Restoration seed and plant material supply chains are complex social networks

Previous studies have advanced the conceptual framing of a “supply chain” to describe and examine key steps, inputs, and flows related to the production and use of seed and plant material in ecological restoration. However, these studies have paid less attention to investigating interrelationships among social actors throughout the “supply chain” stages for ecological restoration and allied activities. We applied social network analysis metrics to evaluate the number, kind, and strength of relationships among 157 social actors in the nine‐state region of the Northeastern United States, where rapid growth in restoration activities is driving a demand surge for native seed and plant materials. Restoration supply chains are more complex than previous conceptualization suggests, and we argue that the term “restoration supply networks” is more illustrative of this complexity. Results highlighted interdependency among different sectors, marked variation in input and output flows across spatial–temporal scales, and interplay among linear and nonlinear supply chain steps. The restoration supply network in the study area had a core–periphery structure, with a core comprising end‐users such as government agencies, design and build contractors, and non‐profit organizations surrounded by a periphery of seed and plant material suppliers. It is important to avoid oversimplifying seed and plant material supply chains as linear systems with strong linkages. Understanding relationship patterns among supply network actors can enhance communication, coordination, and collaboration among actors in all key restoration supply chain steps, a prerequisite to overcoming seed and plant material bottlenecks and meeting global restoration goals in the coming decades.