Washington