Structural Equation Modeling: Theory and Applications in Forest Management
Table 5
Estimated total effects (i.e., direct path and all possible indirect paths) on the endogenous latent variables in the overstory-understory SR model, along with corresponding standard errors and values.
Path model
Total effect
Standard error
valued
Late-seral herb cover (LSHERB) =
Overstory cover (TREE)
−0.244
0.069
0.000
Tree size (QMD)
−0.028
0.023
0.235
Tree density (ln(TPH) × 10)
−0.361
0.216
0.095
Stand age (AGE)
0.160
0.043
0.000
Aspect (ASPECT × 10)
0.725
0.187
0.000
Fine litter (FLITTER)
0.273
0.181
0.132
Coarse litter (CLITTER)
0.149
0.216
0.490
Understory cover (UNDER)
0.196
0.046
0.000
Fine litter (FLITTER) =
Overstory cover (TREE)
0.135
0.031
0.000
Tree size (QMD)
−0.102
0.038
0.007
Tree density (ln(TPH) × 10)
−0.474
0.120
0.000
Stand age (AGE)
−0.001
0.001
0.327
Aspect (ASPECT × 10)
0.111
0.053
0.038
Coarse litter (CLITTER)
−0.020
0.020
0.296
Understory cover (UNDER)
0.072
0.012
0.000
Coarse litter (CLITTER) =
Tree density (ln(TPH) × 10)
0.170
0.055
0.002
Stand age (AGE)
0.030
0.011
0.007
Understory cover (UNDER) =
Overstory cover (TREE)
−0.508
0.181
0.005
Tree density (ln(TPH) × 10)
−1.037
0.400
0.010
Stand age (AGE)
−0.009
0.009
0.337
Aspect (ASPECT × 10)
1.543
0.418
0.000
Coarse litter (CLITTER)
−0.284
0.281
0.313
dStatistical tests were based on a t-distribution with 1180 degree of freedom as the effects of the nesting structure on standard errors have been adjusted.