Promoting Terminalia brownii as a commercial indigenous tree species in drylands, East Africa

Abstract

Kenya’s forest cover is estimated at 7.4% of the land mass cover. Forests are important in ensuring biodiversity conservation and providing ecosystem goods and services, improving community livelihoods and national GDP. There is need to enhance afforestation and reforestation programmes to achieve the envisioned 10% tree cover target. However, this effort is constrained by climate change issues arising from unsustainable exploitation of wood for charcoal and firewood leading to the depletion of important tree species such as T. brownii. The domestication of T. brownii under agroforestry systems and other tree planting programmes are constrained by lack of adequate supply of superior and high quality seeds and seedlings, poor silvi-cultural management techniques, low rates of integration into smallholder agroforestry programs, limited knowledge on crop-tree interactions and lack of allometric models to estimate biomass yield and carbon stock.

A multidisciplinary research project funded by the National Research Fund (NRF) is ongoing and is geared towards promoting the propagation and regeneration of T. brownii under agroforestry systems in the drylands of Kenya to mitigate climate change. A number of preliminary findings have been reported, such are; (1) Terminalia brownii fruits have mechanical dormancy imposed by the hard samara fruit and that extracted T. brownii seeds record a high percentage of above 80% under warm conditions; (2) germination of T. brownii fruits and seeds are significantly affected by fungal pathogens and insect pests; (3) five variables significantly influence the decision to domesticate T. brownii these are; education level of household head, importance of farm to the household income, access to credit, dependency ratio and intercropping; (4) studies on the spatial distribution and occurrence and development of allometric equation for estimating above and below-ground biomass of T. brownii in the drylands of Kenya are ongoing. Further assessment on growth performance have shown that T. brownii is generally fast growing; can attain an increase in height of (~1.0 m) and DGL (3.0 cm) annually, with significance difference in growth within and between provenances and that the it can withstand many other growth challenges despite the harsh weather conditions.

These findings suggest that T. brownii is a promising tree species in agroforestry systems and afforestation in drylands and that there exist genetic variability among the available provenances thus the need to involve more stakeholders in seedling production and to embark on......

Key words: T. brownii, Commercial tree, growth performance, drylands of Kenya

ID: 3623166