By Wendy Langhans
If you spend any time at all outdoors, you can’t help but notice that our valley is rich with new growth. Trees are budding, flowers are in bloom, and even normally sane people are purchasing Topsy-Turvy upside-down tomato planters.
Over time, plants have evolved to take advantage of our growing season. They have developed three strategies to maximize their growth:
(1) grow as quickly as possible,
(2) develop direct defenses against herbivores, such as toxins or prickly leaves, and
(3) attract predators, like ladybugs, who will eat the herbivores.
Note the prickly defense against herbivores on this Stinging Lupine
Note the size of this milkweed plant
But each strategy comes with a “price-tag”; each strategy requires the expenditure of limited metabolic energy. And plants do not have the resources to use all three strategies at once. But current research shows that, at least for some species of milkweed, they can get “two for the price of one”. In this little drama, we have 3 characters:
(1) The aphid, that eats milkweed
(2) The ladybug, that eats aphids
(3) The milkweed, that produces chemicals known as sesquiterpenes (which attract ladybugs).
Common sense tells us that more ladybugs lead to fewer aphids which results in bigger milkweed plants. But when scientists measured milkweed growth, they discovered that the size increased even when ladybugs were not present. How do they explain this? They hypothesize that the genes linked to sesquiterpene production are also linked to rapid growth: “In the case of milkweed, some favored fast growth and the ability to attract predators while putting less energy into resisting herbivores.”
Two for the price of one. Those milkweed plants must be wiser than they look: “Life is change. Growth is optional. Choose wisely.”
Upcoming Outdoor Events:
Saturday, April 17, 8-10 AM. Early morning bird hike at Towsley Canyon. It’s an easy 1 mile walk and beginning birders are welcome. For map, click here.
Saturday, April 17, 10 AM – 5 PM. Earth Arbor Day Festival at Newhall Park. Sponsored by the City of Santa Clarita. For more information, click here.
Sunday, April 18, 1-3 PM. Spring Wildflowers at East & Rice Canyons. It’s that time of year! Join Wendy on a hunt for the colorful wildflowers. For map, click here.
Trail Maintenance Schedule. Come join our volunteers as they help maintain our trails. Contact Steve at firstname.lastname@example.org for time and place.
Wednesday mornings, April 7, 14, 21 & 28.
Saturday mornings, April 10 & 24
You can listen to stories like this every Friday morning at 7:10 a.m. on “The Hike Report”, brought to you by your hometown radio station KHTS (AM1220) and by the Mountains Recreation and Conservation Authority.