Ecological Archives E087-040-A3

Susan Harrison, James B. Grace, Kendi F. Davies, Hugh D. Safford, and Joshua H. Viers. 2006. Invasion in a diversity hotspot: exotic cover and native richness in the Californian serpentine flora. Ecology 87:695–703.

Appendix C (Table C1). Results for the “reduced form” of the model of native richness (Fig. 2 in main article) presenting unstandardized estimates, test statistics, and standardized parameters. The reduced form model omits the composite variables and permits tests of the relationships among observed variables for significance. Z values are analogous to t-values and judged similarly. LNR = log native richness, OV = overstory canopy cover, OV2 = overstory canopy cover squared, BUR = density of animal burrows, LPPT = log mean precipitation, K = soil potassium concentration, LEC = log exotic plant cover, B = soil boron concentration, C/M = soil calcium to magnesium ratio, GR = whether the site was actively grazed or not, LELV = log mean elevation. Mplus code for both reduced form and composite models can be obtained from JBG.
 
Estimates
SE
z value
StdYX
LNR =        
OV 0.014 0.005 3.113 0.842
OV2 -2.523 0.564 -4.477 -1.178
BUR 0.021 0.006 3.734 0.311
LPPT 0.352 0.077 4.580 0.441
K 0.002 0.001 3.316 0.321
LEC=        
K 0.006 0.002 3.761 0.238
B 1.710 0.546 3.133 0.178
C/M 0.207 0.058 3.584 0.167
OV -0.017 0.004 -4.824 -0.266
BUR 0.045 0.014 3.282 0.171
GR 0.778 0.283 2.753 0.156
LELEV -0.583 0.112 -5.207 -0.307
Residual Variances        
LNR 0.132 0.018 7.348 0.679
LEC 0.699 0.095 7.348 0.248


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