Impact of Drought on Ecohydrology of Southern California Grassland and Shrubland

Abstract Through their rooting profiles and water demands, plants affect the distribution of in soil profile. Simultaneously, content controls plant development interactions within between communities. These plant-soil feedbacks might vary across communities with different depths species composition. In semiarid environments, understanding these differences will be essential to predict how ecosystems respond drought, which may become more frequent severe climate change. this study, we tested responded drought two contrasting ecosystem types—grassland shrubland—in coastal foothills southern California. During years 5–8 an ongoing precipitation manipulation experiment, measured changes moisture up 2 m depth. We observed use patterns grassland shrubland distinct functional types strategies. Drought treatment did not perennial, deep-rooted shrubs because they could access deep pools. However, mid-rooted were sensitive experienced decreased productivity die-off. As a result, actually increased at from 50–150 cm. grassland, biomass production by annual species, including grasses forbs, declined resulting lower uptake surface layer. An opportunistic “live fast, die young“ life strategy allowed recover quickly once availability increased. Our results show interacts community composition balance ecosystems, information that integrated into global scale models.