Tuesday, July 13, 2010

Pondering Leafy Spurge

July morning in the Waterman Prairie Complex
(click on image for a larger view)

Spent a morning recently on a photo field trip to a section of the Waterman Prairie complex just south of us.  Was curious about the Leafy Spurge situation on a favorite gravel esker; I hadn't been there in "season" in some time.

I found some very nice stands of Echinacea (E. angustifolia), 4 species of Asclepias (milkweeds - Green, Sullivant's, Butterfly, and Common), Compass plants (Silphium lancinatum), Toothed Evening primrose (Calylophus serrulatus), amd many other forbs, with plenty of native grasses such as Hairy grama (Bouteloua hirsuta), Prairie muhly (Muhlenbergia ?), Big bluestem (Andropogon gerardii) and Side oats grama (Bouteloua curtipendula) - all beginning to flower already.  Things seem to be ahead of past years due to our region's record rainfall and warm weather.

 Leafy Spurge
(Euphorbia esula)

The Leafy Spurge situation in this particular locale has not improved, it has nearly engulfed the disturbed slope leading up the esker and is now making some inroads onto the crest of the knob.  A few years ago a grad student from Michigan University would show up for a few weeks and spend a great deal of time documenting the incursion and it's affects on the neighboring plant communities.  I had some secret hope that he'd have some recommendations or an epiphany or something that'd help the situation!  But that was a few years ago now and nothing has changed there.

I can't fault the county or DNR on this predicament...I see it all over.  I do believe that if it were a legislated issue, we could get it under control.  That's a real can of worms though and don't really care to get into where that conversation would lead!  But if land owners over the county and state took this plant seriously, the rest of the areas still fighting it off would make real progress.

I don't know if Iowa has started a flea beetle program or not?  Some neighboring and regional states have and give out the flea beetles to land owners to disperse and I'm reading some encouraging results.  But it's a complicated situation and often requires several control approaches, not just one (flea beetles).

Apparently Leafy Spurge is toxic to cattle so any pasture ground effected by it becomes pasture lost for grazing.  However, sheep and goats can and will graze on Leafy Spurge, and studies have been done the past several years on grazing sheep or goats as part of a multi control approach.  Goats will apparently graze spurge completely down but it will return after they are rotated off a site.  Some success has been found combining flea beetles with goats or sheep though.  Maybe fencing small portions of an affected site and moving the enclosure periodically could be a helpful approach?

I was reading a paper from the Colorado State Extension, it mentioned that there are 4 types of flea beetles they use, as not all are suitable for "all" locations.  Interesting - I thought a Leafy Spurge Flea Beetle was just one insect, but there are several types and that's been part of the studies done the past several years.  Their habitat requirements vary, and although they don't entirely understand, they have identified which beetles prefer which type of habitat - you'd tailor your situation to suit a particular beetle for the best results.

For people that are unaware of invasive/exotic plants, none of this may seem the least bit important.  But if you witness this phenomenon first hand in a habitat you personally care about, it is most disheartening.  It is something like watching a loved one slowly succumb to a disease from which they apparently will never recover.

Our natural heritage is harder to secure as each year passes.  It is not wise to squander what your grand children deserve to experience and enjoy!  Look for answers and make inquiries...volunteer to help the environment in your area...do whatever you can, it's worth the effort.

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