Forest restoration must balance the needs of wood production and environmental protection.

For the greatest climate and environmental benefits, forest restoration programs should prioritize restoration of native forests. However, these benefits come at a cost to wood production compared to tree plantations.

A major new study in the journal Nature today revealed that diverse native forests store more carbon above ground, provide more water to nearby stream, and better support biodiversity than simple tree plantings. SciencePlantations have a distinct advantage in wood production, according to research.

The study examined the relative benefits of restoring natural forests to establishing simple tree plantations. It also looked at four key functions of value to humans or ‘ecosystem services’ provided by forests: carbon storage, soil erosion control and water provisioning.

Forest restoration is growing in popularity around the world, partly because it is a way to combat climate change. Deforestation is a major source for carbon emissions and forest restoration could be a ‘nature based climate solution’ to global warming. Forest restoration is often used to provide water for forests and flood control functions. It also serves as a way to prevent soil erosion and make wood products.

“Establishment a tree planting is good for producing wood but not for restoring biodiversity. This is a huge opportunity for conservation,” said Dr. Fangyuan Hua (first author of the paper), a researcher who was previously based at the University of Cambridge’s Department of Zoology. Hua now works for the Institute of Ecology at Peking University in China.

She said, “When a forest restoration program includes wood production, then there is a trade-off between environmental and production outcomes.”

For ecosystem services, forest restoration schemes tend to focus on tree plantations of a few tree species rather than restoration of diverse native forests. This is based on the assumption that tree plantings are equally effective in delivering these services. The authors claim that there is no solid scientific evidence to support this.

The current synthesis was performed by an international cross-disciplinary team of researchers representing seven countries. It is based upon an unprecedentedly large database of nearly 26,000 records compiled from 264 studies that were conducted in 53 different countries.

“This is the first time that different forest restoration methods have been compared in terms of delivering the most important services to forests. Professor Andrew Balmford from the University of Cambridge’s Department of Zoology is the senior author of this paper.

The study showed that all three ecosystem-oriented services aboveground carbon storage, soil control and water provisioning are better delivered by native forests than tree plantations. The most significant loss in soil erosion control is due to plantation-style tree restoration. Water provisioning problems are more severe in drier areas, precisely where water is scarcer.

Hua stated, “When restoration goals concern environmental benefits, even if they are not specifically for biodiversity conservation, we should aim at restoring native forestsand biodiversity will benefit as a cobenefit.”

However, wood production is a difficult trade-off. The limited evidence showed that tree plantations outperform native forest, which was not shown in the limited evidence.

Worldwide, tree plantations typically use fast-growing species, such as pines, or firs. Eucalyptus. These trees tend to grow taller and straighter, and are often encouraged to grow in plantations that are actively managed.

The native forests are a mixture of different tree, shrub and herbaceous species. They are also not managed for growth. This provides a better habitat with a wider range of food and other resources, which can be beneficial for a wide variety of animals and plants. However, it may also mean that wood production may be less efficient.

“The trade-off between environmental and production benefits that a forest can provide has never been discussed much before. “Restoration cannot meet all the goals at once,” stated Professor David Edwards of the University of Sheffield’s School of Biosciences. He is also a senior author of the study.

This finding means that plantations could indirectly provide environmental benefits. Plantations can be used to prevent other forests of higher biodiversity from being cut down for wood products.

Balmford stated that “Plantations must be integrated into an organized land-use plan so that their better performance at producing timber can translate into improved conservation efforts elsewhere.”

The study also showed that many abandoned or old plantations around the world, which are not being used for wood production no longer have a high environmental performance. These plantations are common and can be restored to native forests. This could have significant environmental benefits.

The United Nations has designated 2021-2030 as the UN Decade on Ecosystem Restoration. Along with many other climate-related projects, this encourages the scaling-up restoration efforts on a worldwide scale to breathe life into our degraded ecosystems. This includes the restoration forests on millions of hectares across the globe. These restoration efforts can have enormous environmental and social benefits, but only if they are accompanied by a solid understanding of the consequences for other outcomes.