Faidherbia albida (Delile) Tree Dieback Effects on Crop Production in the Parkland Agroforests of Southwestern Niger

Faidherbiaalbida is an agroforestry tree species playing important agroecological and socioeconomic roles in arid and semiarid zones in Africa. For many years, anthropogenic and abiotic stresses were considered as the main threats for the species in West African parkland agroforests. Considerable dieback has recently occurred in F. albida trees of parkland agroforests in central southwestern Niger, and the causes are unknown. The objectives of this study are to (i) investigate the magnitude of dieback of F. albida trees and (ii) assess local community perceptions of the effects of F. albida dieback on crop production. The health status and phenology of 213 F. albida trees were observed in the area where the dieback is occurring. Similarly, a sample of 144 people, 86% of which were farmers, was surveyed. Dieback incidence of F. albida trees was 19%, with mortality of 6%. Large-diameter trees had greater dieback than small-diameter trees. The most affected parts of the tree were the branches at 54% and the trunks at 39%. The populations noted a 33–55% reduction in the yields of major crops. This dieback of F. albida trees poses a serious threat to the survival of rural communities. Further studies can be conducted to identify the cause or cause of the dieback to guide the suitable agroforestry parkland management strategies.

Trade-off of Tree Conservation and Crop Production on Agroforestry Parklands in Burkina Faso

Rapid population growth coupled with food demand make land for agriculture scarcer obliging farmers to make use of any available piece of land at their disposal for crops production. This preferential use of land for crops production may appear to be competitive with tree keeping on farm. To elucidate that, the trade-off between crop production and tree conservation on farms was assessed in Bouroum-Bourmoum, Sapouy and Ouahigouya, three municipalities of Burkina Faso. More than 3 000 individual trees which spreading was 1 154 in Bouroum-Bourom, 884 in Ouahigouya and 1 054 in Sapouy were used. The mean tree canopy cover and tree cover in the farms were calculated. The three principal crops (millet, red sorghum and white sorghum) yield were used to estimate the trade-off using the mean tree canopy cover as the potential no cropping area. The results revealed a tree canopy cover of 66.25 m2 in Bouroum-Bourom, 59.92 m2 in Sapouy and 42.1 m2 in Ouahigouya. The average tree cover was 23.99% in Bouroum-Bouroum, 18.23% in Sapouy and 14.88% in Ouahigouya. This represents a loss in grain production of 109.5 kg/ha in Bouroum-Bouroum, 247.6 kg/ha in Sapouy and 252.8kg/ha in Ouahigouya. A higher tree cover implies a higher trade-off in the agroforestry parkland and suggests reduction in tree density. There is urgent need to work out the balance between smallholders’ farmer continuous requirement for increase food crop production and the need to maintain tree diversity in the farm for carbon credit payment promotion.