Table 2. Summarized themes, their significance for knowledge integration, and key lessons identified in reviewed literature. Introductions and synthesis chapter of Reid et al. (2006) were excluded from analysis. IK = indigenous knowledge. Theme(s) Significance Key Lessons Similarities and differences between IK and science, and benefits and challenges of using and integrating IK. An understanding of similarities and differences between IK and scientific knowledge, and the benefits and challenges of integrating these different knowledge systems, is a prerequisite to knowledge integration. - IK and Western knowledge systems are complementary or parallel rather than fundamentally incommensurable. - Differences between IK and science can be resolved through collaborative approaches and by finding common ground. - Some IK-based practices resemble Western science but former tend to be based on important social mechanisms. - Science is better equipped to detect causal links, and to evolve quickly enough to accommodate new information. - Tensions between IK and science persist: some IK holders reject Western philosophy’s focus on truth, belief, and worldview. - Difficulties of including IK in ecological research may outweigh the benefits. Methods for using and integrating IK, and institutions, processes, and partnerships for maintenance and integration of IK. Advances in methods and processes are essential to join knowledge integration theory and practice. - The methodological toolkit is expanding beyond collection of IK to methods for bringing different sources and forms of knowledge together, i.e., scenarios, mapping, community theater. - A sophisticated array of institutions, processes, and partnerships to integrate knowledge exist as well as reflection on their success. IK and culture, scale, politics, law, and policy. Culture, scale, politics, law, and policy all form the social context of knowledge integration. - Knowledge integration needs to be cognizant of the culture-knowledge link, and its evolution in response to global and regional change. - Choice of scale can influence the agendas or contexts in which knowledge is organized and decisions made, and whose knowledge is relevant. - How knowledge holders position their knowledge in political arenas is important. - Scientists who engage with IK need to understand the international law and policy contexts in which IK is situated, and implications for access to knowledge. - National laws and policies need to make space for indigenous forms of cultural practice. Evaluation of IK and integration. Need to assess different types of knowledge, the combined products of integration, and the process by which they are combined. - Much evaluation of integrated knowledge has largely concerned the credibility of IK in the eyes of science. - Recent initiatives recognize a need for a broader set of evaluative criteria to assess knowledge. - IK has its own rules about processes of knowing, which diverge from the rules of science. - Evaluation processes need to distribute power more equally across knowledge producers. - IK has a crucial role for evaluation of science: through integration, IK holders can scrutinize scientific predictions themselves, increasing the potential for science to be trusted.