Staged-scale restoration: A systematic approach for improving restoration effectiveness

Background/Question/Methods

Over the last several decades, the art of ecological restoration is increasingly being enhanced by science as the discipline continues to mature. Nevertheless, the process by which managers go about deciding upon restoration strategies often draws largely on anecdotal observations, inferences from past experience at other sites, extrapolations from ecological theory, and educated guesses, rather than growing out of rigorous experimental evidence. As a result, this can lead to failures that are both costly and time-consuming.  In many prairie ecosystems, the lack of large, intact habitats compels managers to restore communities de novo, creating assemblages of native species in abandoned agricultural fields. These efforts often face formidable challenges in controlling invasive weeds, selecting appropriate native species to match local site conditions, developing effective methods to establish plant communities, securing adequate quantities of seed for desired species, and directing successional processes with appropriate management tools to facilitate ecological restoration. To develop more efficient solutions to these restoration challenges, we tested a “staged-scale” restoration strategy that rigorously explores multiple solutions to these problems in an adaptive management context. This systematic approach promotes the development of more effective restoration protocols closely tailored to particular site conditions.

Results/Conclusions

The staged-scale approach begins by identifying several promising restoration strategies that can be feasibly applied at large scales, and testing them in small, replicated experimental plots. Ideally, these tests are repeated several times, as we have observed significant between-year differences in restoration outcomes. Based on the results of these small-scale tests, the most successful treatments are then applied in scaled-up plots (e.g., increasing area by a factor of 10) while incorporating refinements suggested during the small-scale experiments. Restoration proceeds in increasingly larger steps, scaling up the most successful approaches and building on the accumulating, site-specific experience.  By delaying treatment of large areas until later in the process, we have been able to achieve desired results and reduce the likelihood of large, costly failures. Furthermore, the additional time before treating large areas also allows practitioners to increase essential resources such as seed quantity and diversity, and to carry out critical site preparation actions more effectively. We suggest that this more rigorous approach is applicable in a variety of restorations contexts, and is likely to produce more successful and cost-effective outcomes.