Stress ecophysiology of polar terrestrial invertebrates and the impact of climate change

Everatt, Matthew (2014). Stress ecophysiology of polar terrestrial invertebrates and the impact of climate change. University of Birmingham. Ph.D.

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Abstract

Terrestrial invertebrates are small poikilothermic ectotherms and are thus susceptible to chronic cold, rapid temperature change and desiccation. In the polar regions, where buffered microhabitat temperatures regularly fall below 0°C and water availability is low, they are particularly vulnerable. However, polar terrestrial invertebrates successfully exist within these climes. Using whole organism experimental techniques, this thesis aims to further understand the capacity of invertebrates to tolerate different stressors, the underpinning physiological adaptations, and the potential impact of continued climate change. For just the second time in a freeze-tolerant polar insect, rapid cold hardening is observed. Acclimation to sub-lethal low temperatures is also demonstrated, through depression of the critical thermal minimum (CTmin) and chill coma temperature. Contrasting strategies of desiccation tolerance vs. resistance are noted, as well as evidence of cross-tolerance to temperature stress. At the opposite extreme, water submergence experiments confirm the first example of an amphibious terrestrial midge. A remarkable capacity to tolerate high temperatures, including those that may occur as a result of climate change, is also observed. This body of work underscores the physiological flexibility of polar invertebrates, which allows them to flourish in environments considered too extreme and inhospitable for most terrestrial species.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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