Baobab trees in Africa? Yes please! Mesquite trees? No thank you. If these trees helped African environment, then that would be fine. The thing is, they’re invasive species that ruins biodiversity and that affects humans (including economy), animals, and other plants.
Just about ten years ago, there were a lot of lush shrubs that grow from the sand and rocks of Sudan. Local people thought he growing vegetation could provide for livestock which had been suffering from continuous droughts.
It turned out that these lush shrubs are a type of mesquite called Prosopis juliflora. When the locals realized that this vegetation is a problem, it was too late. The trees have flourished and they’re still thriving.
Where it all began
Mesquite is a species originally from the Americas. Back in the 1920s, development agencies introduced this tree into the arid parts of South Africa in hope that it would help with fodder production, produce firewood, and provide shade for livestock. It was meant to combat desertification.
And around that time, the result was great. Farmers loved the species’ ability to stop sand and others loved the fact that they could get charcoal from the trees, as people couldn’t cut trees too frequently back then
The purpose of this production was a noble one and other did enjoy the benefits. But who knew that this would lead into an environmental disaster. Mesquite has invaded large parts of the country and it’s now the second most widespread invasive tree after Australian acacias. It’s so bad that The International Union for the Conservation of Nature (IUCN) lists this mesquite as one of the worst invasive species.
These trees grew slowly at first and then it skyrocketed all across Africa. Mesquite is more to an aggressive type so the weaker, more nutritious species can’t compete with it. Livestock that consume its pods get poisoned–more problem. Moreover, these trees absorb water through their roots, making living beings in dryer areas suffer even more and they have a role to the spread of malaria.
Simply put, this species has given negative impact on livestock production, land value, human health, infrastructure, and water supply, which are crucial for people’s livelihoods as well as the economy.
“If you could potentially manage it better, it might be ok, but you can’t. It’s just a pretty nasty plant. It’s destroying habitats. It’s creating monocultures. It’s not going to stay where you’ve planted it,” said Arne Witt, coordinator for invasive species at the Center for Bioscience Agriculture International (CABI). Witt has spent decades tracking the plant’s spread.
The characteristics of mesquite
Mesquite trees got roots which can grow deep down up to 50 meters, they’re also robust shrubs as they can withstand extreme temperatures. This enables them to get water in drylands and thrive where other plants can’t survive. Additionally, they’ve got no natural predators and they’ve invaded lands of Africa in the last few years alone. Much like lionfish in the Atlantic ocean
In some areas, mesquite has made agriculture suffer. Farmers are forced to spend time and money they don’t have to clear those trees out of their fields. But even so, the mesquite has already taken much water that the farmers need for their crops.
A South African study suggests that the country loses up to 700 million cubic meters of groundwater annually, which equals to half of New York City’s annual usage. As countries like Sudan and Kenya have difficulties to use mechanized diggers (because of a fuel crisis and lack of access), this issue gets more frustrating.
Different opinions on the invasive species
There is a widespread deforestation in Kenya, and the government has banned cutting any trees temporarily. The government think of mesquite trees as an alternative to native species which are getting smaller in population. The ministry of environment and forestry suggests that these trees could bring in up to $300 million worth of charcoal.
The ministry also suggests that mesquite trees might give the country timber and biomass energy potential. The plan’s advocates realize that the drawbacks of this plan might be bigger, but they think that this is the best move they’ve got amidst the mesquite invasion and little cash situation.
“Looking at the budgets, the amount of money that will be needed, it may not be possible to get rid of it. So looking at the challenges, we have to utilize it,” said said George Muthike, a senior research scientist at the Kenya Forestry Research Institute.
On the other hand, scientists insist that getting rid of these mesquite trees are more important and thus must be done first. They think that utilizing these trees will encourage their invasion even more.
One thing to eradicate mesquite is releasing the species’ natural enemies such as the evippe moth. However, officials believe that this moth could be another problem in the future, which is understandable because they certainly don’t want any more possible invasive species.
As if things are not bad enough for Africa, mesquite can spread very quickly in today’s conditions. Climate change leads to flood and it could carry its seeds far and wide. Considering mesquite’s robust characteristics, they could possibly adapt to extreme conditions and might spread even farther.
So unfortunately as of now, we don’t have effective solution to get rid of this invasive species. The least we can do is support groups that work to solve this problem such as Working for Water and do our best to reduce the impact of climate change so that mesquite trees won’t spread more.
What do you think African countries government should do? Tell us your thoughts in the comments down below.
Read: 10 Invasive Species (Animals and Plants) That You Might Not Know Yet
Source(s)
https://theconversation.com/how-south-africas-second-most-invasive-tree-can-be-managed-better-62723
https://www.nationalgeographic.com/environment/2019/04/invasive-mesquite-spreads-across-east-north-south-africa/
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