Community Resilience to Climate Change: Theory, Research and Practice

44 to the connectivity of a system, whereas diversity relates to the variety among elements of the system. Table 1. Enabling conditions for general resilience [1,27,45] Openness of a social-ecological system is related to modularity at larger scales. Free trade among social-ecological systems often improves human well-being, for example. In ecosystems, seed dispersal plays a key role in recovery from large infrequent disturbances [28]. On the other hand, too much openness can transmit harmful shocks, as when bank collapses spread from country to country or an invasive species moves easily across a rather homogeneous and connected landscape. Tradeoffs between modularity and openness with respect to system fragility are understood for some ecosystems [27,29], and ecological principles have been applied to banking networks [30]. However the analysis of modularity versus openness is a research frontier for social-ecological systems. Reserves—of organisms, knowledge, or skills for example—also contribute to recovery from disturbance. Residual plants and animals are important in ecological recovery from disturbance, even in extraordinarily devastating fires and volcanic eruptions [31]. Social memory and residual social networks play somewhat similar roles in recovery of social systems after major disasters [2]. Feedbacks in social-ecological systems are sometimes manageable, at least in part. Where it is possible, feedbacks should be managed to move the social-ecological system away from thresholds that trigger harmful outcomes. For example, reductions in soil phosphorus content move watersheds farther away from the threshold that causes toxic algae blooms and fish mortality in lakes and reservoirs [32]. In social-ecological systems, incentives or sanctions to conserve common-property resource stocks should be transparent, effective, and tied closely to the human actions that affect the resource, but implementation of such practices is not easy [33,34].