Figure 3.

Quantification of the major pools and fluxes of ¹³C labelled recent plant assimilate in response to food web trophic complexity (1, 2 or 3 trophic groups) and drought (control in white and drought in grey). Net ¹³C (mg) in plant shoots immediately after the pulse labelling (a) and ¹³C exported from plant shoots (comprising either allocation to roots or lost as plant respiration) after 3 days expressed as a percentage of the net ¹³C fixed (b). From the amount of ¹³C (mg) exported from plant shoots, we calculate the percentage transfer to different carbon pools comprising bacteria (c), fungi (d), Collembola (e), predatory Acari (f) and soil CO₂ efflux (g). The soil CO₂ efflux includes root respiration and was measured during the first 24 hr after the labelling. Mean ± SE, significant differences among drought are indicated by asterisks (*p < .05; **p < .01; ***p < .001)