fundamental processes in ecology an earth systems approach oct 2006

[...]... confusingly complex, one of the most famous images of this complexity in the scientific literature being Charles Darwin’s description of an entangled bank (Fig 1.1) In the closing pages of The Origin of Species he wrote, ‘It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about and worms crawling through... twentieth century This approach has an even longer pedigree in plant 6 Introducing the thought experiment ecology with an important early text (Warming, 1909) using a different entitybased strategy, being arranged around various plant communities Indeed an entity approach is an obvious way of organizing natural history into species, habitats, biomes, and so forth An early exception to these approaches was... way of organizing ecology in a novel and hopefully thought-provoking way, where the emphasis is on placing ecology in a planetary— or Earth Systems context These processes (and their Gaian effects) are summarized in Table 1.2 Some processes, such as natural selection and Overview 13 Table 1.2: Summary of the fundamental processes of ecology The suggested Gaian effect (ϩ, Ϫ, or ?) is given in parentheses... due to an asteroid or a comet impact (O’Brien et al., 2005) Although questions about the possibility of life on planets other than the Earth are fascinating, my main intention with this book is to use an astrobiological perspective as a means of thinking about the fundamental processes of ecology on Earth In the context of all the changes we are making to our planet, an attempt to recast academic ecology. .. through the damp earth. ’ (Darwin, 1859, p 489) Some years ago in an essay in the journal Oikos I argued that Darwin’s image ignored many of the most important parts of the system, such as the microorganisms in the soil and the mycorrhizal fungi in the plant roots (Wilkinson, 1998) Indeed, while Darwin stressed the animals (birds, insects, and worms), it is the plants, fungi, and, most importantly, the microbes... thunder bolt: chance and change in history 10.2 Historical contingency and ecology 10.3 Historical contingency and the Earth System 10.4 Overview 11 117 117 118 119 120 123 124 124 125 128 129 From processes to systems 11.1 An Earth Systems approach to ecology 11.2 Cybernetics, regulation, and Gaia 11.3 Rotten apples: a conceptual model of the evolution of Gaia 11.4 Conservation biology and the Earth System... nature Indeed organisms have been described as ‘islands of order in an ocean of chaos’ (Margulis and Sagan, 1995) The way in which organisms manage to achieve this is well known, but far from trivial, as it lies at the core of ecology As is so often the case with overly familiar points, there is a real danger of ignoring them, indeed many ecology textbooks fail to emphasize the ideas I discuss in this... space; for example interplanetary dust particles currently add approximately 300 tonnes of organic matter to Earth every year (Gribbin, 2000) Studies of Comet Halley on its last close approach to the Earth in 1986 inferred the identity of a wide range of organic chemicals, ranging from simple compounds such as pentyne and hexyne to more complex ones such as iminopropene and xanthine (Kissel and Krueger,... measure of ‘randomness’ in a system whereas information can be thought of as a certain kind of lack of randomness A more formal definition of entropy requires the concepts of ‘phase space’ and ‘coarse graining’ (see Penrose 2004, chapter 27) However, for the arguments developed in this book all that is required is an understanding of the reciprocal relationship between entropy and information and a ‘feel’... planetary ecology 6.2 Daisyworld 6.3 Examples of the role of life in planetary physiology on Earth 6.4 The importance of biomass, an illustration from the Earth s past 6.5 Biomass and Gaia 6.6 Overview 68 68 69 77 79 81 7 Photosynthesis 7.1 Quantification and mysticism in the seventeenth century 7.2 The diversity of photosynthesis on Earth 7.3 Photosynthesis and the Earth System 7.4 Oxygen and the Earth . class="bi x0 y0 w0 h1" alt="" Fundamental Processes in Ecology This page intentionally left blank Fundamental Processes in Ecology An Earth Systems Approach David M. Wilkinson Liverpool John Moores. contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about and worms crawling through the damp earth. ’ (Darwin, 1859,. Historical contingency and ecology 125 10.3. Historical contingency and the Earth System 128 10.4. Overview 129 11. From processes to systems 131 11.1. An Earth Systems approach to ecology 131 11.2.