CONICET | Buscador de Institutos y Recursos Humanos

Overgrazing of Semiarid Chaco Forest (Argentina) drastically diminishes the vegetation cover and compacts the soil creating "peladares" (vegetation gaps). To recover these environments, it is necessary to perform environmental restoration techniques. Reintroducing nurse plant species is a convenient technique because these plants provide a favorable microsite to protect other plant species that may have been dispersed to the site and have regenerated from seeds. Capparaceae shrubs could perform as good nurse plants because they are not palatable and form perennial canopies. However, to produce new individuals for restoration activities, we must know their germination requirements. We studied the germination requirements of five species of Capparaceae shrubs from Semiarid Chaco Forest: Anisocapparis speciosa, Cynophalla retusa, Capparis atamisquea, Capparicordis tweedieana, and Sarcotoxicum salicifolium. We evaluated seed germination in light/dark at 27°C. For those species with less than 70% germination, we evaluated the ability of seeds to imbibe water and we applied dormancy-breaking treatments (dry storage at room temperature, cold and warm stratification, and hormone treatments). Seeds of A. speciosa and C. retusa were not dormant and germinated to high percentages. Nevertheless, C. atamisquea, C. tweedieana, and S. salicifolium seeds germinated to less than 70%; furthermore, they had water-permeable seed coats. The best treatment to promote germination of C. tweedieana seeds was warm stratification at 30°C during 6 weeks. Still, we could not improve germination of S. salicifolium and C. atamisquea seeds with the pretreatments tested; thus, further studies are needed. Propagation of some Capparaceae species, in some cases using a pretreatment, is now possible; which means that seedlings of these species can be produced for restoration programs in Semiarid Chaco Forest (Argentina).