Demographic trends in Claremont California’s street tree population

The effects of climate change provide a compelling case for planting a greater diversity of resilient tree species to minimize future canopy losses due to climate induced stressors. This paper assesses the impact of growth, removal, and replacement planting on urban forest resilience. The authors measured and monitored various tree characteristics, including their condition and growing space, to investigate species-level dynamics within the population and assess temporal patterns. Using a repeated measures survey and the hierarchical Bayesian framework, the authors were able to analyze demography and quantify street tree growth, mortality, and recruitment in the city of Claremont, California. The results of this study suggest that a shift to less vulnerable tree species, in addition to an increase in the percentage of full stocking and ongoing monitoring, is essential for ensuring the resilience of tree populations. Long-term monitoring and transitioning to a more heterogeneous species structure in urban tree populations can help increase forest stability. These factors are critical for sustaining the ecological benefits of urban forests. Adoption of these methods by municipal forestry programs could help foster a better understanding of the conditions of their urban forests and assist in the refinement and optimization of future management efforts.