The Loma Ridge Global Change Experiment (LRGCE) sits on 6.5 hectares located in the foothills of the Santa Ana Mountains, just a few miles from Irvine’s northern neighborhoods. The land is owned by Orange County Parks and managed by the Irvine Ranch Conservancy (IRC). University of California, Irvine, researchers established the LRGCE to conduct long-term research that informs land conservation and mitigation of climate change in Southern California.
The landscape around the LRGCE is part of the Irvine Ranch Open Space (IROS). As such, land management follows standards outlined by the Natural Community Conservation Planning (NCCP) program and the Habitat Conservation Plan (HCP) which have provided important protections for biological diversity. Moreover, Loma Ridge is located on the ancestral lands of the Tongva and Acjachemen tribes who have long-tem, ongoing cultural ties to the area.
The dominant vegetation types are annual grassland and coastal sage scrubland. Over time, the site has experienced multiple natural and human disturbances. Up until the late 1990s, the site was grazed by cattle and sheep. More recently, the site has experienced two major wildfires, the 2007 Santiago fire and the 2020 Silverado fire.
To understand ecosystem responses to environmental change, the LRGCE manipulates water and nitrogen inputs in both dominant vegetation types. The manipulations have been applied to annual grassland since fall 2006 and to coastal sage shrubland since fall 2008.