Tuesday, March 17, 2015

What stand density is optimal in Ponderosa pine forest restoration?

 In my humble opinion, there is really only one chart needed to answer the question of what density is best for Ponderosa pine trees:
Source: The role of stand density on growth efficiency, leaf area index, and resin flow in southwestern ponderosa pine forests.  McDowell, Adams, Bailey, and Kolb.  (link)
 The lower the basal area, the more trees grow.  Growth is especially important in drought-stressed trees because lower growth can weaken tree defenses.  The lowest treatment in this study reduced trees to 7 m2 ha-1, and trees in this treatment had the highest leaf area per tree, indicating that they were healthiest at the time of the study.

Leaf area of understory plants was also highest at the lowest stand densities:
Source: ibid.
However, in the interest of full disclosure, this chart also shows (in panel B) that total forest resource utilization, measured by total leaf area, is highest at medium tree densities.

1 comment:

亚历山德拉 | Alexandra said...

This post is great! I want to complement your comment regarding "total forest resource utilization," however. Have you considered that such a measurement and its associated values may indicate the forest community members are potentially struggling at medium tree densities? Perhaps higher resource utilization is an indication of starvation-induced energy sequestration, or competition...