Restoration of overgrazed areas in the semi-arid Chaco (Argentina): studying germination requirements to grow nurse plants

BASKIN CAROL; DALMASSO ANTONIO; CROCE JOHANA; MARTÍNEZ GÁLVEZ, MARÍA FERNANDA; ALAUIE EMILIANO; ANDRES TÁLAMO

Foz do Iguassu

Congreso; VII World Conference on Ecological Restoration, V Congreso Iberoamericano y del Caribe de Restauración Ecológica y I Conferência Brasileira de Restauração Ecológica; 2017

Society for Ecological Restoration, SIACRE

Among the dry forests of Latin America, the Chaco has the largest extent of continuous forests. People in the Chaco live by usingtraditional livestock management in ?puestos? (groups of houses, farmyards and artificial water sources). Overgrazing causesvegetation loss and soil compaction generating areas without vegetation cover. Reintroducing thorny or non-palatable plants isuseful as a starting point to create fertility islands, these potential nurse plants protect plants from grazing and improve naturalregeneration. However, there is no information about the dormancy-breaking and germination requirements of Chaco plants. Inorder to raise new nurse plants for restoration programs in the Chaco, we studied the germination requirements of five woodyspecies: Castela coccinea, Celtis ehrenbergiana, Anisocapparis speciosa, Sarcotoxicum salicifolium, and Capparicordis twediana.Germination of each species was tested at 25°C in light (12hr light/12hr darkness) and in continuous darkness (Petri dishes coveredwith aluminum foil). A seed germinated if it had a 2 mm radicle, and a species was dormant if their germination percentageis lower than 80. We found that seeds of A. speciosa are not dormant, and those of C. cocinea are not dormant in darkness. Seedsof C. ehrenbergiana, S. salicifolium and C. tweediana are dormant; therefore, to increase their germination percentages, we areperforming a seed stratification treatment. The best candidates to introduce into the puestos are A. speciosa and C. cocinea(both can be easily propagated). This information is useful to grow potential nurse plants to restore the overgrazed areas in thesemi-arid Chaco.