Dual Ecosystems

The plants of Cabrillo National Monument inhabit two ecosystems: the coastal Mediterranean ecosystem on the peninsula and the marine ecosystem off the coast.

The Mediterranean ecosystem at Cabrillo is dominated by coastal sage scrub plants which have adapted to warm, dry summers with cool winters with a few storms lasting a few days at a time.  To survive through the dry season, some plants found in the habitats have large roots, or bodies, where they store water to use when needed. Other plants have leaf adaptations that prevent the loss of water. These adaptations include leaves that fall off during dry seasons, leaves that curl up and make a small moisture chamber within the leaf, leaves with a waxy coating that protects them from evaporation, leaves with hairs that reflect light penetrating the plant, or leaves that are small in size so there is not a lot of area for evaporation.

The coastal sage scrub habitat is not known for having strong winds, so plants are pollinated by animals.  The seeds of some plants are easily caught in animals’ fur so a fox, coyote, rabbit, or mouse carries them to a new germination spot. The plants are also highly aromatic, but not visually vivid, so they can attract moths in the dark of night through the moth’s sense of smell rather than their vision.  Not only does the aroma of the plant attract pollinators, but it also deters foragers.  Animals that would otherwise eat some of these plants are averted by the strong odors they emit.  The animals are further discouraged by some plants’ tough leaves and branches and other plants’ spines.

The marine habitat also contains numerous species of plants.  These are non-vascular plants called algae, more commonly called seaweed.  The seaweeds in the intertidal zone at CabrilloNational Monument are very important to the sea life.  They provide food for most of the sea slugs, snails, and crabs, but - equally important - the plants also provide shelter for the animals.  Most often the seaweeds are homes for juvenile animals.  In the seaweeds, the young are protected from strong currents, crashing waves, and foraging predators. All this protection and plenty of food surround them.

Seaweeds have also adapted to their environment. These plants are exposed to the dry air during low tide and are submerged under the water during high tide. To adapt to this condition, different plants have developed different adaptations. To keep from being eaten, some plants have developed tough branches that are hard to bite into – some have adapted so well that they have a calcareous shell that cannot be bitten into by small snails and crabs, not to mention the unpleasant taste of calcium carbonate.  Some plants are very dense and spongy keeping in the moisture, others are succulent and sometimes woody preventing moisture loss, and some are so small and grow close to one another that they all keep each other moist by storing the water in their “colony.”