More people, more trees in South Eastern Tanzania: local and global drivers of land-use/cover changes

Abstract

Land degradation in South Eastern Tanzania, the country's major cashew producing area, has been attributed to deforestation. By comparing land-use/cover maps derived from aerial photographs of 1965 with maps derived from satellite images of 2002, we assessed how land-use changed in six villages, and relate these to local and global drivers. Land-use/cover changes are complex processes, which we analyzed by determining the relative net changes, losses, persistence and gains of each land-use/cover categories. Widespread planting of cashew trees only started in the 1960s; while the 'villagisation' program in the 1970s, altered settlement patterns as centrally planned villages were created. Population growth and rural development policies were major local drivers for land-use/cover change; international trade and technological innovations were principal global drivers. Though population increase led to a reduction of natural vegetation, the spread of cashew trees resulted in a case of 'more people, more trees.' How far the ensuing deforestation affected the biodiversity of the area and how sustainable the production of cashew nuts actually is, remains yet unresolved questions.

Anthropogenic Drivers of Forest Change in Miombo Ecosystems of South-eastern Tanzania: Implications for REDD+

“…The situation in Kilwa and Lindi appear to be parallel to findings reported in a study from Makonde plateau, in south-eastern Tanzania (Kabanza et al, 2013) where the spread of commercial cashew production has led to substantial forest and land use changes. Increasing international demand for cashew nuts, combined with population growth and the villagisation program, have led to widespread transformation of land use since the 1960s.…”

Transition from Forest‐based to Cereal‐based Agricultural Systems: A Review of the Drivers of Land use Change and Degradation in Southwest Ethiopia

“…From the perspective of forest cover change, Reusing (); Mekuria (); Bedru (); Dereje () and Belay () are in agreement with the identified causes of Geist & Lambin (); Lambin et al () and Kabanza et al (), who showed that forest cover changes are driven by a complex of underlying causes rather than by single factors such as ‘shifting cultivation’ or ‘increasing population’ pressure.…”

“…Similarly, Kikula () indicated that the villagisation programme in Tanzania has had long‐term negative environmental impacts such as forest cover decrease and land degradation. Kabanza et al () also showed that villagisation resulted in a decline in forest cover in the Makonde plateau in southeastern Tanzania, even though the villagisation policy was enacted with the intention to reduce the impact on the forests and to provide collective social services. However, villagisation works only when the people consent to the programme; otherwise, it has a strong impact on the environment by alternating the utilisation of resources in the new and in the previous place.…”

“…Similarly, Geist & Lambin (2002) indicate that the immigration of settlers in less populated regions increased the deforestation in Africa and Latin America (Geist & Lambin, 2002). In contrast, Kabanza et al (2013) showed that where population density was the highest in southeastern Tanzania, large areas of cropland and bushland were converted to cashew tree cultivation, which represents a case of 'more people, more trees'.…”

Evaluating the socio-environmental impacts of monoculture cashew expansion in the Northern Western Ghats, India

“…With the consistently high global demand for cashew and its products, it is possible that the demand for cashew could lead to significant socio-environmental costs in the tropics, as has been documented for superfoods Cho et al, 2021). Evidence shows that cashew cultivation has expanded over native forests, savannah woodlands, and rice fields across Brazil, Guinea-Bissau, Benin, Burkina Faso, Tanzania, Cambodia, Laos and Vietnam (Augusseau et al, 2006;Barry ed., 2007;Boubacar-Sid et al, 2007;Ntongani et al, 2010;Dinh et al, 2010;Temudo & Abrantes 2013;Kabanza et al 2013;Hurni et al 2017;Temudo & Santos 2017;de Alencar et al, 2018;. A recent study by showed that cashew replaced forests, rubber, mixed farming, shifting cultivation, shrubs and grasslands in mainland tropical Southeast Asia.…”