A fresh framework for the ecology of arid Australia
Authors:Morton, S. R. Smith, D. M. Stafford Dickman, C. R. Dunkerley, D. L. Friedel, M. H. McAllister, R. R. J. Reid, J. R. W. Roshier, D. A. Smith, M. A. Walsh, F. J. Wardle, G. M. Watson, I. W. Westoby, M.
Volume:75
DOI:10.1016/j.jaridenv.2010.11.001
Published:2011
Document Type:Review
Abstract:A revised set of propositions about ecology in arid Australia is presented, based on research literature since publication of Stafford Smith and Morton (1990). Fourteen propositions distil our argument that most features of the Australian deserts are explicable in terms of two dominant physical and climatic elements: rainfall variability, leading to extended droughts and occasional flooding rains; and widespread nutrient poverty. Different landscapes within the arid zone show these features to varying degrees, and so it is important to think about different places separately when considering our propositions. Plant life-histories strongly reflect temporal patterns of soil moisture; because Australian deserts receive more variable rainfall than most others, there is a distinctive spectrum of life-histories. Low levels of phosphorus (together with abundant soil moisture on irregular occasions) favour plants producing a relative excess of carbohydrate (C). In turn, C-rich plant products sometimes lead to fire-prone ecosystems, assemblages dominated by consumers of sap and other C-based products, and abundant detritivores (particularly termites). Fluctuations in production due to variable rainfall provide openings for consumers with opportunistic life-histories, including inhabitants of extensive but ephemeral rivers and lakes. Most consumer species exhibit some dietary flexibility or utilise more dependable resources: these strategies give rise to greater stability in species dynamics and composition of assemblages than might first be imagined under the variable rainfall regime. Aboriginal people have had long-standing ecological influence as they accessed resources. For each proposition we suggest the extent to which it is 'different', 'accentuated' or 'universal' in comparison with other deserts of the world, recognising that this categorisation is in need of critical testing. Further tests of each proposition are also suggested to fill the many gaps that still exist in our knowledge of the structure and functioning of Australia's deserts. (C) 2010 Elsevier Ltd. All rights reserved.
Author Information
Corresponding Author:Morton, SR (通讯作者)，CSIRO Ecosyst Sci, POB 2111, Alice Springs, NT 0871, Australia.
Reprint Address:Morton, SR (通讯作者)，CSIRO Ecosyst Sci, POB 2111, Alice Springs, NT 0871, Australia.
Addresses:[Morton, S. R.; Friedel, M. H.; Walsh, F. J.] CSIRO Ecosyst Sci, Alice Springs, NT 0871, Australia; [Smith, D. M. Stafford] CSIRO Ecosyst Sci, Canberra, ACT 2601, Australia; [Dickman, C. R.; Wardle, G. M.] Univ Sydney, Sch Biol Sci, Inst Wildlife Res, Sydney, NSW 2006, Australia; [Dunkerley, D. L.] Monash Univ, Sch Geog & Environm Sci, Clayton, Vic 3800, Australia; [McAllister, R. R. J.] Queensland Biosci Precinct, CSIRO Ecosyst Sci, St Lucia, Qld 4067, Australia; [Reid, J. R. W.] Australian Natl Univ, Fenner Sch Environm & Soc, Acton, ACT 0200, Australia; [Roshier, D. A.] Deakin Univ, Sch Life & Environm Sci, Geelong, Vic 3217, Australia; [Smith, M. A.] Natl Museum Australia, Ctr Hist Res, Canberra, ACT 2601, Australia; [Watson, I. W.] Dept Agr & Food Western Australia, Northam, WA 6401, Australia; [Westoby, M.] Macquarie Univ, Dept Biol Sci, Sydney, NSW 2109, Australia
E-mail Addresses:steve.morton@csiro.au