Novel ecosystems—assemblages that diverge from historical baselines in composition, function, and dynamics—are increasingly widespread, yet their role in biodiversity futures remains contested. Some view novelty as a loss of ecological integrity, while others emphasize its potential to sustain biodiversity, ecosystem functions, and human well-being under accelerating global change. This session seeks to advance conceptual clarity by critically examining what constitutes novelty, how it differs across ecological and cultural contexts, and how these definitions shape scientific, management, and policy responses.

We will explore implications for biodiversity futures, recognising how novel ecosystems both challenge conservation targets based on historical reference conditions and open opportunities for resilience, ecosystem service provision, and adaptive governance. The session will also showcase emerging methods for anticipating novelty, including detection frameworks, scenario modelling, and early-warning indicators that can identify thresholds, forecast trajectories, and assess trade-offs between resisting, guiding, or accepting novelty.

Finally, contributors will examine governance and ethical dimensions of ecological novelty. Central to this discussion are questions of when, and under what conditions, acceptance of novelty is ecologically, socially, or ethically legitimate. By engaging diverse disciplinary and practice-based perspectives, the session will provide critical insights into how we define, anticipate, and govern novel ecosystems, and how these choices shape pathways to biodiversity futures.