Purple loosestrife on the loose
Purple loosestrife
- also known as Lythrum salicaria
- ah what a beautiful spring bloom
- or so we thought
- this lovely plant is actually an invasive species
- that has invaded the entirety of the continental United States
- aside from Florida
- it is of European origin
- and likely made it’s way to North America by hitch hiking across the Atlantic in a ship ballast
- it was also purposefully brought over by European settlers who used loosestrife as a medicinal herb
- to treat dysentery, ulcers, sores, diarrhea, and the like
- by the 1830s
- purple loosestrife had established itself up and down the New England coast
- as it is a wetland plant that also does particularly well in a wide range of habitats
- it was the perfect invader
- it was also introduced to a habitat with no natural competitors
- so the take over came with little resistance
- we also helped it along quite a bit
- human construction of canals allowed its spread inland
- road systems also helped with distribution
- people even commercially distributed it
- planting it all over the place to feed the bees
- but what’s the problem?
- aren’t purple swamp flowers prettier than brown cattails?
- well
- introduction of L. salicaria disrupts the resident plant community
- which ultimately upsets entire wetland ecosystems
- large populations of purple loosestrife have compromise the survival of rare wetland plant species
- and wetland wildlife
- organisms that depend on indigenous plants for sustenance may find that their food source has been outcompeted by a purple alien
- so long fishies
- and the other problem?
- we don’t really know how to control it
- we’ve tried uprooting them by hand
- but they have very extensive root systems and propagate clonally
- meaning that a whole plant can sprout from something as small as a few left behind root cells
- we’ve tried, cutting, burning, herbicides, and controlling water flow from infested areas
- but these methods are expensive
- and potentially harmful to plants other than purple loosestrife
- there have been attempts at releasing natural insect predators to keep the purple loosestrife population under control
- but that one is still in the works
Invasive species are tricky. Sometimes an invasion happens by accident and sometimes we help it along. There are many gaps in our current understanding of how ecosystems function and there were even more gaps way back in the 1830s. How could those European settlers have known that them planting purple flowers for the bees could have negative effects on wetlands across the continent for hundreds of years? And now, how are we supposed to know how releasing predatory insects will affect these same wetland communities? It’s a tough situation, but science is pushing forward, one sticky step at a time.
Better bring your galoshes.
Source
“Purple Loosestrife.” Purple Loosestrife. N.p., n.d. Web. 28 Apr. 2016. <http://www.invasiveplants.net/plants/purpleloosestrife.htm>.
