Here's a recap of Driftless Area phenology from the past month, written by our very own Pat Trochlell. Pat's inspiration comes from her career as a wetland ecologist with the Wisconsin DNR. She and her husband, Ken Wade, live near and are stewards of TPE's 30-acre Parrish Oak Savanna, a diverse woodland ecosystem of over 240 native species.
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1 October 2020
Autumn is well underway, with trees turning bright colors. In southern Wisconsin, a few tree species – ash, aspen, hickory and maples - are red, yellow, and orange, but the oak-rich landscape is still predominantly green. Some understory plants, like Indian grass and staghorn sumac, also turn brilliant colors. Another plant that is now very colorful is Virginia creeper or woodbine (Parthenocissus quinquefolia). This plant is a climbing vine with palmately compound leaves. It is a strong climber, with tendrils that form an adhesive disc when they come in contact with a support. It is also our only species besides poison ivy that develops short roots along the vine to hold onto tree trunks. It’s also found climbing on human-constructed structures and rock walls.
Woodbine on sandstone wall. Photo by Pat Trochlell
The woodbine in my photograph is growing on a tall vertical wall of sandstone. Using a nifty app called Rockd, I was able to determine the type and age of the sandstone formation. It is Cambrian-age sandstone from the Tunnel City Formation, which is approximately 495 million years old. The Rockd app is a great tool developed by UW-Madison geologists. You can download the free app onto your mobile phone. As long as you have cell reception, the app can provide information about the geology and rocks in the areas that you visit.
8 October 2020
Signs of autumn continue with oak trees turning rust-colored, the scent of falling leaves, flocks of white-throated sparrows singing in the woods, and prairie plant seeds piling up in sheds and barns across the area. At TPE’s Mounds View Grassland, seed collecting started around the first of June when pasque flower seeds were ripe. Volunteers will continue into early November to harvest seed from the last remaining asters and stiff gentians. Last week, we collected boneset and mountain mint; this week, we collect prairie cordgrass and rough blazing-star.
Mounds View is just one of TPE’s many sites where seeds are harvested, processed, mixed, and stored for planting. Over the season, about 50 people show up for collecting, but the number of people has increased this year. This is probably due to the current need for us to get outside and also because TPE is reaching out to more people. Last Sunday, a record high of 17 people showed up to help with the harvest on a beautiful sunny day.
How many species are collected? Rich Henderson estimates that at Mounds View about 150 plant species are harvested, though not all in every year. Volunteers collect 300 to 400 pounds of seed with a "street value" of $100,000 to $150,000!
The monetary value of the seed is high, but the value to the prairies and other natural areas under restoration is higher. Perhaps the most important value, though, is to those of us who help collect and process the seed. We can watch the progress over time as an old cornfield or pasture is restored into the yellow and purple wildflowers and sea of bluestem that make up a tallgrass prairie. We can say that we played a part in this amazing transformation.
Seeds drying in a TPE-owned barn. Photo by Pat Trochlell
Jan Ketelle searches for western sunflower gone to seed. Photo by Pat Trochlell
15 October 2020: Asters (again!)
Asters are again (or still) in the spotlight for this week. We still have some species continuing to bloom, despite the colder weather and shorter day lengths. But most of them are showing signs of senescence. One species I hope to harvest seeds from along the hilly roadsides at this time of year is the flat-top aster (Doellingeria umbellata). When it blooms in late summer, the plant has numerous white flower heads in a flat-top cluster. It has many 3- to 6-inch leaves arranged alternately along the stem. At this time of year, the fluffy seed is ripe and ready to collect.
I associate this species with northern wetlands, especially in ditches along roadsides where it can be quite common. However, the plant is found throughout Wisconsin, including in the Driftless Area. Though mostly found in wetlands, it also grows in uplands. The range of habitat types in the Atlas of the Wisconsin Prairie and Savanna Flora lists “marshy, swampy or peaty ground, also in sandy or rocky uplands (such as bracken grasslands), north of the Tension Zone in spruce-cedar-ash swamps, moist fir-yellow birch-hemlock woods, and second-growth aspen, white birch, pine or red maple stands, edge of tamarack or sphagnum bogs… in the south …in fens, low prairies, sedge meadows, shrub cars, openings in low sandy woods, drained, burned or cut-over lowlands, margins of tamarack bogs and cranberry marshes, weedy in drainage ditches, roadsides and old grassy fields.”
With that broad range of habitat types, it seems capable of tolerating many conditions. But it is not a species that I have had much luck establishing from seed, despite my efforts. Maybe this year…
Sky-blue aster and a cold bumblebee. Photo by Pat Trochlell
22 October 2020
What a difference a week makes! Vibrant-hued oak trees are turning brown and losing leaves, which cover the forest floor. Weather changes are bringing rain and, in some areas, record early snowfall. Many migrating birds, like the pine siskins which were feeding heavily on stiff goldenrod seeds, have moved south. So it’s nice to see the occasional late-blooming flower, such as biennial gaura (Oenothera gaura). The plant is a mesic prairie species in the evening-primrose family. The name “gaura” comes from the Greek word gauros, meaning proud. The name is apt, as the plant grows up to 7 feet tall with numerous showy white flowers that turn pink as they age.
Late-blooming gaura. Photo by Pat Trochlell
Fall is a good time to look for signs of springs and seeps. As the vegetation senesces, more ground is exposed. In areas where there is standing water you may see signs of groundwater influence, such as the presence of iron bacteria where soluble ferrous (reduced) iron leached from rocks discharged with the groundwater. Iron bacteria are thread-like cells that oxidize the ferrous iron to ferric iron for energy. The ferric iron is insoluble and precipitates as a rust-colored deposit. Once the bacteria cells decay, they release a reddish or brownish slime that has the appearance of petroleum. Petroleum contamination is unlikely in most natural seepage areas, but you can confirm that the oily sheen is from bacteria and not petroleum by pushing on this layer with a stick. If it breaks apart, it is caused by iron bacteria.
Iron bacteria showing up as an oily, orangeish deposit. Photo by Pat Trochlell
29 October 2020
Native plant foliage has largely fallen or changed color, but several non-native plants are still green. This makes searching for them very easy if you're intent on controlling them. This is especially true of common buckthorn (Rhamnus cathartica) and non-native bush-honeysuckles (Lonicera spp.). Staying green when other plants have senesced and dropped their leaves gives these invasive plants an advantage over native species. Both buckthorn and honeysuckle have wide ecological habitat ranges, tolerating both wetland and upland conditions. Both species can dominate the landscape, shading out native species. Buckthorn is also allelopathic, creating soil conditions that suppress native vegetation and reduce habitat.
For those of us who want to rid our natural areas of these non-native species, a great way to remove them is pulling them up, roots and all. While this may give us a good feeling, it’s limited to small plants only. For large plants or large infestations, herbicides are usually required. One great source of information on controlling invasive plants is the Midwest Invasive Plant Control Network (MIPN) Invasive Plant Control Database. This database is a great tool to determine the most effective means of invasive plant control. It contains information gathered from both the scientific literature and the opinions of experts. You can search for a particular species and indicate the habitat, season, and whether you are a novice or expert. The search results can give you information on different means of treatment and the short and long-term effectiveness of those treatments.
We can’t control invasive plants everywhere, but we can work toward this goal on the properties that we manage and where we volunteer. Every invasive plant you remove can help, and this may eventually result in a fall landscape without a green understory.