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Tom's Journal (Blog)

 

Late Fall Burn: Crane and Barn Prairies

We wanted to burn the Crane Prairie this fall, because we have plans for an early spring herbicide spraying of the remaining exotic cool-season grasses. Since the Crane Prairie is low and wet, an early spring burn is often difficult. However, getting off a late fall burn is also tricky. One needs to wait until the fuel is dry enough to burn, but by then there isn't any warm weather left, and the days are getting short. We tried a test burn two weeks ago during a warm spell but the prairie was still too green.

The planets seemed to have been in alignment today, as the conditions were right. More important, we had a crew available, working on another project but willing to drop their chain saws and take up some burn equipment. The weather was cold, dry, sunny, and quite windy. Also, the wind was out of the west, exactly what we needed to burn the prairie without burning the marsh. In contrast to our usual practice, this was strictly a head-fire burn. This worked because Pleasant Valley Road acted as a good wide fire break. We were counting on the strong wind to push the fire away from the marsh and toward the road.

Todd Shumate ran the burn, with five others from the Michler/Brown crew. I took photos. The burn had to be done in two phases. We first burned the stretch along the fire break that separates the prairie from the wetland. The wind pushed the fire along until it reached an old lane in the middle, where it stopped because of the strip of green grass. Once we got the whole strip along the marsh black, we returned and lit above the old lane, with the wind now pushing the fire up toward the road. The photo here shows this second phase. You can't see it, but the strip next to the vehicle was already black.

The second photo below shows what happened when the fire reach the road cut. Here there was lots of fox tail grass and other good fuel. Because of the steep slope, the fire burned really hot. Across the road from these flames was the large south slope prairie remnant, that we won't burn until spring. We had two crew members with water tanks standing on the road, to watch for spot fires above. Although there were lots of black embers blowing uphill, the weather was so cold that their fire was extinguished as soon as they hit the air, so we had no spot fires.

My estimate was that about 90% of the Crane Prairie burned, which is better than we had any right to expect. We're now set for the farm coop herbicide spray rig next spring.

We also burned the small Barn Prairie (photo below). This did not burn as well as the Crane Prairie, probably because the fuel was not as favorable. We probably had 40-50% coverage.

 

 

Sorting Out the Seeds

Thanksgiving weekend is a good time to sort seeds and get ready for winter planting. It's deer hunting season, a good time to keep out of the woods, and the weather has crashed, making a lot of outdoor work unpleasant. We have been diligently collecting seeds since early July (starting with spiderwort and lupine). Although I am involved in all aspects of seed collecting, Kathie is the one who really runs the show here.

Using a spreadsheet that I prepared, Kathie has just finished a log/inventory of all the seeds. When I counted the totals, I was stunned to find that we had over 160 species!

The species are listed in alphabetical order, by Latin name. Next to the names are columns for dry, dry-mesic, savanna, wet-mesic, wet, and woods. A check in a column indicates where that species will be used. Some species are specialists, others more generalists. But rarely is a species used in more than three categories.

We will be using this spreadsheet to put together our seed mixes for planting. Most of the planting will not be done until spring, after we have finished our prescribed burns. (We always plant on bare ground.) The seeds will be hung in the barn until spring.

Seedlings of a few of the more interesting or specialized species will also be raised in the greenhouse this winter. These will then be set out as plants next May.

It's big job getting all these seeds ready, but it is worth it. Only in this way can the species diversity of a restoration be really increased. We don't have time to wait for nature to "take its course"!

Like a Needle in a Haystack!

Today, Susan and I made a concerted effort to find and spray all buckthorn plants in Unit 9, which is the upper part of the south-slope savanna. There were lots of buckthorn stems, but they were very scattered, so we had to keep a sharp eye out. Usually when we saw one plant, there were others also, coming from the same root mass. In the background of this photo is an original prairie remnant (Unit 4), which grades into the savanna. The hill was fairly steep, and rocky, so one had to work to maintain good footing. These buckthorn plants were often low and hidden among the tall forbs and grasses.

 

The photo to the left shows a single buckthorn plant with its green leaves. The trick here is to spray these leaves without spraying any of the "good" green stuff that might be around. Although most good species have died back, there are a few which remain green a long time in the fall. Also in the area are other "bad" plants that we spray, such as sweet clover, hedge parsley, barberry, and honeysuckle.

 

More Spraying

Honeysuckles and buckthorns are still green so I am continuing spraying the oak savanna areas. Today I finished spraying Unit 10, one of the finer savanna areas. Buckthorns were scattered but when present there were usually four or five stems.

Honeysuckles were concentrated mainly in the eastern part of the unit, and some of them were fairly good sized, although only two-years old. The honeysuckles were in an area that we had cut and treated in the winter of 2005-2006. At that time, the honeysuckles removed were fairly large, and needed a brush cutter. Those I sprayed today were probably not resprouts that had missed getting treated. Rather, I think that they were too small. Without leaves, these small honeysuckles are hard to find. Now with their bright greenish yellow leaves they really stand out.

It took me about 8 hours (spread over three days) to do the complete circuit of Unit 10 (2.5 acres; 3.2 hours per acre).

Altlhough I had to push my way through some rather large bramble patches (which will be dealt with after next spring's burn), there were some very nice prairie/savanna areas, especially on the lower south-facing slope. Lots of Indian grass, little bluestem, showy goldenrod, cream gentian, Tinker's weed, etc etc. There is lots of fuel here for the upcoming spring burn.

Dealing with the buckthorn and honeysuckle now makes a lot of sense, since all the burn would do would be to top kill them. The herbicide should kill the roots as well, getting them out of here for good.

In 1998 the understory of Unit 10 was virtually solid buckthorn and honeysuckle. The photo below shows what it looks like now. What a difference a decade of restoration work makes!

 

A Few Joys of Herbicide Spraying

It sounds a bit ridiculous, but I have been enjoying my work spraying honeysuckle and buckthorn this past few days. Since I have to completely cover a unit, I am forced to see all the plants in that unit. While making sure I am not spraying something good, unusual species stand out.

Today I was working in Unit 19C, an open savanna. Among the bad plants and the common things such as Canada goldenrod and brambles, I saw two quite interesting plants that I had not known were present. One was Great St. John's wort (Hypericum pyramidatum), a tall handsome plant that is not especially common at Pleasant Valley. According to Cochrane and Iltis, this is a plant of sedge meadows, wet and open habitats, and mesic forest edges. What is it doing, then, in a dry oak savanna? In passing through this unit, I saw three separate populations of this species, suggesting that its presence is not accidental.

I have found a number of other wetland or wetmesic species in our oak savannas, including great blue lobelia, fringed loosestrife, Culver's root, and sweet Indian plantain. My interpretation is that the groundlayer habitat of savannas is moister than that of prairies, while still providing enough light for some of the species found in wide open habitats.

Another species I saw during my traverse of Unit 19C was cream gentian (Gentiana alba), a species of mesic and wet mesic prairies, that also is commonly found in savannas. Although I had seen this species in some of our other savannas, this was the first record for Unit 19.

Ten years ago, Unit 19C had a clone of big tooth aspen (Populus grandidentata), which we killed by girdling and removed. I observed today that all parts of Unit 19C had scattered buckthorn plants (which I sprayed), except areas where the aspen had been growing. My interpretation is that it was too shady under the aspens for buckthorn to have become established, and they have been slow to invade after the area was opened up.

It is interesting that the "history" of a site remains for quite a period of years after it has been restored.

Mowing Fire Breaks

Today, Kathie and I mowed fire breaks at Black Earth Rettenmund Prairie. We aren't burning until next spring, but it is always advisable to get the fire breaks ready ahead of time.

There was a howling wind and the temperature barely got above 40 F. It was not good weather for much else, so it seemed an opportune time to get these breaks in.

We used our small Kubota tractor, which is ideal for this sort of task. Its underdeck mower is powerful and sturdy, and made short shrift of the task.

Most of the fire breaks for Pleasant Valley Conservancy are already in. The few that remain are in savanna/woodland areas where leaf fall will continue all winter, so we have to wait until spring.

Mowing a break between the original prairie remnant on the right (north unit) and a former ag field on the left. The ag field has been planted to prairie and is doing fairly well, but needs a burn every year. The remnant was burned last year.

 

 

Fall Spraying of Honeysuckles

In my post of 10/24/2007 I discussed the fall spraying of small buckthorn plants. Honeysuckle is another species that can be sprayed in the fall. As with buckthorn, the idea is to wait until all the native species have died back and then do a foliar spray with glyphosate. Honeysuckles retain their leaves long after the native plants have senesced. It is much faster to spray these small honeysuckles than to cut them and treat the cut stems with herbicide. I can spray a plant in about 30 seconds whereas it takes 4-5 minutes to cut and treat.

As the first photo shows, these honeysuckles stand out very well among the fall brown of the native plants. The second photo is a closeup, showing what the leaves look like. The blueish color of the leaves is due to the dye that I add to the spray mixture. This helps to insure that all honeysuckles are sprayed.

I am using 7% Roundup WeatherMax, a fairly high concentration, but I want to be sure that enough glyphosate gets down to the roots. The cost of the herbicide is a small part of the cost of this work, so there is no point in skimping.

The small honeysuckle bushes stand out among all the brown of the native species.

 

Close-up of sprayed honeysuckle leaves.

 

Regrowth of Prairie Plants in the Autumn

Quite a few prairie plants die back after flowering and then regrow in the autumn as vegetative rosettes. One that is quite visible this time of year is yellow cone flower (Ratibida pinnata), which makes a large amount of lush-looking green leaves (see photo).

There must be some interesting plant physiology here, but I am not aware of any specific research studies. Since yellow cone flower is a summer-flowering plant, I assume that the main consequence of this fall regrowth is an increase in food storage in the roots via photosynthesis.

This time of year we are spraying the leaves of small honeysuckle plants with glyphosate, so it is important not to spray the cone flower leaves by accident. (Anything green will be damaged by glyphosate.)

 

Among the other prairie plants that show a flush of new growth in the fall are pale Indian plantain (see photo), rosin weed (see photo), columbine, alum root, and prairie violet.

Fall regrowth of rosin weed, Silphium integrifolium

 

Fall regrowth of pale Indian plantain, Arnoglossum atriplicifolia.

 

In addition to these good plants, a number of bad plants also show fall regrowth. In the case of the bad plants, fall regrowth provides an opportunity for control, since they can be sprayed with glyphosate also. Depending on rains, those showing substantial fall regrowth include Canada thistle, sweet clover, hedge parsley, and spotted knapweed.

I sprayed a large patch of Canada thistle on 23 October and a check a week later showed that all of the thistle plants had been visibly damaged. Let's hope this patch will not return next spring.