3.4 Effects of key soil properties on fungal community
composition
Soil properties explained 37.4%
of the total variance of the fungal community composition at the OTU
level (RDA analysis). The
community structure of Forest was more closely associated with soil SWC,
SOC, DOC, C/N, TN, and NH4+, and
activities of SC, ACPT, ACP, and ALP (Fig. 7a). By contrast, those of
the Berry and Peach were more strongly affected by pH, TP, AP,
NO3-, Ca, Mg, TK, AK, BD, GLS and UR
activities (p < 0.05). Pearson’s correlation indicated
that the dominant phyla had strong correlation with soil quality
indicators (Fig. 7b; Table S5). For instance, the relative abundance of
Basidiomycota decreased with the reduction of SOC content (p=0.033) and GLS (p =0.042).
The SEM model indicated that the key predictors collectively accounted
for 42% of the variation in fungal community diversity (Fig. 8). This
model depended on the contents of pH, TP, TN and SOC affected by
conversion. In particular, fungal diversity was directly and positively
mediated by the key soil quality indicators including TP (path
coefficient = 0.54, p <0.01) and pH (path coefficient =
0.51, p <0.001), and probably indirectly affected by
the contents of SOC, DOC and TN (Fig. 8). The fungal diversity also had
a direct negative impact on DOC contents (path coefficient = -0.19,p <0.001), SC (path coefficient =-0.38, p<0.01) and ALP activities (Fig. 8). The key soil quality
indicator SOC was positively and directly related to TN, DOC and SC
activities (Table S7), and it also increased with ALP activities via SC.
However, SOC exerted a direct positive impact on TP (Fig. 8).