Modelling effects of disturbance on population dynamics of generalized crayfish life history strategies.
Crayfish play a crucial ecological role and are often considered a keystone species within freshwater ecosystems; however, North American crayfish species face disturbance and ecological threats including invasive species and intensified drought. Demographic models can allow examination of population dynamics of a targeted species under a wide variety of disturbance scenarios. In this study, crayfish population dynamics were modelled and their responses to simulated biological invasions and drought were assessed. As life history data on crayfish are relatively rare, models were used to explore the population viability of four generalized species with distinct life history strategies under 11 disturbance scenarios. RAMAS-Metapop was used to construct stage-based demographic metapopulation models parameterized using vital rates from established literature sources. Models indicated that populations respond differentially to disturbance based on life history. However, both r- and K-selected species appear to be highly susceptible to decline when faced with the additive effects of reduced carrying capacity resulting from invasion and reduced survival rates caused by drought. Constructing models that explore a broad array of life histories and disturbance regimes can provide managers with tools to develop generalized, widely applicable conservation strategies in data-depauperate systems.