Research Article
Christopher Potter
Abstract
The satellite Enhanced Vegetation Index (EVI) from the NASA Moderate-resolution Imaging Spectroradiometer (MODIS) over the years 2000 to 2016 was used to study impacts of the historic 2013-2015 drought period on woodland ecosystems of the Carmel River watershed in central California. EVI time series analysis supplemented with in situ measurements of soil moisture showed that the historic drought period of 2013-2015 had contrasting effects on different oak woodland types. The correlation of water year anomaly for precipitation amounts since the year 2000 with peak seasonal EVI was higher for deciduous oak stands than for the evergreen oak stands. Among woodland cover types, only peak deciduous woodland EVI increased significantly again across the watershed during the near-normal water year of 2016 following the 2013-2015 extreme drought period. Shrubland cover showed average EVI values for most years just below those of deciduous woodland cover, while average EVI of grassland cover showed that herbaceous vegetation growth declined to the lowest levels of any cover type during the drought of 2013-2015 across the Carmel River basin.