Variations and phenotypic correlation of growth attributes of Calliandra calothyrsus in the Blue Mountains of Jamaica

Forested land cleared for agriculture in the Blue Mountains of Jamaica rapi dly loses its productivity leading to further slash-and-burn cultivation an d the degradation of more forest. Contour hedgerows of Calliandra calothyrs us Meissner have been shown to reduce water runoff and soil erosion, and pr oducts of the species have a wide range of uses in the local farming commun ity. A trial was established at 1550 m in which the locally naturalised pop ulation of C. calothyrsus was compared with seven provenances from across t he species' ecological range. There was considerable variation between prov enances of C. calothyrsus in all the above-ground growth variables measured and, although the local provenance performed moderately well, it was clear that there is potential to improve the suitability of the species for a ra nge of local uses by the introduction of new provenances. One provenance co mbined high above-ground productivity with low fine root-length density, es pecially in the inter-hedgerow area: it offers particular potential for use in simultaneous agroforestry systems providing wood and foliage products w hilst not imposing high levels of competition with crop plants for below-gr ound resources. Although there were significant differences between provena nces in the distribution of roots between the hedgerow and inter-row areas, they did not differ in the distribution of roots between soil depths. Ther e were only limited differences between provenances in the response of thei r subsequent growth to harvesting. However, significant block x provenance interactions suggested that the performance of C. calothyrsus provenances m ay be difficult to predict between sites and farmers should be encouraged t o carry out trial planting of a number of provenances to find those which b est match their farm environment and needs.