加入於:2017 8 月 07 最近活躍:2024 9 月 24 iNaturalist
I am a self-taught naturalist, focusing mainly on woody plants. When I was young, my family spent many weekends in southeast Texas, often in remnants of the Big Thicket, and I grew fascinated with all the trees and shrubs that grew in the canebrakes, piney forests, and river bottoms. I went to camp in the Hill Country, went to college in north central Texas, and have come to live in Austin, right where the Blackland Prairie meets the Edwards aquifer outcrop.
In Austin, I participated in various nonprofits that promoted the use of trees to combat the impact of urban heat islands and, to some small extent, global warming. I helped write the Tree-Growing Guide for Austin and the Hill Country, which has become a publication of TreeFolks (I was president way back then). I'm glad to see that they have continued using the guide as a tool to promote the use of native trees. I can take credit for removing the Arizona ash from it; I wish I had found more support for my effort to remove one other tree—the Chinese pistache. Foresters and nurserymen insisted that it was not invasive. I was skeptical, because when each female tree produces over a million berries a year, it doesn't matter if only one in a thousand is viable. That's still a lot of bird-borne botanical pestilence. (I suspect the real ratio is closer to one in a hundred—and maybe even one in 25 or so.)
Today, I lead volunteers in Walnut Creek Metropolitan Park to remove invasive plants and replant natives, in an effort to make the woods, meadows, and stream banks more nearly natural. With the city's approval, we are girdling big invasive trees, uprooting smaller ones, and replanting native saplings and seeds of all types. We also tackle Nandina, giant reed, Japanese honeysuckle, and other invasive vines, grasses, and forbs. We don't let anything go to waste, either. Shredded ligustrums went back where they came from and smothered their own seedlings. Ligustrums that have died from being girdled are being cut and used to hold soil on slopes and give native plants a chance to establish themselves. Berries and seedheads go to Hornsby Bend, to be processed into Dillo Dirt. (Triple composting does wonders to reduce viability.)
Of all the invasives we are battling, the most challenging is glossy privet, or Ligustrum lucidum. It has choked out everything else in many areas of the park. But the scariest foe, to me, is Chinese pistache. We have perhaps five mature female Chinese pistache in the park's 220 acres. We have thousands, perhaps even tens of thousands, of mature ligustrums. Find any thick shrub in the park that is neither under nor downhill of a berry-producing ligustrum or pistache and see what you find sprouting beneath the branches where the songbirds perch. I'll give you 10 to 1 odds that it's going to be pistache, not ligustrum.
So what does that mean? It means that in spite of how prolific ligustrums have proved themselves to be, if we work from uphill to down, from hilltop to streambank, and take all the berry-producing ligustrums out of action, we have a chance to eliminate them. Birds won't be replanting them faster than we can get rid of them.
But for Chinese pistache, we might already be too late. The first seedlings of trees planted 30 years ago are starting to get big enough to produce significant seed crops themselves. We need nurseries to quit supplying the female plant, and we need to uproot or kill every sapling we find in the wild, no matter how small. If we don't, the roadside vistas in Central Texas are less likely to be dominated by oaks, elms, and juniper and more likely to become a monoculture of Chinese pistache.
And every now and then I lead hikes through the park, sharing more about the many different ecozones it supports. It is amazing how many different species of plants you can find in a short walk through Walnut Creek Park. You really can appreciate the effect of being at the nexus of two, if not three, of Texas' botanical regions—the Hill Country, the Blackland Prairie, and the Gulf Coast Plains, with interlopers from post oak savannahs, the Lost Pines, and even the Cross Timbers.
If you'd like to join me in restoring natural beauty to Walnut Creek Park, send me a message. To learn a little more about the work we do, check out the website of a meetup group I use to tell volunteers about upcoming events: https://www.meetup.com/Keep-Walnut-Creek-Wild-The-Meetup-Group/.
See you in the parks!
Cliff Tyllick
(Yes, I am an Eagle. And people who can see the top of my head tell me I am definitely bald.)