Germination of South Brazilian grassland herbaceous species: state of knowledge and research needs for advancing grassland restoration

Ecological restoration of grasslands is widely dependent on seed addition to reestablish native plants. Thus, it is important to know the seed ecology of native species. The South Brazilian grasslands are species-rich ecosystems seriously threatened by land use conversion and invasive species, which makes their restoration extremely urgent. Nevertheless, poor knowledge about the germination of native herbaceous species limits ecological restoration efforts. Here we present, based on a literature search, a synthesis of the knowledge on germination and seedling emergence of native herbaceous species from South Brazilian grasslands, identify knowledge gaps, and present directions to enhance research and its application in restoration. We found 907 tests performed on 127 native species, mostly conducted in a germination chamber, but with a wide variety of seed storage conditions, seed dormancy break treatments, and germination conditions during tests. Poaceae and Fabaceae are the most tested botanical families. We recommend (1) the inclusion of more species, also from more plant families, into testing, considering also a better coverage of different grassland regions in seed collecting; (2) publicizing and making test data openly accessible; (3) developing standardized protocols for seed collection, storage, and germination tests; and (4) increase testing of emergence under field conditions.

Keywords:
Campos Sulinos; ecological restoration; emergence test; germination test; seeds