Native leguminous plants for mineland revegetation in the eastern Amazon: seed characteristics and germination

For the effective use of native plants for mineland revegetation, an understanding of seed dormancy break and germination requirements, and seed storage tolerance is indispensable. In the present study, eight native species (Bauhinia pulchella, Bauhinia longipedicellata, Dioclea apurensis, Mimosa camporum, Mimosa acutistipula var. ferrea, Mimosa pudica, Parkia platycephala, and Stryphnodendron pulcherrimum) from the metalliferous savannas (cangas) and forests of Carajas Mineral Province, eastern Amazon-Brazil, were studied to determine seed size, seed quality (X-ray and tetrazolium tests), germination, and dormancy break requirements (boiling water, acid and mechanical scarification), and seed storage behavior. Our results showed considerable variation in seed size and percentage germination among the species. There was a strong relationship between seed size and germination, and the germination was greater for larger seeds from forests than smaller seeds from canga. All three scarification methods increased germination of M. camporum and M. acutistipula var. ferrea. Seeds of D. apurensis, M. acutistipula var. ferrea, M. pudica, and P. platycephala did not show a significant decline in germination after storage, indicating possible orthodox behavior. In contrast, B. pulchella, B. longipedicellata, M. camporum, and S. pulcherrimum showed behavior typical of recalcitrant or intermediate seeds since the germination of these species was reduced after storage. Further studies addressing seed dormancy break and seed storage in other native species are encouraged for a better use of native species in mineland revegetation.