Table 3: Estimated direct effects on the endogenous latent variables in the overstory-understory SR model, along with corresponding standard errors and values (see Figure 4).

Path ModelDirect effectStandard error valueb

Late-seral herb cover (LSHERB) =
  Overstory cover (TREE)−0.1910.0750.011
  Tree density (ln(TPH) × 10)−0.0830.1680.620
  Stand age (AGE)0.1560.0440.000
  Aspect (ASPECT × 10)0.4230.1620.009
  Fine litter (FLITTER)0.2730.1810.132
  Coarse litter (CLITTER)0.2050.2190.351
  Understory cover (UNDER)0.1760.0470.000

Fine litter (FLITTER) =
  Overstory cover (TREE)0.1710.0320.000
  Tree size (QMD)−0.1020.0380.007
  Tree density (ln(TPH) × 10)−0.4000.1270.002
  Aspect (ASPECT × 10)0.0000.0400.999
  Understory cover (UNDER)0.0720.0120.000

Coarse litter (CLITTER) =
  Tree density (ln(TPH) × 10)0.1690.0550.002
  Stand age (AGE)0.0300.0110.007

Understory cover (UNDER) =
  Overstory cover (TREE)−0.5080.1810.005
  Tree density (ln(TPH) × 10)−0.9890.3910.012
  Aspect (ASPECT × 10)1.5430.4190.000
  Coarse litter (CLITTER)−0.2840.2810.313

bStatistical tests were based on a t-distribution with 1180 degrees of freedom, with adjustments for the nested sampling structure on standard errors.