Abstract
Climate change and disruptions to disturbance regimes contribute to
uncertainty about the best ways to manage forests and promote individual
tree health. Indicators of tree health include annual growth, formation
of defensive structures (resin ducts), and ability to produce defensive
compounds (resin). Higher growth and resin duct area are associated with
a lower chance of mortality from disturbances (Ferrenberg et al. 2014).
Past research suggests that prescribed burning and thinning treatments
can have positive impacts on growth and resin duct metrics (Kolb et al.
1998; Hood et al. 2016), indicating that management activities have the
potential to help increase and restore tree health. However, there is
limited research comparing different disturbances and management
activities in terms of impacts on tree growth, resin ducts, and resin
flow. In this research we explore the questions: 1) What factors most
influence resin flow in ponderosa pine (Pinus ponderosa)? 2) What is the
impact of fire or timber harvest on tree growth, resin flow, and resin
ducts? 3) Are there changes in the relationships between tree growth and
resin duct metrics that occur after disturbance, which may indicate
shifts in tree resource allocation to growth vs. defenses?