Lorence (Loren) R. Oki
Associate Specialist in Cooperative Extension, Landscape Horticulture
I have been a member of the faculty at UC Davis since 2002 and serve as the Cooperative Extension Specialist in Landscape Horticulture. This appointment is held jointly with the Department of Plant Sciences (80%) and the Landscape Architecture Program in the Department of Environmental Design (20%).
My research focuses on water issues in urban horticulture. I currently lead a large project funded by the California State Water Resources Control Board and the CALFED Bay-Delta Program that is characterizing runoff from residential areas and studies the effectiveness of management methods to reduce the runoff and the pollutants that may be included in it. There are four study sites in Sacramento County and four more in Orange County used in this project. This project also develops information to promote the implementation of low impact landscape management methods and measures the effectiveness of outreach methods. From our data, pollutant loading models are being developed to demonstrate how changes in landscape features might affect loading.
To refine irrigation management in urban landscapes, my research group is examining the water use of plants selected from the UC Davis Arboretum that have ornamental landscape potential. Selected plants are distributed to several demonstration sites around the State for further evaluations by UCCE Master Gardeners for garden performance in different climate zones.
A completed project funded by the Santa Clara Valley Water District quantified the tolerance of Coast Redwood to sodium and chloride when they are irrigated with low quality water. Future work will look at the tolerance of landscape plants to irrigation with low quality water such as reclaimed municipal water.
My group is examining how slow sand filtration and other natural water treatment systems remove plant pathogens, including Phytophthora ramorum, the organism that causes Sudden Oak Death disease, and other pollutants from nursery irrigation runoff. The treated water could then be safely reused for irrigation.
My Ph.D. is in Ecology (2002) from UC Davis and I conducted my dissertation research in the Environmental Horticulture (now Plant Sciences) Department quantifying the effects of salinity on rose stem elongation rates. I hold an M.S. in Plant Science from UC Riverside (1976) where I worked in plant tissue culture studying the role of chromosomal proteins in cell differentiation. My B.S. in Ornamental Horticulture (1974) is from California State Polytechnic University, San Luis Obispo. Prior to receiving my Doctorate, I worked in the horticulture industry as a grower of nursery and greenhouse crops in the Sacramento area.