Figure 1.
Sampling strategy in the field.
40 sediment cores were sampled at two stations (20 cores each) located on different sandbars of the intertidal, and hosting communities of high or low diversities respectively. A: Samples were taken with a metal cylinder to 10 cm depth. B: Entire sediment cores were placed into containers. C: The sampling corer fitted exactly in the container so that the internal structure of the sediment core remained as intact as possible. D: The metal corer was carefully removed.
Figure 2.
4 microcosm containers were placed in each of 10 tubs. The time0 control (A) was analyzed at the start of the experimental treatment when temperature was changed in the high temperature treatments. The experimental groups of high (B1) and low (B2) diversity were kept at constant temperature throughout the experiment: elevated (36°C) for the test group and normal (31°C) for the "temperature control" group. Each experimental group was replicated 5 times. The live control (C) was used to monitor nematodes throughout the experiment.
Table 1.
Abbreviations for experimental groups.
Figure 3.
Comparison of the two field assemblages.
Mean (± Standard deviation) of A: Species richness (S), B: Diversity (H’; Index of Shannon Wiener), C: Trophic diversity (IDT−1), and D: Abundance (individuals per 10 cm2).
Table 2.
Student’s t-test of community attributes between the two field sampling stations (n = 4).
Figure 4.
Graphical representation of typical species of each diversity group.
Species are represented by different colors. The corresponding percentage (up to 90%) of contribution was calculated by SIMPER and is listed in Table 3. HD = High diversity, LD = low diversity. A: The two communities sampled in the field, B: Experimental control groups (before the start of the experiment), C: Assemblages exposed to normal temperature and D: Assemblages exposed to high temperatures.
Table 3.
Percentages contribution (%) of the top 90% discriminating genera of the two field stations and the six experimental groups.
Table 4.
Student’s t-test of environmental variables between the two field sampling stations (n = 4).
Figure 5.
Comparison of the experimental assemblages.
Mean (± standard deviation) of A: Species richness (S), B: Diversity (H’; Index of Shannon Wiener), C: Abundance (individuals per 10 cm−2), D: Trophic diversity (IDT−1), E: Individual biomass (in µg wet weight), and F: Community biomass (in mg wet weight). HD = High diversity, LD = Low diversity. White bars = time0 controls, light gray bars = control temperature (31°C), dark gray bars = high temperature (36°C). Asterisks indicate significance levels after multiple comparisons with Dunnett test between xDt0 and xD31 and xD36 respectively. Significance between xD31 and xD36 were assessed with Student’s t-tests. *<0.05, **<0.01, ***<0.001.
Table 5.
F- and p-values of 2×3 factorial ANOVA (n = 5).
Table 6.
F- and p-values of 1-way ANOVAs for each diversity group (n = 5).