Key to understanding the discussion around Natural Climate Solutions is understanding the terms commonly-used in scientific studies, policy briefs and other literature. This glossary is compiled from a variety of sources, including government agencies and non-profit organizations, to provide plain-English definitions of these terms. Links to the original sources are provided after each definition. In some cases, terms were edited for clarity.

Climate Smart Forestry

Climate Smart Forestry, also called Improved Forest Management, increases carbon sequestration in working forests through various improved practices. Potential management activities could include reduced-impact logging practices, deferred harvest, enhanced forest regeneration in post-harvest timber stands and other actions. (TNC)


Reforestation is the process of restoring and replanting forest areas that have been depleted, usually through deforestation. It can be used to rectify the effects of deforestation or improve the quality of human life by improving air quality and providing other ecosystem co-benefits. Reforestation can also rebuild natural habitats and ecosystems, and can increase carbon sequestration to mitigate global warming. (Global N4C)


Afforestation is the act of establishing a forest in an area not previously forested, helping to alleviate the pressure on natural forests by acting as an alternative source of woodland. Where reforestation will enhance the number of trees in a forest, afforestation will effectively create a whole new one. (Global N4C)

Avoided Forest Conversion

Avoided Forest Conversion is the practice of avoiding greenhouse gas emissions into the atmosphere by preventing human conversion of forest to non-forest land uses such as agricultural, urban, or industrial lands. (TNC)

Forest Fire Risk Management

Forest Fire Risk Management is the practice of reducing greenhouse gas emissions in fire-prone forests and savannas through management practices such as prescribed burning to reduce the risk of high-intensity wildfire or thinning high-density forests. (TNC)

Forest Pests and Pathogens

Forest Pests and Pathogens refers to insects and diseases present in forests in the United States. Invasive insects and diseases originating from outside the United States, as well as native pests and pathogens, can damage and kill trees, reducing the ability of American forests to capture and store carbon. (TNC)

Assisted Natural Regeneration

Assisted Natural Regeneration is a simple, low-cost restoration method that can effectively enhance the productivity and ecosystem functions of deforested or degraded lands by accelerating, rather than replacing, natural successional processes by removing or reducing barriers to natural regeneration such as soil degradation, competition with weedy species, and recurring disturbances (e.g. fire, grazing and wood harvesting). (FAO)

Natural Forest Regrowth

Natural Forest Regrowth, or Natural Regeneration, is an ecological process in which trees or forests may regrow on unused crop fields and pastures that had replaced native forests. Woodlands can also be restocked by trees that develop from seeds that fall and germinate on site. (Global N4C)

Mass Timber

Mass Timber is a wooden building material that is composed of many wood layers nailed or glued together to create a high-strength product that uses dramatically less energy to create than building materials like steel. When wood is used as a building material, the CO2 trapped during the growth of the tree remains stored throughout the period of use of the wood product, which may be several hundred years.(American Forests)

Reforestation Pipeline

Reforestation Pipeline is a term that refers to activities necessary to support reforestation projects, as well as the capacity necessary to undertake those activities. This includes seed collection and storage, tree nursery production, the development of a workforce to undertake tree planting processes and improvements in pre-and post-planting practices. (TNC)