Abstract Detail

Ecology

Holkeboer, Noah [1], Greer, Gary [1].

Forest stand structure in relationship to basal node architecture. .

Trees compete for light and thus above-ground space by optimizing structural integrity and hydraulic efficiency of their woody stems. Secondary xylem is responsible for structural integrity and hydraulic supply and, given their independent physical principles, tradeoffs are likely between these functions. Thus, the resulting architecture of a tree (i.e., rates of branching and taper and the angle of branching) should reflect the evolutionary history of its species plus plastic responses to local environmental circumstances. To our knowledge, all published field-based research regarding tree architecture has, by necessity, employed destructive data collection techniques, prohibiting or complicating long term or stand-level study. Here we report on a pilot study using photograph-based measurements to study the architecture of a quarter-hectare forest plot dominated by Acer saccharum and Quercus rubra. A destructive assessment of the reliability of this approach is reported in an oral presentation at this conference; see Holkeboer, Polaski, May, Foy, and Greer. In this study, we mapped each tree in the plot, measured d.b.h. directly, and photographed each tree in its entirety plus its basal node; the latter under the assumption that the largest limb is under greatest demand and will display branch proportions and angles that are a function of smaller-scale anatomical traits typical of a given species. We investigated the following questions: (1) Does species dominance correspond to a specific hydraulic x structural-support optimization per widely-used models (e.g., Murray’s Law and the Uniform Stress Model)? (2) Did the two dominant species exhibit different tradeoffs and levels of variation in architecture, the latter a presumptive measure of plasticity. We found that species dominance did not correspond to tree architecture, however, the two dominant species differed markedly in the allometries of their hydraulic efficiency and structural support. We are currently investigating spatially-explicit effects of neighboring trees on architectural optimization.

1 - Grand Valley State University, Biology, 1 Campus Drive, Kindschi Hall 3319, Allendale, MI, 49401, USA

Keywords:
Trees
hydraulic efficiency
structural support
forest stand structure
species dominance.

Presentation Type: Poster
Session: P1, Ecology Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1EC028
Abstract ID:476
Candidate for Awards:None