Figure legends
Figure 1 . Scheme of the experimental design. (1)Dilution . Fresh field soil was kept undiluted or diluted 1 ×
103 and 1 × 106 times using
sterilized soil to create high, moderate and low soil biodiversity
inocula, respectively. (2) Incubation . Each soil bag was sealed
using a sterilized cotton plug to avoid aerial microbial contamination
while permitting gas exchange, and then incubated at room temperature in
the dark until similar microbial abundance was observed among dilution
treatments. (3) Soil inoculation and transplanting . After
incubation, 200 g of soil inoculum was homogenized with 6800 g of
sterilized soil and sand mixture (1:1) in each microcosm. Each microcosm
received 24 seedlings from 1, 4, 8 or 12 plant species depending on
plant diversity treatment. (4) Simulating environmental
variation in precipitation . Three wet-dry cycles were implemented by
maintaining gravimetric soil moisture of 12-18% during the wetting
periods and by watering until most plants started to wilt during the
drying periods. At the end of each period, plant shoots were cut at 5 cm
above the soil surface to determine shoot biomass production.
Figure 2. The effect of the dilution-to-extinction approach on
soil microbial diversity, biomass (indicated by soil respiration rate
after incubation) and community composition. (A) The
dilution-to-extinction approach successfully reduced soil microbial
diversity (solid line) but did not alter the soil respiration rate (dash
line). The dilution-to-extinction approach dramatically reduced fungal
(B) and bacterial (C) diversity and altered the community composition of
soil microbes based on amplicon sequence variant (ASV) detection. Error
bar represents standard deviation (n = 3).
Figure 3. Soil biodiversity and plant diversity independently
influence stability-related indices. (A - E) The effects of plant
species richness (PS) and soil biodiversity on the temporal stability,
mean and standard deviation of community biomass production, and plant
species asynchrony and population variance. (F - J) The effects of plant
functional richness and soil biodiversity loss on these
stability-related indices. Effects of treatments on temporal stability
were partitioned into effects on plant species asynchrony and population
variance, or effects on temporal mean and standard deviation of
community biomass production. Light bands represent 95% confidence
intervals. Note: moderate and low soil biodiversity effects refer to the
differences to the high soil biodiversity treatment. ***P< 0.001; **P < 0.01; *P <
0.05; ns P > 0.05.
Figure 4.Relationships
between multitrophic biodiversity
and (A) the temporal stability of community biomass production, (B)
plant species asynchrony, (D) population variance, (C) the temporal mean
and (E) standard deviation of community biomass production. Effects of
treatments on temporal stability were partitioned into effects on plant
species asynchrony and population variance, or effects on temporal mean
and standard deviation of community biomass production. Light bands
represent 95% confidence intervals.
Figure 5 . Shoot biomass of grasses, herbs and legumes at each
harvest when microcosms were inoculated with high, moderate or low soil
biodiversity inoculum in the plant communities with 1, 4, 8 or 12
species.