Landscape-Scale Variation in Redwood Response to Climate Variability

Fine-scale variation in topography within forest ecosystems causes substantial variation in climate and water availability across landscapes. In redwood forests, maritime fog interacts with topography and forest structure, adding complexity to spatial patterns of ecosystem water availability. To test the consistency of spatial patterns in water availability over time, we collected cores from 90 trees along gradients in fog cover and elevation above the nearest stream. The fog cover gradient was identified from a NASA MODIS-derived fog cover map, and the elevation above the nearest stream gradient was calculated from high-resolution airborne LiDAR data. We analyzed patterns in annual tree growth from the cores to determine whether trees with better access to fog and stream water show higher resistance to periods with anomalously low rainfall. We also related patterns in tree growth to data on tree canopy water content derived from airborne imaging spectroscopy data taken from before and during the recent California drought.