Today I decided to share an old essay about one of my favorite adventures in conservation. I wrote the first draft of this when I worked as a plant ecology intern at Archbold Biological Station in south central Florida. I’m thinking about putting together a series of stories featuring other ridiculous adventures in the name of science- interested in reading them or have a good story to tell, let me know in the comments. Now — on to a spiky endangered shrub!
Conservation work is not always cute bear cubs, scenic landscapes, and bumper sticker slogans. Once, one a quest to save of one very uncharismatic endangered species, I ended up lying in the sand, with my head in a crown of thorns, digging carefully with my hands. I dug like a dog for hours, following a woody taproot, and looking for a branch.
The plant whose root I was chasing is one of the most endangered plants in Florida, a spiky shrub named Ziziphus celata. It’s commonly known, to the handful of people who know it, as Florida Ziziphus. A spiky shrub from the buckthorn family, Ziziphus grows in sandy upland sites along the Lake Wales Ridge in south central Florida. It can reach 6 ft tall- sometimes on a single upright stem, but more frequently, in a twisted, zig-zagging mess of stems, branches and spines, making it difficult to tell where one plant ends and another begins. It has small, alternate leaves that are typically dark green with a shiny upper surface. On many older individuals, the older, woody branches are leaf-less, just gray bark and thorns.
Saving Ziziphus is hard work. The plant ecology researchers at the Archbold Biological Station have tagged and monitored every known individual. When I worked as an intern for Archbold in 2007, we measured the size of every known plant in only two weeks. That includes the considerable amount of time wasted pulling thorns free from fingers and whining. Interns crawl into each spiky mess of twigs to hunt for identification tags, totally grown-over since the last census. We recorded the health and flowering status for each shrub.
The flowers begin in clusters of small green buds along the leafless older branches. On some of the plants, these buds are the only green present. They bloom for about two weeks, at some point between late December and early February, depending on environmental factors and the plants’ personal sense of humor. Thousands of the tiny flowers can bloom on the larger plants.
Despite the sometimes prolific flowering, Ziziphus is not thriving. Today, they refuse to reproduce sexually in the wild. It’s not stubbornness, it’s their genetics. Within each population, the shrubs turn out to be mostly clones, separate stems growing up from a shared colony of roots. What looks like a field full of individual shrubs could actually be considered just the surface structures of one giant plant. These clones are self-incompatible- they can not fertilize flowers and produce viable seeds together. Most of the viable seeds have been produced from painstaking hand-pollinations by biologists working with the captive population at the Bok Botanical Garden in Lake Wales, Florida.
To grow plants for the captive collections, researchers need root-pieces, cut from healthy wild plants. If Ziziphus could conceive of a long term perspective on the survival of their species, they might try to cooperate with biologists in this process. Alas, each individual selfishly focuses on short-term survival; Ziziphus comes prepared to battle with biologists for its roots. Like woody dandelions, they send one long, thick tap root into the sandy soil, often stretching for a meter before branching. You can’t just cut the tap root itself– that would make you a murderer of an endangered shrub. Instead, I found myself on my belly under the bush, digging all day for root-branches. A branch of about an inch thick and several inches long was our buried treasure.
Unlike the lucky roots that can be used to carry new genes to a new population, most of the Ziziphus are stuck in their clonal communities. Habitat degradation and destruction threatens these populations, growing in cow pastures, orange groves, and eroding hillsides between housing developments. The habitat that remains is threatened by weeds.
To eliminate competing plants like pasture grasses and invasive species, researchers employ fire. Like most of the plants endemic to the dry Lake Wales Ridge, Ziziphus is adapted to wildfires. Burning all of the competitors in close proximity to the Ziziphus without harming shrub itself is a thorny issue, literally. My boss advocated the cardboard box method. The offending grass is light from a drip torch on one side of the shrub, while a lucky intern holds a large, folded cardboard box between the Ziziphus and the oncoming flames.
I know what you are thinking- cardboard boxes are flammable! But, to my surprise, the technique actually works. We carefully light the grasses around the shrubs from each side, moving the box-shield ahead of the path of the leading flames. However, after about an hour, my cardboard defenses were breached, and suddenly my fire-protecting shield turned into flames in my hands– singeing the very plant it was supposed to protect. A sudden increase in wind kicked the fire up a notch and sent smoke everywhere. The endangered shrubs were suddenly in need of very immediate saving. You think fast in a fire: to save myself or the spiky shrub? I ended up running around, smoke-blind, stomping out the flaming grass in front of each plant I could find, only to turn and realize that imminent disaster was approaching this one, and then that one, and oh shit- that one over there in the corner.
Eventually, the land manager turned on the hose, and put out the smoldering grass. As the smoke cleared we could clearly see, even through smoke blurry eyes, the absurdity of our afternoon. We lit endangered shrubs on fire, in the name of saving them. Conservation can be confusing work.
For all that Ziziphus celata is lacking in charisma, cooperation, and reproductive ambition- in a twisted way, we all came to love it anyway. Every new plant is a new chance to learn more about how to save them. One day, with almost 150 new plants tagged in a pasture, it was hard to believe the plant is really in danger of extinction. But the truth is that my coworkers and I were stabbed by every single Ziziphus plant known to exist. Although some days that felt like a lot of spines, it remains a species in real trouble. Saving an endangered species isn’t always pretty, feel good-work. But, I am rooting for the Ziziphus, hoping these giant communities of roots will put up more shoots, spread their spiny branches and grow.