Author Affiliations
1Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China2University of Chinese Academy of Sciences, Beijing 100049, Chinashow less
Fig. 1. Effect sizes of nitrogen (N), phosphorus (P), nitrogen+phosphorus (NP), phosphorus+potassium (PK), nitrogen+phosphorus+potassium (NPK), organic fertilizers (OF), and organic fertilizers + NPK (OF+NPK) on soil total PLFA. The error bars indicate effect sizes and 95% bootstrap confidence intervals. The effect was statistically significant if the 95%CI did not bracket zero. The dashed line is drawn at effect size = 0. The sample size for each variable is shown next to the bar.
Fig. 2. Effect sizes of nitrogen (N), phosphorus (P), nitrogen+ phosphorus (NP), nitrogen+phosphorus+potassium (NPK), organic fertilizers (OF), and organic fertilizers+NPK (OF+ NPK) on soil (a) fungi, (b) bacteria and (c) actinomycetes. The error bars indicate effect sizes and 95% bootstrap confidence intervals. The effect was statistically significant if the 95%CI did not bracket zero. The dashed lines are drawn at effect size = 0. The sample size for each variable is shown next to the bar.
Fig. 3. Effect sizes of nitrogen (N), phosphorus (P), nitrogen+phosphorus (NP), nitrogen+phosphorus+potassium (NPK) and organic fertilizers (OF) on soil (a) gram-positive bacteria, and (b) gram-negative bacteria. The error bars indicate effect sizes and 95% bootstrap confidence intervals. The effect was statistically significant if the 95%CI did not bracket zero. The dashed lines are drawn at effect size = 0. The sample size for each variable is shown next to the bar.
Fig. 4. Effect sizes of nitrogen (N), phosphorus (P), nitrogen+phosphorus (NP), and nitrogen+phosphorus+potassium (NPK) on the ratio of soil fungi to bacteria (F/B ratio). The error bars indicate effect sizes and 95% bootstrap confidence intervals. The effect was statistically significant if the 95%CI did not bracket zero. The dashed line is drawn at effect size = 0. The sample size for each variable is shown next to the bar.
Fig. 5. Effect sizes of nitrogen (N) on PLFA, fungi, bacteria, actinomycetes, gram-positive bacteria (G+) and gram-negative bacteria (G-) in (a) forest (b) grassland and (c) cropland. The error bars indicate effect sizes and 95% bootstrap confidence intervals. The effect was statistically significant if the 95%CI did not bracket zero. The dashed lines are drawn at effect size = 0. The sample size for each variable is shown next to the bar.
Fig. 6. Effect sizes of (a) ammonium nitrate and (b) urea on PLFA, fungi, bacteria, actinomycetes, gram-positive bacteria (G+) and gram-negative bacteria (G-). The error bars indicate effect sizes and 95% bootstrap confidence intervals. The effect was statistically significant if the 95%CI did not bracket zero. The dashed lines are drawn at effect size = 0. The sample size for each variable is shown next to the bar.
Variables | Slope | P | n |
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Latitude | | | PLFA | 0.012 | 0.155 | 34 | Fungi | 0.007 | 0.575 | 30 | Bacteria | 0.006 | 0.477 | 26 | G- | -0.003 | 0.812 | 22 | Longitude | | | PLFA | -0.002 | 0.090 | 34 | Fungi | -0.001 | 0.492 | 30 | Bacteria | -0.001 | 0.466 | 26 | G- | -0.0010 | 0.439 | 22 | MAT | | | | PLFA | 0.018 | 0.183 | 23 | Fungi | 0.018 | 0.296 | 22 | MAP | | | | PLFA | 0.000 | 0.531 | 28 | Fungi | 0.000 | 0.885 | 27 | Bacteria | 0.000 | 0.907 | 23 | G- | 0.000 | 0.361 | 21 | Nitrogen addition rate | | PLFA | 0.001 | 0.153 | 31 | Fungi | 0.001 | 0.090 | 32 | Bacteria | 0.001 | 0.051 | 28 | Actinomycetes | 0.001 | 0.392 | 22 | G+ | 0.002 | 0.015 | 22 | G- | 0.002 | 0.001 | 24 | F/B ratio | 0.000 | 0.513 | 21 | Nitrogen load | | | Fungi | 0.000 | 0.425 | 21 | Nitrogen duration | | PLFA | -0.0001 | 0.906 | 30 | Fungi | 0.0002 | 0.841 | 26 | Bacteria | 0.0005 | 0.524 | 22 | G- | 0.0006 | 0.434 | 21 |
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Table 1. Relationships between the effect sizes of nitrogen addition on microbial indicators (total PLFA, fungi, bacteria, actinomycetes, G+, G-, and F/B ratio), and experimental variables (latitude, longitude, MAT, MAP, nitrogen addition rate, nitrogen load, and nitrogen addition duration) based on a random effects model with a continuous variable meta- analysis.