Bet hedging through fine-scale intraspecific variation in seed dormancy and seed germination cues in the Australian arid tropics

Adam Cross

Publication Date:

Seed biology in the annual herbaceous flora of ecologically stressful, seasonally wet habitats remains largely unexplored. Temporal and spatial species turnover among these habitats is often high, yet little is known about how fine-scale habitat variation drives intraspecific variability in seed dormancy depth and seed germination requirements. We present seed biology data from over 50 species of wetland plants from the Australian Monsoon Tropics, as well as complementary habitat data, and show that fine-scale differences in the thermal and hydrological conditions of seasonally wet habitats appear to be strong drivers of dormancy depth. Widely distributed species exhibit high levels of plasticity in seed-dormancy depth and germination response to germination stimuli such as biogenic ethylene among different habitats, with similar responses being observed for sympatric species. Sediment seed banks may represent significant drivers of species persistence and diversification in these ecosystems, and inhabitant flora display a high degree of adaptation to local hydro-geological conditions, potentially reflecting a long and relatively geologically and climatically stable evolutionary history.

Resource Type:
Audio/Video, Conference Presentation, SER2019

Pre-approved for CECs under SER's CERP program

Society for Ecological Restoration