Topographical constraints, ecological units, and system memory.

Most philosophers that study constraints consider them noncausal. But Ross (2023, 2024) posits an account that attributes causality to one category of constraint (i.e., "causal constraints"). In this essay, I extrapolate and add to Ross' account to argue that topographical features causally constrain complex ecological dynamics. Topographical features possess four defining characteristics that are common to all constraints and satisfy the two criteria to qualify as causal (on the interventionist account of causal explanation). I refer to these as topographical constraints. Furthermore, I suggest that the existence of topographical constraints compels a reimagination of the ecological unit question as it appears in the philosophy of ecology. The ecological unit question asks what method adequately delimits the boundaries of organizational units (e.g., populations, communities, ecosystems, etc.). I propose the topographical-ecological unit delimitation (TEUD). The TEUD is a novel method to integrate topographical constraints into descriptions of ecological units, which enhances understanding of both openness and historical contingency. Finally, I demonstrate how the TEUD is applicable to contemporary spatial resilience research that studies system memory.