Increasingly, severe wildfires have led to declines in biodiversity across all of Earth’s vegetated biomes [D. B. McWethy et al., Nat. Sustain. 2, 797–804 (2019)]. Unfortunately, the displacement of Indigenous peoples and place-based societies that rely on and routinely practice fire stewardship has resulted in significant declines in biodiversity and the functional roles of people in shaping pyrodiverse systems [R. Bliege Bird et al., Proc. Natl. Acad. Sci. U.S.A. 117, 12904–12914 (2020)]. With the aim of assessing the impacts of Indigenous fire stewardship on biodiversity and species function across Earth’s major terrestrial biomes, we conducted a review of relevant primary data papers published from 1900 to present. We examined how the frequency, seasonality, and severity of human-ignited fires can improve or reduce reported metrics of biodiversity and habitat heterogeneity as well as changes to species composition across a range of taxa and spatial and temporal scales. A total of 79% of applicable studies reported increases in biodiversity as a result of fire stewardship, and 63% concluded that habitat heterogeneity was increased by the use of fire. All studies reported that fire stewardship occurred outside of the window of uncontrollable fire activity, and plants (woody and nonwoody vegetation) were the most intensively studied life forms. Three studies reported declines in biodiversity associated with increases in the use of high-severity fire as a result of the disruption of Indigenous-controlled fire regimes with the onset of colonization. Supporting Indigenous-led fire stewardship can assist with reviving important cultural practices while protecting human communities from increasingly severe wildfires, enhancing biodiversity, and increasing ecosystem heterogeneity.

Transdisciplinary sustainability training is a recognized need in many graduate programs. However, there is limited analysis of specific pedagogical tools to support this effort, particularly from the perspective of graduate students. Here, we reflect on the application of a "theory of change" process to support transdisciplinary thinking among early career researchers with diverse disciplinary backgrounds. For class participants, the theory of change process helped to clarify the diversity of actors associated with their research, to unpack their assumptions about complex problems, to clarify important causal linkages, and to support the development of a systems perspective. Challenges in using the theory of change in the classroom context included the difficulty of putting boundaries around student projects, and the additional time requirements involved in completing a detailed theory of change. The process helped class participants situate their specific and more disciplinary research projects in a broader sustainability context.

The relationship between Indigenous peoples and the functioning of terrestrial ecosystems has received increased attention in recent years. As a result, it is becoming more critical for researchers focusing on terrestrial ecosystems to work with Indigenous groups to gain a better understanding of how past and current stewardship of these lands may influence results. As a case study to explore these ideas, we systematically reviewed articles from 2008 to 2018 where research was conducted in North America, South America, and Australia. Of the 159 articles included, 11 included acknowledgement of Indigenous stewardship, acknowledged the Indigenous Territories or lands, or named the Indigenous group on whose Territory the research was conducted. Within the scope of this case study, our results demonstrate an overall lack of Indigenous acknowledgement or consideration within the scope of our review. Given the recent advancements in our understanding of how Indigenous groups have shaped their lands, we implore researchers to consider collaboration among local Indigenous groups as to better cultivate relationships and foster a greater understanding of their ecosystems.

In this perspective paper, we aim to provide insights that can help academic institutions and transdisciplinary doctoral programs position themselves within a changing research landscape and prepare for future disruption. We are a group of eight first-year, transdisciplinary doctoral students at the University of Waterloo, representing diverse disciplinary perspectives and gender and cultural experiences. In the process of orienting ourselves as sustainability researchers, we conducted collaborative workshops to critically examine our intellectual and disciplinary positionality by reflecting on the question: What will a PhD look like in the future? Amid this process, the coronavirus pandemic happened, causing a major disruption to our research activity and personal lives. What began as a reflective process on doctoral research shifted toward a more substantive and far reaching discussion about disruption and academia. Through our workshops we identified four emerging trends in the domain of sustainability scholarship that are shaping the future of the academic experience: shifts from disciplinarity to transdisciplinarity; researchers as knowledge holders to knowledge brokers; researcher competencies as bounded to boundary-less; and metrics of success as citation impact to societal impact. We also identified three broad trends in the context of academia that were accelerated by the coronavirus pandemic and may be exacerbated by future disruptions: (1) increasing virtualization of research and teaching; (2) increasing need for flexibility of academic structures and processes; and (3) growing economic and socio-political uncertainty. We offer concrete recommendations that encourage doctoral students and programs to play a more fundamental role in solving complex challenges in a disrupted academic and social landscape. We conclude with our vision of the PhD student of the future as one who thrives in transdisciplinary settings, links society and science through knowledge brokering, spans boundaries between multiple epistemologies to communicate and collaborate through uncertainty, and prioritizes societal impact.

Identifying how past human actions have influenced their environment is essential for understanding the ecological factors that structure contemporary ecosystems. Intertidal resource use by Indigenous Peoples for thousands of years has led to habitation sites containing vast shell midden deposits and facilitating long-term impacts on soil chemistry and drainage. Here we examine how these shell middens have impacted various forest metrics, such as species diversity, community composition, canopy height, and regeneration recruitment to determine if forests on habitation sites differ from the surrounding matrix. We surveyed known habitation sites with archeological evidence indicating past year-round human occupation, within the Hakai Lúxvbálís Conservancy on Calvert and Hecate Islands within the Great Bear Rainforest along British Columbia’s Central Coast. Our results demonstrate that habitation sites exhibit lower tree species richness, less relative species abundances, as such, displayed lower Shannon diversity and inverse Simpson values. The composition of tree communities on habitation sites was statistically different, with western hemlock and western redcedar densities increasing on non-habitation sites. Conversely, regeneration diversity at habitation sites was more even and exhibited elevated Shannon diversity and inverse Simpson values. The community composition of regeneration was more consistent among habitation and non-habitation sites; however, western redcedar, western hemlock and Sitka spruce were more abundant at habitation sites. For all tree species, maximum height was higher within the habitation sites; however, this trend was the most notable in western redcedar and Sitka spruce, which increased by an average of 4.8 m relative to non-habitation sites. Collectively, our findings suggest that long-term habitation alters forest community compositions. The landscape alterations within habitation sites promote conditions needed to support diverse, even, and abundant regeneration communities and consequently increase the height of the dominant coastal tree species. Thus, our results offer evidence that long-term influence by Indigenous communities have a persistent influence on coastal forests.