Annual species’ experimental germination responses to light and temperature do not correspond with their microhabitat associations in the field

Annual species have evolved sets of germination cues that are thought to be predictive of the post-germination environment. In naturally patchy environments, germination microsites often vary considerably in the amount of light they receive and in the diurnal temperature fluctuations they experience. However, whether species’ differential germination responses to light and temperature are associated with their spatial patterns of occurrence remains largely untested.
We surveyed species’ occurrences in annual plant communities in 150 quadrats across gradients of canopy cover and litter cover. Nineteen species recorded in this survey were then included in a germination experiment that manipulated (1) Light vs. Dark (12h light or continuous dark) approximating seeds near the soil surface versus those covered by litter and (2) Cold vs. Warm temperature regimes (7/18 °C and 7/24 °C) approximating diurnal fluctuations experienced in shaded versus sun-exposed microsites, respectively.
In the g..., We surveyed species’ occurrences in annual plant communities in 150 quadrats across gradients of canopy cover and litter cover. Nineteen species recorded in this survey were then included in a germination experiment that manipulated (1) Light vs. Dark (12h light or continuous dark) approximating seeds near the soil surface versus those covered by litter and (2) Cold vs. Warm temperature regimes (7/18 °C and 7/24 °C) approximating diurnal fluctuations experienced in shaded versus sun-exposed microsites, respectively.
Analyses were performed in R., , # Annual species’ experimental germination responses to light and temperature do not correspond with their microhabitat associations in the field

Date created 01/03/2024

Authors:
Isis A. da Silva, School of the Environment, The University of Queensland, St Lucia, QLD, Australia
David J. Merrit, Kings Park Science, Department of Biodiversity Conservation and Attractions, Kings Park, WA, 6005, Australia and School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia

Todd E. Erickson, Kings Park Science, Department of Biodiversity Conservation and Attractions, Kings Park, WA, 6005, Australia and Centre for Engineering Innovation: Agriculture and Ecological Restoration, School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia

Margaret M. Mayfield, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia

John M. Dwyer, School of the Envi...