By Wendy Langhans
[view:node_ad=5]Image you're taking astroll on a clear and sunny Spring morning – birds chirping and there's a hint
of moisture in the air from yesterday's rain.
As you turn the corner, suddenly you are face to face with a snarling dog
with gleaming white teeth and laid-back ears.
Immediately, the dog's owner appears and manages to bring his dog back
under control. Whew! That was too close.
But now your body is shaky
and your starting to feel a bit queasy.
You are experiencing the effects of the "fight or flight" reflex. In
response to fear, your body produced adrenaline (epinephrine and
norepinephrine). These chemicals caused
your body to re-direct the supply of oxygen to your brain and skeletal muscles
while diverting it away from non-essential tasks (like digesting that juice and
cereal you had for breakfast).
So you promise yourself a
soothing pot of jasmine tea when you get home.
But did you know that plants do something similar?
Plants produce jasmonic
acid when they undergo stress, the same chemical used to flavor jasmine
tea. It's part of their "fight or flight
reflex".
Don't be fooled – this seemingly harmless caterpillar has a voracious appetite.
When a plant leaf is
chewed on by an insect, it produces jasmonic acid. This
triggers a variety of defensive responses:
Note the bite marks on the edge of the leaf.
-
protective chemicals that make the plant taste
bad -
protective chemicals that hinder the attacking
insect's digestion -
protective chemicals that attracts attacking
insect's predators - protective bio-mechanical structures (sharp, pointed trichomes). (1)
Ya' know, on second
thought, maybe that cup of Jasmine tea doesn't sound so good after all.
Notes:
(1) Proceedings of the National Academy of Sciences. http://www.pnas.org/content/95/8/4410.full
Upcoming Outdoor Events:
Saturday, March 21, 8:00-10:00
AM. Morning Bird Hike in Towsley
Canyon. Towsley Canyon is a year-round home for birds.
They like our Mediterranean climate, the local bounty and the California sunshine.
Bring your binoculars and meet at the entrance. Heavy rain cancels. For map and directions go here.
Sponsored by the Mountains
Recreation and Conservation Authority.
Saturday, March 21, 10-12 AM. Wildflower hike at Elsmere
Canyon.
Heavy rain cancels. For map and directions go here. Park at the
entrance to Whitney Canyon.
Sponsored by the Mountains
Recreation and Conservation Authority.
Saturdays, March 14 & 28, and every Wednesday, 8:00 AM.
Trail Maintenance Volunteers at Towsley
Canyon.
Come join our trail
maintenance volunteers for camaraderie and a heart-thumping workout. For
more information contact Steve Ioerger at 661-291-1565.
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.
For the complete MRCA hike
and activity schedule and for trail maps, click here or go to www.LAMountains.com.