Figure 2

Mantel correlogram (a: nitrogen niche; b: temporal niche) between the Euclidean distance matrix of OTU niche values and phylogenetic distance matrix. Solid symbols denoted significant (P < 0.05, 1000 permutations) correlations (phylogenetic signal), and open symbols denoted non-significant points. The OTU niche values were estimated using abundance-weighted approach. The phylogenetic distance was obtained by transforming phylogenetic tree into Patristic distance and partitioned into classes by 0.02 units for calculations. LN: low nitrogen soil (N deposition rate: 5.25 g N m⁻² yr⁻¹); HN: high nitrogen soil (28 g N m⁻² yr⁻¹).