Soil Seed Bank Study and Propagation Methods of Selected Gums and Resin Producing Tree Species in Wachile District of Borana Zone

Abstract

Gum and resin bearing tree species were one of the very important resources in Ethiopia. Particularly, Borana pastoralists were used these resources as a source of income generation for their livelihoods. However, the resource was declining over a time due to different natural and human made problems. Therefore, it is important to study for its future sustainability through soil seed bank, seed germinations, vegetative propagations and analyzing its natural regeneration status.<i> Commiphora myrrha, Boswelia neglecta, Boswellia microphylla</i> and<i> Acacia senegal</i> were gum and resin bearing tree species selected for this study. With this; soil seed bank samples were collected from under and outside the canopy of selected tree species. Five tree species of each tree were used to collect soil seed bank sample at two canopy cover and three different soil depth, and 120 soil seed bank samples were taken from all types of tree species and evaluated for its germination. Seeds of selected species were also collected and evaluated for their germination. Moreover, stems and branches of those species were cut, planted and evaluated for their sprout. As a result, the absence of seeds of those species both inside and outside the canopy of trees in all soil depth layers was confirmed. This may be due to seed losses through (fire, degradation and over grazing), improper settlement, over logging, debarking, human over use for food, improper tapping. The result of analysis of variance also showed that, seedling germination percentage, survival percentage, shoot height and root height were highly significant different at (p<0.001) among all the treatments. The observed mean value of germination percentage were 99%, 46%, 40% and 25% for <i>Acacia senegal</i>, <i>Boswellia microphylla, Boswelia neglecta </i>and<i> Commiphora myrrha </i>respectively. Thus, the seed of those species doesn’t have dormancy and all healthy and filled seeds had high germination rates. About 60% of<i> Boswellia microphylla </i>and <i>50% </i>of both<i> Commiphora myrrha</i> and<i> Boswelia neglecta</i> were sprouted in the fourth year of the studies. Hence, it is advisable to use stem propagations for any conservation purposes incase seeds of those species fail to germinate except for <i>Acacia senegal</i> as it is naturally not propagated by stem cutting. Therefore, it is recommended to increase the regenerations of those species by reducing overgrazing, avoiding burning of those species and reduce land degradations and also using seeds and vegetative propagations if any management aims for conservations.