Tom's Blog

Tuesday, January 15, 2019

Prairie burns: how complete should they be?



The completeness of a prairie burn is often determined by the continuity of the fuel. If the fuel is patchy, the burn may also end up being patchy. Some people think burn patchiness is a good thing.

I have never agreed with this. Perhaps it was because we were trying to restore sites that had become heavily wooded (due to years without fire). If good prairie was to be brought back to these sites, as soon as the woody vegetation was removed it was essential to get prairie established again. In order to do a proper prairie burn, the fuel had to be continuous. If it wasn’t, then the patches that did not burn had probably been wooded and without fire would quickly become wooded again.

In fact, it is so difficult to get conditions “right” to do a burn, that when you have the weather and the crew, you should work hard to do a complete burn. Don’t say “heterogeneity is OK” and go home. The secret, of course, is “interior lighting” (stripping). In the early years of a restoration, it may be necessary to “force” the burn. (See photo)

I’ve seen a burn crew leave a site which had unburned patches because they ran out of drip torch fuel. Always have lots more drip torch fuel than you think you will need.

Perhaps it’s the microbiologist in me, but if I see small patches of sumac, or brambles, or scattered honeysuckles, I get really nervous. The burn did not pass through these areas for a reason (no fuel). Next year they would likely be worse.

Heterogeneity of a burn is not a good thing if it is due to woody vegetation. It is also not good if it is due to smooth brome or quack grass or Kentucky bluegrass.

Note that heterogeneity and diversity are two different things!

The above refers to real prairie habitats. If the site has areas of wet meadow or shaded ravine, obviously those were not “meant” to be prairie. Heterogeneity then means something different.

Forcing a recently cleared prairie area to burn.
After frequent seeding and lots of burns, it turned into a tallgrass prairie (see below).

The green patches are smooth brome, an exotic grass that develops in the shade.




The same area as in the above photo, some years (and many burns) later

Friday, January 4, 2019

Last day to comment on the American Transmission Company project in southwestern Wisconsin

The American Transmission Company project has potential for great harm to southwestern Wisconsin ecologies and natural areas. Lots of opposition, but who knows what the Public Service Commission will do?

I had a post back in 2016 when this proposal first came  up. They have moved the right-of-way a few miles, but the main focus has not changed.

This is an important issue for the Driftless Area, and lots of groups have become aroused.

Photo courtesy of Driftless Area Land Conservancy
Comments should be made on-line at the following website:
http://bit.ly/CHCeSCOPE


Wednesday, December 19, 2018

Burning a Wisconsin prairie in the winter!


I’ve discussed the problems with fall prairie burns in our part of the country. 

So if fall burns are so difficult, winter burns must be impossible?

Yesterday (December 18, 2018) we had a very successful winter burn at Black Earth Rettenmund Prairie. How was that??

The November/December weather had not been good. No sun, mostly cold and cloudy, little snow, not much rain. We had given up doing any burns. But then, December 15-18 a dry air mass arrived, with dew point 20-22, clear sunny weather, strong south wind, and temperatures reaching the low 40’s (F) by noon. It certainly wasn’t Indian Summer, but we had burned with these sort of conditions last spring. Fire, of course, makes its own temperature, so if the fuel has good prairie grass, it should burn.

Fortunately, our burn crew was available. We decided to do it.

One problem with a winter burn is you need water, and the pump at our well had been drained for the winter. Since the temperature was slightly above freezing, we primed the pump and filled all the water jugs and backcans. (At the end of the day the pump was drained again and all backcans emptied and the spray wands brought indoors.)

Kathie had already mowed the fire breaks, so the prairie was ready to burn. The map at the end of this post shows the burn area. Amanda ran the burn.

The weather continued favorable. We met at BE Rettenmund at 11:30 AM for a noon start. We had eight crew, all experienced, and one trainee. 

Because of the south wind, we started at the north end of the North Unit. One crew moved west and south, the other east and south. Each person had a radio, so the two crews could keep in touch.

One problem with burning this prairie is that it is a long, narrow unit with two moderate hills that break up the wind. So a south wind is often a southwest or southeast wind, often at the same time on different parts of the burn unit. Fortunately, the prairie is surrounded on most sides by crops, which at this time of year have been harvested. The bare fields show well in the photos.

The North Burn unit (on the right) is almost finished burning. The head fire at top will be coalescing with the back fire from the north.
Jared is starting to light the Saddle.

Kathie and Denny are preventing the fire line from creeping over the lane into the crop field.
Creep was a problem and they had to monitor it the whole way.
It is unlikely the field would burn, but it would be embarrassing if it did!
Note the solid black burned unit.

Burning the Fesenfeld Road embankment. The trail from the entrance is visible snaking up the hill.
The fuel in the lower, planted, Gateway Prairie (a former alfalfa field) below the top is not as good as the
fuel of the remnant prairie above. 
 After the whole burn was completed, the crew returned to the North Unit and burned the Fesenfeld Road embankment, which is separated from the burn unit by the peripheral lane.

A satisfied crew.
Denny, Jared, Amanda, Tiffany, Chris (kneeling, with two drip torches)
Susan, Josh, Kathie. (Tom, who drove the truck, behind the camera).




Saturday, December 8, 2018

How long does it really take to get rid of invasive brush?

We first cleared the South Slope of Pleasant Valley Conservancy in 1998-1999. We instituted an annual burn program almost immediately, although some of the areas were hard to burn  (not enough fuel). Also, lots of brush that had been suppressed because of the deep shade popped up almost immediately. Brambles, buckthorn, and honeysuckle were the worst, although sumac was bad in some areas. The annual burns kept the shrubs fairly small, but did not eradicate them. We kept cutting and treating, and burning and burning.

The two photos shown here are interesting. They were both taken from about the same location, looking down from the top of the slope. When I took the 2003 photo it was a photo point as part of a series I did every year. It's hard to believe, but I thought the area was in pretty good shape. (It's also hard to believe, but this photo was taken with a Nikon "film" camera!)

The second photo was taken last summer from almost the same location. What a difference! Visible in the photo are Echinacea pallida and Silphium lacinatum. And of course, prairie grasses to carry a fire.

View from the Far Overlook (Leopold bench) in early September 2003

View from the same location at the end of July 2018. All the woodies visible are bur oaks!

The moral of this story? The restoration ecologist needs patience!

Sunday, November 25, 2018

What happened to our fall burn weather?

At Pleasant Valley Conservancy we have been doing major burns in both the spring and the fall since 1999. Here is a link to the complete burn record.

I just went through the history and found that we have burned in the fall 16 years, every year since 1999 except 2009, 2013, and 2015. Most of our fall burns have been North Woods burns, but for various reasons we have occasionally done some prairie burns.

We were all set to do another North Woods burn this fall, but the weather has not cooperated. I haven't looked at the weather  bureau  data, but I am certain that this has been the coldest October and November since we have started  doing restoration work.

Although the fall burn season is always shorter than the spring, we have always had at least a few days of favorable burn weather. October 1999 was the warmest and driest on record, and we had a fantastic North Woods burn on Hallowe'en when the temperature was in the low 70s and the R.H. % was in the upper 20s.

Recently, 2014 and 2016 were great years for fall burns.

Nov 5, 2014 Vahldieck photo

Note how well the oak leaves are burning! Vahldieck photo

Hopefully, we will be able to get our planned North Woods burn done this next spring. We'll see!


Wednesday, October 31, 2018

October is a great time to basal bark buckthorn in prairie and savanna remnants!

Even a single stem of buckthorn stands out among all the brown senesced native species.

Killed yesterday

Killed in 2013

Killed in 2015

Killed in 2008
If it's green this time of year, it's probably bad.

It may be too late for a foliar spray, but basal bark with triclopyr works all year long. Use 20% Garlon 4 in bark oil (20 parts  Garlon 4 plus 80 parts bark oil). If you don't have bark oil, use diesel.

Even a natural area where buckthorn has been eradicated will always have a few new shoots. If  they are not treated NOW, they will be bigger next year! We always budget time in the fall for control of invasive shrubs. Not only buckthorn, but also honeysuckle, sumac, and brambles, all of which are easy to spot.

In a tour of known buckthorn areas at Pleasant Valley Conservancy yesterday, we found only two stems. It took less than a minute to basal bark each one.

Monday, October 22, 2018

How viable are our hand-collected seeds?


Kathie and I often discussed the quality of our collected seeds. Would they grow when planted? Would the seeds germinate?

Seed germination tests are not that hard to do and in early January 2008 I set up number of tests.

Most prairie and savanna species need a period of cold moist conditions to overcome dormancy. I used conventional petri plates with warm absorbent paper (filter paper) in the bottom. 25 seeds were placed in each plate, which was wrapped in Saran and placed in the back of the refrigerator. In early January 2008 the plates were placed under lights (16 hours light; 8 hours dark), rewatered when necessary, and observed daily for germination.


Petri plate with germinated seeds of purple milkweed. The root comes out first. All the seeds have germinated. 2/15/2008

Seed germination tests


Species


State-listed
Seed Year
% germ #1
% germ #2
% germ both plates
Aureolaria

2007
20%
12%
16%
Butterfly MW BE

2007
60%
80%
70%
Butterfly MW PVC

2007
76%
92%
84%
Cacalia tuberosa
X
2005
11%
0%
3%
Cacalia tuberosa PVC
X
2007
8%
0%
4%
Eupatorium sessilifolium
X
2005
0%
0%
0%
Eupatorium sessilifolium
X
2007
4%
0%
2%
Eupatorium sessilifolium Parrish

X
2007
4%
0%
2%
Green MW BE

2007
96%
72%
84%
Indian grass

2007
56%
60%
58%
Little bluestem

2005
16%
16%
16%
Little bluestem

2007
12%
12%
12%
Napaea
X
2005
4%
0%
2%
Napaea
X
2007
4%
8%
6%
Poke MW PVC

2007
80%
92%
86%
Prairie dropseed forbs garden

2007
24%
20%
22%
Prenanthes crepidinia
X
2005
0%
0%
0%
Purple MW
X
2005
100%
Purple MW forbs garden
X
2007
100%
84%
92%
Sweet Indian plantain
X
2005
28%
28%
28%
Sweet Indian plantain
X
2007
12%
32%
22%
Taenidia integrifolium

2005
0%
0%
0%
Taenidia integrifolium PVC

2007
0%
0%
0%
Wood betony Mark

2007
0%
0%
0%
Yellow hyssop
X
2007
60%
44%
52%
BE: From Black Earth Rettenmund Prairie
PVC: From Pleasant Valley Conservancy

As the table shows, the milkweeds germinated very well, as did the grasses, but some of the other forbs germinated poorly or not at all. We confirmed some of these data with greenhouse studies in future years. Obviously, if the seeds do not germinate, the chance of getting plants from planted seeds is not good. However, with most species we generally plant a lot of seed, so if the % germination is only 1-2%, there is still chance of getting some plants started from seed.

The best approach for those poor germinators was to use the greenhouse. We planted large amounts of seeds in flats and put them under lights after cold, moist stratification. We transferred the few plants we got to tubes and raised plugs. Most of the plugs we transplanted to the field grew, and became established. This worked especially well for E. sessilifolium, one of the state-listed species.

Of course, every year will be different, depending on conditions at the time seed formation is taking place.