Mixed-conifer Reference Conditions and Forest Dynamics


Reconstructed (1880) and contemporary (2012) size distributions for the Black Mesa mixed-conifer site utilizing dendrochronology reconstruction methods

Mixed conifer forests of the American Southwest have been impacted similarly to other conifer forests, yet reference condition information vital to restoration is limited. This is especially true with respect to spatial patterns, long term dynamics and the influence of site productivity; information critical to informing management decisions. It has been shown that landscape structures such as meadows, discrete tree patches, large trees, and aspen communities have declined as an interlocking understory of shade-tolerant and fire intolerant tree species increased and expanded their ranges, yet the spatial and temporal dynamics associated with these changes are rarely quantified and poorly understood.

Questions addressed by this research include:

  1. What is the contemporary and historical fine-scale spatial pattern in mixed conifer forests and how do shade tolerance and fire tolerance appear to affect these patterns.
  2. How do patterns of tree establishment correspond to a) site productivity, b) disturbance history, and c) climate?
  3. How do species composition, age distribution, and spatial pattern vary with fine and course spatial scales?
  4. Can we consistently detect growth and mortality events (as releases) using tree ring chronologies? What patterns emerge? How did historical competition conditions differ from those observed today?
  5. How does vegetation structure (aboveground biomass, canopy closure, vertical heterogeneity, etc.) vary by site and land-use legacies?