Table 2. Summary of means and standard errors (SE) for ecosystem functions and predator densities for 10 plots over three years across treatments.
Experiment 1: Plots | Experiment 2: Enclosures | |||||||
2009 | 2010 | 2011 | 2011 | |||||
Function and Predator Abundance | Mean | SE | Mean | SE | Mean | SE | Mean | SE |
Nitrogen Mineralization Rate | 0.268 | 0.043 | −0.245 | 0.091 | 0.825 | 0.109 | 0.980 | 0.071 |
Nitrification Rate | −0.002 | 0.003 | 0.008 | 0.003 | −0.001 | 0.001 | −0.020 | 0.014 |
Proportion acorns germinated | 0.213 | 0.048 | 0.085 | 0.042 | 0.010 | 0.006 | 0.443 | 0.072 |
Litterbag Decomposition Rate (g g−1yr−1) | 0.302 | 0.011 | 0.190 | 0.013 | 0.263 | 0.013 | 0.524 | 0.035 |
Litterbox Decomposition (g g−1 yr−1) | 0.125 | 0.028 | 0.176 | 0.038 | 0.252 | 0.028 | 0.392 | 0.011 |
Wood Decomposition (g g−1 yr−1) | 0.353 | 0.038 | 0.237 | 0.040 | 0.144 | 0.020 | 0.867 | 0.091 |
Proportion Foliar Insect Damage | 0.022 | 0.004 | ||||||
Carabid Beetles (m−2) | 1.7 | 0.3 | 0.3 | 0.1 | 1.6 | 0.5 | 0.1 | 0.1 |
Centipedes (m−2) | 4.9 | 0.9 | 7.8 | 2.4 | 8.8 | 1.9 | 2.1 | 0.4 |
Spiders (m−2) | 26.9 | 3.3 | 52.5 | 12.3 | 62.7 | 11.0 | 173.5 | 16.3 |
Data are from American beech stands in a New Hampshire forest where half the plots had reduced red-backed salamander abundance and from enclosures in similar stands with densities of salamanders from 0–4/m2.