The bioecological basis for the symbiotic relationship between grazing animals and Samanea is analysed. The contributory factors enhancing such relationships are examined, with the aim of evolving a successful reforestation model that builds on the natural process of regeneration on degraded grasslands. The study site was in the Province of Cagayan, Luzon Philippines. The methodology consisted of a series of bioecological experiments, plus a socioeconomic survey. The bioecological experiments addressed seed germination, seed digestibility and forage preference by grazing animals. A socioeconomic component is included to determine the income gains to the farmer from Samanea.