Resilience in landscape exploitation systems

A generic model is developed that describes the broad properties of land-exploitation systems from hunting-gathering societies to modern, intensive agriculture. The framework includes social, economic and ecological drivers of change, going beyond the concept of “sustainability” to establish a paradigm of “resilient exploitation” that calculates the capacity of landscape exploitation systems to survive in uncertain and variable human and natural environments. The model is highly aggregated, consisting of two state variables: (1) human-made capital and labour (H) and (2) natural capital (N). Depending on the parameters, the model displays a single non-trivial equilibrium, two equilibria, or stable limit cycles. Our analysis focuses on the strategies that exploiters employ, through varying their investment in H, and how this affects resilience of the system. We measure resilience as the size of the basin of attraction near a desirable equilibrium and the return time following small perturbations. Four general strategies are analysed and discussed using grazing systems as a particular example: (1) constant stocking rate, (2) maintaining grass stock, (3) constant utilization rate, and (4) a non-linear, compound strategy.