The Pros and Cons of Planting Trees

Managing forests can be challenging. On the one hand, people need wood products for construction and other household uses. On the other hand, mass deforestation is regarded as a major environmental threat. Is there any way to reconcile the two?

Addressing global deforestation effectively is further complicated because the two main data sources for tree loss often disagree about basic information – such as how fast is the planet losing its leafy canopies:

The Global Forest Watch (GFW) compiles data from satellite images by the World Resources Institute, a Washington think tank. The decline in tree cover in 2017 was pegged at 72.6 million acres, nearly a 50 percent increase from 2015. That number was supported by on-the-ground observations, particularly in Southeast Asia where forested areas continue to be converted to growing oil palm.

But the Global Forest Resources Assessment (FRA), which is compiled from government inventories by the UN Food and Agriculture Organization based in Rome, Italy, is much less alarming. The estimated annual net loss, after factoring in forest regrowth, was a much lower 8.2 million acres. These experts concluded that deforestation rates have declined over the past 10 years by more than 50 percent.

The two forestry data sources have drawbacks. The FRA relies on governments admitting to and reporting forest loss, something they don’t always like to do for political reasons. Of equal importance, the GFW focuses only on loss and fails to account for forest regrowth (gain).

Foresters say that to get a healthy 20-year-old tree, about twelve trees of various species need to be planted relatively close together so that they all grow straight upward. Young trees occupy less space than larger, older trees, so they can be spaced closer together. Progressive cutting over 10-20 years leaves a single tree that can grow for over a hundred years.

Mixed-species forests are less susceptible to pests and disease than mono-culture forests popularized by the U.S. Forest Service in the last century. “Pines in lines” became the industry standard as native mixed-species forests of Western conifers were replaced by varieties suitable for commercial lumber farming.

Mono-culture forests are also at high risk of devastating wildfires. In 2017, Agriculture Secretary Sonny Perdue <https://pulitzercenter.org/reporting/tree-planting-programs-can-do-more-harm-good> said</a>:

“Forest Service spending on fire suppression has gone from 15 percent of the budget to 55 percent. That means we have to keep borrowing from funds that are intended for forest management.”

At first glance, going outside and planting a tree seems like a no-brainer benefit for the planet and all its inhabitants. We’re told one tree can absorb 10 pounds of polluted air each year and release 260 pounds of oxygen.

Consider all these advantages tall, leafy plants offer:

  • Trees recycle toxic carbon dioxide (CO2) into oxygen (necessary for humans)
  • Trees absorb odors and toxins such as nitrogen oxides, ammonia, sulfur dioxide, and ozone
  • Tree roots prevent soil erosion and rainwater runoff
  • Shade from trees lower energy costs and increase comfort during summer heat and winter winds
  • Trees increase property value and curb appeal
  • Trees provide habitat for other living creatures
  • Trees are beautiful and promote calmness and peace of mind
  • Trees will outlast you and leave a wonderful gift as your legacy

The United Nations’ Climate Summit decided that more than 11 billion trees will be planted to sequester (remove) CO2 from the atmosphere. According to this group, ending deforestation can play a key part in capping global warming at 1.5 degrees Celsius.

UN officials representing environment, development, and agriculture <https://e360.yale.edu/features/conflicting-data-how-fast-is-the-worlds-losing-its-

forests> stated</a> that “forests are a major, requisite front of action in the global fight against catastrophic climate change – thanks to their unparalleled capacity to absorb and store carbon. Stopping deforestation and restoring damaged forests could provide up to 30 percent of the climate solution.”

But some experts caution that the wrong reforestation policies can be worse than no reforestation at all.

For example, in the 1980s, the Canadian government experimented with transforming useless bogs to timber-producing forests. Large areas of the Alberta swamps were drained and planted with black spruce, that was carefully spaced for maximum growth.

The new spruce trees sucked the groundwater out of the swamps and produced unusually wide canopies, killing the peat moss. Nature abhors a vacuum and a drier variety of moss filled the void, providing a natural source of kindling instead of fire-retardant peat. As the land dried, the trees stored an enormous amount of fuel.

The growing spruce trees bound carbon from the atmosphere. When the Fort McMurray fires nearly wiped out the oil town in April 2016, destroying 2,400 homes, all the carbon stored in the burnt black spruce trees was released back into the atmosphere.

Ironically, growing trees in Alberta had inadvertently turned a carbon sink (the swamp) into a carbon emitter (the tinder-dry forest) in what proved to be the costliest natural disaster in Canadian history.

Other well-intentioned tree planting initiatives have not worked out as planned. The ecology of our planet is much more complex than many realize. So be wise: think twice and plant once.

Leave a Reply

Your email address will not be published. Required fields are marked *

Copyright Rational Energy LLC 2020, all rights reserved