Long-Term Data Three Ways: Using Longitudinal Data from Different Sources to Examine Sapling Canopy Recruitment Dynamics

by

Lance A. Vickers, David R. Larsen

PhD Graduate (LAV), University of Missouri, 203 Natural Resources Building, Columbia, MO 65211 ; Professor (DRL), University of Missouri, 203 Natural Resources Building, Columbia, MO 65211.

Abstract – Canopy recruitment is a critical component of the regeneration process which may span several years to decades. During this process, inter-tree dynamics can have lasting consequences on the composition and character of a forest. Because of the inherent complexity of this process, a need for continued effort towards developing and strengthening quantitative analysis and interpretation of these dynamics remains. The objective of this study was to utilize long-term data from multiple sources to examine canopy recruitment dynamics in regenerating stands. First, stem analysis data was used to chronicle height-age trajectories of trees that successfully recruited in to the canopy at the end of the regeneration period. These height-age trajectories were used to establish developmental milestones for canopy recruitment success. Next, these developmental milestones for successful canopy recruitment were compared to longitudinal height distributions derived from a chronosequence of several stands with similar characteristics. This provided inference into whether successful canopy recruits tended to exhibit outstanding height development relative to the general population throughout the regeneration process or only during certain times. Finally, the influence of neighborhood dynamics on the probability of an individual tree successfully recruiting into the canopy was modeled using data from long-term, canopy-mapped plots. Together, analyses from these three sources of long-term data provide needed inference into the following basic questions of recruitment dynamics: How fast do trees need to grow to successfully recruit into the canopy? Do only exceptional trees successfully recruit into the canopy? What is the influence of neighborhood composition on recruitment dynamics?