Effects of Smoke on Leaf Function of Broadleaf and Conifer Tree Species

Event Website

http://www.nafew2009.org/

Start Date

6-22-2009 12:00 AM

End Date

6-26-2009 12:00 AM

Description

During summer months, wildfires in western North America can produce large amounts of smoke. Nearly all of the studies that examine the effects of smoke on plants, have been tied to seedling germination, while the effects of smoke on leaf function are nearly uninvestigated. There is emerging evidence suggesting there may be a link between smoke produced from wildfires and patterns of sudden oak disease in California, although smokes’ role in this interaction is unknown. We hypothesize that plants may alter their defense chemistry strategy in response to fire and that smoke is the cue. The objectives of the study were: 1) to compare the effects of smoke exposure on leaf gas exchange and growth of several broadleaf and evergreen species (Populus tremuloides, Acer glabrum, Quercus gambeili, Pinus ponderosa, Pseudotsuga menziesii, and Picea pungens) common in the western North America forests where fires are common; and 2) to examine whether leaf defense chemistry changes in response to smoke exposure. Treated plants were exposed to smoke for 30 minutes in mid May and then again in early June. Following smoke exposure photosynthesis was measured at 30 minute intervals for 6 hours at both ambient and saturating CO2 levels (385 and 1000 ppm) to examine whether smoke affects stomatal or biochemical function. At the end of summer, plant tissues were harvested and weighed and leaves were analyzed for condensed tannins and phenolic glycosides. The results show that smoke negatively affects both stomatal and biochemical function, resulting in significant reductions in photosynthesis and that broadleaf species are more sensitive than conifers. Smoke had no significant affect on growth in any of the tree species, or phenolic glycoside concentrations in Populus tremuloides.

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Jun 22nd, 12:00 AM Jun 26th, 12:00 AM

Effects of Smoke on Leaf Function of Broadleaf and Conifer Tree Species

During summer months, wildfires in western North America can produce large amounts of smoke. Nearly all of the studies that examine the effects of smoke on plants, have been tied to seedling germination, while the effects of smoke on leaf function are nearly uninvestigated. There is emerging evidence suggesting there may be a link between smoke produced from wildfires and patterns of sudden oak disease in California, although smokes’ role in this interaction is unknown. We hypothesize that plants may alter their defense chemistry strategy in response to fire and that smoke is the cue. The objectives of the study were: 1) to compare the effects of smoke exposure on leaf gas exchange and growth of several broadleaf and evergreen species (Populus tremuloides, Acer glabrum, Quercus gambeili, Pinus ponderosa, Pseudotsuga menziesii, and Picea pungens) common in the western North America forests where fires are common; and 2) to examine whether leaf defense chemistry changes in response to smoke exposure. Treated plants were exposed to smoke for 30 minutes in mid May and then again in early June. Following smoke exposure photosynthesis was measured at 30 minute intervals for 6 hours at both ambient and saturating CO2 levels (385 and 1000 ppm) to examine whether smoke affects stomatal or biochemical function. At the end of summer, plant tissues were harvested and weighed and leaves were analyzed for condensed tannins and phenolic glycosides. The results show that smoke negatively affects both stomatal and biochemical function, resulting in significant reductions in photosynthesis and that broadleaf species are more sensitive than conifers. Smoke had no significant affect on growth in any of the tree species, or phenolic glycoside concentrations in Populus tremuloides.

https://digitalcommons.usu.edu/nafecology/sessions/posters/9