Incorporating temporal dynamics to enhance grazing management outcomes for a long-lived species

Identifying successful management strategies for long-lived species is challenging, especially in fluctuating environments, because the response of individual vital rates and overall growth rates to management action can vary over time. A demographic approach that isolates the impact of management and environment on individual vital rates, and assesses their importance for growth rate over time, can indicate whether and why a management strategy is successful.
Here we take a demographic approach to assess the success of grazing management for the perennial grass Stipa pulchra, the state grass of California and a focus of conservation efforts. We tracked S. pulchra populations in paired grazed and ungrazed plots over six years, which included an historic drought and an El Niño rain year, and calculated summary transition matrices for the main effects of year, grazing, and year x grazing interaction for each site. We averaged these summary transition matrices to calculate population growt...