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The specific questions addressed from this research include: (1) Does high-intensity acute exercise improve memory?, (2) If so, do the mechanisms occur via encoding, consolidation, or retrieval? and (3) If acute exercise occurs in multiple phases of memory (e.g., before encoding and during consolidation), does this have an additive effect on memory? Three experimental, within-subject, counterbalanced studies were conducted among young adults. High-intensity exercise involved a 20-minutes bout of exercise at 75% of heart rate reserve. Memory was evaluated from a word-list task, including multiple evaluations out to 24-hours post-encoding. The timing of the exercise and memory assessments were carefully positioned to evaluate whether any improvements in memory were driven by mechanisms related to encoding, consolidation, and/or retrieval. We demonstrated that high-intensity acute exercise enhanced memory. This effect was robust (repeatable) and occurred through encoding, consolidation and retrieval-based mechanisms. Further, incorporating acute exercise into multiple phases of memory additively enhanced memory function.

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The influence of soil temperature on rhizome depths of four intertidal seagrass species was investigated in central Queensland, Australia. We postulated that certain intertidal seagrass species are soil temperature-sensitive and vertically stratify rhizome depths. Below-ground vertical stratification of intertidal seagrass rhizome depths was analysed based upon microclimate (soil temperature) and microhabitat (soil type). Soil temperature profiles exhibited heat transfer from surface layers to depth that varied by microhabitat, with vertical stratification of rhizome depths between species. Halodule uninervis rhizomes maintain a narrow median soil temperature envelope; compensating for high surface temperatures by occupying deeper, cooler soil substrates. Halophila decipiens, Halophila ovalis and Zostera muelleri rhizomes are shallow-rooted and exposed to fluctuating temperatures, with broader median temperature envelopes. Halodule uninervis appears to be a niche specialist, with the two Halophila species considered as generalist niche usage species. The implications of niche use based upon soil temperature profiles and rhizome rooting depths are discussed in the context of species' thermal tolerances and below-ground biomass O demand associated with respiration and maintenance of oxic microshields. This preliminary evidence suggests that soil temperature interaction with rhizome rooting depths may be a factor that influences the distribution of intertidal seagrasses.

The ultramafic endemic shrub Neoroepera buxifolia Muell.Arg. & F.Muell (Picrodendraceae) has high habitat specificity and is mostly restricted to the perennial and ephemeral creeks and drainage lines of the central Queensland ultramafic landscape. It has an association with high magnesium (Mg) concentrations in the soil and the present study seeks to determine whether there is a correlation between populations of N. buxifolia and the soil extractable Mg and/or Mg : calcium (Ca) quotients in the soil. This was achieved by measuring the standing volume, height and seedling counts of N. buxifolia against the soil elements and other plot characteristics. Whereas correlations were found between increased height of N. buxifolia and the Mg : Ca quotients, soil extractable nickel (Ni) had the greatest influence. The standing volume of N. buxifolia also increased with soil extractable Ni. The standing volume of N. buxifolia was greatest in the upper tributaries of the first-order ephemeral creeks and presence of permanent water of the perennial creeks did not influence the standing volume or height of N. buxfolia.