According to Statistica.com, the value of wood and paper shipments from mills in the United States during 2017 was $282 billion. The industry supported 953,000 jobs with a payroll of $53 billion (https://www.statista.com/statistics/252844/us-industry-shipments-value-of-the-forest-products-industry-2012/). That is the economic value of the forestry industry but forests provide much more than wood and paper to our society.
Ecosystem services are the many and varied benefits that humans freely gain from the natural environment and from properly functioning ecosystems. The Millennium Ecosystem Assessment identified ecosystem services provided by forests as: nutrient cycling (returning nutrients to the environment for reuse), climate regulation, raw materials, erosion control, water treatment, recreation, food production, genetic resources, soil formation, water supply, disturbance regulation, water regulation, biological control, and cultural values (http://www.fao.org/docrep/w7714e/w7714e05.htm). During the year 1997 Robert Constanza attempted to put a value or those ecosystem services (nature. Vol. 387. May 15, 1997). He arrived at a value of $969 per hectare per year. Using the CPI inflation calculator for 1996 – 2018, the current value of Constanza’s estimate is $1588 per hectare per year. The total forested area in the United States during 2012 was 766 million acres or roughly 310 million hectares (https://www.fia.fs.fed.us/library/brochures/docs/2012/ForestFacts_1952-2012_English.pdf). So, by multiplication the value of our forest comes out to be 492 billion dollars per year, a little over 2 1/2 % of the US Gross Domestic Product for 2017 (https://tradingeconomics.com/united-states/gdp). These are not actual dollars, but if the forest was lost we would have to find those dollars to replace those free services.
As impressive as these figures are, they still don’t represent the entire value of our forest land. There is a large and increasing body of literature that shows beneficial effects of exposure to forest ecosystems on our health, social, and cognitive well-being. In her new book ‘The Nature Fix’, Florence Williams delves into these aspects of forest’s value (W.W. Norton & Company. New York). Williams interviewed researchers looking into the value of forests and in many cases was able to participate in the research herself. The data show when people are exposed to forests, heart rate drops, blood pressure goes down, stress is reduced, immunity to disease is increased and mood improves. Researchers, according to Williams, are not yet fully sure what drives this correlation. Scientists are looking into several possibilities including: exposure to the immensely diverse microbiological community of the forest; an aroma-therapy type response to chemicals that trees exude; or possible human evolution in a forest environment and natural relaxation when they return. Nevertheless, the effect is real. In fact, Japan and South Korea have started dedicating forest therapy units in their public forests to take advantage of the benefits. Closer to home, a study by Donovan et al in 2013 (available at: https://www.researchgate.net/publication/234697703 looked at death trends from cardiovascular and lower respiratory disease before and after infestation by the emerald ash borer infested the mid-west. According to Donovan, the loss of ash trees in the infected area resulted in approximately 21,000 extra deaths up to 2007. Those 21,000 deaths definitely had both economic and social value in the infected area.
With respect to the cognitive value of forests, we can look at Florence Williams discussion of Kindergarten. Kindergarten is a German term meaning ‘Garden for the Children’. During the year 1837, Freidrich Fröbel established the first Kindergarten. Fröbel’s idea was that the children would learn by absorbing the natural world with all of their senses. Through play in the woods, they would intrinsically learn the laws of geometry, form, physics and design despite themselves. After a few years, The Prussian government shut Fröbel down fearing a generation of free-thinking citizens. Can you imagine the impact a bunch of free-thinking kids could have on an authoritarian government! Nevertheless, the concept has endured. Today, Germany has over a thousand Waldkindergärtens or ‘Forest Kindergartens’. In these schools the students spend most of their day outdoors exploring nature and by extension learning the fundamental laws of science as well as getting along. The benefits are not confined to children. In a 1995 study ( willsull.net/resources/KaplanS1995.pdf) Kaplan found that contact with nature had a restorative effect on adults providing them with improved focused attention and reduced mental fatigue.
Forests do provide a wide variety of benefits including economic return, environmental services as well as providing for health and education. A managed forest need not consider only a single objective. Well managed forests could provide for all of these benefits over time. When looking at the economic value of ecosystem services such as those provided by forest, it is important to consider the values or improved health and cognitive ability.