Blame Bambi for Bountiful Garlic Mustard
From Ellen Jacquart, here’s a brief summary of the seminar on the interaction of deer and garlic mustard by Dr. Susan Kalisz at IU on 4/10:
Take away deer and garlic mustard goes away.
OK, that’s a little bereft of details, but pretty much sums it up. Dr. Kalisz has done quite thorough and impressive studies on the topic and as explained in her recent publication (http://www.pnas.org/content/111/12/4501), to successfully invade a site, garlic mustard needs deer to browse on the native plants. Then garlic mustard simply fills in the holes that are left.
Surprisingly, it’s not just the palatable native plants like trillium that go into decline with deer overabundance. Though deer did not eat it, the researchers also found that Jack in the pulpit declined in size and in number of reproductive individuals in heavily browsed areas in a study that included a site at IN Dunes (Heckel et al 2010). This is an indirect effect due to the great decrease in soil quality caused by the removal of vegetation by overabundant deer, which increases compaction and decreases moisture.
There was lots more, but those were the main take home messages for me. I’m rethinking my hostility towards garlic mustard, which turns out to be a somewhat innocent passenger following in the footsteps of the real culprit – Bambi. Bottom line – we need to support good deer management in the state, which means removing a lot of deer from natural areas that are getting browsed to the ground.
Kalisz’s 2014 PNAS paper on this topic is at www.pnas.org/cgi/doi/10.1073/pnas.1310121111 and her lab webpage can be found at http://kaliszlab.weebly.com/.