Aboveground-Belowground Interactions under Global-Environmental Change are Complex -- But not Beyond Generalization

Abstract:

As we try to make sense of how global environmental change influences ecosystems, and in turn, how changes in ecosystems feedback to influence carbon cycle and climate dynamics, aboveground-belowground interactions logically must be part of the picture. Soil processes, plant-microbe interactions and root-shoot dynamics influence plant productivity, competitive outcomes, compositional change and biogeochemical cycling; and the quality and quantity of elemental inputs to soils (from plants) help drive ecosystem (plant plus soil) carbon storage. Given the myriad of possible aboveground-belowground interactions, and the challenges of studying them under global change, one might presume that responses are so context-specific that generalization and an associated path to improved modeling are beyond our reach today and in the near future. I argue that trait trade-offs, optimality, allometry, stoichiometry, biodiversity-ecosystem function, trophic cascades and other constraints and mechanisms narrow the possible responses, and that by incorporating such ideas into our thinking and doing (theory, experiments, syntheses, observations and modeling), we can make sense out of this natural complexity