Afforestation vs Reforestation: What’s the Difference and Why Do They Matter?

As the world has become more climate conscious, the concept of planting trees to fight climate change has become ubiquitous. Organizations from local nonprofits to for profit/for good startups to huge multinational corporations talk about how they are doing tree planting to soak up CO₂ and help the fight against climate change.

But as with everything, the reality is rather complex. Are all efforts to reforest our planet equally beneficial? How are these refores efforts being executed? What is reforestation and how does it differ from afforestation? We’ll answer this and more here.

Afforestation creates new forests

While both reforestation and afforestation plant new trees where there are currently none, afforestation is planting trees where there have not been any for a long period of time. Technically, there could have been a forest that was felled centuries ago, as is the case in the tree-planting efforts in Iceland. In either case, afforestation is the process of turning long-standing non-forested land into a forest.

With a concept as broad as planting trees where none have been historically, there are three main types:

Natural regeneration

This is the process of planting native trees to create what would most resemble a natural forest. Not only does this kind of forest hold the most carbon — anywhere from 300–600 tons per hectare — but it also does the most for promoting biodiversity. However, while this does the most for the environment, it does the least for the organizations planting the trees. This has led to the popularity of the other two kinds of tree planting.

Commercial plantation

This happens when an organization plants trees with the intention of later turning them into products like timber and pulp for paper. While this does help soak up carbon dioxide (CO₂) in the short term, this benefit is mitigated if the wood products created from them end up releasing their CO₂ back into the atmosphere. Such is the case if they are turned into firewood, for example.

Agroforestry

Agroforestry is planting trees for crop production. This is often a financial boon for whomever lives near the new forest. However, it does come at the cost of less carbon capture and not being as beneficial to the biodiversity of the region. Since this is still a managed forest, it does not have the same breadth of plant life to soak up carbon as what is found in a naturally regenerated forest.

Reforestation regrows current forests

Reforestation is the quintessential idea of taking a piece of land and planting new trees to replace the old ones. They are usually being (re)planted because the area has been ravaged by logging, fires, or some other natural or climate change-created problem. Within this realm, there are two main kinds of restored land: urban and rural.

Urban, as the name implies, entails turning unused plots of land in inhabited areas back into forests. There are quite a few good reasons to add forested areas to cities like reducing local CO₂ levels caused by traffic and providing residents shade while beautifying communities. Rural reforestation is going out into the wilderness to replace forests that have recently been cut down or died. Both of these types help to absorb CO₂ from the atmosphere and boost biodiversity.

Planting trees, not a panacea

As hinted at earlier, while many organizations tout their tree planting efforts to battle climate change, not all efforts are created equal and all come with a cost. This is especially true when it comes to commercial plantations. Much more thought and effort can sometimes be put into prioritizing the profitability of the enterprise rather than the climate or ecological impacts.

Instead of planting native trees that would encourage a greater diversity of life, these plantations can tend to plant vast swathes of the same kinds of fast-growing, non-native trees. In fact, a recent study from University College London and the University of Edinburgh found that 45% of national commitments toward reforestation and restoration were put towards “planting vast monocultures of trees as profitable enterprises.”

When the ecological impacts of planting certain trees in certain locations is not properly addressed, it can even have a negative impact on the environment it is ostensibly trying to protect. In China, efforts have long been underway to plant trees leading to the country planting over 60 billion trees since the 1970s. However, not enough research was done into the effects of the trees they selected for the Loess Plateau. The non-native black locust trees planted in the region have had a massive negative impact on the hydrologic cycle of the region.

While the black locust trees capture carbon from the atmosphere, they also use much more water than the grasses native to the region. In fact, the trees use up a whopping 92% of the annual rainfall, leaving only the remaining 8% for everything else. “As a result, not enough water remains to recharge groundwater or flow into rivers and lakes,” said United Nations University researcher Lulu Zhang.

We Must Protect the Forests We Have

Considering the complicated and complex world of planting new trees, it is more important than ever to protect the forests we already have. That’s why efforts like Proyecto Titi are so important. Natural, native forests both absorb the most carbon and encourage the greatest amount of biodiversity. So, keeping the ones we have intact is critical to both our climate and environmental problems. Whether it’s one acre or a thousand, every bit counts and every inch is worth protecting.