Tom's Blog

Sunday, June 28, 2015

Paul West returns to Pleasant Valley Conservancy

Yesterday we had a nice visit at Pleasant Valley Conservancy from Paul West, his family, and friends. 

Paul played a major role in the early days of Pleasant Valley Conservancy, giving Kathie and me the key advice that we needed to get restoration work started properly. In those days, Paul was working only part-time at the Nature Conservancy, so that we could hire him for work and advice. He and his colleague Pat Schrader did some of the first savanna restoration work (Unit 12B). Paul also set up the protocols for control of brush (buckthorn, honeysuckle, prickly ash, etc.) and weeds (sweet clover, wild parsnip). He also wrote our first grant proposal (one of the first WHIP grants in Wisconsin). He set up the first major burn that was run by the Prairie Enthusiasts in April 1998. Finally, Paul encouraged Kathie to initiate a seed collecting program, which played such an important role in enhancing the biodiversity of the Conservancy.

Paul was soon hired full time by TNC and became heavily involved in Wisconsin's chapter Ecoregional Planning initiative. While continuing work at TNC, Paul continued graduate school at UW-Madison, and received his Ph.D. in 2010 (thesis title "Quantifying the effects of land use change on ecosystem services"). He is now the co-director and lead scientist for the Global Landscapes Initiative, a program within the Institute on the Environment at the University of Minnesota. 

We were delighted to have Paul back to show him how the Conservancy has prospered as the result of his initial guidance.

Paul West and group being guided through restored oak savanna by Kathie Brock, June 27, 2015

Paul West spraying honeysuckle cut stems, Pleasant Valley Conservancy, 1999

Friday, June 26, 2015

Mowing a field of wild parsnip!

Wild parsnip (Pastinaca sativa) is one of the "bad guys" in southern Wisconsin, and many restoration projects spend a lot of time attempting to eradicate it.

We had lots of wild parsnip when we started restoration work at Pleasant Valley Conservancy 20 years ago, but have almost none today. Unfortunately, we are surrounded by major infestations on adjacent lands. One area that is particularly bad is along the Valley Prairie fence line. Fortunately, we have permission to mow this area.

Wild parnsip is a biennial, so after it flowers and sets seed it dies. Mowing is best done when the plants are in full bloom but before there is any seed production. Yesterday was the day!

Our Kubota tractor/mower is ideal for this job, because the parsnip plants are easily cut with the deck mower.

A major problem with wild parsnip is the toxic juice that it produces. The operator has to be fully covered, with no bare skin showing. This is not so nice on a warm, humid day (such as yesterday!). Kathie had to tough this out, as the photo shows.

In order to ensure that all stems were cut, Kathie mowed the field twice, at right angles.

The field was 2.5 acres (as measured by GIS). A whole afternoon's work!

Sunday, June 21, 2015

Another good year for pale purple coneflower

The year 2013 was a great year for pale purple coneflower (Echinacea pallida) and 2015 seems to be another good year.

Pale purple coneflower patch on a dry lime prairie site, 2015.

The photo here shows the large population that has developed at what we call the "Far Overlook", Unit 5A. At this area, dolomite is very near the surface, leading to the formation of high-lime soils. This is thus a typical dry lime prairie area.

Although Echinacea was not present here before restoration began, there were only a very few plants here until 2013, when the site really blossomed! There were lots fewer plants last year (2014), but this is another boom year.

Although E. pallida is considered a Threatened species in Wisconsin, it is very easy to get established in planted prairies. Also, its seed is cheap, so most seed mixes have large amounts of this species.

There is another species, E. purpurea, that is sometimes planted. Although this is also native to the U.S., it is apparently not native to Wisconsin. However, many years ago it was planted at the University of Wisconsin Arboretum in the Curtis Prairie restoration, where it became well established and may have become a seed source for prairie plantings elsewhere. Its seeds may even "contaminate" seed mixes of E. pallida. In fact, small amounts of E. purpurea have appeared in some of the prairie and savanna plantings at Pleasant Valley Conservancy.

A few plants of Echinacea purpureum have been found growing
at Pleasant Valley Conservancy
Nonflowering plants of the two species can be distinguished because the leaves of E. purpurea are broad whereas those of E. pallida are narrow.

Some "purists" in southern Wisconsin work hard to eradicate E. purpurea from their prairie plantings, treating it like a weed, although I think this is carrying things a little too far.

Friday, June 12, 2015

Wood lily time is now!

Wood lilies (Lilium philadelphicum) are blooming now but you have to be quick or you will miss them.

Last year we had more success than usual at Pleasant Valley Conservancy, but this year is even better. Perhaps the consistent rains we have been having this year are helping. The table below shows where we saw wood lilies during our searches on 11 and 13 June 2015.

Wood lily location
Character of site
# plants
Cabin Prairie
Planted prairie
East Basin
Planted prairie
Forbs Garden
Planted prairie
Pocket Prairie East
Planted prairie
Pocket Prairie West
Planted prairie
Ridge Prairie
Planted prairie
Toby’s Prairie North
Planted prairie
Toby’s Prairie South
Planted prairie
Unit 1
Prairie remnant (south-facing slope)
Unit 6
Prairie remnant (south-facing slope)
Unit 7
Prairie remnant (south-facing slope)
Valley Prairie
Planted prairie

Total plants at PVC

The source of the lilies in two of the remnants (Units 1 and 7) is questionable, as we have no records that these sites have ever been planted with this species.

Some of the sites on the above table have had wood lilies for some years. We first saw plants in the Valley Prairie about 5 years ago. We also had a single plant in the Pocket Prairie about 5 years ago, but it was in bloom for about 24 hours before a deer came along and ate it. We are fairly certain that this same plant is one of those found this year in Pocket Prairie West.

Last year was the first year we had lilies in Toby's Prairie. These arose from seeds that Kathie had "knifed" into the ground 4 or 5 years before.

What are the chances that any of these plants will become pollinated and set seed? According to the literature, wood lilies must be cross pollinated, so the same insect must move from one plant to another on the same day. Thus, the chance of seed set will be higher at those sites where several flowering plants are close together. In order to monitor these plants for seed set, a numbered flag was placed at each location.

In addition, Kathie hand pollinated a number of plants. Using a Q-tip, she carefully lifted pollen from the anthers of pollen-producing plants and transferred it to the pistil (female organ) of nearby plants. Hopefully, this will lead to higher rates of seed set.

Hand pollinating wood lilies

Close-up of the wood lily flower

Friday, June 5, 2015

Edge effects at Pleasant Valley Conservancy

In a recent discussion with our summer interns, the topic turned to the movement of invasive species into Pleasant Valley Conservancy from surrounding lands. Good question. PVC is an island of high-quality ecosystems surrounded by invasive-rich lands. I quickly cited the presence of wild parsnip, garlic mustard, reed canary grass, and honeysuckle on neighboring lands. We have worked hard to eradicate these (and other) invasives from PVC, but there are no barriers to keep them from coming in again and again from outside.

Ecologists refer to the changes that occur in a community at the boundary of two habitats as an “edge effect”. (Wikipedia has a nice discussion of this topic.) Small natural areas in particular are subject to these effects because they have large surface/area ratios. (The smaller the site, the larger is the danger from outside. A million acre woods is pretty safe!)

PVC is approximately rectangular in shape, with the shorter dimension about 40% of the longer. This isn’t the worst possible shape for access by invaders, but there are still numerous dangers.

The map shows the major invasives that we have to be aware of.

There is a large patch of wild parsnip (Pastinaca sativa) in our neighbor to the south. This field is immediately adjacent to our Valley Prairie, and every summer we find a few wild parsnip plants that have moved in. Fortunately, dealing with these is not too much trouble, although we worry about forgetting that they might be there.

There is a large area of garlic mustard (Alliaria petiolata) in a degraded woods in our neighbor to the east. This is hidden among prickly ash, walnut, and other woody plants. This was probably the source of the garlic mustard we had in the East Basin when we first started clearing it. Fortunately, the East Basin GM populations were small and easily dealt with. We do have a small patch at the top of our North Woods (Unit 16) that we deal with every year, but it keeps coming back. (The garlic mustard seed bank will last more than 10 years.)

Wild parsnip and honeysuckle are nearby along the county highway to the north (Cty F) and can easily cross the road into our high-quality prairie/savanna road cut. Each year we have to patrol our side of the road (about ¾ mile in length) and pull about 20 or so wild parsnip plants. Honeysuckle has so far not spread.

Reed canary grass (Phalaris arundinacea) is scattered throughout the wetland to our west. We hire a contractor every year to spray reed canary grass in our wetland. 

The important thing is to keep track of the natural area boundaries, since that is where invasive plants will first show up. Fortunately, dealing with these edge effects is not too time consuming or expensive. We just have to be sure we don't forget about them.

Wednesday, June 3, 2015

Encouraging spiderwort growth

Right now is peak season for the flowering of spiderwort (Tradescantia ohiensis) in southern Wisconsin. This interesting plant finds a niche in the flowering sequence between the earlier lupine and the later ox-eye sunflower and pale purple coneflower. Right now spiderwort is almost the only showy plant flowering.

Spiderwort is a monocot in the Commelinaceae or spiderwort family. It grows primarily in sunny habitats, including dry, dry-mesic, mesic, and wet-mesic areas. It seems to thrive in disturbed areas, including railroad rights-of-way. At one time we had large populations growing in the railroad ballast of the Wisconsin and Southern Railroad west of Middleton, until the railroad in its wisdom did a major spraying job.

The first growing season after we cleared the large black walnut grove from Unit 18 we had a large population of spiderwort. Walnut produces a toxic chemical called juglone that inhibits the growth of other plants. However, juglone is only active against dicots and since spiderwort is a monocot it was unaffected.

Even before restoration began we also had 2 small remnant populations along the road cut above Pleasant Valley Road. We were able to encourage spiderwort spread by collecting seeds and throwing them in other parts of the road cut. Eventually we established it along our whole stretch of road. We were also able to encourage its spread by throwing seeds uphill. As the years have gone by, and with our annual burns, spiderwort is now well established throughout the whole south slope. Small populations can also be found in all our planted prairies as well as in the sunnier patches of the savannas.

On sunny days, spiderwort flowers close up by noon so that best viewing is on overcast days.

The best time to collect spiderwort seeds is when there is still a bloom or two at the top and the bottom seed pods are starting to open. Drying spiderwort seeds is a challenge. The seed pods hold lots of moisture, and getting rid of all this water is a difficult task. We have found it best to spread out the pods on plastic sleds and put them in a heated room. It might seem strange to need heat in summer, but even then, the seeds usually take four or five days to dry, sometime longer.

Some of the information here repeats material I gave in posts back in 2008 and 2011. Use the search box with the term "spiderwort" to bring up links to these earlier posts.