Human Abuses of Coral Reefs- Adaptive Responses and Regime Transitions

During the last few decades, coral reefs have become a disappearing feature of tropical marine environments, and those reefs that do remain are severely threatened. It is understood that humans have greately altered the environment under which these ecosystems previously have thrived and evoloved. Overharvesting of fish stocks, global warming and pollution are some of the most prominent threats, acting on coral reefs at several spatial and temporal scales. Presently, it is common that coral reefs have been degraded into alternative ecosystem regimes, such as macroalgae-dominated or sea urchin-barren. Although these ecosystems could potentially return to coral dominance in a long-term perspective, when considdering current conditions, it seems likely that they will persist in their degraded states. Thus, recovery of coral reefs cannot be taken for granted on a human timescale. Multiple stressors and disturbances, which are increasingly characteristic of coral reef environments today, are believed to act synergistically and produce ecological surprises. However, current knowledge of effects of compounded disturbances and stress is limited. Based on five papers, this thesis investigates the sublethal response of multiple stressors on coral physiology, as well as the effects of compounded stress and disturbance on coral reef structure and function. Adaptive responses to stress and disturbance in relation to prior experience are highlighted. The thesis further explores how inherent characteristics (traits) of corals and macroalgae may influence regime expression when faced with altered disturbance regimes, in particular overfishing, eutrophication, elevated temperature, and enhanced substrate availability. Finally, possibilities of affecting the resilience of macroalgae-dominaed reefs and shifting the community composition towards a coral-dominated regime are explored.

Land Use, Freshwater Flows and Ecosystem Services in an Era of Global Change

The purpose of this thesis is to analyse interactions between freshwater flows, terrestrial ecosystems and human well-being. Freshwater management and policy has mainly focused on the liquid water part (surface and ground water run off) of the hydrological cycle including aquatic ecosystems. Although of great significance, this thesis shows that such a focus will not be sufficient for coping with freshwater related social-ecological vulnerability. The thesis illustrates that the terrestrial component of the hydrological cycle, reflected in vapour flows (or evapotranspiration), serves multiple functions in the human life-support system. A broader understanding of the interactions between terrestrial systems and freshwater flows is particularly important in light of present widespread land cover change in terrestrial ecosystems. The water vapour flows from continental ecosystems were quantified at a global scale in Paper I of the thesis. It was estimated that in order to sustain the majority of global terrestrial ecosystem services on which humanity depends, an annual water vapour flow of 63 000 km3/yr is needed, including 6800 km3/yr for crop production. In comparison, the annual human withdrawal of liquid water amounts to roughly 4000 km3/yr. A potential conflict between freshwater for future food production and for terrestrial ecosystem services was identified. Human redistribution of water vapour flows as a consequence of long-term land cover change was addressed at both continental (Australia) (Paper II) and global scales (Paper III). It was estimated that the annual vapour flow had decreased by 10% in Australia during the last 200 years. This is due to a decrease in woody vegetation for agricultural production. The reduction in vapour flows has caused severe problems with salinity of soils and rivers. The human-induced alteration of vapour flows was estimated at more than 15 times the volume of human-induced change in liquid water (Paper II).

Allegory, It Happens: A Multi-Perspective Case Study of The Lord of the Rings

Allegory is not obsolete as Samuel Coleridge and Johann Wolfgang von Goethe have claimed. It is alive and well and has transformed from a restrictive concept to a concept that is flexible and can form to meet the needs of the author or reader. The most efficient way to evidence this is by making a case study of it with a suitable work that will allow us to perceive its plasticity. This essay uses J.R.R. Tolkien’s The Lord of the Rings as a multi-perspective case study of the concept of allegory; the size and complexity of the narrative make it a suitable choice. My aim is to illustrate the plasticity of allegory as a concept and illuminate some of the possibilities and pitfalls of allegory and allegoresis. As to whether The Lord of the Rings can be treated as an allegory, it will be examined from three different perspectives: as a purely writerly process, a middle ground of writer and reader and as a purely readerly process. The Lord of the Rings will then be compared to a series of concepts of allegorical theory such as Plato’s classical “The Ring of Gyges”, William Langland’s classic The Vision of William Concerning Piers the Plowman and contemporary allegories of racism and homoeroticism to demonstrate just how adaptable this concept is. The position of this essay is that the concept of allegory has changed over time since its conception and become more malleable. This poses certain dangers as allegory has become an all-round tool for anyone to do anything that has few limitations and has lost its early rigid form and now favours an almost anything goes approach.