Table 2 Effects of nitrogen (N) enrichment on plant and soil biodiversity with the sub-dataset from the independent studies in our global dataset that include both plant and any group of soil biota (bacteria, fungi, or nematodes)

From: Global nitrogen enrichment impacts plant diversity more than soil bacterial and fungal diversity: a meta-analysis

Comparison

Biodiversity index

na

EComN (%)

Z

P

Plant

Soil biota

Plant vs. soil bacteria

Shannon index

40 (7)

−11.96% (*)

0% (ns)

6.75

<0.001

Richness

35 (7)

−7.92% (*)

-0.90% (*)

5.37

<0.001

Plant vs. soil fungi

Shannon index

14 (5)

−10.06% (*)

3.01% (ns)

6.51

<0.001

Richness

34 (5)

−17.02% (*)

3.28% (*)

6.92

<0.001

Plant vs. soil nematodes

Shannon index

9 (3)

−3.23% (ns)

−8.14% (ns)

0.38

0.705

  1. The Z-test is conducted to examine the effects of N enrichment between plants and soil biota. When the 95% confidence intervals, represented by error bars, do not overlap with zero, the effect is significant at P < 0.05 (marked with an *), otherwise, the effect is not significant (P > 0.05, marked with ns). The Z value with a P < 0.05 (two-sided test) indicates significant difference in N enrichment effects between plants and soil biota. The effect sizes (EComN, %) are standardized to a common rate (25 kg N ha−1 year−1) and duration (10 years) of N enrichment.
  2. aThe number of observations and total number of studies are included in the datasets.
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