Post-fire recovery of leaf area index in California chaparral: A remote sensing-chronosequence approach

Abstract

Fire is a major driver of land surface transformation in California Mediterranean-type shrublands (i.e. chaparral). The re-growth of leaves following fire impacts a wide variety of ecosystem processes and information on the post-fire recovery of leaf area index (LAI) is often required in eco-hydrologic modelling studies. A few studies have reported LAI values for chaparral, but none have tracked LAI dynamics over the entire post-fire recovery sequence. In this study we used a chronosequence approach with satellite imagery to determine the post-fire development sequence of LAI for chaparral shrublands in central California. Moreover, we explored how LAI varied with differences in annual antecedent precipitation conditions (APC) and physical site factors. LAI recovery following fire was most rapid during the first 15 years, after which it remained relatively constant with increasing stand age. For a given stand age, LAI varied nonlinearly with annual APC, while spatial variations in LAI were associated with differences in topographic aspect and landscape wetness potential. However, a better understanding of the nature and interaction of these controls on LAI is needed if realistic post-fire LAI trajectories (for historic, present and future periods) for eco-hydrological modelling studies in chaparral catchments are to be developed in the future.