February 16, 2017. Earth / A Geography of Hope
Cyril F. Kormos, Russell A. Mittermeier, Tilman Jaeger, Brendan Mackey
Primary forests provide a wide range of benefits to people through natural goods and services that are highly valuable from local to global levels. These “ecosystem services” include the provision of food, fresh water, medicine, fuel, and building material; regulation of hydrological and carbon cycles; recreational, spiritual, and educational values, and soil formation, nutrient cycling, and primary production.
Primary forests have been dubbed the planet’s “lungs.” Through the process of photosynthesis, plants absorb (sequester) atmospheric carbon dioxide (CO2) through their leaves and store the carbon in the woody biomass of long-lived trees and the soil, at the same time releasing oxygen back into the atmosphere. When they are logged, most of the biomass carbon is ultimately released back into the atmosphere as CO2, which is a global-warming greenhouse gas. Primary forests store 30 to 70 percent more carbon than logged and degraded forests. Therefore, protecting primary forests plays a major role in mitigating climate change.
Forests and water are intrinsically linked. Trees need a lot of water to support their immense growth as photosynthesis and biomass production is a water-demanding process, which means that forests are found in areas with higher rainfall. Forests also store huge volumes of water and shape and manage watersheds and the rivers and lakes that form a part of them.
Adaptation and Local Climate
In addition to helping regulate local climate through evapotranspiration and cloud formation, primary forests also moderate wind speeds and reflect and absorb sunlight by the forest canopy, thus reducing surface evaporation and increasing humidity levels on the forest floor, and also buffering the understory from extremes of temperature and dryness. In terms of adaptation, this helps reduce the spread of wildfires and stabilizes various ecological processes.
Nature and Culture Linkages
The importance of forests for human well-being has long been recognized across past and contemporary societies and cultures. In forested countries, Indigenous Peoples form an integral part of the forest and can derive their entire livelihoods from it
The latest science clearly demonstrates that biodiversity is not just a nice-to-have “co-benefit” of conserving primary forests, but a fundamental functional necessity for their long-term persistence and the delivery of critical ecosystem services. The critical role primary forests play in planetary life-support systems is clear, especially in maintaining the global carbon cycle and in meeting international biodiversity and sustainable development goals.
This is an excerpt from the CEMEX Nature Series Book “A Geography of Hope: Saving the Last Primary Forests” (2016)