Human-driven degradation impacts on mangroves in southern Sierra Leone

A newly published research article by Huber et al. (2023) in Trees, Forests and People with main contributions of Lea Christin Huber and Aida Cuni-Sanchez, both associated with the Tropical Forest Arena, draws attention to one specific type of tropical forest: mangroves.

Mangroves are salt-tolerant forest ecosystems growing in the intertidal zone in tropical and subtropical regions. They are one of the most carbon-rich ecosystems per unit area, particularly due to high amounts of carbon stored in their soils. Moreover, they protect coasts from erosion, tides and tropical cyclones, serve as habitats and provide important ecosystem services to local communities.

Despite their importance, mangroves diminish 3–5 times faster than other forest ecosystems, mostly due to anthropogenic causes. Restoration of mangroves is difficult and viable pathways for restoring, preserving and managing mangroves affected by human-driven degradation, depend on the exact context and a comprehensive understanding of mangrove ecology.

This is where the article by Huber et al. (2023) comes in. Their study focused on oceanic, riverine, and interior mangroves in the Sherbro river estuary in Sierra Leone and looked at the effect of human-driven degradation on mangrove forests structure, different carbon pools, tree species composition and population structures of dominant tree species.

Degradation had a significant effect on forest structure with declining basal area, fewer large trees, and higher stem density of small trees, with increasing degradation level. Notably, above-ground carbon of pristine mangroves was higher than in many other mangrove forests in Africa. All carbon pools decreased with increasing degradation, limiting the potential for climate change mitigation. Results also showed that heavy degradation resulted in a change in the dominating species from Rhizophora racemosa to Rhizophora mangle.

Overall, the study demonstrated the importance of conservation of remaining pristine mangroves in the Sherbro river estuary and laid the basis for developing viable approaches both for restoration and sustainable management of the degraded parts.

If you are curious to read the full article, you can find it here: https://www.sciencedirect.com/science/article/pii/S2666719323000778

Huber, L. C., Sainge, M. N., Feka, Z. N., Kamara, R. A., Kamara, A., Sullivan, M., & Cuni-Sanchez, A. (2023). Human-driven degradation impacts on mangroves in southern Sierra Leone. Trees, Forests and People (Online), 14, 100445. https://doi.org/10.1016/j.tfp.2023.100445