Sunday, April 24, 2016

Back to the Steyermark Site

Everyone in the office knows the routine: when Missouri's morel season is two weeks underway, so too is the bloom cycle of Amethyst Shooting Star (Dodecatheon amethystinum), known from only a handful of locations in the Ozarks. This glacial relict plant resembles the more common shooting star (Dodecatheon meadii) found on both glades and rock faces, but there are distinct genetic differences between the two. The location of the rare Amethyst Shooting Star was noted by Julian Steyermark in his discussion of the species in his landmark 1963 Flora of Missouri. Unfortunately, the homogenization of this site through the conversion of the woodlands to a monoculture of bush honeysuckle makes the shooting star location highly vulnerable. So, since 2008, every April we dedicate several days to pulling and cutting and stump treating bush honeysuckle around this moist cliff face. Unfortunately, the rest of the woods are doomed.

This is not the job for one person. The Steyermark site of the rare shooting star covers about ten square meters with hundreds of basal rosettes of this plant poking through thick moss and surrounded by other small spring wildflowers. The entire shrub layer in the photo to the right is bush honeysuckle. If we stopped making our annual trek to the shooting star location, these plants would vanish. Bush honeysuckle not only blocks light to the woodland floor, thereby blocking any hope of flora growing, but it's also allelopathic which means it poisons everything around it. Once the canopy trees die, there will not be regeneration in bush honeysuckle-filled woods. And sadly, one plant can produce thousands of seeds, manifest in those pretty shiny berries each fall.

At a recent conference, attendees from Montana asked our presenter on non-native invasive species if Missouri had any native flora left, considering how many species of exotics have taken a foothold in recent years. Of course, we do still have native flora, but fire-starved woodlands (thousands of acres in the Ozarks) with their closed canopy has not met an exotic species as detrimental to biodiversity as bush honeysuckle. Japanese stiltgrass is running a close second, but it has not been documented from every county like bush honeysuckle has in recent years. Exotics that can thrive in closed canopy conditions are certainly a bigger threat than roadside exotics.

After our day of honeysuckle removal, the area we worked in was free of honeysuckle. The cliff face is obviously very steep, so pulling plants required a lot of holding onto trees so we didn't fall into the river valley below. There are still hundreds of shooting star plants, not all in bloom that day, but hundreds of rosettes. The increasing urbanization and the lack of regularly occurring prescribed fire have left us with a new plant association: bush honeysuckle, deer, wintercreeper association. Sadly, this is what homogenization looks like and to protect landscapes from the ever-burgeoning threat of this detrimental process, it takes a lot of work. In the long run, bush honeysuckle will win.

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