Comparing Leaf Properties of Inland and Coastal Malosma laurina in the Santa Monica Mountains

Our group chose Malosma laurina, commonly known as Laurel Sumac, to observe and test. We hypothesized that there would be difference in photosynthetic trade-offs and capabilities between coastal and inland populations, specifically with respect to leaves. This was based on the low freezing tolerance in Malosma laurina (Pratt et al. 2005), and hypothesized that based on this stress, resources would be allocated differently in inland leaves than in coastal leaves. This hypothesis was tested using the indices of Normalized Difference Vegetation Index (NDVI), the Photochemical Reflectance Index (PRI), the ratio of green to red reflectance, and Leaf Specific Area (LSA). The first three indices were tested using a Unispec Spectral Analysis system, and the LSA was tested using a simple Leaf Area Meter and balance. We collected two leaves fifteen from the tip of the branchlet off of eight coastal individuals and eight inland individuals to test. We found a statistically significant difference in NDVI, indicating that coastal individuals had higher chlorophyll amounts and higher photosynthetic efficiency as compared to inland individuals. We also found that the green to red ratios were statistically significant, indicating that inland individuals are more highly light stressed than coastal individuals. Based on these significant differences, we concluded that our hypothesis was correct and there was indeed a difference in the photosynthetic abilities between coastal and inland populations