We expected to find relationships between stand age and cost factors, and we found them
Proximity to markets is correlated with stand age
New mills should bring down harvest ages; stands closer to mills may well produce more pulpwood and less sawtimber; and other stand age-dependent values obtained from forests should be similarly affected by mills
As we expected, our analysis found statistically significant relationships between stand ages and variables associated with harvest and transport costs. Most significantly, distance to mill does affect the age distribution of stands, and this finding has implications for economic and ecological research.
One implication of the research is that an area with a new mill should experience general reductions in stand ages in the vicinity of the mill, and the reductions should correspond with the distance to that new mill. While we did not test this question directly, there are sound theoretical reasons why the relationship should be causal.
Our research showed that, at least within fifteen road miles of a sawmill, stand ages increase by 0.8 years per road mile for NIPF and industry-managed stands. For government-owned stands, stand age increases by 0.36 years per road mile. Pulp mills also apparently affect stand ages in the southern Appalachians of Virginia and North Carolina: within 80 road miles of the mill, each road mile of distance adds 0.17 years for NIPF-managed stands and 0.33 years for industry-managed stands.