Abstract Detail

Pteridological Section/AFS

Krieg, Christopher [1], Watkins, James [2].

Sunfleck utilization across ferns, cycads, and angiosperms.

Plants face a significant challenge in managing the variability of light in nature. Of particular importance for many understory plants are sunflecks: brief moments of high light that penetrate the canopy to reach plants on the forest floor. Sunflecks are an important phenomenon that expose plants to irregular patterns of light with variable intensities against a background of low diffuse light. These fluctuating, intermittent flecks of light can account for up to 80% of some plant’s daily carbon gain. A significant amount of research over the years has explored sunfleck utilization from many perspectives: from sun and shade adapted plants to global perspectives including climate change.  Little effort has been invested in understanding how sunfleck utilization varies across different lineages. Some research indicates that ferns lack an important photoreceptor that may impact light utilization in low light conditions.  Ferns also have other unique aspects of photobiology that may further impact light use relative to other plants. The goal of our current research is to compare differences in sunfleck utilization among angiosperms, cycads, and ferns. We were specifically interested in understanding if and how ferns vary in sunfleck use efficiency and other aspects of photosynthetic physiology relative to seed plants. To address this, plants were grown in a common garden greenhouse environment. Light response curves were generated from 11 ferns (both epiphytic and terrestrial), six angiosperms, and 4 cycads to derive several photosynthetic parameters. Plants were then dark adapted under shade cloth of approximately 4% light for at least 2 hours. Species were then exposed to a set of sunflecks: 1) 5 flecks at 800 umol m^-2 s^-1 for 10 seconds each, separated by 120 seconds of low light,  2) 5 flecks at 800 umol m^-2 s^-1 for 60 seconds each, again separated by 120 seconds of low light.  We found that plant responses to sunflecks were complex and different among taxa and functional groups. Ongoing work and data analysis will shed light on how these differences relate to plant lineage. 

1 - Colgate University, Biology, 13 Oak Dr, Hamilton, NY, 13346, United States
2 - Colgate University, Department Of Botany, 129 Ho Science Center, 13 Oak Drive, Hamilton, NY, 13346-1338, USA

Keywords:
Sunfleck
ecophysiology
fern
pteridophyte
cycad
Photosynthesis
light.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PPD006
Abstract ID:737
Candidate for Awards:None