Additional Files captions
Table S1 Coverage of plant species at the different
desertification stages.
Table S2 Primers and thermal profiles used for real-time PCR
quantification of the different phylogenetic and functional genes.
Table S3 ANOSIM and ADONIS analyses of microbial
beta-diversities between desertification stages.
Table S4 ANOSIM and ADONIS analyses of microbial
beta-diversities between superficial and deep layers.
Table S5 Results of least-squares linear regressions analysing
ecosystem functions and community metrics. The multifunctionality index
calculated with all possible combinations of one, two and three
functions.
Figure S1 Vertical variation in C, N, and P functions during
desertification. Significant differences between desertification sites
were based on a one-way ANOVA followed by an LSD test. Linear
least-squares regression relationships between multifunctionality and
soil depth were estimated. The bold lines denote the least-squares
linear regressions across soil depth, with their 95% confidence
intervals (grey-shaded areas). PD: potential desertification; MD:
moderate desertification; SD: severe desertification.
Figure S2 Variation in dominant phyla of soil microbiomes
during desertification development.
(A): Bacteria; (b): fungi; (C): archaea. Significant differences between
desertification stages were tested by the Kruskal-Wallis H test. PD:
potential desertification; MD: moderate desertification; SD: severe
desertification.
Figure S3 Variation in dominant phyla of soil microbiomes in
superficial and deep soils during desertification. Significant
differences between desertification sites were based on a one-way ANOVA
followed by an LSD test. PD: potential desertification; MD: moderate
desertification; SD: severe desertification.
Figure S4 Relationships between the dominant phyla of soil
microbiomes and multifunctionality at all sites. The red lines denote
the least-squares linear regressions with their 95% confidence
intervals (grey-shaded areas).
Figure S5 Relationships between the dominant phyla of soil
microbiomes and multifunctionality at different desertification stages.
The red lines denote the least-squares linear regressions with their
95% confidence intervals (grey-shaded areas). S : slope. PD:
potential desertification; MD: moderate desertification; SD: severe
desertification.
Figure S6 Variation in microbial alpha-diversity in superficial
and deep soils during desertification. Significant differences between
desertification sites were based on a one-way ANOVA followed by an LSD
test. PD: potential desertification; MD: moderate desertification; SD:
severe desertification.
Figure S7 Direct and indirect effects of soil depth, pH,
electrical conductivity (EC), bulk density (BD), microbial species index
or biodiversity index on multifunctionality. Structural equation models
are shown for the all data sets. Numbers adjacent to arrows are
indicative of the effect-size (bootstrap P value) of the
relationship. R2 denotes the proportion of variance
explained. Standardized total effects (direct plus indirect effects)
derived from the structural equation models depicted above. The
abundances of standardized dominant phyla of soil bacteria (Chloroflexi
and Acidobacteria), fungi (Ascomycota and Basidiomycota), and archaea
(Thaumarchaeota and Euryarchaeota) were then averaged to obtain an
overall microbial species index. These standardized diversity indexes
(Shannon and phylogenetic diversity) of soil bacteria, fungi, and
archaea were then averaged to obtain an overall biodiversity index.
Figure S8 Changes of plant litter and belowground biomass
during desertification development. Significant differences between
desertification sites were based on a one-way ANOVA followed by an LSD
test. The plant was dug up and the aboveground litter were clipped and
dried to obtain the litter biomass, and the roots were washed with tap
water and dried at 70 °C for 48 h to obtain belowground biomass.