Stunt Ranch Santa Monica Mountains Reserve

15 Oct, 01 PM - 15 Oct, 10 AM

Southern California black walnut (Juglans californica var. californica) is a winter-deciduous tree that occurs from the southern end of the Coastal Range to the northern Peninsular Ranges and is the dominant tree in walnut woodlands. Black walnut is especially interesting because it retains its leaves during the driest seasons of the year and is leafless during some of the rainiest months, indicating that its roots are in a stable water source. Although it occurs on slopes of all aspects, black walnut it usually is largest and most abundant on north-facing slopes. Furthermore, black walnut occurs near the coast and in the inland valleys, which is intersesting because rainfall is greater in the inland valleys than it is on the coast, but humidity is greater near the coast, which decreases the vapor pressure deficit from leaves to the air. The proposed research will combine ecophysiological measurements of predawn and midday leaf water potential, soil water potential to, hopefully, depths of 1 m, and measurements of stomatal conductance with phenological, morphological, and anatomical measurements to address several questions, including: From where in the soil profile are black walnuts taking up water? Is there more available water for walnuts on north-facing slopes than on other slopes? Does phenology differ between slopes? Are inland plants less or more resistant to cavitation than coastal plants? The proposed research will be the most comprehensive ecophysiological study of California black walnut and should draw needed attention to this threatened species.

Visit #11146 @Stunt Ranch Santa Monica Mountains Reserve

Approved

Under Project # 7350 | Research

Phenology and Water Relations of California Black Walnut

faculty - California Polytechnic State University (CSU), Pomona

Reservation Members(s)

Group of 2 Graduate Student Oct 15, 2006 (1 days)
Edward Bobich Oct 15, 2006 (1 days)
Edward Bobich Oct 15, 2006 (1 days)

Reserve Resources(s) | Create Invoice

Day Use Only 4 Oct 15 (-3 hours)