Fire is a cornerstone to Mediterranean ecosystems but increased droughts, climate change and human interference has caused a shift in fire frequency and severity. This experiment accessed the physiological performance of Malosma laurina resprouts in burned areas compared to mature Malosma laurina in unburned areas. Specifically, we hypothesized that the stomatal conductance, photosynthesis rate, and electron transport rate of the burned resprouts would all be higher than the unburned shrubs as there are more nutrients available in the soil post-fire and the resprouts have a larger root to stem ratio. Using the LI-6400 Portable Photosynthesis System, we measured the physiological performance of M. laurina resprouts in burned and unburned sites. We found that in burned resprouts of M. laurina stomatal conductance was significantly higher on both Day 1 and Day 2, photosynthetic rate was significantly higher in burned resprouts only on Day 1, and Electron Transport Rate was significantly lower in burned resprouts only on Day 2. These results are mostly consistent with our hypothesis that physiological performance of M. laurina will be higher in resprouts in burned areas. Both stomatal conductance and photosynthetic rate were higher in burned resprouts which supports our hypothesis, but electron transport rate is lower in burned resprouts which contradicts our hypothesis.
Adducci, Anthony Joseph II; Smith, Sierra Jo; and Waddill, Dylan Jesse, "A Post-Fire Comparison of Resprouts to Unburned Malosma laurina Shrubs in the Santa Monica Mountains of Southern California" (2019). Pepperdine University, Featured Research. Paper 167.