By Story and photos by Cathy Watson
Thirty years ago, Kampala was a town of half a million people on seven green hills. Today it has 1.5 million and is far less green. It is also, partly as a consequence, 1.5°C hotter and much dustier than it used to be. Some areas have no trees at all.
The steady loss of trees has not gone unnoticed, however. In 2016, the body that administers Kampala launched its Climate Change Action Plan, and trees suddenly began to climb up the agenda.
The plan identified “proper management of urban natural assets” and the planting of 500,000 trees as ways for Kampala to become a lower carbon and more climate-resilient city. One of its desired impacts was “increased green spaces and trees in households for improved health and income”.
For all who had watched trees being removed and green spaces being encroached, it was a dream come true. But the hard work fell to the small Landscaping Unit of the Kampala Capital City Authority (KCCA).
Needing more resources, the Unit sought funds from the European Union Covenant of Mayors for Sub-Saharan Africa – and succeeded. This was the gamechanger. It was able to take on ten foresters and natural resource experts and conduct a tree audit.
Four years later the team probably knows more about its city trees than any other town hall in Africa. It is exciting to meet them.
“We did the audit because we wanted to understand our tree resource, to lay the backbone for an urban forestry management plan,” explains KCCA landscaping officer Franco Kiwanuka. “It’s not good to manage a resource that you don’t know or have data on.”
“We currently have 13 trees per acre and would love to have 50. That’s a long-term goal,” says urban forester Daniel Padde. “We want to ensure that every tiny place, we plant it. If it means grass, we grass it. We want to reach 26 per cent tree cover in less than 5 years.”
The audit was arduous. The team used aerial and satellite images and Open Foris Collect, Arc GIS and Open Street Map software technology. It logged 23 parameters, including tree species, location, GPS coordinates, height, diameter at breast height, crown diameter, and health condition.
Sometimes it met with disbelief. “People would ask – why are you counting the trees?” recalls Padde. But this opened useful conversations. “We would explain the value of trees and how they make cities more livable.”
One way of explaining was to talk about pollution. Kampala’s vehicles are mostly old. Most households cook on wood or charcoal. Rubbish is burnt. The result is air with a particulate matter on average two times greater than the recommended amount and often reaching into the unhealthy and very unhealthy zones. In 2019, Kampala’s air was the third most polluted in Sub-Saharan Africa after Accra and Kinshasa.
“The audit acted as a sensitization tool,” said Kiwanuka, “We would tell communities that if you have many trees in an area, pollution levels go down. Green areas have less particulate matter per million. It’s not surprising. The particles settle on the leaves and trees. There is less diffusion.”
Hearing about that and other benefits, local leaders were helpful. “It was because of them that the tree audit was a success,” according to Padde. And communities asked for trees, which was exactly the outcome the team was looking for.
“That’s how we want to work – with the community owning it, driving it from the front and us leading from behind,” said Kiwanuka. “We want monthly tree planting. We will give them seedlings as long as they plant them. Our target is 10,000 a year”
The audit surveyed Kololo, Makerere, Mulago and Nakasero — four out of Kampala’s 25 precincts – and generated deeply interesting findings.
Some were expected. Affluent Kololo was the greenest precinct: Sixty per cent of the average plot was not built upon. Some findings were encouraging: The four precincts had a total of 328 species of tree – a high tree diversity.
But the tree canopy was found to be 13 per cent — lower than desirable. For context, the land area covered in trees in London is 21 per cent. It is 24 per cent in New York. Both cities want it to increase.
Further, there was a startling preponderance of exotic trees. Out of the 328 species, 80 per cent were exotic. Out of the 53,268 trees surveyed, 37,868 or 71 per cent were exotic.
Other East African capitals are similar.
In Addis Ababa in 2012, Eyob Shikur and colleagues found that 87 per cent of seedlings planted along the main road were exotic and that the “density of exotic trees in the three public parks was higher than indigenous trees by about 70 per cent”. In Kigali in 2013, Jean Leonard Seburanga and fellow researchers found that green space was “largely dominated by alien species (75 per cent).”
But the fact that this is a widespread phenomenon is not reassuring. “We are concerned about biodiversity and urban pollinators,” said Padde. “People only know the marabout storks that nest in Kampala, but there are many birds in Kampala that need different trees. And bats come to feed on the Ficus sycomorus. People plant exotic palms, but we are discouraging them. There are very many other trees.”
The most common exotic species in the four precincts in descending order were Persea americana (avocado), Mangifera indica (mango), Artocarpus heterophyllus (jackfruit), Eucalyptus grandis, Ficus benjamina (an Asian fig tree), Tectona grandis (teak), Psidium guajava (guava), Grevillea robusta, Tabebuia rosea, and Senna siamea.
The most common indigenous species in descending order were Markhamia lutea (Lusambya), Sapium ellipticum (Musasa), Khaya anthotheca (African mahogany), Elaesis guineensis (Oil palm), Antiaris toxicara (Kirundu), three fig species (Ficus exasperata, F. natalensis – the bark cloth tree, and F.ovata), Vernonia anygdalina (Mululuza), Maesopsis eminii (Musizi), and Milicia excelsa (Mvule).
The popularity of exotic fruits like avocado is understandable. But the landscaping unit believes that exotic timber trees like Eucalyptus, which the audit found to be eight times more common than the iconic Mvule, should be less than welcome.
“As a Unit and a city, we would like to reduce such trees. They are allelopathic, suppressing other plants,” said Rhona Masudo, forester for Makindye division.
KCCA spokeswoman Gloria Naava says KCCA intends to plant more indigenous trees “for their aesthetic, food and medicinal values and their urban cooling and air quality improvement effects.”
Besides those listed above, in the city’s tree nursery and nearing readiness for planting are the medicinal tree Prunus africana, Canarium schweinfurthii (Muwafu), a towering indigenous fruit tree), and Entandrophragma angolense, an even larger – up to 50 metres tall – deciduous forest tree.
“Options for planting are road reserves, in public green spaces and around public facilities such as schools, hospitals and markets,” says Naava. And, because most Kampala trees are on private land, private gardens are a priority too.
Naava also points out that to sensitize the public on urban forestry, the city Authority has developed the country’s first online tree and palm directory. This enables the public to identify trees and learn more about their benefits and how to propagate them. It also helps the Landscaping Unit to track each tree.
“We want to record everything so that we know when pollarding was last done [and] when something else was done,” said Padde, the forester.
As if this were not enough, the team has been prodigious in producing foundational documents for Kampala’s tree future. The city now has a draft Urban Forestry Management Plan and a draft Kampala Urban Green Infrastructure Ordinance.
The ordinance proposes tax breaks to incentivize land and plot owners to keep and plant trees. Other recommendations are that every plot must be at least 20 per cent green, and frontages of buildings have to have trees.
Green corridors and channels will also be a must, and KCCA has already boldly turned bustling Luwum Street into a largely pedestrianized thoroughfare with pink flowering Tabebuia. Not all the traders are happy, however, saying that pedestrianization rather than COVID-19 depressed sales in 2020. “We want money, not clean air,” said one.
But David Ouma, the lead researcher for a study entitled “Availability and Quality of Parks in Kampala”, said that customers like him will go there more frequently when they learn that the street is cooler and the shopping experience more serene.
The Landscaping Unit seeks to attach a value to Kampala trees and believes 1.3 million Ugandan shillings per tree (about $360) is fair. “By putting a price tag, we hope to deter people from cutting a tree without permission from KCCA,” said Padde.
The city trees are a vital carbon sink. The carbon stock of the surveyed trees is estimated to be 0.0012 mtCO2 eq. They are estimated to be able to sequester a further 1,172 mtCO2. a year.
Standing in the tree nursery at Wankoko, which feeds their planting, Padde and Kiwanuka express their dreams.
“Our Unit is planning for 20 years. We want to enhance maintain, conserve and protect the urban tree canopy,” says Padde. “If we manage to do this in Kampala, we can do it in other cities.”
“I believe the public will be grateful in the future,” said Kiwanuka. “They may not understand it now. But imagine if we left the public to do whatever they want with trees. We’d have no trees. We’d be in a pit we can’t get out of.”
To see the tree and palm directory, go to https://www.kcca.go.ug/tree-directory
Cathy Watson is Chief of Partnerships at the Center for International Forestry Research CIFOR-World Agroforestry ICRAF. She tweets at @CWatsonICRAF