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on socioecological systems (Redman and Kinzig 2003, Costanza et al. 2007, Van der Leeuw
et al. 2011, Dearing et al. 2012, Gillson and Marchant, 2014); how did societies adapt and
respond to changing conditions and what combinations of factors led to their collapse and
re-organization? (also see Chapters 5 and 6).
Understanding the resilience of socioecological systems is critical to adapting to environ-
mental change and in predicting the thresholds, or tipping points, at which ecosystems may
undergo drastic change and re-organization. The concepts of resilience and thresholds are
central to our ability to cope with, adapt to and ameliorate the effects of climate change (see
Chapter 1). If throughout time, we have repeatedly met and exceeded the resilience of socio-
ecological system, we might wonder why the entire biosphere has not collapsed. The reason is
that after a tipping point or threshold has been exceeded, systems reorganize, and complexity
is gradually rebuilt. So, rather than a threshold being seen as a point of collapse, it might more
usefully be seen as part of an adaptive cycle (Figure 7.1a) (Gunderson and Holling 2001).
Adaptive cycles begin with innovation and change, followed by maturation and complexi-
fication as new interactions and feedbacks are established (Gunderson and Holling 2001).
During periods of conservation, governance and social systems may become too rigid, or
overly attuned to present environmental conditions, so that they lose flexibility and the abil-
ity to adapt to changing environmental conditions. Collapse will occur when socioecological
thresholds are crossed, leading to a new cycle of innovation, adaptation, and building (Hol-
ling 1973, Redman and Kinzig 2003, Folke et al. 2004).
By combining long-term archaeological, palaeoecological, and neoecological data, with
modelling and simulation techniques, we can begin to understand how societies withstand
some environmental changes but succumb when environmental and social factors combine
to create a perfect storm (Dearing et al. 2012). Patterns of innovation, growth, collapse, and
reorganization have been observed in the palaeoecological and archaeological record. For
example, Dearing (2008) used a multiproxy study of speleothem, pollen, magnetic suscepti-
bility, and sand content to study millennial-scale patterns of land-use, erosion, and mon-
soonal intensity in the Erhai lake-catchment system, Yunnan, south-west China. Surface
erosion showed two distinct phases, the first, between 2,960 and 1,430 years b p, was resilient
to monsoon intensity and corresponded to landscapes undisturbed by people. However,
from 800 years bp, erosional intensity increased with monsoonal intensity, indicating a loss of
resilience in a landscape that had been more heavily influenced by anthropogenic activity
(Dearing 2008). Critically, the loss of resilience occurred not when intensive agriculture was
first initiated, but during periods of social upheaval, when agricultural landscapes were
abandoned, allowing rapid erosion of steep slopes, unbuffered by well-maintained terrace
systems (Figure 7.1b). Furthermore, this loss of ecosystem resilience appears to be hysteretic
(irreversible), even with reforestation, because erosion gullies formed in the degraded land-
scape. The study elegantly demonstrates how changes in social capital and land-use inter-
acted with environmental variables to drive an ecosystem across a threshold of reorganization,
to a new phase, itself maintained by emergent properties (Dearing 2008). This pattern maps
well onto the adaptive cycle of conservation, collapse, reorganisation and rapid growth,
shown in Figure 7.1a (Holling 2001, Holling et al. 2001, Gunderson and Holling 2001).
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