The Usambaras are one of four major highlands (i.e. Mt Meru near Arusha, Kilimanjaro near Moshi, the Pare Mts around Same, and the Usambaras around Lushoto) in North East Tanzania. Each of these highlands has higher rainfall than the surrounding lowlands, so greater agricultural productivity and higher population densities also distinguish them from those lowlands. The steep gradients which are common in these highlands present special problems for farming, especially when tree clearance precedes cultivation of the soil. Tree felling is often followed by surface runoff of rainwater and soil erosion, which results in the rapid environmental damage. Some of these problems can be avoided by the use of terraces on the steep hillsides, replanting of trees, and careful channeling of waterflow – as can be seen in the photo below.
However, these activities require much laborious effort and on many hillsides such soil conservation work is missing. The consequence of inattention to soil conservation practices is widespread soil erosion on the slopes around Soni.
The Usambaras are also part of a series of highland blocks known as the Eastern Arc. They include the Taita Hills in Kenya, the Pare Mts, the Usambaras, the Uluguru Mts near Morogoro, and the Udzungwa Highlands near Iringa. These mountains are characterized by exceptional biodiversity of global significance, so tree-planting to provide an alternative source of fuelwood to indigenous species is encouraged.
The prime intention is to plant the upper slopes of Soni Seminary with tree species that will be quick-growing, so that the soil erosion and environmental damage occurring in 2007 can be halted. The species planted are also expected to provide a significant income for the Seminary and thereby enable the cost & quality of the boys’ education there to be improved.
When the initial planting of those slopes is complete it is planned to promote reafforestation elsewhere within Lushoto District – especially at those schools with significant underused grounds.
Most of the land where tree planting is currently happening have been planted with exotic species e.g. eucalyptus, pines or grevillea. Thus, original indigenous forest now covers less than 5% of the Usambaras around Soni. SGG is now encouraging partners in this locality to plant at least 10% of new ground with indigenous species before they entirely disappear from the local scenery.
The initial proposal was that there would be a two stage project planned to run for at least five years. The initial work would be the full replanting of the Seminary upper slopes. Before the end of 2006 there had been some replanting of this slope with a mixture of 2000 young grevillea and pines. However, on a visit to the site in January 2007 time those small trees were overgrown with weeds, so that it was difficult to establish the survival rate of those trees. Thus, initial work required:
- immediate employment of two labourers for two weeks to clear away the weeds + to use such weeds to make trash lines on the steep slope and thereby discourage surface runoff and soil erosion + to prepare holes for new trees in unplanted areas and where young trees from the previous planting have been lost.
- a tree census to identify both mature exotic(eucalyptus) & indigenous trees to be preserved + young gravillea/pines planted in 2006 + other useful trees found within Seminary grounds.
- consultation with the Forestry Officer Mr Kombo Siwa at Lushoto with a view to purchase of trees to reafforest the upper Seminary lands. From a quick appraisal it was estimated that the slope would require some 5,000 new trees. Between 1,000 and 2,000 young seedlings were to be planted during the expected March-April 2007 rains.
- consideration of what would be appropriate tree-planting or agroforestry for the Soni environment and elsewhere in the Usambaras. For this SGG is indebted to Lars Johannson, author of the book “Ten Million Trees Later : Land Use Change in the West Usambara Mountains”, for information about what has been successful and unsuccessful development in the Usambaras since 1980.
- an investigation within the parish of Soni concerning the potential for tree-planting, increased fruit production and marketing of such fruit. In January some initial discussions suggested that avocado may be the most appropriate fruit. However, there is much avocado production that is wasted in North-East Tanzania, so SGG would need to be satisfied that there is a stable market for any tree crop before providing funds for planting.
- an investigation concerning the possibility of replanting some of the watershed sites & upper slopes with high-density indigenous cover in order to stabilize water supply and reduce soil degradation. At present many of these very steep & upper slopes are cultivated for maize. Yields are usually low and unsustainable, so it has been suggested that payment at/above maize yield income for farmers to convert to tree-planting may prove a sustainable policy. There is some evidence to favour such an approach . However, this will require significant finance which may not be available in the 2007-2012 period.
- SGG looks for substantial funds in UK, the European Union, and within Tanzania to support such tree-planting anywhere within Soni locality.
One limitation of this work is that St Joseph’s Seminary is a Catholic institution, whereas the majority of the population around Soni village is Muslim. Thus, it was agreed that the take up of increased tree-planting by the local Muslim population would be minimal. Accordingly, contact was made with the local Muslim village council and consideration given to the planting of trees on the very steep slopes which surround the new Islamic school in Soni. This school is sited on a spur above the village and has approximately 4 hectares of land, which require reafforestation. There were a few trees already planted here, but much of this land was unused except for rough grazing in 2007. If grevillea were planted 2.5m apart, it was estimated that approximately 5,000 trees would be required to replant this site. Furthermore, it was pointed out to SGG that Soni village would greatly appreciate help in the reafforestation of the large hillslope to the west of the village. At present there is scattered cultivation on this steep, largely deforested land. It is easy to see the rills which indicate the high risk of soil erosion on this hillslope. Successful reafforestation at this location would require tens of thousands of trees, so SGG would be able to undertake such a task only with the backing of significant funding. It was agreed that SGG should look for such funding.
As SGG had been asked as early as December 2006 to establish a tree-planting project at Soni, there were sufficient small funds to get started before the rains in 2007. Accordingly, by 26/1/2007 we three workers were employed to clear the land, prepare holes for the trees, and wait for the March rains. This work proved difficult and progress was slow with only three workers, so it was agreed that the Seminarians would provide work gangs every afternoon to complete the work more quickly.
As clearance of the slope continued, the following trees were ordered from the Tanzania Tree Seed Agency in Lushoto:
- 700 Grevillea robusta, considered to be the most suitable fast-growing exotic for the slopes,
- 50 Pinus patula to fill in spaces between previously planted pine seedlings,
- 50 Eucalyptus grandis & 50 Eucalyptus saligna to extend the area of such trees on the lower and wetter grounds of the Seminary,
- 100 indigenous trees to be planted to extend a small area of native trees close to Maweni Farm. These trees included 30 Albizia schimperiana (mshai), 30 Cordia Africans (mringaringa), 10 Khaya anthotheca (mkangazi/African mahogany), and 30 Podocarpus usambarensis (mpodo)
- 20 Caliandra spp to experiment with agroforestry on the Seminary shamba & at VMM garden.
- 20 Persia Americana (mparachicha) or avocado, a common local fruit,
- 20 Mangerifera indica (mwembe) or mango.
- 10 Atocarpus spp.
These trees were ordered to be ready by 1/3/07, the approximate start of the heavy rains, at a total cost of Tsh367,500/=, which is approximately £147. This sum was to be paid by SGG in March 2007.
At the same time a person was appointed to act as a ‘treeworker’ for the following 3 months (Feb/March/April 2007) until the above trees are planted. The treeworker’s duties include : weeding & clearing a space around each of the trees planted in 2006; making sure that the young trees remain vertical & are not half-buried by soil etc; using the weeds + plants which were cut in late January to make ‘trash lines’ to discourage surface runoff & soil erosion; to fill any erosion rills with dead plant material to discourage soil erosion; to regularly cut the grass as necessary in the tree area so that all young trees were clearly visible; to help plant the trees ordered above when the long rains arrived; to establish a tree nursery with at least 2000 seedlings for future planting in and around the Seminary grounds.
On 17/3/07 SGG began a second visit of one week to the Seminary. By this date most of the long grass had been cleared. Also a total of 1006 trees from the 2006 planting had been found, and an area cleared of vegetation around each young tree. On 19/3/07 the Tanzanian Tree Seed Agency delivered 860 trees for planting within the Seminary grounds at a cost of Tsh 302,500/- (about ₤121). This meant that not all the trees ordered on 1/2/07 were ready. In particular most of the indigenous species requested were either too small or not produced, but it was agreed that this part of the programme could be delayed until after Easter when most of the Seminary slope would be replanted.
On 21/3/07 700 grevillea robusta and 50 pinus patula were planted on the Seminary upper slopes by the Form 3 and Form 4 students. If the majority of these trees survive it will mean that about half of the upper slopes have some tree cover. Also a new agreement was made with the ‘treeworker’ Amoro. It was agreed that the project would provide Amoro with a monthly salary for his taking care of all trees within the Seminary grounds. Part of Amoro’s duties would include the establishment of a tree nursery to grow several thousand seedlings. At the beginning such a nursery should produce mainly grevillea, but later it was intended to produce many seedlings, including indigenous species. To encourage Amoro in this new development it was agreed that 50% of the seedlings produced belonged to Amoro. Thus, he had the opportunity to greatly increase his income through sales of his own produce. It was hoped that the Seminary would have several thousand grevillea for sale by November 2007.
On 22/3/07 there was a further inspection of the Seminary lands by a forester, SGG, Bill Neale and Fr Tom. This established that there were large areas of cleared land on steep gradients without any young trees. It was estimated that at least 2000 young trees would be needed in order to give some protection to soil on these slopes. It was therefore decided to use remaining funds to purchase 1000 grevillea robusta for ₤100 and to plant these as soon as possible. Such work was felt to be more urgent than the planting of indigenous trees on the lower hill.
On 23/3/07 the Tanzanian Tree Seed Agency delivered 1000 grevillea robusta to the Seminary. About 800 of these trees were planted on the same morning. The remaining 200 trees will be used to fill in the numerous gaps left by the seminarians during hot and dusty work on the very steep upper slopes next to Maweni Farm. Most of this filling in of gaps and checking of the seminarians work would be done by Amoro during the next two weeks.
SGG was not entirely happy with this second planting session. One reason was that the slope planted was very steep – too steep for cultivation of maize & beans without terracing, grass bunds or some soil conservation measures. Yet by 23/3/07 this steep ground was almost entirely cleared of vegetative cover by local cultivators. Furthermore, the period around planting was dry and the soil powdery. As planting of maize & beans was already underway, it seemed better to continue with the tree-planting. However, it was anticipated that this was the part of the Seminary ground where success was least likely. It would require regular watering here or good rains if these trees were to survive their first few months until well established.
It was also appreciated that a great deal of the manual labour had been undertaken by young pupils. Would they be prepared to take good care of these young trees, to water and weed as necessary during the trees first year of growth?
SGG’s monitoring visit to Soni in 2008 included another several days of hard work as the weeds had grown rapidly during the Seminary holidays and the short rains of those months. Once the weeds were cut down a tree census was undertaken. The estimate from that count of the seedlings which had survived from the 2006 & 2007 plantings was that there were some 2,333 young trees growing on the hillside within Soni Seminary grounds. In addition, there were some large indigenous trees which were the remnant of the original forest or much earlier plantings.
In 2009 the corresponding tree count estimated that there were 3,283 young trees planted since 2006 as well as about 1400 grevillea seedlings which were given to Soni Parish and Kongei Primary School. This is regarded as a considerable success, so SGG since has been investigating other locations within the Usambaras where there are opportunities for tree planting & conservation.
There are 3 locations which are currently of particular interest to SGG. One is the Amani Forest area in the Eastern Usambaras. Amani is one of the biodiversity ‘hotspots’ in East Africa, yet the forest is disappearing rapidly under the impact of logging and new agricultural settlement. There is an urgent need to encourage tree conservation of indigenous species and replanting on available land.
In the village lands of Ubiri there is abundant land which is of very limited use. In 2009 the hill near the village was almost completely lacking trees, and the hillside and escarpment vulnerable to seasonal fires and soil erosion. A discussion between SGG and the village community established that the villagers are willing to replant the hill with indigenous trees in exchange for funds which the community could spend on a dispensary. At present SGG is unaware of how much planting has actually been done in this locality and no funds have yet been raised for that purpose.
Attached to Kifungilo Girls Secondary School near Lushoto is a large area of ground which could be used for tree-planting and conservation. In 2009 SGG gave a small grant to start tree-planting here, and we hope to extend this work in the future.
An excellent example of tree conservation and forest restoration in the Usambaras is the Irente Biodiversity Reserve near Lushoto. Plenty of details concerning this project can be found on the website www.elct-ned.org, which is particularly good at giving advice on how to restore the natural forest which used to grace this region in the past. SGG has made only two visits to this site, but in 2012 we intend to make a more substantial commitment to this work. One aspect of this project is that it is located close to Irente Viewpoint, which is one of the major tourist attractions in the Western Usambaras. The Biodiversity Reserve offers good opportunities for ecotourism and developments which could provide economic benefits for the local population.