The theme for World Environment Day 2024 celebrated on 05 June was land restoration, desertification and drought resilience.
By Rita Nyaga
Several types of invasive weeds have been introduced to Africa. The ipomoea carnea, originally from South America was introduced to the rest of the world as a hedge plant. The beauty of it’s pink and white flowers, plus it’s ever green nature make it very attractive. In Kenya’s Kajiado County, the plant has spread vastly, impeding pasture growth, yet it cannot be consumed by Livestock.
Quinto Juma, a geo spatial engineer says that; “Geospatial modelling as science can be used to better understand the extents and extremes of the invasive weeds and this can inform policies on strategic and targeted management of the weeds’’.
He explained that pastoralist communities say that when animals eat this plant, they choke on it and die. They learnt very late that the only solution is to uproot the plant. The challenge presented by uprooting is that seeds have matured and already propagated. They are blown away by wind or carried to different locations by water or animal action, thus continuing to grow.
Another weed with similar effect is prosopis juliflora known in Kenya as Mathenge. Professor Sosten Chiotha, a director at Leadership for Environment and Development (LEAD) in Malawi says that mathenge was introduced to protect seedlings and crops against Livestock. The Conditions for it’s growth seem favourable in Africa and it has grown and multiplied. In Asia, it is also a problem in India.
Through LEAD from Malawi, studies on Mathenge have been carried out in partnership with Masinde Muliro University in Kenya and the University of Ghana. Prof. Chiotha says deforestation is very serious problem in Malawi because majority of the population uses biomass energy, especially wood and charcoal “Thus, some of the extreme climate impacts we are witnessing are actually a result of environmental degradation, much as we choose to blame climate change”.
The weed is also displacing biodiversity and affecting not just plants but specific species of insects and birds. In Kenya, Livestock rearing, and production is common, yet Mathenge has spread into rangelands where animals graze. Veterinarians say it affects the teeth of the livestock and interferes with their feeding habits.
Positive outcomes
In retrospect, Mathenge can be used to produce energy after uprooting. “In Malawi, it’s used for cooking, making briquets and bricks, while in Kenya, l witnessed it being used as shade in arid and semiarid areas like Isiolo. We need to trade off between the benefits it gives or whether it should be uprooted to protect biodiversity”, says Professor Chiotha.
Recent interventions and advancement in cooking technologies that reduce the impact of environmental degradation are music to the ears of environmentalists. Petronilla Adhiambo, a climate scientist says that; “Energy poverty, has a direct link to health. Burning biomass exposes people to pollutants. Eye cataracts caused by smoke and cardiovascular disease due to inhalation, especially among women and children in enclosed kitchens, are a consequence of reliance on biomass fuel”.
During the rainy season, wet wood produces more smoke. Over exploitation of biomass also leads to lack of fuel and people resort to burning papers, clothes or plastic cans to cook. Sometimes, they eat semi raw food. There is a need for governments to incentivize clean cooking by encouraging innovations that are climate resilient.
The hyacinth weed that grows in Kenya’s Lake Victoria was introduced to Africa and has also interfered with water systems, rivers and lakes”. ‘Being that it is already here, studies are ongoing to see if it can be turned into fertiliser’, says Prof. Chiotha. People living around Lake Victoria have been harvesting and drying the weed, and making baskets, mats and furniture, turning themselves into entrepreneurs.
As we celebrate World Environment Day, , let us heed to the call for protection and revival of eco systems all around the world.
Lessons learnt
These weeds were introduced as solutions, but the consequences were unintended.
‘Whenever we recommend solutions, we must do a thorough assessment of potential unintended consequences”, says Prof. Chiotha.
The United Nations says that up to 40 per cent of the world’s land is already degraded directly affecting half of humanity, and an estimated 3.2 billion people worldwide are negatively impacted by desertification. By 2025, more that three-quarter of the world’s population is expected to be affected by droughts.
The time to act on land restoration, desertification and drought resilience is now!
