Daimen and I have visited more sites on Pemba, some having the same problems starting seedlings, but one community doing quite well, Shumba Viamboni. However, this community has been running for awhile, and will facilitate training for other communities. The problems of deforestation have become apparent to the community of Shumba Viamboni, in an area close to the village. Twenty or more years ago a piece of land was deforested and without the shade, mulch, and root structures conserving water in the soil, it quickly turned to desert. The people of the surrounding communities, with aid of an NGO in the UK, replanted the site with Acacia, and now 20 years later, a forest has once again emerged. It was great to learn that the community was not going to cut this forest, rather, they were going to conserve it for environmental and ecological purposes.
Desert turned Acacia forest
It is clear that Acacia would grow well in sandy desert-like soils and we have suggested planting Acacia in sandy areas such as Tundua. However, the idea is not being taken well, as an exotic Acacia species has been over planted and mono-planted in the past. Biodiversity is an important consideration when replanting a forest, to insure its longevity in times of drought, flood or other environmental hardships. If no other trees will grow in a site, such as Tundua, indigenous Acacia should be considered as a nurse crop to make the soil more suitable for other tree species to be planted in the future. Acacia sp. will build the soil by adding mulch from fallen leaves, conserving water in the soil through its roots and hydraulic lift (water evaporating from the ground to its leaves creating a cool moist environment under its canopy), and buy adding nitrogen to the soil, a necessary nutrient for tree growth. The trees then can be selectively cut to allow sunlight for other trees (small areas only) or shade tolerant species can be planted.
Another issue that came up as we drove down the winding roads of Pemba, was the cutting of mangroves. This resulted in sea water spilling in on their once productive land, creating salty soil where farming could not continue. As we saw in one area, only black soil remained, as sea adapted plants had not yet moved in, and the soil is nutrient depleted from over farming.
Shumba Kwale Nursery
