Sunday, May 19, 2013

What Does Collapse Tell Us About Resilience?

The adaptve cycle is key to understanding resilience as an integrated ecological and social construct.  The cycle is introduced elsewhere in this Web Log ( as well as briefly defined in the BES Urban Lexicon (  One of the key aspects of the cycle is the movement of systems in a conceptual space defined by the accumulation of capital in the structure of the system, and the increasing complexity of the system at the same time (Figure 1).
Fig. 1. Capital and complexity as two axes of the
adaptive cycle of resilience. r-K contrasts
trace out the blue trajectory.

Ecological Foundation of Increasing Complexity

As an ecologist, I find these these increases easy to understand, since they parallel changes that have long been understood from ecological succession.  One of these shifts is based on resource capture.  Dominance of the plant community shifts from species that specialize in the capture of resources that are freely available in the environment, to dominance by species that specialize in conserving the resources they have already captured.  Think of fast growing, high resource-demanding colonizing species or weeds, compared to slow growing, resource hoarding trees that get by on modest fluxes of nutrients and light.  This kind of contrast is labeled in both plants and animals as r versus K strategies. 

The biological contrast in complexity emerges from the similar successional differences.  For example, later successional communities typically have a larger number of canopy layers, as well as greater spatial heterogeneity.  These patterns result from the growth of long-lived canopy-forming plants, insertion of lower layers dominated by shade-tolerant species, and the emergence of species that spread clonally.  The massive, long-lived, and spatially extensive structures are good at storing and allocating assimilated resources. 

However, the slow growth rates and massive structures associated with dominance in late successional comminities also make those systems vulnerable to external disturbances, such as wind, fire, or disease outbreak.  The same species that manage assimilated resources have evolved structures and processes that ill suit them to deal with environments where resources are freely available.  This is what sets up the adaptive cycle of r-K shift with subsequent release and reorganization.

In social systems, accumulation of capital or wealth is a familiar trajectory.  Settlements are often initiated in sites where resources or the opportunity to concentrate resources is high.  In such situations the external resources, be they rich soil for crops, industrially valuable minerals, or fossil fuels for example, are initially untapped.  As the settlement accumulates more residents and built structure, it assimilates more resources.  Furthermore, urbanization is associated with increasing capacity to assimilate and process more resources.  All this is expressed as wealth embodied in the system.

Driving Complexity in Social Systems

But what strategic contrast might explain the shift in the social complexity of the system?  Joseph Tainter's (1988, 2006) analysis of the collapse of social systems exposes the sources of social complexity.  The built structure of settlements clearly becomes more complex.  In addition to raw density of structures, often the height and heterogeneity of structures increases.  Infrastructure to move people, goods, resources, and wastes is developed.  Specialization of jobs and lifestyles emerges, and the demographic differentiation of the population typically increases as residents are drawn from other settlements or different rural areas.  Of great importance is the elaboration of increasingly layered, spatially extensive administrative and governance structures.  Specialized knowledge and training echo the increasing administrative compelxity.   

This suite of differences, along with many others, consolidate into fixed, self-perpetuating structures that are initially adaptive.  As an already complex society attempts to solve its problems it can only add additional layers or kinds of organizational complexity.  Yet, each new innovation involves a cost that necessarily produces less return on the investment.  Thus, according to Tainter, the growth of complexity in societies will trace out a curve of decreasing marginal return over time.  Once marginal return declines to lower levels, the society is poised to disintegrate because the fixed investment leaves the society vulnerable to such things as resource depletion, invasion, internal unrest, or simply voluntary migration to a less burdensome region.  Environment and resources play a role, but the lens through which the crisis comes into focus is through the economics of marginal return on investment.

Tainter’s model explains the social component of the “front loop” of the adaptive cycle in social-ecological systems.  Many analyses in the literature have focused on the inertia and rigidity that result from high levels of social complexity (Biggs et al. 2010).  What Tainter exposes is the mechanism for the increase in social complexity.  Social complexity results from the accumulation of incremental solutions to the problems that society identifies.  Such complexity may interact with external and internal shocks of either social or biophysical origin to either cause collapse or to generate adaptive reorganization.


Biggs, R., F. R. Westley, and S. R. Carpenter. 2010. Navigating the back loop: fostering social innovation and transformation in ecosystem management. Ecology and Society 15:Article 9.

Tainter, J. A. 1988. The collapse of complex societies. Cambridge University Press, New York.

Tainter, J. A. 2006. Social complexity and sustainability. Ecological Complexity 3:91-103.

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