Figure legends
Figure 1. Experimental design and sampling scheme (white dots, three replicates) of the litterbags in the three exposure scenarios: 0:100 (0 days terrestrial followed by 56 days aquatic), 25:75 (14 days terrestrial followed by 42 days aquatic), and 50:50 (28 days terrestrial followed by 28 days aquatic). The day 0 samples were used to assess initial oven-dry mass of the other samples. On the transition between the terrestrial and the aquatic environment, one set of samples was collected for assessing decomposition on the terrestrial environment.
Figure 2. Relationship between expected and observed values during 56 days decomposition under the three terrestrial:aquatic exposure scenarios: 0:100 (100% aquatic), 25:75 (25% terrestrial and 75% aquatic), and 50:50 (50% terrestrial and 50% aquatic). A,B,C. % mass loss; D,E,F. mg ergosterol gAFDM-1; G,H,I. number of conidia gAFDM-1 day-1; J,K,L,N,O. number bag‑1; M. mg bag-1. The dashed line represents 1:1 (no difference between expected and observed values). N=number of data-pairs and percentage of values higher-than-expected (above the 1:1 line), lower-than-expected (below the 1:1 line) or equal-to-expected (on the 1:1 line). Inset shows average (± 95% CL) of observed (O) and expected (E) values across the three exposure scenarios, an asterisk indicating significant differences after 2-way ANOVA (Table 2). Exposure scenarios with different superscript letters are significantly different after Tukey HSD test, an asterisk indicates a significant effect not detected by Tukey’s HSD test.
Figure 3. Global relative mixture effect (RME, mean ± 95% CL) and relative individual performance (RIP, mean ± 95% CL) on the study variables during 56 days decomposition under the three terrestrial:aquatic exposure scenarios, 0:100 (100% aquatic), 25:75 (25% terrestrial and 75% aquatic), and 50:50 (50% terrestrial and 50% aquatic). Closed red symbols denote significant RME or RIP effects, i.e., the 95% CL do not cross the zero line. Number of data-pairs: (a)  39, 50, 117; (b) 22, 14, 14; (c) 39, 39, 39; (d)  39, 49; (e) 21, 14, 14; (f) 39, 85;(g) 33, 26, 26.
Figure 4. Relative mixture effect (RME, mean ± 95% CL) on the study variables during 56 days decomposition under each of the three terrestrial:aquatic exposure scenarios, 0:100 (100% aquatic), 25:75 (25% terrestrial and 75% aquatic), and 50:50 (50% terrestrial and 50% aquatic). Closed red symbols denote significant RME effects, i.e., the 95% CL do not cross the zero line. Number of data-pairs: (a, e, g, i) 12, 15, 12; (b) 19, 19, 12; (c) 36, 45, 36; (d) 7, 9, 6; (f, h) 6, 5, 3.
Figure 5. Relative individual performance (RIP, mean ± 95% CL) on the study variables for alder and poplar leaf litter during 56 days decomposition under each of the three terrestrial:aquatic exposure scenarios, 0:100 (100% aquatic), 25:75 (25% terrestrial and 75% aquatic), and 50:50 (50% terrestrial and 50% aquatic). Closed red symbols denote significant RIP effects, i.e., the 95% CL do not cross the zero line. Number of data-pairs: (a) 12, 15, 12; (b, c) 18, 19, 12; (d) 27, 28, 30; (e) 6, 9, 6; (f) 9, 12, 12; (g, j) 6, 5, 3; (h, i) 9, 8, 9.
Figure 6. Relative mixture effect (RME, mean ± 95% CL) on the process of decomposition (1/3 mass loss, 1/3 decomposers, and 1/3 detritivores) during 56 days, globally across scenarios (global) and under each of the three terrestrial:aquatic exposure scenarios, 0:100 (100% aquatic), 25:75 (25% terrestrial and 75% aquatic), and 50:50 (50% terrestrial and 50% aquatic). Closed red symbols denote significant RME effects, i.e., the 95% CL do not cross the zero line. Number of data-pairs: 206, 67, 79, 60.