Controls on terrestrial ecosystem processes: an historical perspective -- Species and biotic interactions as ecosystem drivers -- Aboveground-belowground interactions as drivers of ecosystem processes -- Aboveground-belowground interactions and global change -- Emerging issues and trends -- Biotic interactions in soil as drivers of ecosystem properties. Introduction ; Influence of decomposers on aboveground communities and ecosystem processes ; Free-living soil microbes, nutrient availability, and plant growth ; Trophic interactions in soil, nutrient availability, and plant growth ; Functional consequences of trophic cascades in the soil food web ; Bacterial-based and fungal-based energy channels and nutrient cycling ; Influence of root-associated organisms on plant communities and ecosystem processes ; Microbial symbionts and plant community dynamics ; Belowground pathogens, herbivores, and plant community dynamics ; Soil ecosystem engineers and plant community dynamics -- Soil biotic interactions, carbon dynamics, and global change. Soil biotic interactions and ecosystem carbon exchange ; Contribution of soil biotic interactions to climate change via carbon-cycle feedbacks ; Multiple global change drivers and soil biotic interactions ; Conclusions -- Plant community influences on the soil community and plant-soil feedbacks. Introduction ; How plants affect the belowground subsystem ; Differential effects of different plant species ; Effects of within-species variation ; Spatial and temporal variability ; Multiple species effects -- Overriding effects of plant traits. Contrasting plant species and trait axes ; Trait dominance, trait dissimilarity, and multiple species effects ; Ecosystem stoichiometery ; Plant-soil feedbacks ; Succession and disturbance ; The build-up phase of succession ; Ecosystem retrogression ; Succession and plant-soil feedbacks -- Indirect belowground effects of global change via vegetation. Indirect belowground effects of climate change ; Indirect belowground effects of nitrogen deposition -- Ecosystem-level significance of aboveground consumers. Introduction ; Herbivore-mediated effects on plant-soil feedbacks and ecosystem processes ; Positive effects of herbivores on belowground properties and ecosystem functioning ; Negative effects of herbivores on belowground properties and ecosystem functioning ; Landscape-scale herbivore effects and multiple stable states ; The role of plant traits in regulating herbivore impacts ; Aboveground trophic cascades and consequences for belowground properties ; Spatial movement of resources by consumer organisms ; Resource transfers across land ; Resource transfers from aquatic to terrestrial ecosystems ; Aboveground consumers, carbon dynamics, and global change ; Conclusions -- Aboveground and belowground consequences of species losses and gains ; Introduction ; Species losses through extinction and aboveground-belowground linkages ; The diversity-function issue from an aboveground-belowground perspective ; Removal experiments for studying effects of species losses ; Effects of species losses in real ecosystems ; Species gains through invasion and aboveground-belowground linkages ; Invasions by plants ; Belowground invaders ; Invasions by aboveground consumers ; Consequences of global change through causing species gains and losses ; Conclusions -- Introduction ; Biotic interactions, feedbacks, and ecosystem processes ; Linkages and feedbacks between the aboveground and belowground subsystems ; Organism traits as ecological drivers ; Drivers of spatial and temporal variability ; Drivers of variation over time ; Drivers of variation over space ; Differences across ecosystems ; Global-scale contrasts ; Global change phenomena.