Effects of forest management on biomass stocks in Romanian beech forests

Forest Ecosystems

Table 4 Model of the productivity (5-years aboveground biomass increment, Mg·ha⁻¹·y⁻¹) as a function of the dominant height, the stem density, the stand age and the forest treatment, analysed for production forest only before harvest

Parameter	Estimate	std error	t value	Pr(>\|t\|)
Model 3: Productivity = f (treatment, dominant height, age, stem density)
N = 1530, RMSE = 1.851, R² = 0.647
Intercept	2.056	0.307	6.694	3.04e–11
Treatment: Shelterwood	−0.013	0.111	−0.120	0.904
Aboveground biomass	0.016	4.9e–04	32.252	< 2e–16
Dominant height	0.009	1.1e–03	5.184	4.77e–16
Stem density	0.001	8.9e–05	16.171	< 2e–16
Stand age	−0.038	3.1e–03	−12.388	< 2e–16
Model 4: Productivity = f (forest management type, age, stem density, removal)
N = 1530, RMSE = 1.847, R² = 0.647
Intercept	2.042	0.308	6.637	0.00258 **
Treatment: Shelterwood	−0.018	0.111	−0.158	0.874
Aboveground biomass	0.016	5.1e–04	31.759	< 2e–16 ***
Dominant height	0.009	1.1e–03	8.118	3.86e–07 ***
Stem density	0.001	8.9e–05	16.190	< 2e–16 ***
Stand age	−0.038	0.111	−12.394	< 2e–16 ***
Biomass removed	0.002	0.002	0.825	0.410