Development of Ecosystem Research
Total Page：16
File Type：pdf, Size：1020Kb
International Scholarly Research Network ISRN Ecology Volume 2011, Article ID 897578, 20 pages doi:10.5402/2011/897578 Review Article Development of Ecosystem Research Raymond Louis Specht1, 2, 3, 4, 5 1 Department of Botany, The University of Queensland, Brisbane QLD 4072, Australia 2 Department of Botany, The University of Adelaide, Adelaide, SA 5005, Australia 3 Department of Botany, The University of Melbourne, Melbourne, VIC 3010, Australia 4 Kearney Foundation of Mineral Nutrition, University of California, Berkeley, CA 94720, USA 5 Agriculture and Forestry Departments, University of Oxford, Oxford OX1 2JD, UK Correspondence should be addressed to Raymond Louis Specht, [email protected] Received 15 January 2011; Accepted 10 February 2011 Academic Editor: D. Pimentel Copyright © 2011 Raymond Louis Specht. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Experimental studies established the major community-physiological processes that determine the structure, growth and biodiversity of overstorey and understorey plants and resident vertebrates in an ecosystem. These community-physiological studies were promoted internationally by the UNESCO Arid Zone Research Program, the International Biological Program (Sections Productivity, Production Processes and Conservation), the International Union for the Conservation of Nature and, finally, the International Geosphere-Biosphere Program that is studying the impact of Global Warming on the World’s ecosystems. During the short period of annual foliage growth in evergreen plant communities, aerodynamic fluxes (frictional, thermal, evaporative) in the atmosphere as it flows over and through a plant community determine the foliage projective covers and leaf attributes in overstorey and understorey strata. These foliar attributes determine the community-physiological constant, the evaporative coefficient, of the plant community. An increase in air temperature of 2◦C during this period of annual foliage growth will affect the structure of the plant community, so that tall open-forests → open forests → woodlands → open scrub → low open-shrubland → desert communities. Variation in available soil water during this short period of annual foliage growth will influence vertical shoot growth but not foliage projective covers and leaf attributes produced in the overstorey stratum. 1. Introduction: Ecosystem Professor Prescott, jointly Director of the Waite Agricul- Science—University of Adelaide (1940s) tural Research Institute and C.S.I.R.O. Soils Division, had investigated the effect of climate (monthly values of the The integrated study of producers, consumers, and decom- Transeau Ratio P/E, the Meyer Ratio P/s.d., the Prescott Ratio posers in relation to climate, topography, and soils in space P/s.d.0.75, where P = precipitation, E = pan evaporation, and time—ecosystem research—was proposed by Professor equivalent to optimal evapotranspiration, s.d. = satura- Tansley of Oxford University in Volume 16 of Ecology [1]. My tion deficit) on the development of soils and agriculture initiation into ecological research in the 1940s occurred at throughout the continent [8]. In the late 1940s, Butler was the same time as pedologist-ecologist, Crocker, of the Waite using gypsum blocks to monitor soil water levels under the Agricultural Research Institute and Prof. Wood, the Professor rotational wheat field on the Waite Institute grounds [9]. of Botany of the University of Adelaide, were attempting to integrate the changing climates of the Quaternary with Two distinctive plant formations [10]—with a grassy the soil-forming processes and vegetation patterns of South understorey on medium-nutrient soils and with a heathy Australia [2–5]. The input of calcareous dust and sodium understorey on nutrient-poor soils—had survived in the chloride blown inland from the sea-beds exposed when sea humid to subhumid areas of the State for over 50 million levels fell had a marked effect on both soils and vegetation. years, since the break-up of Gondwanaland [11]. Massive movements of sand dunes swept across the South Intensive research was being undertaken on improving East into Victoria [6]; a swirling system of sand-dunes the nutrition of crops and pastures on medium-nutrient resulted in the Arid Centre of Australia [7]. soils in the State—all of which needed added phosphate 2 ISRN Ecology fertiliser (+ nitrogen fixed by legumes) to survive. Pastures that the “inquiry method” was the best way to understand on the nutrient-poor soils, however, needed added trace the intricacies of the native vegetation of Australia. As elements, such as copper, zinc, even cobalt (for animals) for the education of secondary school students in biology was development. The truncated lateritic podzols of the Fleurieu a responsibility of the Professor of Botany, the Botany Peninsula and on Kangaroo Island not only fixed large Department of the University of Adelaide conducted an amounts of superphosphate within the crystalline lattice of introductory workshop for science teachers in December their kaolinite clay, but fixed traces of molybdenum, making 1942 and introduced an evening subject, titled Biology I, to these nutrients unavailable to plants [12, 13]. enable these teachers to feel confident in teaching the biology Professor Wood, a world leader in plant biochemistry section of “Intermediate General Science”[29]. Thanks to the who had previously studied the water-conservation phys- inspiring example of my Mathematics–Science teacher and iology of arid zone and sclerophyllous (heathy) plants lifelong colleague Stanley J. Edmonds [30], University Schol- [14–16], had turned the talents of the Botany Depart- arship recipient Ray Specht was diverted, by the Education ment to study the biochemistry of nitrogen (ammonium Department of South Australia, from Physics-Mathematics versus nitrate metabolism), phosphate, potassium, copper, to study Biology, Educational Methods, and Educational zinc, and molybdenum nutrition. My postgraduate student, Psychology—disciplines that provided a sound basis for Brownell, demonstrated that minute traces of sodium in sea- the development of teaching and holistic research into the spray were essential for the nutrition of Arid Zone chenopods physicochemical processes operating in plant communities [17]—and, later in James Cook University at Townsville, in and associated consumers and decomposers (Specht 1976) tropical grasses [18]—most of which are C4-photosynthetic [31]. plants [19]. The usual way of teaching biological concepts is by the “chalk-and-talk” or “lecturing” method. It was only after the Field experiments were established on Dark Russian satellite Sputnik was launched in 1958 that educators Island heathland north-east of Keith in the in Europe and the United States began to question the Ninety-Mile Plain to examine the effect of added training of students in science. Materials for the “inquiry superphosphate, nitrate, copper and zinc fer- method of teaching” of biology were developed by the tilizers [20–22]. This vegetation had flourished Biological Sciences Curriculum Study (BSCS) in Colorado, for millions of years on nutrient-poor soils United States; three alternative sets of resource materials with exceedingly low levels of these nutrients— (teaching strategies to discover “major ideas”) were produced essential for the establishment of pastures in based either on the cell, the whole organism, or the ecosys- the region. Remarkably, most heathland species tem.TheBSCSapproachtoteachingbiologywaseagerly responded to the addition of superphosphate— promoted by biological science teachers in South Australia greatly in short-lived understorey species, least and Victoria, but teaching materials had to be adapted in species that survived for a long time in to the distinctive Australian biota. The “inquiry” teaching postfire succession. strategy was strongly supported in the Australian Academy Comparative studies were made on the uptake of of Science by Robertson and Turner who were, respectively, radioactive-labelled phosphate and its translo- Professors of Botany in the University of Adelaide and cation from roots to tops on seedlings of Melbourne at that time. The Academy mortgaged its building Banksia ornata and Avena sativa [23,page to provide the necessary finance for the preparation of 295]. The polyphosphate-conservation strategy teaching materials for an advanced secondary biology course, that enables low-nutrient heathland and euca- “Biological Science: The Web of Life”[32], in which a team of lypts to survive was elucidated in the Univer- biological scientists and teachers integrated the three BSCS sity of Melbourne [24–28]. In southern Aus- sets of teaching materials dealing with cell, organism, and tralia where a cool wet season alternates with ecosystem. The teaching materials were used initially in summer drought, orthophosphate is released South Australia, Victoria, and Queensland [33, 34]andsoon from decomposing litter during spring to be spread to all States of the Commonwealth. For many years, stored as polyphosphate granules in rootlets the number of copies of these teaching materials that were and associated rhizosphere organisms; these published annually by the Academy was exceeded only by the polyphosphate granules are later hydrolysed print run of the N.S.W. telephone book. to orthophosphate and transported to foliage