PARENT SESSION
Poster Session 11: Disturbance Ecology
Tuesday, August 9, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Effect of wildfire on chaparral light-use efficiency detected by optical pigment assays.
Silva Sepulveda, Jose*,1, Gamon, John1, Cheng, Yufu 1, Lima, Evelyn1, 1 California State University, Los Angeles, CA, USA
ABSTRACT- Studies have demonstrated that wildfire in California chaparral increases nutrient availability for plants, presumably enhancing photosynthetic light-use efficiency. Leaf optical assays provide useful tools for understanding pigment and photosynthetic responses to different nitrogen levels. To learn more about the effect of fire on chaparral species, this study explored the xanthophyll to chlorophyll (X:Chl) ratio change for chaparral species, chamise (Adenostama fasiculatum) and red shank (Adenostoma sparsifolium), before and after fire. The photochemical reflectance index (PRI) and a modified normalized difference vegetation index (NDVI) were used to analyze pigment concentrations. PRI and NDVI were correlated with the X:Chl ratio, which was determined using high performance liquid chromatography (HPLC). Our results indicated that after a fire, chaparral species have a higher PRI and NDVI, but a lower X:Chl ratio. These results indicate that wildfire increases the photosynthetic light use efficiency of chaparral due to a high nitrogen concentration.
Key words: light-use efficiency, xanthophyll cycle, California chaparral, fire