The Ecosystems

The Ecosystems


An ecosystem consists of all the organisms in a given area as well as the non-living factors with which they interact. The Wildlife Sanctuary includes representative samples of six ecosystems: Meadow, Riparian, Woodland, Swamp, Lake and Pond.


THE MEADOW / COASTAL SAGE SCRUBThe Meadow consists of a few varieties of deciduous and evergreen trees and a large open area of wild radish, wild mustard, grasses and other low-growing plants. The animals that inhabit this area include terrestrial mammals and reptiles, along with a wide variety of seed and insect-eating birds. An array of Coastal Sage Scrub plants are located near the meadow and near the new amphitheater.

Coastal sage scrub is a drought-deciduous community found at low elevations on the coastal side of mountain ranges in Southern California. This community consists of small shrubs with an understory of grasses and wildflowers. This community is sometimes called "soft chaparral" due to the texture of the soft, hairy leaves found on most coastal sage species. Many plants in this community have leaves that produce a strong but pleasant odor. Characteristic species include coastal sage, California buckwheat, coast brittlebush, and a variety of sage species. Common animals that are often seen or heard when walking in coastal sage scrub include western fence lizards, coyotes, California ground squirrels, wren tits, and brown towhees.

Coastal sage scrub is disappearing rapidly in southern California due to development in both Orange and Riverside Counties. The decline of the California Gnatcatcher is associated with the loss of this community. Continued development of coastal hillsides in Southern California may ultimately result in the extinction of this bird species as well as the loss of significant biodiversity in California.



THE RIPARIAN WOODLANDRiparian woodland is found along the margins of streams and springs in California. At lower elevations in southern California riparian woodland species include big leaf maple, California sycamore, white alder, Fremont cottonwood, mulefat, and many species of willow.

Riparian woodlands perform many important ecosystem services. They filter sediment and they store and slowly release water from spring runoff. This improves floodwater retention and groundwater recharge. Plant roots stabilize stream banks. Riparian areas also provide resting and nesting areas for wildlife.

Riparian areas support a high diversity of animal species due to a number of factors. The trees are fast growing, wind-pollinated hardwoods that produce abundant seeds and fruits. They support a large and diverse insect community that in turn provides a food source for a great diversity of bird species. The presence of water in a region characterized by summer drought, combined with the cover created by the vegetation, makes riparian areas magnets for wildlife.



THE OAK WOODLANDOak woodland is a widespread community in the hills of coastal California, vulnerable to urban sprawl. The flowers of oak trees (Quercus spp.) are wind-pollinated and the nuts they produce are called acorns. Acorns are an important part of the diet of many animals that inhabit oak woodlands including California ground squirrels, western gray squirrels, and acorn woodpeckers. 

The acorn woodpecker is a species that is completely dependent on oak woodland. This bird stores acorns for use in winter in communal storage trees called granaries. Oaks are highly adapted to fire. Old trees have a thick, fire resistant bark that enables them to survive fairly hot fires. Fire is a natural component of the California landscape. Historically fires were caused by lightning strikes and carried by the dry grasses found beneath the oak canopy.




The Southern California black walnut (Juglans californica Wats. var. californica) dominates walnut woodland. The distribution of California walnut is limited to Southern California, and the remaining stands that exist today are in or near urban areas. They are in great danger of being lost due to urban development. The hills around Mount San Antonio College are one of the few areas left with intact walnut groves. In fact, the city of Walnut was named because of the walnut groves that used to be abundant on its hillsides.

California ground squirrels and western gray squirrels eat mature walnut fruits. The fruits develop quickly from wind-pollinated flowers in the spring, and by late summer the walnuts are mature. Most of the fruits fall to the ground, but some remain on the tree through the winter. Since some nuts remain on the tree during winter, the California walnut is important to the winter survival of these two species of squirrels.

Heart rot is common in older walnut trees. This characteristic, combined with the rich foliage and abundant leaf litter, creates a community with abundant insects and other invertebrates. The invertebrates attract numerous bird species. Cindy Shannon, an instructor in the MSAC biology department, did a two-year bird survey in the walnut woodland on the hillsides surrounding MSAC. She found 29 species of diurnal birds. Over half of these species were present due to the existence of the walnut woodland community.


The swampThe swamp is an aquatic environment of shallow water containing primarily cattails and a few willows. Because of the shallow water it is comprised of mainly top feeding fish (the mosquito fish), tadpoles and crayfish. Fresh water swamps are one of the most productive fresh water systems. Cattails and sedges are found in and at the waters edge. Visitors include: Green Herons, Common Egrets, Snow Egrets, Great Blue Herons, and Black-crowned Night Herons.



The lakeThe lake is a large body of water that spills over into a stream at its south end. Many aquatic birds require a large area in which to take off and land. Bullrush and cattails surround its perimeter. Red-winded blackbirds and an occasional tri-colored black bird can be found nesting in the cattails. Nesting Great-horned owls, Coopers hawks, and Red-tail hawks are found in trees near the lake and stream.



The PondThe pond is an enclosed body of water with a lot of floating and extruding aquatic vegetation. It is a nutrient-rich water system that supports a large number of organisms. Bullrush and cattails surround its perimeter. Red-winged blackbirds, Moore hens, and Mallards have nested in this body of water.




* Content of this page is taken from "Animals of the Mt. San Antonio College Wildlife Sanctuary" by Jeff J. Bolln, and also contributed by Betsy Lawlor, Karyn Kakiba-Russel and Sherry Schmidt