Tom's Blog

Monday, September 29, 2014

Fall color: good time to find sumac invaders

Those following these posts know that sumac has been one of our serious threats and that we have worked out methods for its eradication. One of the secrets is early detection followed by immediate control. Because of its intense red color in the fall, this is an ideal time for making sumac surveys.

Large clones are of course easy to find. However, a prairie restorationist may be unaware, during the summer when the sumac leaves are green, of how serious a clone has become. (See the photo below, which is not from either of our sites.)

High quality prairie remnant being invaded by three sumac clones.
Left unchecked, these clones might eventually take over the whole site.
For the two sites that we manage, we have worked hard to eradicate sumac. Our goal is to have no sumac on the site, not even single plants. We wait patiently for sumac's intense red color to develop and then do a thorough canvas. We pick a good day when the sky is clear and the sun is shining. Yesterday was perfect and Kathie and I spent most of the day looking for sumac plants. A good pair of binoculars is very useful, as single patches of red on a hillside can be due to various species, most of which are lots less harmful than sumac.

These include woodbine (Parthenocissus quinquefolia; intense red), hazel (Corylis americana; deep maroon), and gray dogwood (Cornus racemosa; dark red). Only sumac has compound leaves, which are usually easy to discern at a distance. The photo below shows how easy it is to spot a single sumac plant.


At Pleasant Valley Conservancy we found 10 single plants scattered over about 50 acres of oak savanna. None of these were on prairies, either planted or remnant. Only two patches were clones, but each of these was small (ca. 5 feet in diameter). When found, clones or single plants can be immediately treated by basal bark with Garlon 4 in oil. It is important to even treat single plants, because each plant has the potential for forming a clone. It was indeed satisfying that we saw so very little red!

At Black Earth Rettenmund Prairie we found only one clone of any size, and this was on the neighbor's pasture. There were 8 plants scattered over this 16 acre remnant prairie.
So little sumac? How could we be so lucky? Hard work and persistence.

Although we started to work on sumac in 2008, it was not until 2011 that we got serious. Using GPS (and GIS) we had mapped all the sumac clones on each site. The details of how we eliminated sumac are given in several posts, which are summarized in this link.

I should emphasize that we can't relax just because we have essentially eradicated sumac from these sites. Sumac is a prolific seed producer, and birds move these seeds around very effectively. If we drop our guard, we may soon find new clones. Also, single plants that we have missed have the potential for starting new clones. 

Restoration work is never finished.


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