Ecological Archives E087-165-A7
Amy L. Freestone. 2006. Facilitation drives local abundance and regional distribution of a rare plant in a harsh environment. Ecology 87:2728–2735.
Appendix G. Results of nominal logistic regression modeling presence of Delphinium uliginosum at a 1-m2 scale with presence of moss and important environmental variables. Nonsignificant variables, including early-season soil moisture (P = 0.2), P (P = 0.3), K (P = 0.3), Mg (P = 0.3), Ca (P = 0.6), Na (P = 0.8), S (P = 0.2), Zn (P = 0.4), Mn (P = 0.5), community biomass (P = 0.3), Ca/Mg (P = 0.1), % bare cover (P = 0.5), % woody cover (P = 0.9), soil depth (P = 0.8), and the interactions between moss and early season soil moisture (P = 0.8), late-season soil moisture (P = 0.5), Ca/Mg (P = 0.4), and community biomass (P = 0.7), were not retained in reduced model.
Term |
Estimate |
SE |
|
P |
Late-season soil moisture (% saturation) |
0.092 |
0.016 |
34.8 |
<0.0001 |
Sand (%) |
0.186 |
0.034 |
29.2 |
<0.0001 |
Silt (%) |
0.524 |
0.088 |
35.4 |
<0.0001 |
Organic matter (%) |
-0.451 |
0.088 |
26.4 |
<0.0001 |
pH |
-5.59 |
0.821 |
46.4 |
<0.0001 |
Nitrate-N (ppm) |
-0.056 |
0.012 |
20.0 |
<0.0001 |
Fe (ppm) |
-0.104 |
0.030 |
12.4 |
0.0004 |
Cu (ppm) |
-3.79 |
0.643 |
34.8 |
<0.0001 |
B (ppm) |
1.57 |
0.255 |
37.8 |
<0.0001 |
Soluble salts (mmhos/cm) |
3.94 |
0.809 |
23.8 |
<0.0001 |
Rock cover (%) |
-2.20 |
0.399 |
30.3 |
<0.0001 |
Herb cover (%) |
-1.79 |
0.462 |
15.1 |
0.0001 |
Presence of moss |
0.340 |
0.106 |
10.3 |
0.001 |
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