Abstract Detail

Physiology

Worden, Katie [1], Wollman, Katherine [2], Stookey, Courtney [3], Waring, Elizabeth [4].

Proximity to Illinois River Impacts Photosynthetic Leaf Traits in Oaks.

Oaks (Quercus species) thrive in considerably varied ranges of light availability yet possess unique moisture content in riparian and upland environments. Differing environments from riparian to upland allow oak tree health and function to be collected, quantified, and analyzed in various ecosystems. One method to determine the health of the photosynthetic systems in oaks is by measuring chlorophyll fluorescence, acquiring detailed information on the light reactions of photosystem II. Tree leaf traits varied across a riparian and upland gradient as well as between species of Quercus at ten sites along the riparian Upper Illinois River and upland Northeastern State University’s campus in Tahlequah, Oklahoma. Gathering leaf traits for comparison provides an understanding of changes in leaf photosynthetic machinery, leaf shape, leaf nutrient content, and soil moisture. Photosynthetic traits and leaf traits influenced by the proximity to the river were evaluated through plant and environmental parameters. Soil moisture was measured under each tree and leaves that were in full sunlight were measured using Photosynq MultispeQ 2.0 to assess photosynthetic machinery function and chlorophyll content. Leaves were then measured for leaf area and transported to the lab to be dried and weighed for leaf specific area. While there was no effect of species of oak on photosynthetic traits, as distance from the river increases, nonphotochemical quenching and photosynthetic rates as measured as linear electron flow increased (p<0.01 for both measurements). The leaf specific area of the oaks increased with proximity to the river (p<0.0001) indicating that leaves closer to the river are broader and thinner to allow for greater light capture. Due to the nature of the sites, riparian environments were denser than their upland counterparts, elucidating the riparian leaves’ broadness and lower photosynthetic rates despite proximity to the river as a consequence of light competition.

1 - 1524 N YELLOWOOD AVE, BROKEN ARROW, OK, 74012, United States
2 - Grand River Dam Authority, Biology, 15971 N. Highway 10, PO Box 292, Tahlequah, OK, 74464, USA
3 - Grand River Dam Authority, Biology, 15971 N. Highway 10, PO Box 292, Tahlequah, OK, 74464, United States
4 - Northeastern State University, Biology, 611 N Grand Ave, Tahlequah, OK, 74464, USA

Keywords:
Quercus
leaf traits
oaks
photosystem II
specific leaf area
non-photochemical quenching
linear electron flow
photosynthetically active radiation
riparian vs upland
light competition
river proximity on leaf traits in oaks
Illinois River.

Presentation Type: Oral Paper
Session: PHYS, Physiology
Location: /
Date: Wednesday, July 21st, 2021
Time: 1:15 PM(EDT)
Number: PHYS010
Abstract ID:334
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize,Physiological Section Best Paper Presentation