Dawson Los Monos Canyon Reserve

Dawson Los Monos Canyon Reserve
Dawson LosMonos Canyon Reserve/Photo by Peggy Fiedler

Flowing through the bottom of the Dawson Los Monos Canyon Reserve is Agua Hedionda Creek, one of the few perennial streams in Southern California, as it winds its way through the San Diego county foothills to the Pacific Ocean. Along the stream banks of the canyon floor grows a lush riparian woodland, which gives way to dense chaparral spreading up the steep north- and south-facing slopes. The wide upper canyon opens out onto old pastures of introduced annual grasses, the result of a century of grazing. Other reserve habitats, some of which were once common throughout Southern California, include coast live oak woodland, inland sage scrub, and a mixed grassland of native bunchgrasses and introduced annuals.

Downstream from the reserve’s western boundary lie the coastal wetlands of the Agua Hedionda Lagoon, which are preserved through state and federal legislation. These neighboring protected lands enable the movement of species between open spaces, which in turn encourages diversity and helps keep the reserve from becoming an isolated natural island in this growing region.

The varied landscape of Los Monos Canyon supports a rich fauna featuring more than 75 species of birds, including several pairs of nesting black-shouldered kites.

Restoration Ecology

Stream bank restoration

Fire Ecology

Old-growth and post-burn chaparral monitored since a 1982 fire

Field Courses

Site visits by university courses in ecology, human biology, education, and natural history; high school courses in environmental science.

Public Outreach

UC’s California Naturalist Program uses the reserve as one of their field sites for student independent projects. The San Diego Natural History Museum collects plant specimens.

Selected Research

  • Stigma behavior in Mimulus aurantiacus (Scrophulariaceae).
  • Parasite diversity of small mammals in fragmented areas.
  • Suitability of soils and habitat types for the federally endangered Pacific pocket mouse.
  • Systematics of the genus Zygnema (Zygnematophyceae, Charophyta) from Californian watersheds.
  • Honey bee displacement of carpenter bees as the main pollinator and effects on fertility of Salvia apiana.
  • Evolutionary genetics of the self-incompatibility in Solanaceae and Papaveraceae.

Isabelle Kay
Natural Reserve System
Applied Physics and Math Annex
Rooms 2802 and 2808
9500 Gilman Drive
UC San Diego
La Jolla, CA 92093-0116
Dawson Los Monos Canyon Reserve website

Western San Diego County within the cities of Carlsbad and Vista; 48 km (30 mi.) north of San Diego. Reserve straddles middle reach of Agua Hedionda Creek.

Field station includes a trailer for staging and research, a classroom, and short-stay accommodations for up to four; storage shed; Internet connection and wireless access. Two weather stations offer real-time data accessible over the web.

The reserve bibliography includes citations of journal articles, books, theses, art, and other works published about or based on activities conducted at the reserve.

Plant List
Aerial and historic photo archive; plant-recovery records from post-fire monitoring since 1982; species lists for vascular plants and vertebrates; reserve-based publications since 1995; preliminary archaeological survey report; extensive data on stream habitat conditions; benthic macroinvertebrate collection from Agua Hedionda Creek.

Reserve manager and academic coordinator on San Diego campus; no personnel on site.

95 hectares (234 acres)

67 to 179 m (220 to 587 ft.)

40 cm (16 in.) per year

9.7 – 24 ºC (49.5 – 75 ºF)
Mean: 17 ºC (62 ºF)
August maximum: 31 ºC (88 ºF)
December minimum: 4 ºC (39 ºF)