Tom's Blog

Wednesday, June 21, 2017

Detailed summary of the wetlands at Pleasant Valley Conservancy

Restoration work on the Pleasant Valley Conservancy wetland has been underway for over 15 years. This work has been carried out by Craig Annen and his company, Integrated Restorations (IR).

Recently, as part of a survey for hybrid cattails, Craig has prepared a detailed summary of the wetland, including an extensive species list which includes a Floristic Quality Index (FQI).

Craig's paper has now been posted on the PVC website and is available for download.

According to the report, the 35-acre complex is a mosaic of seven unique wetland types: riparian floodplain, emergent aquatic, open water, shrub-carr, peaty sedge meadow, wet prairie, and calcareous fen/spring.

View of the PVC wetland from the bench at the Far Overlook. Although there is a substantial stream running through the wetland, most of the water is from springs and seeps.

Early Autumn view of the wetland, showing the location of the boardwalk.

The wetland complex supports 163 indigenous species of native plants, all listed in the report. The Floristic Quality Index (FQI) has a value of 62.2, indicative of a remnant natural area of remarkable quality. Thirty-eight species have a coefficient of conservatism (C-value) greater than or equal to 7, and 16 species have a C value greater than or equal to 8. These values are indicative of remnants of high-quality and with the least amount disturbance. Thus PVC has been justified in placing high priority on its wetland restoration work.

One plant species, sweet Indian plantain (Hasteola suaveolens), is a species of Special Concern in Wisconsin.

A gallery of flower photos and further information on the wetland can be found on the wetlands page on the PVC website.

Saturday, June 10, 2017

Fire Management in Midwest Oak Savannas

We have been burning oak savannas and oak woodlands at Pleasant Valley Conservancy for 20 years. In the early years we made lots of mistakes, as there were no sources of good information on the use of fire. (The Internet was still in its early stages.) As the years have gone by, our mistakes have been less and the sizes of our burns have been bigger.

See past posts of Tom's Blog for summaries of our annual spring and fall burns. (To access posts of earlier years' burns, do a Search for "Fire" and "Savanna" in the search box.)

In 2015 I was asked to give a presentation on "Fire management in oak savannas" at the annual meeting of the Prairie Enthusiasts, which prompted me to assemble photos and data for a Power Point presentation. I finally found time this past winter/early spring to convert that presentation into a PDF, which is provided in this link.

Here is a brief precis from the introduction to the tutorial:

"Oak savannas are fire dependent communities. Fire management in oak savannas differs from that of prairies or oak woodlands. This document provides details on how to conduct an oak savanna burn.

Fire is especially important in oak savanna restoration. An oak savanna restoration project should not be initiated if fire is not an option. Ideally, fire should be used annually for at least 10 years. After 10 years, fire can continue to be used annually, but should be used at least two out of every three years indefinitely."

Early stage in an oak savanna burn. October 2002
This was the first time this savanna had been burned,
and to get good burn coverage the burn was run as a headfire.

The second photo shows the first burn we did in the ridge-top savanna (Unit 12B/11B). At that time, although there was good fuel (oak leaves), the fire did not carry well because of all the downed timber and coarse woody debris. Here Kathie is doing extensive interior lighting (stripping), literally "forcing" the savanna to burn. As the years went by, the savannas burned more readily and did not need so much work to burn.

The tutorial goes into details on the savanna burn process.

Friday, May 26, 2017

Should colorful invasive plants be controlled?

Many of the invasive plants that we deal with in restoration ecology are rather unremarkable in appearance, so one doesn’t mind getting rid of them. But there are also invasive plants that are colorfully attractive and there may be a temptation to let them be. Two species in this category are dame’s rocket (Hesperis matronalis) and creeping bellflower (Campanula rapunculoides). Both are decorative and would appear to be welcome additions to a native garden or prairie. But they aren’t, and should be eradicated.

Fortunately, because these two species are colorful, they are easy to spot. It would be an embarrassment to have a whole field of one of these plants.

Dame’s rocket
Although this plant is often mistaken for a woodland phlox, it is really a mustard (note the 4 petals). Like garlic mustard, it is often found in wooded areas, but it also invades open areas such as roadsides. This is one of those species that is often included in seed packets labeled “wildflowers”. To many people, “wildflower” implies “native”, but this species was introduced from Europe in the 1600s and is highly invasive.

Like garlic mustard, dame’s rocket is a biennial, and this gives a clue to control methods. The number one point is not to let it set seed. Cut the flower heads off or hand pull the plants before seed formation. Like garlic mustard, bag flowering plants, because even pulled plants can go on to make viable seeds.

Large infestations can be sprayed with glyphosate. Also, first year plants remain green in the fall long after native species have senesced and can be sprayed with glyphosate (again, like garlic mustard). [Native species that have senesced will not be affected by glyphosate. The rule with glyphosate is: if it’s green, it will be killed. Thus, when spraying with glyphosate keep an eye out for the green of fall regrowth of native species.]

In contrast with garlic mustard, colorful dame’s rocket is very easy to spot. With care, it should be possible to eradicate dame’s rocket from a site.

Dame's rocket moving into a wooded area

Creeping bellflower
Creeping bellflower is a perennial which spreads rapidly via rhizomes. It has the potential to form large clones. Its rhizomes can be up to 6” deep, with vertical storage roots. If cut or mowed, the plant will readily regenerate from rhizomes or perennial roots. The number one point is do not let it get started, because once established it is very difficult to eradicate.

Because of the deep roots and rhizomes, it is virtually impossible to get rid of creeping bellflower by digging without tearing up the whole yard. My approach is to handle it like a woody plant, which means cut the stems and treat the cut stems with 15-20% Garlon 4 in oil. Just a single spritz at the center of each cut stem is all that is needed. The herbicide will be translocated to the roots and rhizomes. [I verified this procedure by marking treated plants and checking them the following year.]

Large patches can be sprayed with glyphosate or an herbicide labeled for broad-leaf species.

I should emphasize that creeping bellflower is a very undesirable plant, despite its colorful character.

University of Wisconsin Extension has a good flyer on creeping bellflower, available at this link.

American bellflower
There are two “native” species of Campanula which are attractive and desirable in a restoration. Harebell (C. rotundifolia) is a small, delicate perennial that is found individually or in small patches in dry or rocky habitats where it is free from competition from larger species. American bellflower (C. Americana) is an annual or biennial that reproduces exclusively from seed and is found scattered in wooded or savanna areas.

Monday, May 15, 2017

Shooting star: prairie or savanna plant?

This is shooting star (Dodecatheon meadia) time. At Pleasant Valley Conservancy, we had many sites where this species was remnant. Some even flowered before any restoration work, but lots had also been suffering along in deep shade and only flourished after brush clearing and a burn. Of course, we also collected seeds and used those to plant prairies in our former ag fields.

Shooting star is one of those species (like golden Alexanders and New Jersey tea) that do well in both prairies and savannas. There has been some good research on the growth and cultivation of shooting star, most importantly the nice paper by Paul Sorenson that was published in one of the North American Prairie Conference reports.

The photo below was taken the other day in the White Oak Savanna (Unit 12A), which was one of the first areas we restored (2001-2002). As soon as the brush was removed, shooting star bloomed extensively, and has been doing so ever since. (This unit is burned annually.)

Right now you should find shooting star in bloom in almost every prairie or savanna in southern Wisconsin.

Wednesday, April 19, 2017

Spring 2017 burn of the oak woodland at Pleasant Valley Conservancy

Oak woodlands need fire, and at Pleasant Valley Conservancy we try to burn our major oak woodland (Units 15 and 16) at least biennially.

The big burn in November 2016 was fairly successful, but some areas did not burn well, and the County F road cut, which has a lot of good savanna forb species, did not burn at all. Yesterday, since all of the surrounding units at PVC had been burned, we had no need for fire breaks, and simply lighted from the bottom of the hill along County F. The fire easily moved up from County F into the woods, and in most areas burned through the woods until it reached some barrier. In several areas, the fire line moved all the way to the top of the hill, where it reached the North Fire Break and stopped.

This was a two-person burn (Amanda and Susan), with two drip torches and no water at all. (We had water backcans as back up, but they were not needed.) There was a strong wind out of the south, but on this north-facing hill everything was fairly quiet. The temperature was 70 F and the R.H. about 45%. There had been several sunny, windy days, so oak leaves, the principal fuel, were dry and crackly. All that was required is to light along the bottom of the County F road cut and watch the fire move.

Fire line moving through the woods from lighting at the bottom of the County F road cut.

Looking down from the top of the hill (along the North Fire Break).
In this area the fire had moved all the way from the bottom to the top of the hill in about an hour.

Zig-zag goldenrod, a woodland species, is an early starter. In this area, the fire went around the patch on the left, but burned the other two patches. Because this is a low-intensity fire (around 200 C), root buds of the burned patches will soon replace the damaged plants.

See more photos on the PVC Facebook page.

Friday, April 14, 2017

Genetic (DNA) taxonomy of three species of oaks at Pleasant Valley Conservancy

It is easy to identify a tree as a member of the genus Quercus (“oak”), yet often difficult to distinguish a specimen at the species level. This is especially true for oaks of the section Lobatae, which includes red, black, and Hill’s oak, three species that are prolific at Pleasant Valley Conservancy. To keep things simple, I will call this the “red oak group”.

Key taxonomic characteristics of oaks include bud and leaf morphology, acorn shape (including the cap), and bark thickness and structure. If the specimen is a “good species”, the characteristics fit well, and a species name can be attached. But confusion often arises, and this is often due to hybridization.

It has been known for some years that hybridization is common in the red oak group, which explains why these species are hard to pin down taxonomically. It seems reasonable that if two or more of these species are growing in the same general area, hybridization might occur.

Present day plant taxonomy makes extensive use of DNA analyses, which provide “ground truth” for traditional morphological taxonomy.

We have been fortunate that botanist Andrew Hipp, Senior Researcher at the Morton Arboretum, has taken an interest in the oaks at Pleasant Valley Conservancy. (Andrew worked as a naturalist at the UW-Madison Arboretum, and received his Ph.D. working on sedges. He wrote an outstanding book on the Sedges of Wisconsin.)

Since Andrew took up his post at the Morton Arboretum, he has been working on the taxonomy of oaks, using DNA techniques.

Later he returned with a research team and sampled a number of oak specimens for DNA analysis.

The details of the DNA studies are too complicated to present here, but can be found at the following link: 
Owusu, Sandra A., Sullivan, Alexis R., Weber, Jaime A., Hipp, Andrew L. and Gailing, Oliver. 2015. Taxonomic relationships and gene flow in four North America Quercus species (Quercus section Lobatae). “Systematic Botany”, Vol. 40(2): 510-521.

Andrew’s group studied red oak-group specimens from 17 separate geographic sites in the Midwest. My post here deals just with the oaks he sampled from PVC.

The map here is from Andrew’s paper, with a few labels added to indicate the approximate locations where the samples were taken. It shows the distribution of genetically pure, hybrid, and misclassified individuals. Each specimen is shown with the classification originally made based on traditional taxonomic criteria. Symbols with open centers indicate that the DNA data agreed with the taxonomy. If the symbol has a black circle, it means that the DNA indicated that specimen was a black oak but had been misclassified. Those with a black star indicate black X red oak hybrids. Those with a white plus sign are black X Hill’s oak hybrids.

Figure showing distribution of members of the red oak group from the research paper,
with labels added to show the approximate location at Pleasant Valley Conservancy.

The table below summarizes the data from this figure.

Analysis of hybridization in the red oak group, based on an analysis of 64 specimens from the north and east side of Toby’s Prairie.
Tree identity
How many?
Hill’s oak (Q. ellipsoidalis)
Red oak (Q. rubra)
Black oak (Q. velutina)
Hills X Black
Red X Black
Black misclassified as Hill’s
Black misclassified as Red

In sites such as PVC, where all three species are living close together, it is perhaps not surprising that hybrids (based on DNA) are common. A significant number of specimens of Hill’s and black oak had been misclassified (based on DNA). However, the DNA analysis indicated that quite a few tree specimens at PVC were not misclassified.

Andrew has now moved on to a study of the bur oak/white oak group, and will be back this summer to do DNA sampling from some of these trees.

Sunday, April 9, 2017

Early prairie flower blooms in fall-burned sites

Generally prairie burns in the fall are not too successful because grass, the principal fuel, has not yet fully cured. However, last fall was especially favorable for curing and prairie burns were quite successful.

The advantage of a fall burn? You don’t have to burn in the following spring. Depending on the weather, a spring burn might have to occur late enough so that species that flower early, such as pasque flowers, take a major “hit”. (I once watched a whole hillside of stunning pasque flowers at Koltes Prairie get burned up!)

Last fall two outstanding prairies were burned in the fall, thus giving them a “head-start” for this spring: Walking Iron and Black EarthRettenmund.

Yesterday, Kathie and I visited these prairies to see how they had responded. Although this has been a cold March and early April, lots of early prairie species were above ground. Pasque Flower Hill at Walking Iron Prairie indeed had quite a few pasque flowers (Anemone patens) in flower, although the major bloom will probably be next week.

Pasque Flower Hill at Walking Iron County Park in April 8, 2017. This prairie was burned the previous fall.
Lots of new growth scattered across the site, and a few dozen pasque flowers.

Pasque flower in bloom at Walking Iron. Pascha is Latin for Easter, which is often the time this species is in bloom.

Prairie smoke, a species that is especially prolific at Walking Iron.
Early buttercup (Ranunculus fascicularis). This species is the earliest bloomer in the Upper Midwest, but
generally found only in mowed lanes or other areas where the vegetation is short.
Because of the burn at Walking Iron, all the vegetation is short, so early buttercup is thriving.

At Rettenmund, where pasque flowers are fairly uncommon, shooting star shoots were all over the South Unit. Also, wood betony was in bud everywhere, prairie smoke was in the vegetative state but flourishing, and there were lots of rattlesnake master shoots.

Wood betony with a few buds already showing, and a vigorous rosette of shooting star;
the South Unit (burned Fall 2016) at Black Earth Rettenmund Prairie

From now until the end of October, there should be something new to see each week at these two nice prairies in western Dane County.