Allelopathy, I discovered yesterday—is the effect one species has upon the growth, survival and reproduction of another species by chemical, biological or ecological processes. For instance, a tree that grows to be tall and wide benefits the humans beneath it by providing shade where they may have a picnic, make sweet love and carve their initials into the pliable bark marking the first moment of their life-long commitment to benefit each other and their future children. The same tree does not allow any other species to thrive beneath it because of the very shade that benefits the humans.
I also discovered that plants aren’t the only ones with allelopathic tendencies.
It was a typical Tuesday morning eradication session at the Leon Creek Greenway where the Invaders volunteer their time to eradicate non-native invasive species. Ie. Kill things, record how and when they were killed, pinpoint a GPS location of the slaying and record it in a national database. It’s satisfying work because you can see the difference you are making in a landscape right away. Where once there was a mono-culture of invasive species, you can see the potential for new native growth almost immediately. Kind of like getting a haircut: It always makes you feel better about your future somehow.
This day was going along par for the course. I had my first kill and a fat one at that—around six inches in diameter. I had to use my Gomboy or folding handsaw. Felt good to get a big one under my belt first thing. I called out my count and the code for loathed Chinaberry Tree. Most of the trees we eradicated that morning were big Chinas. We had a crew of about 10 and it only took two to do the work of even the biggest tree. So the rest of us just sort of milled about watching or looking for our own pre-flagged specimen to fell.
I’ve been on several of these expeditions before but this one was different in so many ways, it really made me stop and think. The work we did at Rancho Diana seemed much more unobtrusive. We weren’t felling large trees but we were pulling, chopping and spraying hundreds of Nandina every week. There was the “Nandina Forest” where the bamboo-like plant had taken over an entire area of underbrush. That week I learned how to identify Nandia in every stage of life from a newly formed sprig to a mature bush with berries. Somehow it seemed not only physically easier to hand-pluck the babies from the lush fertile forest floor but cognitively, I didn’t suffer other decisions. Like, which weapon to most effectively destroy the thing. I didn’t have to spend a lot of time with the same plant sawing or even break a sweat. All I had to do was seek, identify and destroy. Now look out honey, ’cause I’m usin’ tech-knowledgey…Somebody come and help me please…Somebody better save my soul! Wha? Oh, sorry Iggy Pop sideline. Happens every time.
So, the other thing is that something gets me out there in the civilized wild. A trail runs through it, but nature remains in control. Very early in our first effort to girdle a hug-sized Ligustrum we were verbally accosted by a few well-intentioned tree evangelists who proclaimed us “black-hearted sinners” for our defiant act of ecological restoration.“We’re all invasive species!” She exclaimed passionately.
I see her point. So who decides?
If nature or her G-d for that matter saw fit for this plant to grow and thrive who are we to destroy it?
My rebuttle was weak. “But it will KILL all the other plants.”“
Interesting perspective. Not true though.
It in fact, does nothing actively to kill anything. It only exists for the sole-purpose of existing.
Sure, its leaves drop and make the soil beneath it more alkaline insuring its own survival and the survival of other plants whose tastes agree. Sure, its canopy is large and dense to the detriment of many beneath it, earning it its nickname The Umbrella Tree. Sure, its prolific berries fall and turn to seeds and take their turns growing where they are unsurreptitiously planted. But if blame is due, it might just as well rest on the wings of that ill-fated bird who eats—gorges itself actually—becomes drunk on the toxic berries, flies downstream and deposits the seed at the mouth of another river where Chinaberry has never grown before and then dies. But not before making another even less desirable deposit of bloody seed encrusted feces on your freshly washed but unfortunately unwaxed clear coat instantly lowering your resale value.
Ultimately, we are the ones responsible for introducing the plant here in the first place. It’s a beautiful tree. Resilient. Hardy. Fast growing. Deciduous and flowering; it provides a brilliant if not common display of something in every season. It only becomes ugly when you see it choke out every other species or block a river from flowing freely. If you never saw a snake strike, you could assume it had no fangs. In these woods, the Chinaberry are sparse but large. They aren’t showing their fangs here. But as anyone who has ever been bitten by a snake knows: Size does matter.
Somewhere downstream or over the next hill or around the far bend the effects of these and several other non-native invasives that you can buy and are often touted as best use landscaping plants because of their tolerance for neglect and extreme weather. And that’s our justification for killing. G-d save our black-hearted souls! Funny thing though, they always seem to sprout back up in threes for each individual we take down to a stump. Some say it’s a futile effort. We call it job security.
Makes ya kinda wonder though, doesn’t it.