Invading Acacia Threatens Unique Northern Kenya Ecosystem

Tom Lalampaa, CEO of the Northern Rangelands Trust, remembers, “When I was a child, the grasslands here were in very good condition. But there were fewer people then, and fewer livestock than there are now.” The bare earth, scarred by deep gullies in many of the trust’s member conservancies, serves as a somber reminder of what were once vibrant landscapes.

The extensive arid and semi-arid lands of northern Kenya are home to a variety of communities. Livelihoods are predominantly livestock based, with limited small-scale crop production. The productivity of the rangelands has been in decline, mainly due to poor management practices. Lalampaa adds that shifts in settlement and grazing patterns, rising human populations, and increasing climate variability have had a devastating impact on the rangelands.

All too often, one sees herds of undernourished animals moving over tracts of bare red earth, searching for scarce fodder. This is an unhappy state of affairs not just for the livestock and their owners, but for wild animals too.

Priscilla Kushi (kneeling), Northern Rangelands Trust,  surrounded by the invasive plant, Acacia reficiens.

Priscilla Kushi, a rangelands specialist at the trust, says the heart of the problem is overgrazing. This problem, however, is compounded by the spread of Acacia reficiens, an invasive plant species indigenous to South Africa that is wreaking havoc on pastoralists in parts of Samburu, Isiolo and Marsabit counties in Kenya. Acacia spreads quickly in areas where overgrazing has caused highly degraded soils and has no forage value to either livestock or wildlife. To make matters worse, Acacia releases a chemical that displaces other species and further degrades the rangeland by suppressing the growth of grasses—a preferred livestock forage.

As more forests are cleared, rangelands that cattle depend on are becoming increasingly degraded, allowing for acacia and other invasive plant species – such as the prickly pear cactus - to gain a toehold. Heavy rains hasten this process by opening up deep gullies in the landscape, providing an ideal environment for this invasive shrub to take over.

The Northern Rangelands Trust - a non-governmental organization established in 2004 in northern Kenya by a coalition of local leaders, politicians, and conservationists - reached out to SERVIR-Eastern and Southern Africa (E&SA) at the Regional Centre for Mapping of Resources for Development (RCMRD) for assistance in the mapping of acacia and other invasive plant species. Members of the trust worried that if left uncontrolled, the spread of invasive species would continue to hurt the economies of these arid and semi-arid areas where over 70 percent of Kenya’s livestock and wildlife are found.

To address this challenge, SERVIR-E&SA developed an Invasive Species Mapper to plot areas infested by acacia, providing a valuable tool for local communities to develop strategies to slow the spread of this unwanted plant. Using a smartphone, staff at the trust can now download an app to collect data that charts the current distribution of acacia and other invasive species, providing precise GIS coordinates. These data are then forwarded to RCMRD and detailed satellite maps are produced with the coordinates, highlighting the current range of acacia.

Screenshot of Invasive Species Tracker

Edward Ouko, Ecosystems and Landscapes thematic lead at RCMRD/SERVIR-E&SA, developed the invasive species mobile application because Kenya lacked detailed satellite maps to manage invasive species. “This led to the design and development of an application. Data on invasive species are collected using this tool and shared with partners. We then disseminate and train the stakeholders on the correct use of this app.”

Edward Ouko, RCMRD, with Priscilla Kushi, Northern Rangelands Trust,  using the Invasive Species Tracker in the field to mark  a patch of Acacia reficiens.

Ouko explains that once areas infested with acacia are identified through this application, an accurate map of degraded and healthy lands can be developed. This information empowers pastoralists to make better-informed local decisions of where to graze their animals, directing their herds to healthy rangeland rather than degraded areas. “Data is collected using the Invasive Species App and it is hosted on an RCMRD database; then the current range of invasive species is modeled, and finally an estimation of the historical range covered by invasive species in the northern Kenya rangelands in recent decades is made.” He adds that the information can improve plans for forage space available to both livestock and wildlife, helping to minimize conflicts.

Once completed, maps pinpointing the location of acacia are shared with pastoralists, public institutions, and non-governmental organizations (such as the Northern Range Land Trust) that are supporting affected communities in developing strategies to eradicate these invasive plants, restoring the rangelands. These maps are also open-access and can be retrieved by the public at no cost.

Through the Invasive Species Tracker, SERVIR-E&SA and RCMRD will continue to support local communities in northern Kenya with innovative solutions critical to addressing this development challenge.

Uploaded data can be viewed and downloaded through: http://mobiledata.rcmrd.org/invspec

Written by Dorah Nesoba of SERVIR-E&SA/RCMRD.