Early survival and growth of Allanblackia stuhlmannii (Clusiaceae): A threatened tropical rainforest tree of high economic value in Tanzania

2015

English

Rural households living in tropical ecosystems depend heavily on forest trees for valuable nontimber forest products that are, however, undergoing unsustainable harvesting. This study assessed early survival and growth of Allanblackia stuhlmannii (Clusiaceae), a nontimber tree species endemic to Tanzania. A total of 400 seedlings sourced from twenty elite female trees were planted in two adjacent locations. Data were collected over 59 months for survival, height and root collar diameter. Seedling survival at 59 months was significantly different between Emau and Shebomeza, being on average ~11% higher in Shebomeza. However, survival of the progenies of each female tree at 59 months was not significantly different. Overall, mean RCD (range: 6.8–59.7 mm) and height (range: 17.1–274.4 cm) were positively correlated (r = 0.84, P < 0.001). The correlations in heights of individuals between 17 and 59, and 23 and 59 months were positive (r = 0.34 versus 0.53, respectively). Results also suggested that if growth rate is related to ontogeny from juvenile to adult, then the progenies of ten female trees that have shown consistently higher growth rates may flower and fruit earlier than other progenies. Future planting for conservation of this threatened, overharvested tree species can therefore be based on data gathered from these field genebanks.

Mathayo, M. M.; Munjuga, M. R.; Cordeiro, N. J.; Coe, R.; Ofori, D. A.; Simons, A. J.; Sawe, C. T.; Jamnadass, R.