Anna & I have been busy this summer conducting research in…you guessed it…wetlands. Specifically, we have surveyed several sites in central Iowa, collecting data on cattail growth form and habitat. The basic question we hope to answer is “how similar are the plants we find, to Broad-leaved cattail (T. latifolia), to Narrow-leaved cattail (T. angustifolia), or to their hybrid (T. x glauca)?” Other researchers are calling into question our past identification of the species, and recent work has suggested that whatever the species identity, growth form has important ecological consequences (especially after the above-ground parts die back and become litter). We aim to investigate what all this might mean. We’re also wondering if we can relate growth form—what I sometimes refer to as “plant architecture”— to interactions with the rest of the wetland.
Watch for future posts with findings from that research. I imagine this to be ongoing work, involving future collaborations with students and faculty colleagues. The questions seem important, since cattail is so common (and often dominant) in our wetlands. My 99wetland wanderings frequently bring me into contact with cattail, all over Iowa.
A recent visit to Finn Pond in Greene County provided some inspiration for my cattail curiosity. There’s plenty of cattails on this approximately 20-acre (8-hectare) wetland. Such a large site feels rather like a sea, or perhaps more colorfully described as a cattail jungle? Towering over my head, and so dense I can see less than arm’s-length in front of me, the cattails feel like an impenetrable thicket. Wouldn’t a wall of cattail be an interesting and important ecological phenomenon? How would this habitat compare to shorter, more sparse, or more diverse, vegetation?
I encounter several animals in the cattails in just a short walk. I imagine the structural characteristics of cattail leaves would be of great significance to birds. At least, if I were building a suspended nest attached to cattail leaves, I’d consider whether they were rigid, or slippery, or tall, or…well, any of the specs of this construction material of the marsh. Then I stop and look closely at the cattail…
Snails glide on the cattails as they scrape food off the leaf surfaces. I was surprised to find them congregating on the flower spikes, high above the water..actually, up above my head in some cases! What they are doing up there I can’t say—leave your thought in the Comments section.
Almost certainly, dragonflies will be affected by cattail architecture. As larvae, they swim in the water around the cattails, and frequently crawl up a cattail stem when it’s time to molt their juvenile exoskeleton and emerge to fly away. Here at Finn Pond, I watched an adult Widow Skimmer (Libellula luctuosa) as it perched on cattail leaves between flights, glamorous in its bright “racing stripes” and skillful in flight.
Later, I recalled these animal sightings, and what I know about the processes at work in wetland ecosystems. Anna and I talked a lot about how things work in a “cattail marsh,” and how the plant architecture might be important. I’m encouraged by the intriguing ideas we discussed, and delighted to explore Iowa wetlands, learning side-by-side with my student-collaborator. And I invite you to read future blog posts, and learn right along with us!