Big Morongo Canyon Preserve is host to a remarkable variety
of plant communities:
Mojave Riparian (streamside) Forest
The Mojave Riparian Forest, which marks the course
of the marshes and streams through the canyon, is formed by stands of
cottonwood trees, willows, alders and mesquite.
Each tree is uniquely adapted to survive: The mesquite
has very deep roots for obtaining water; the cottonwood has fluttering
leaves for capturing sunlight even down to the innermost layers of leaves;
the willow has an extensive root system that allows it to colonize
riparian areas more quickly than other streamside trees; the alder
grows faster and taller in order to overshadow the canopy of other shade-makers.
Fresh-water Marsh occurs where water comes to the
surface in flowing streams or boggy areas. Major plants that love this
environment include cattail, rushes, sedges, watercress, water-parsnip,
Desert Wash occurs in dry streambeds where water flows
only intermittantly after rain. Major plants found here include catalpa,
catsclaw, rabbitbrush, baccharis, etc.
Creosote Bush Scrub
Creosote Bush Scrub occupies most of the flats and
slopes of Morongo Valley. Some conspicuous plants here are creosote,
Mojave Yucca and juniper, bushy perennials and annual flowers. The limiting
growth factor of plants here is water, and consequently the leaves of
most of these plants are small to reduce water loss.
Open fields occur in the Preserve where native vegetation
has been removed in the past for grazing land.
When disturbed land like this is allowed to recover
and revegetate naturally, a predictable succession of plants will move
in. If left undisturbed, the old fields would probably return to
scrub, except for the fact that the area is increasingly wetter and
wetter, so it may even become pockets of fresh water marsh surounded
by riparian woodland.