Diversity deficits in modelled landscape mosaics

a r t i c l e i n f o We outline several diversity factors that modellers and models can include directly or indirectly in order to improve the accuracy and usefulness of the model. Without considering these factors, different types of diversity deficit can arise. These deficits can be considered in three domains: 1) in the real world where actual diversity is less than a potential state that is deemed desirable (hence we worry about loss of biodiversity and cultural diversity); 2) in modelling of the real world (where 'residual variance' may represent a diversity deficit of the model); and 3) in our recognition of the driving forces that are used to construct a model (a diversity deficit due to oversimplification). The goal of this review is to use these three domains of diversity deficit to evaluate existing models, with a longer term goal of creating a more robust framework for assessing landscape models in the future. To that end, we evaluate the behaviour characteristics and routines of agents in some current models. We also address one of the fundamental challenges to modelling diversity, which is the integration of non-economic motivations in the decision making of human agents. Diversity in landscape mosaics influences the production of goods and services and the tradeoffs between them at multiple scales through the lateral flows of water, nutrients, soil, organisms, fire and information (van Noordwijk et al., 2004). Diversity of this sort often gets lost through decision making oriented toward homogenization, which is usually linked to economies of scale in production for markets, or a result of poor awareness of the potential relevance of diversity. Although most of the diversity may be seen as neutral to current or planned functions, and is tolerated rather than actively pursued, loss of diversity can reduce our options for the future. Diversity deficits can be considered in three domains: 1) in the real world where actual diversity is less than a potential state that is deemed desirable (hence we worry about loss of biodiversity and cultural diversity); 2) in modelling of the real world (where 'residual variance' may represent a diversity deficit of the model); and 3) in our recognition of the driving forces that are used to construct a model (a diversity deficit due to oversimplification). The hypotheses we pursue here is that diversity deficits of the third type contribute to those of the second, …