Appendix B. Changes in soil attributes across the boundary of the central G. tricolor population.
The table presents least-squared means and standard errors for soil variables measured within core, edge, and peripheral zones from a mixed model analyses that included boundary type (oak canopy vs. valley bottom), transect nested within boundary type, and the interaction between population zone and boundary type, in addition to the main effect of population zone. P values indicated in bold are significant after application of the sequential Bonferroni correction for eight tests. For each soil attribute showing significant variation among population zones, values not sharing the same letter are significantly different from each other. (N = 30)
Soil attribute |
Core population sites |
Edge population sites |
Peripheral population sites |
P |
Ca:Mg ratio |
0.88 ± 0.27a |
0.90 ± 0.26a |
1.55 ± 0.26b |
0.0060 |
% Organic matter |
4.48 + 0.77a |
6.12 + 0.67a |
10.55 + 0.77b |
< 0.0001 |
Cation exchange capacity (meq /100 g dry soil) |
18.92 ± 1.00a |
21.78 ± 0.92b |
22.18 ± 0.965b |
0.0074 |
pH |
6.66 ± 0.05a |
6.89 ± 0.04b |
6.94 ± 0.05b |
0.0015 |
Nitrate (NO3, ppm) |
20.42 ± 0.54a |
7.89 ± 0.49b |
9.17 ± 0.52b |
0.0017 |
Phosphorous (P, ppm) |
3.33 ± 1.19 |
5.82 ± 1.06 |
6.51 ± 1.15 |
0.0976 |
Potassium (K, ppm) |
269.27 ± 30.27 |
276.85 ± 26.34 |
341.1 ± 29.30 |
0.1441 |
% Clay |
20.42 + 1.20 |
21.32 ± 1.05 |
21.85 ± 1.16 |
0.6388 |