Coastal ecosystems in Southern California’s mountains are breathtaking. They have been sculpted by millions of years of climate change and nature’s ecological broom—fire.
The equator is bombarded with mega amounts of solar radiation; warm, moist air constantly rises, cools, rains, and by the time the air returns to Earth’s surface, its latitude is about 30 degrees north or south of the equator. This coincides with Earth’s great deserts.
Yet, in six unique spots a combination of local factors precludes the occurrence of deserts. Instead, semi-arid shrublands thrive in: southwestern and southern Australia, Southern California, central Chile, the Mediterranean Basin and the Cape of South Africa.
Along Southern California’s coast the vegetation is exquisitely adapted to living with less than 10 inches of precipitation—or desert-like moisture conditions. This plant community is called the Coastal Sage Scrub ecosystem.
Moisture within fog bathes this zone, it’s crucial for survival. Not surprisingly, plant leaves have ingeniously adapted to trap fog, funneling fog-drip to their roots.
The rarest pines in America—Torrey pines—live along a sliver of coastline near Del Mar and on a couple Channel Islands within coastal sage community. Torrey pines have long, blue-gray, flat, wide needles that efficiently trap fog with roots miraculously tolerant of high levels of sodium from sea spray of waves crashing along the seashore beneath the mesa or bluff where they exist.
Torrey pines are well adapted to fire, keeping some of their cones shut tight with viable seeds awaiting the heat of wild fires to open them.
In the springtime, when the sage community is in full bloom with a kaleidoscope of vibrant colors, it attracts pollinators like: bees, hummingbirds, moths and butterflies—the air is pungent with floral scents.
Plant odors help attract pollinators and repel herbivores from noshing upon leaves. Odors evolved alongside gooey resinous coatings of many plant leaves, precluding water loss.
At least three species of prickly-pear live in this community as well as black, white and purple sages, the bodacious orange bushmonkey flowers and the lemonade berry plants. Its fleshy seeds taste like lemon, when mixed with water they make a salubrious lemonade tonic.
Moving from seashore up the hillside the vegetation and ecosystem receives about double the moisture or 18 inches of precipitation. These plants are frost-tolerant but not snow-tolerant. This zone is called Lower Chaparral extending from about 1,000 to 5,000 feet above sea level.
South facing slopes are drier and warmer therefore shrubs have small leaves compared to the larger leaves on both shrubs and trees on cooler north facing slopes. Plants are evergreen with resinous or waxy coatings on their hard leaves.
The word ‘chaparral’ comes from chaparro—Spanish for the ‘land of scrub oaks’—discovered by early Spanish explorers.
Chaparral vegetation has a two-layered root system allowing plants some summer growth when the drought prone sage ecosystem has shutdown.
Lightning-induced fire in the Chaparral occurs at intervals between 30 and 150 years with fascinating adaptations like sprouting from the stump, seed storage in the soil requiring both heat and smoke to germinate, cones only opening after the heat of a fire, e.g. knobcone pines, or a combination of these strategies.
Chamise is a common plant in the Lower Chaparral; it responds to fire by stump sprouting and from seed germination post-wildfire. It’s legendary for withstanding heat, bursting into flames when temperatures exceed 800 degrees!
The Upper Chaparral zone occurs between 4,000 and 5,000 feet; it is home to drought tolerant conifers including big-cone Douglas-fir that re-sprout new needles after its entire crown burns—a trait more common to Australian eucalyptus rather than conifers.
Although the last recorded California grizzly was seen in 1908, it too regularly frequented these Southern Californian mountains. I’ve found a couple of old grizzly trails next to big-cone Douglas-firs. These beauties of beasts used the same trails for generations, placing their paws in the same depressions repeatedly until the trails became a series of potholes.
Southern California’s coastal ecosystems are a magical place to reconnect with nature and explore her wonders.
Earth Dr. Reese Halter is a broadcaster, conservation biologist, educator and co-author of “Life, The Wonder of it All.“