Recovering trophic structure through habitat restoration: A review

Restoration ecologists have long-called for more holistic approaches to ecosystem restoration and tools for monitoring restoration success. There has been an increased number of restoration projects assessing ecosystem-scale processes, such as nutrient cycling and productivity. However, an examination of trophic interactions (e.g., trophic position, linkages, and diversity) as a tool for assessing restoration success is limited and can provide a more complete depiction of restoration success when coupled with traditional community metrics. Here, the impact of habitat restoration on trophic recovery was assessed through a targeted literature review, analyzing how trophic structure responds to habitat restoration over time, compared to control sites, and viewed across ecosystems. Overall, trophic structure recovers following restoration but may require several years. Comparing systems, restoration of trophic structure in terrestrial environments has received less attention (19%) as compared to freshwater (31%) and coastal (50%) systems. Community metrics and stable isotopes were the most common methods for assessing trophic interactions and will likely continue to be valuable tools when assessing how restoration impacts ecosystems. In terms of best practices to achieve and quantify trophic restoration success, future studies should increase frequency and duration of pre- and post-restoration monitoring, establish consistency in selecting control sites, and incorporate habitat structural elements compatible with restoration to attract higher trophic level species. The inclusion of trophic interactions in restoration projects generates a more comprehensive understanding of trophic structure and ecosystem function and offers insights to develop more effective management strategies for achieving long-term restoration success.