The Hidden Carbon Potential of Namibia’s Dry Woodlands

Carbon sequestration by vegetation can be described as how plants capture and store carbon dioxide (CO2) from the air.

This happens through photosynthesis, where plants absorb CO2 and convert it into organic matter such as wood, leaves, roots, and soil carbon. 

WHY IT MATTERS

As the world struggles with climate change, forests and woodlands are often seen as natural solutions to reduce the atmosphere’s most common greenhouse gas, CO2, and slow global warming.
Large trees store carbon for decades or even centuries, and small trees and shrubs store carbon for shorter periods but regenerate quickly, maintaining an active carbon cycle.

Further, not all forests store carbon the same way.

While wet tropical rainforests primarily store carbon in massive trees, Namibia’s dry woodlands function differently.

Here, small trees and shrubs play a much bigger role than previously thought.

Ignoring them could lead to major miscalculations in global carbon budgets.

A recent study I was involved in shows that small trees and shrubs contribute nearly one-third of total woody biomass in Namibia’s northern and north-eastern woodlands.

This finding has major implications for conservation, carbon credits and climate policies.

This means that small trees and shrubs play a key role in absorbing and cycling carbon in dry forests, where large trees grow slowly.

Excluding them from carbon assessments significantly underestimates these ecosystems’ total carbon storage capacity.

WHAT WE DISCOVERED: SMALL TREES MATTER

Namibia’s dry woodlands, found among others in Kavango, Zambezi and Otjozondjupa where our study sites were, store more carbon than we think.

Our research found that small trees and shrubs contribute up to 30% of total biomass in dry woodlands. Yet, traditional carbon assessments that focus only on large trees miss a crucial part of the ecosystem.

Another key discovery from our study is how large trees influence the growth of small trees and shrubs. We found that:

• When the overstorey is open, shrubs thrive because they receive more sunlight.
• When the canopy is dense, large trees dominate, shading out smaller plants and reducing their contribution to biomass.

This means woodland structure, not just rainfall, plays a huge role in shaping the ecosystem.

In wet regions, large trees grow bigger, reducing the contribution of understorey plants to total biomass.

In contrast, in drier regions, where tree cover is more open, shrubs and small trees play a much larger role in carbon storage.

ACCURATE CARBON MEASUREMENT

Most global carbon assessments exclude trees smaller than 5cm or 10 cm in diameter, a standard largely based on studies from wet forests. This oversight has serious consequences, some of which include:

• Underestimated total carbon storage in dry woodlands.
• Limited funding opportunities in carbon credit programmes.
• Inadequate conservation policies that overlook smaller vegetation.
  Improving how we measure woodland carbon will help us to manage better and protect these ecosystems.

CLIMATE POLICIES AND NAMIBIA

The findings of our study are directly relevant to several global environmental agreements and climate policies, including the Carbon Credit Markets, the Intergovernmental Panel on Climate Change and the Reducing Emissions from Deforestation and Forest Degradation programme.

These initiatives provide guidelines for carbon assessments, pay for carbon offsets and provide funding for forest conservation based on carbon sequestration.

But if small trees are ignored, Namibia’s dry woodlands will not receive the full financial benefits they deserve.

Namibia’s woodlands are a key part of the landscape but they are often undervalued when it comes to climate action.

Our study suggests three major changes in managing and assessing these ecosystems. These suggestions include the following:

• Include small trees and shrubs in carbon assessments. Ignoring them leads to significant underestimations.
• Recognise the full carbon storage potential of dry woodlands. Conservation and climate change mitigation should not focus only on rainforests.
• Develop policies that consider the entire woodland structure, not just big trees. Protecting the full ecosystem, including understorey vegetation, maximises carbon storage.

A CALL TO ACTION

As climate change threatens forests worldwide, every piece of stored carbon matters.

Namibia’s dry woodlands are not empty landscapes; they are hidden carbon reserves.

Scientists, policymakers, and conservationists must rethink how they measure and value carbon in these ecosystems. Including understorey plants in carbon accounting could unlock new opportunities for Namibia in global climate policies and carbon markets.

It’s time to change how we see Namibia’s forests.

We can improve conservation strategies, gain better access to international funding, and take stronger climate action for future generations by recognising the true carbon potential of dry woodlands.

• The study on carbon sequestration was led by Hermane Diesse, a doctoral student from the Namibia University of Science and Technology, in collaboration with a multi-national team from Namibia, the Democratic republic of Congo and the United Kingdom.