You may be familiar with the benefits of wetlands. They provide us an impressive list of ecological services such as flood water control, water filtration, outdoor recreation, erosion control and biodiversity preservation. You also likely know that too many of our wetlands have been destroyed by us to serve other purposes. So what’s the fix? How do we build a wetland? Is it as simple as digging a hole, adding water, sprinkling in a few wetland plant species seeds, and waiting?
If you’re shaking your head “no,” you’re right. It’s amazingly complicated. Wetland restoration efforts are hampered by our ignorance of the very ecosystems that sustain our lives. But it’s also fascinating. The excitement of participating, engaging, discovering and learning fuels the passion of a wetland restoration practitioner.
Let’s look at one aspect of a wetland restoration - establishing a native plant community. Leaping past the obvious issues such as too few intact remnant wetlands to use as models, how/where to obtain appropriate native plant seeds, and how to keep out invasive species, let’s instead focus on how to deal with aggressive native plants.
It’s a common issue for us practitioners. A few years after a new planting, we end up with some native species that dominate the planting and appear to limit native plants’ richness and diversity. Why does this happen? One reason could be a lack of native plants to help “keep in check” some of these aggressive, often rhizomatous, native species.
Like wood betony (see previous blog posts July 4, 2017 and June 27, 2019) in upland plant communities, marsh betony or swamp lousewort, is a keystone species that helps maintain wetland plant species biodiversity. It’s the “other” betony; wood betony’s wetland cousin. Marsh betony is a hemiparasite, obtaining nutrition from both photosynthesis and its host plant. Its parasitic action on host plants weakens the hosts, allowing niche spaces for other plant species to live.
Marsh betony is typically in peak flower (at least in Wisconsin) in August. Many species of insects, such as bumble bees, visit its flowers. Baltimore checkerspot butterfly larvae will eat its foliage as do deer and many species of rodents.
Fortunately, marsh betony is very easy to establish. The hard part is obtaining seeds. Its preferred habitat, calcareous wet soils such as fens, has largely been converted to agricultural purposes.
I’ve inter-seeded marsh betony into thick stands of prairie cordgrass and rhizomatous sedges such as hairy-fruited sedge with good success. Once the marsh betony gets a foot-hold and weakens the dominant grass or sedge cover, I introduce forb (flower) species such as cream, bottle and fringed gentians, great blue lobelia, marsh milkweed, fen orchid and turtlehead. I don’t know all the species that marsh betony will or will not parasitize. Keep this in mind when considering the introduction of marsh betony into areas where invasive species may still be present.
The image below shows a large stand of prairie cordgrass with clumps of marsh betony (spikey plant with yellow flowers):
Looking deeper into the areas where marsh betony has “opened up” the cordgrass sod, we find great blue lobelia (blue flowers) in the image below:
And we find cream gentian in the image below:
And fringed gentian (blue flowers) in the image below:
Looking very closely, we find a fen orchid (green twayblade) in the image below:
The image below shows hairy fruited sedge (grass-like plant in upper left) sod opened up by marsh betony. Other species include turtlehead (spikey plants in lower left and along bottom), willow herb (tiny pinkish white flowers - bottom right of center), boneset (white flower), sneezeweed (yellow flower lower right) and dark green bulrush (brown seed heads throughout):
Not wanting to forget critters, the image below shows the rare yellow bumble bee (Bombus fervidus) enjoying a marsh betony bloom:
We’ve not been good land stewards when it comes to wetland ecosystems. Our past, and often present, land management actions have destroyed many of these critical ecosystems and severely degraded others that exist today.
Can we balance our quest for prosperity with the ecological knowledge necessary to “rebuild” some of these lost ecosystems? What is the value of a stream with clear running water? Or the value of experiencing the touch, sounds, sights, and smells of marsh life on a spring day?
Nature has provided the tools for us to make it happen; we simply have to pay attention.