No rare or sensitive species are known to be present in the Fern Canyon RNA as of March 1999. Potential species of concern and their current status are shown in Table 1 . The climate at Fern Canyon is Mediterranean with cool, moist winters and hot, dry summers. Mean temperatures are 5.5 o C in February and 23.3 o C in August. Mean annual precipitation is 91cm.
Light snowfall is common in winter.
The RNA is subject to substantial oxidant air pollution from the Los Angeles Basin. Facilities Fern Canyon contains permanent facilities for stream flow monitoring, including small dams, flumes, and weirs, that were operated at the base of three small watersheds prior to 1960. A supplemental dam is located immediately downstream of the Fern triplicate-watershed dams. Fern Canyon was included historically in an extensive network of rain gauges measuring precipitation in mountainous terrain. A recording rain gauge is located at 5200-ft.