Bunia urban trees store carbon, study findsCEFR B1
5 Apr 2026
Adapted from Laura, Global Voices • CC BY 3.0
Photo by Rengan Visweswaran, Unsplash
In October 2025 researchers from the University of Bunia carried out an inventory of urban trees to measure carbon storage in Bunia, northeast D.R. Congo. They sampled 2,311 trees in 21 one-hectare plots across the communes of Mbunya, Nyakasanza and Shari and used non-destructive methods based on diameter, height and wood density to estimate aboveground biomass and carbon stock.
The results show 1,759 tons of aboveground biomass and an estimated 8,795 tons of carbon sequestered, which the study equates to 2,374 tons of CO2 removed from the atmosphere. On average each tree stores about 380 kilograms of carbon (roughly 124 kg of CO2), and an average urban hectare holds 47.6 tons of carbon, a level comparable to some degraded forest areas.
The researchers noted that a few species hold most of the carbon and gave an estimated voluntary market value of about USD 1 to 4 per tree. They conclude that cities could treat trees as climate assets and explore urban carbon-credit pilots while prioritizing high-carbon species and better green-space management.
Difficult words
- inventory — a list or record made after checking items
- biomass — total mass of living plant materialaboveground biomass
- sequester — to store gas or carbon safely awaysequestered
- hectare — area unit equal to 10,000 square metersone-hectare
- density — how much mass is in a given volumewood density
- carbon-credit — a permit to trade or pay for emissions
- species — a group of similar living organisms
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Do you think your city should treat trees as climate assets? Why or why not?
- Which tree species should city managers prioritize for planting to increase carbon storage? Explain your choice.
- What are possible benefits and challenges of creating urban carbon-credit pilots in your city?
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