Figure 2.

Plant or plant community processes affected by shading at different temporal scales compared to the lengths of shading period applied in the previously published experiments with arbuscular mycorrhizal plants. Cumulative numbers of publications are shown for each shading duration. Each closed circle represents one publication, indicating the shortest shading duration tested. Publications shown in red are those listed in Table 1, dark blue are publications without non-mycorrhizal control treatment, light blue are publications with no significant impact of either mycorrhiza or light on the plant biomass, and gray indicates publications with confounding factors such as coincidental treatment with shade and temperature shift or those not reporting on plant biomass or those primarily addressing functioning of common mycorrhizal networks (CMN). Each small empty circle indicates repeated observation (sequential harvest) within a publication that is already shown in the figure. Arrows start at the earliest time point when a shading-induced effect in the respective process has been documented. Please note the log scale of the time axis. P, phosphorus; MGR, mycorrhizal growth response (here regarded broadly as a significant difference in biomass production of mycorrhizal vs. non-mycorrhizal plant at a given time point). Uncertainty related to the onset of the statistically significant difference in mycorrhizal colonization levels between shaded and unshaded plants in the publication by Tester et al. (1986) is indicated with a question mark.