LB 9-90 - Where the trait rubber hits the application road: Can induced trait plasticity increase restoration survival of Encelia californica and Malosma laurina?

As climate change worsens and species ranges shift, ecological restoration becomes more important than ever in ensuring the continued survival and functioning of native plant communities such as southern California shrublands. Restoration remains difficult, however, and there is a dearth of information on best practices in this ecosystem. Previous work has shown a relationship between functional traits, survival and environmental responses across southern California shrubland species. This work has shown that the leaf economic spectrum is correlated with environmental response, and wood density and growth traits are correlated to general survival across a range of conditions. Therefore this experiment tested if different growing conditions (ambient temperature and well-watered, ambient temperature and reduced watering, elevated temperature and well-watered, or elevated temperature and reduced watering) induced plasticity in those same traits for two species (Malosma laurina and Encelia californica). Additionally, this work tests if induced trait plasticity within species leads to within-species survival differences.Measured traits vs. treatment data showed that trait responses to different treatments were species specific and defied expectations. Leaf allocations were more responsive to treatment than root allocations across both species, and leaf size in Malosma laurina decreased from the temperature controlled, fully watered treatment to the elevated temperature, droughted treatment - whereas Encelia californica leaf size increased. PCA analysis shows that in Encelia californica the first axis was primarily positively correlated to Al:As and petiole length, and negatively correlated with leaf mass per area. In Malosma laurina, the first axis was most correlated to stem density and Al:As which both showed a positive correlation, followed by minimum leaf conductance which displayed a negative correlation. Statistically significant trait differences based on treatment were seen only along the second axis in Malosma laurina between the ambient temperature/well-watered treatment and all other treatments.Survival is being monitored through December 2023, with mortality expected to begin during the dry season and preliminary mortality data expected by the conference.