Landscape Restoration: A Pilot Field Course

During J-Term of 2023, Professor Niwaeli Kimambo and three geography students traveled to Kilimanjaro, Tanzania to spend three weeks piloting a field course in landscape restoration. The goal was to experiment with the concept of such a field course, exploring the topics, study sites, coursework, and travel logistics that could be incorporated into a future, full-sized course with up to twenty students. Along the way, we presented what we had learned to potential collaborators at Mweka College of African Wildlife Management and Nelson Mandela University, with the hope that someday the field course will expand to include students from both Middlebury College and Tanzanian colleges.

The first week, we worked with KIVIWAMA, a local community-based organization (CBO), to study tree-based landscape restoration.

The planted area is owned by the Moshi Water Authority and bordered by smallholder agricultural fields. Consequently, a key challenge to this restoration project has been browsing by adjacent livestock herds, including cattle and goats. One area in particular near the edge of the restoration site is noticeably bare and sparsely forested as a result of heavy browsing pressure from goats when the seedlings were first planted. We also noticed a widespread abundance of termite mounds throughout the site, and several areas where the soil had been heavily eroded into deep gullies.

Overall, however, this restoration project appears to have been quite successful. Much of the restored forest exhibits a multi-storied canopy structure, consisting of mature trees with closed canopies, midstory trees, and new seedlings that have begun to naturally regenerate.

When planting this area, KIVIWAMA prioritized ‘water-friendly’ trees that perform well in riparian areas. These include Ficus sycomorus (sycamore fig), Ficus thonningii (strangler fig), Rauvolfia caffra (quinine), Syzygium guineense (water berry), and Albizia spp.

While livestock grazing pressure was a key challenge at Nsere Spring, the primary issue we noticed at Shiri Spring was human disturbance. The restoration site was surrounded by many households, and footpaths weaved throughout the planted area. Along these footpaths, we noticed clear evidence of human disturbance from cutting wood for building materials and firewood.

Along the riparian restoration area there are three distinct restoration zones that are differentiated by the predominant species planted in each zone: Cedrela odorata (stinkwood), Acrocarpus fraxinifolius (Indian ash) and Markhamia lutea (golden bean). The approach of monocropping species resembles a plantation and was used due to the ease of logistics and to decrease interspecific competition.

In contrast to the riparian areas, the main species planted within the coffee fields are Albizia lebbeck, Albizia schimperiana, Grevillea robusta (silky oak), and Cordia africana (East African cordia). These species are economically valuable within the plantation because they grow quickly, produce mulch and shade for the coffee plants, and efficiently fix nitrogen in the soil to reduce fertilizer costs.

In comparison to the Nsere Spring and and the Shiri Spring sites, the Kilimanjaro plantation sites exhibited significantly less occurrences of termites, however the influence of humans observed through machete gashes and pole and firewood collection was quite present. In addition, the Kilimanjaro Plantation is not managed by the Moshi Water Authority, and is instead owned by the Chibo Coffee Estate. Today, the Kilimanjaro plantation is an extensive and productive coffee plantation.

Machare protected and reforested its own riparian areas, rather than contracting out the reforestation work as Chibo did, and strictly prohibited wood harvesting from these areas while still allowing villagers to pass through. As a result of this reforestation, multiple springs that had previously run dry began to flow again. The estate has advanced several development projects in the village of Orera, such as the introduction of more efficient and sustainable cooking stoves to offset the wood collection that is now prohibited in the estate’s riparian areas and the government’s Half Mile Strip.

Mowo is a remote village located near the border of Kilimanjaro National Park. While both villages practice Chagga agroforestry, villagers in Mowo have more densely planted farming systems that include numerous varieties of bananas, plantains, tubers, passion fruit, and avocado trees, among other species. Oftentimes, these farms are planted on seemingly precariously steep slopes and are connected by a network of single-track footpaths across ridges. Livestock are kept in pens near the home, and farmers collect fodder to bring to their cattle, goats, and pigs.

In comparison to Mowo, Orera village is located at a lower elevation and has more direct access to Moshi town. The village is spatially constrained between the National Forest border to the north and the Machare Coffee Estate to the south, and exhibits higher population density than Mowo. Changes to the traditional Chagga agroforestry system reflect this increased agricultural pressure. Orera has a more open canopy structure with a substantially greater area devoted to maize, an efficient source of calories. In addition, Orera village has benefited from development projects implemented by the Machare Estate, such as sustainable biogas stoves and a project to increase household access to water. Due to the relationship with Machare, villagers in Orera plant coffee trees as a part of the agroforestry system because the Estate helps villagers create unions, improve the quality of their coffee beans, and find markets to receive better prices.

Over our time in Moshi, we each had the privilege of living with host families in the neighborhood surrounding our classroom. Living with host families provided an opportunity for cross cultural exchange and allowed us to gain a deeper understanding of Tanzanian culture.

In the foothills of the Mount Kilimanjaro region, gully erosion has become a pervasive challenge due to a combination of physical and human causes. These include topography, slope, elevation, precipitation, and soil properties, as well as construction of roads, increasing amounts of impervious surfaces, and overgrazing of livestock.

Over the second week of the course, we evaluated three gully locations: two sites in the Kimochi Ward and one in Kikarara Village.

In our examination of these sites, it is evident that prioritization of restoration projects depends on the relative scale of the issue in stakeholders’ daily lives, and that gully erosion falls low on the hierarchy of needs of local people. For example, access to fertilizer, irrigation, and other agricultural inputs is of greater immediate priority to a larger number of households and to the government that serves these households. In addition, while there is knowledge of the problem, there is a lack of budget to implement long-term solutions. As a result, limited work has been done to address the growing issue of gully erosion. Where gully restoration projects have been conducted, a one size fits all approach has been taken without any follow-up efforts, and the projects have been largely ineffective.

Finally, it is clear that the issue of gully erosion transcends the scale of a single household or village. Moshi is divided into three zones that descend in elevation down the slopes of Mount Kilimanjaro, and mismanaged water in the highlands region flows downwards to create gullies in the midland and lowland zones. When restoration projects fail to address the root causes of a gully along its full length, including at its source, they are unlikely to succeed.

For the final module of our course, we examined restoration efforts within protected areas.

Arusha National Park’s increasing invasive shrub species such as Solanum incanum (Sodom apple) present a major issue to the wellbeing of the park. Invasive shrubs displace native species and reduce grazing areas and food supply for animals within the park. If left unchecked, the spiky and dense shrubs limit the movement of both wildlife and park rangers on patrol. In recent years, the shrub has had significant encroachment into the park's glades, which reduces the visibility for tourists visiting the park for wildlife viewing. Tourism is the lifeblood of the park and helps provide funding to maintain its necessary functions.

We visited three sites in Arusha National Park overgrown with varying levels of ​​S. incanum. We wanted to explore the effectiveness of the park's efforts for removal and understand the regrowth of the shrub. Using a random sampling method, we collected data on the shrubs’ density, height, and reproductive state in 1m squares and 5m radius.

We found the park's shrub pulling restoration efforts to be moderately successful. While the project did little to completely remove the ​​S. incanum, it significantly reduced the density and height of the shrub. The second site where restoration took place only two months ago provided unobstructed wildlife viewing from the road and unlabored movement for animals and rangers across the glade. Future studies on invasive species removal here could explore with more depth the rate at which ​​S. incanum returns to its undisturbed state or testing effectiveness of different methods for removal.