Nature - autonomous learning

the dis/unity of geography 211biophysical world (like river meanders and atmospheric depressions).Thesepatterns typically occurred at the meso- or macro-scales. Later, smaller-scaleprocess studies revealed that these patterns were not as regular as previouslythought because the processes generating them were affected by various‘intervening factors’. Even so, these process studies still tended to presumea set of fairly consistent (if complex) relationships between environmentalprocesses (like wind and water motion) and environmental patterns andforms (like vegetation height and river profiles). Recently, however, manyphysical geographers have challenged the ‘equilibrium’ ideas that have beenso popular in their discipline (Box 4.5). In simple terms, equilibriumideas suggest that all parts of an environmental system are adjusted to theflows of energy and materials that pass through them. Any perturbationof a system’s equilibrium state (unless it is very strong) will normally leadto a process of ‘negative feedback’ that will restore the system to its originalstate (a process of homeostasis or self-regulation). However, equilibriumideas are now being challenged by those derived from chaos theory, complexitytheory, quantum mechanics and the so-called ‘new ecology’. 12 Theprecursor to these ideas in physical geography were those concerningenvironment thresholds (Brunsden and Thornes 1979), inspired in partby catastrophe theory (Graf 1979).These various non-equilibrium ideascontend that the biophysical world behaves in irregular, inconsistent andnon-deterministic ways.They suggest that it can ‘switch’ between stableand unstable behaviour depending upon the circumstances (see Phillips1999). In short, non-equilibrium thinking challenges the idea that thereis, ontologically speaking, an inherent ‘balance’ between the various elementsof the non-human world. Among other things, this has profoundimplications for environmental management. For instance, if the same setof human actions on an environment can have radically different effectsdepending on the precise environmental conditions, then managementmeasures must adapt to this possibility rather than being of a blanket nature.Phillips (1999) provides a concrete example. He analyses the responseof hardwood swamps on the Atlantic and Gulf coasts of the USA to externalforcing (e.g. sea-level change or alterations of sediment inputs due tohuman influence). He shows that even small alterations in forcing variablescan produce divergent responses within and between hardwood swamps.So rather than responding in a uniform way, Phillips shows that the behaviourof swamps varies over space and time – in some cases remaining stable,in others tending towards drying out or submergence.