Cracking the niche: An investigation into the impact of climatic variables on germination of the rare shrub Verticordia staminosa subspecies staminosa (Myrtaceae)
Simpson, Gregory (2011) Cracking the niche: An investigation into the impact of climatic variables on germination of the rare shrub Verticordia staminosa subspecies staminosa (Myrtaceae). Honours thesis, Murdoch University.
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The influence of annual rainfall and a Mediterranean climate in structuring the indigenous vegetation in the Southwest Botanical Province of Western Australia has long been recognised, especially in relation to seedling germination during the cooler wet season. However, over the past decade numerous authors have hypothesised that a number of climatic factors, including variability in the timing and intensity of rainfall events, may be drivers of germination. Verticordia staminosa subsp. staminosa (Myrtaceae) is a naturally rare narrow range endemic shrub that occurs on only one granite inselberg near Wongan Hills in the „wheatbelt‟ of southwest Western Australia. Smoke and fruit wall weathering have been claimed to be specific dormancy breakers for the seeds of many Australian genera, including Verticordia. However, I found no evidence of smoke and artificial weathering influencing germination of Verticordia staminosa. Using data from a long-term (12 year) investigation into field germination of Verticordia staminosa, my thesis applies logistical regression techniques to model the impact of climatic variables on germination within the only recorded Verticordia staminosa subsp. staminosa meta-population. My analyses reveal that a complex interplay of the amount of rainfall, number of rainy days, diurnal temperature range, and storms related to tropical cyclones/lows, under a traditional four seasons or six Noongar seasons climate, best describes the observed germination of Verticordia staminosa seedlings. Impact of climatic factors on germination of the rare shrub V. staminosa.
|Publication Type:||Thesis (Honours)|
|Murdoch Affiliation:||School of Environmental Science|
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