Dormancy and soil type as determinant for germination and establishment of Chloris berroi in the Flooding Pampa

Abstract

Ecología Austral, 25:75-80 (2015)

In halophytic grassland of the Flooding Pampa, domestic grazing might have induced losses in floristic diversity as well as in soil properties. The recovery of native species with high forage value is a valuable strategy for the system regeneration. This requires a thorough understanding of the ecology of the target species, unknown for Chloris berroi, a native and potential regenerative of degraded environments. We tested two hypotheses: (1) C. berroi dormancy is due to the seed covers that inhibit their germination for a certain interval after harvest; and (2) C. berroi plants, during their germination, are affected by soil type. We carried out two essays: the first evaluated the effect that removal glumes exerted on the seed germination of C. berroi with two storage periods (2 and 8 months) and seeded on three different soils (two typical Natracual´s halophyte steppes adjacent but different stories in grazing management (continuous/rotational) and Vertic Argiudol a wet meadow mesophytes with rotational grazing). The second evaluated the ability of each soil property. The removal of the seed cover alone significantly promoted germination in seeds with lower storage period. Soil type hasn´t affected germination; meanwhile, seedling establishment was significantly reduced on Natracualf under continuous grazing. Results suggest that effectively C. berroi´ seminal covers induce dormancy for a few months (< 8). Rotational grazing would promote preservation of C. berroi in halophyte communities and their absence in vegetal communities corresponding Argiudol vertic soil, would not be for edaphic issues.