Article By: Grace Adams & Ian McGregor
Photos by: Ian McGregor
What would happen if you watered your lawn or garden with saltwater? You’d have a really barren lawn! Have you ever wondered how the plants living at the Bolsa Chica Wetlands, often submerged in salt water throughout the year, can survive? Well, these plants have special adaptations to tolerate high salinity. They are called halophytes, which are plants that are adapted to living in very salty environments.
High levels of salt, or sodium chloride, is toxic to most plants and animals. However, halophytes can handle high levels of salinity. Some halophytes actually demand saltwater (obligatory halophytes) while others are simply able to tolerate saltwater conditions, though they are also able to live in freshwater conditions (facultative halophytes). To survive, many halophytes have mechanisms to get rid of the excess salt. There are several ways halophytes can do this and generally they fall into two categories: “salt excretors” or “salt excluders.”
Typical salt excretors, such as salt grass (Distichlis spicata) and cordgrass (Spartina foliosa) have special glands that excrete excess salt out on the surface of the leaf. If you look closely at the leaves and run your finger along it you will see and feel tiny salt crystals that have been excreted by the plant.
Another way plants can remove salt is by special salt bladders on the leaves. Saltbush (Extriplex californica) and quail bush (Atriplex lentiformis ssp. breweri) have little hairs on their leaves called trichomes, which give the plants a silvery appearance. The trichomes have bulbous tips which store salt that has been pumped there by other cells. When these bulbs burst, the salt is released back into the environment.
Plants like pickleweed (Salicornia sp.) do a little bit of both. Some of the salt gets filtered out in the roots by special cells that actually pump the salt out. The salt that makes it past the roots gets pumped to special storage cells called vacuoles which are located at the tips of the “leaves.” Eventually, these cells become so full of salt that the cells break down, turn red, and fall off. New, younger cells then take over. This is why often the tips of the pickleweed have a red-orange appearance. Next time you visit Bolsa Chica take a close look at some of our halophytes and discover their secrets for survival!
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