- A group of international and local scientists has warned of the threat to a key piece of one of Africa’s most threatened habitats: the Afromontane forests that occur in the highlands of western Angola.
- The scientists recently discovered up to 10 new species living in the patches of evergreen forest in the Namba Mountains.
- But pressure from growing human settlements nearby, mainly uncontrolled fires in the grasslands that surround the forests, threatens to overwhelm this unique ecosystem.
- Scientists are calling for the government and international agencies to establish a protected area to preserve this biodiverse hotspot.
Afromontane forests occur at high altitudes across Africa. They’re thought to be relics of former glacial periods in Africa. Studying genetic data from birds living in these moist temperate forests, scientists have reconstructed the history of this habitat.
A prime example are the forests on Angola’s Namba Mountains, which are a link or stepping stone between similar Afromontane habitats in Zambia, Malawi and Tanzania, and others farther west, in Cameroon, according to Martim Melo, a biodiversity researcher at the University of Porto in Portugal.
In Angola, these forests are naturally defended against fire by belts of vegetation that don’t easily burn, and which typically offer protection to their moist, species-rich interiors. But excessive, uncontrolled burning by farmers around the forests is undermining the ability of that protective belt to recover, and fires are increasingly entering the forests themselves.
If such uncontrolled burning is allowed to persist, the Namba Mountains’ forests could be lost or highly degraded within the next five to 10 years. With them will go the myriad species that live in them, including nearly 90 species of forest bird, some of them unique to Angola.
Melo and other scientists are calling for swift action by the Angolan government and conservation charities to protect Namba’s forests. Now back in Portugal, Melo spoke to Mongabay about the Namba Mountain Forests. The following interview has been lightly edited for length and clarity.
Mongabay: So, are there forest bird species living in the Namba Mountains that are very similar to the ones that are in the other relic forests in East, Central and Southern Africa?
Martim Melo: Yes. For the birds, for example, you’ll find them in Angola in these tiny patches, and then if you go to the Democratic Republic of Congo, or to Zambia, or to Cameroon, you will find them there. Species like the African hill-babbler [Sylvia abyssinica], the orange ground-thrush [Geokichla gurneyi], and Bocage’s akalat [Sheppardia bocagei].
The first forests I worked on in Angola were the ones on Mount Moco, which is near the Namba mountain range. We thought Mount Moco’s forests were the best Afromontane forests in Angola, but they only cover 85 hectares [210 acres], and in very tiny patches — 1 hectare, 2 hectares; the best one is around 11 hectares [27 acres]. Then when we went in 2010 to check what was happening in the Namba mountain range, we were really surprised to see the forest covered almost 600 hectares [1,500 acres], was in fairly big patches, and had many of these Afromontane bird species that are shared between forests.
In the Namba Mountains the birds are still common, and the birds that are extinct in Moco are still there in huge numbers in the Namba forests.
Mongabay: When you first visited the Namba Mountains the forests were largely intact. How have things changed since then, between 2010 and your last expedition in May 2022?
Martim Melo: I think the main thing we noticed is that there is more human presence: small family groups installing themselves in the surrounding grasslands. We’ve seen some areas that have been quite damaged by timber use. You’re also seeing fires more frequently, not only eating at the edges of the forest, but actually burning inside the forest.
That is really a huge problem because these forests have evolved to be, in a way, fireproof. When they’re in good condition, there is a community of plants that develops around the forest, which is made up of species that don’t burn, and create this protection. But when human pressure increases, this protective belt goes and then fires can start penetrating. If you have a high frequency of fires every year, you don’t give space for the regeneration of the edges of the forest. The seed bank of those plants is lost.
What we are afraid of is getting to your typical tipping point where the forest is no longer fireproof. They can disappear very quickly if there is no control of the fire frequency and the fires get into the forest. This may also be compounded if there is less precipitation due to climate change.
Mongabay: What is causing the increase in human population in the area?
Martim Melo: Some of it is due to the natural growth of the population there, but there has also been a tendency in Angola for people from the interior to come into the more fertile areas of the escarpment, and of the plateau where these mountains are. Often when people come from another place their connections to the land are not as strong as the ones who were there [before], so it’s easier to do more damage in a sense.
The population of Angola is increasing a lot, so that will be something that we must always keep in mind when we plan any conservation actions, because these areas of highest biodiversity often correspond to those that are also more fertile and useful for human development.
Most of the people are still local, and so if a protected area is created, I think it really must be done together with the community. When you engage with the community in these situations you do see that there is an understanding of the importance of the forest, and a will for the forest to stay there. But it must be brought forward and be discussed with everyone together, because if not, it’s the bitter tragedy of the commons: You know that it’s important to keep the forest but you also need that tree to make the doors and the windows for the house of your daughter who is going to be married, for example.
But if people work together, that [protection of the forest] is easier to manage.
Mongabay: On your last trip you and your colleagues found up to 10 new species, both vertebrates and invertebrates. It was over an 11-day period, which means you found almost one new species per day. Which discovery for you was the highlight of that trip?
Martim Melo: I think one of the highlights must be the new species of dragonfly. It had been photographed before by Rogério Ferreira. He lives in Angola and is an amateur naturalist.
When Klaas-Douwe Dijkstra, the foremost dragonfly expert in Africa [who was part of the expedition] saw it, he didn’t know which genus it belonged to. Now he has identified it. It’s quite spectacular in terms of being so different, and in terms of its aesthetics. I’m sure there are new things still to be discovered. It was an 11-day trip that came up with all of these new candidate species. It’s a whole new world there.
Mongabay: What is your call to action regarding the future protection of these forests?
Martim Melo: Although this habitat is the most threatened in Angola, the Namba Mountains and neighboring Mount Moco were never in the network of Angola’s protected areas. I see Namba as one place that will give a huge return for conservation, with not necessarily a huge investment of funds. That’s because the forest patches are still in quite good condition. The area has the potential to be a national park. It’s spectacular in terms of landscape, and it has many possibilities for five-day hikes and things like that.
So the priority, I’d say, is to create a protected area where the community can be involved, and have the government on board, with private funders like the Rainforest Trust that might be interested. But it needs to be done now. If we wait five to 10 years, maybe the forests will no longer be there.
Banner image: The orange ground-thrush (Geokichla gurneyi). Image © Luke Powell.
Citation:
Powell, L. L., Vaz Pinto, P., Mills, M. S., Baptista, N. L., Costa, K., Dijkstra, K. D. B., … Melo, M. (2023). The last Afromontane forests in Angola are threatened by fires. Nature Ecology & Evolution, 1-2. doi:10.1038/s41559-023-02025-9
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