Saturday, October 26, 2013

Time-sensitive ecology of the hairy fungus

My friend and colleague Peter Busher was out doing fieldwork near his study site at the Quabbin Reservoir in Massachusetts. He took pictures of this creepy fungus that looked like a giant hairball. It was growing on fresh bear dung. 

Phycomyces is a fungus related to bread mold. Like many of the fungi in the bread mold group (Zygomycetes) it has evolved to grow on substrates that are high in sugar (Peter had seen the steaming pile, full of berries, on the road just a couple of hours before). This fungus is one of the first to colonize the fresh feces of vertebrates. 

Not a lovely proposition but perhaps not as gross as it sounds. Something out there has to get the process of decomposition started. And when the hairy fungus has exhausted the nutrients available to it something else takes over. Sooner or later the pile of shit is consumed and the road is clear again. 

The landscape we observe, human and otherwise, is a time-sensitive space. Things happen in it on time scales that range from nanoseconds to eons. Our time is like a snapshot. There are great volumes of existence in time before and after us. 

What does this have to do with Phycomyces? This ancient fungus, which has been around as long as land mammals (hundreds of millions of years), lives its life cycle in a matter of hours. Other components of the landscape, like the pond where Peter studies beavers, are a longer-lasting feature, though the ponds too are part of a cycle. Hundreds or thousands of years later they are gone, a tiny sliver of time. The flutter of a leaf is part of the landscape too. Something that ephemeral seems too short lived to be of any significance. But is it less important than the Phycomyces? The leaf falls, the hairy fungus disappears. The pond is overgrown and dries up. But at its muddy bottom, perhaps hundreds of feet down, lies pollen that was released in a moment during a day in spring, millions of years before. 

Friday, October 4, 2013

Something useful from something arcane

I focused on lichen morphology and morphogenesis for my PhD work at Harvard and subsequent research. My goal was to identify form and the development of form in lichens. Most authors treating my taxonomic group, the Cladoniaceae, had thrown up their hands trying to make sense of form in these lichens. Lichen chemistry, a more "scientific" approach than microscopy, was the accepted modality for identifying and classifying Cladonia lichens. 

My work kept me busy and it was a lot of fun. I delved into mysteries of lichen form that no one had examined before. And I made some real progress in terms of identifying commonalities among species in my group, based on their inherited developmental process. For me, process was always more important than the "finished product" because mature lichens (just like mature trees only smaller) are affected by the environment. A branch may fall off, a branch may grow bigger, shapes change as things happen in the surroundings.

This was science for its own sake, research without a practical application. At least not one that I could see at the time. Not a sterile pursuit by any means, but an end in itself without "value" outside of its own framework.

I put away that research with some sadness, not knowing the direction I would go in. Since I finished at Harvard teaching has always been my focus and it kind of took over. Not a bad thing. There's a huge amount to learn from the process of teaching. 

This year I made some breakthroughs in my teaching approach. If you've been following my recent posts in my other blog, "Scientist/Artist," you have some idea of what has conspired.

Another breakthrough came along this week as I shared one of my research papers with students. The goal was not to have them understand lichens or lichen morphogenesis, but to have the opportunity to look at some scanning electron micrographs, something new for them. More important, I wanted my students to grapple with issues of form and form making. I reason that engaging with difficult problems like this, students will prepare themselves as critical thinkers, something that will serve them far beyond my classroom. These are some of the pictures they looked at:

So I had students read the article, focusing on the figures rather than the dense scientific text. Their attention, their focus, and their responses showed me that they were encountering something new and interesting. 

Since nature is full of abstract signals, I figured my lichen SEMs would provide material at once adequately abstract and challenging. Once you've looked at the way a lichen tip forms branches you're ready for just about anything. 

For me, using this old, arcane research and fueling excitement in non-science major undergraduates was a kind of completion of a circle. Instead of a dead end, my research photos provided food for thought. Instead of a too-narrow pursuit, my ideas were put to work challenging and expanding young minds. New ways of looking at science and new ways of encountering nature. New ways of thinking. Very rewarding developments.

All photos shown here were drawn from: Hammer, S. 2000. Meristem growth dynamics and branching patterns in the Cladoniaceae. American Journal of Botany 87: 34-47. 

Wednesday, September 18, 2013

Cold soil: a signal from below

Thinking about plant senescence as we turn the corner into fall. I realize it's not just sunlight that affects growth processes in plants. It's also soil temperature. 

Getting ready for the big move in in October, I've started emptying the pots with hot weather plants like coleus. The plants lost most of their color and a lot of their leaves over the past few weeks and the purple spikes of flowers have long gone to seed. As I turn the pots over I realize the soil is cold, even in the afternoon. 

Well it makes sense. Cold nights in the 40s and daytime highs that just reach 60 make for cold soil. A message to the plant roots that encourages slowing down. Some of the soil goes on top of the compost heap in back, now a mass of vegetable peelings, corn husks, and old corn cobs. That soil will introduce microorganisms to break down the remains, almost as if the black soil self regenerated. 

Some of the soil, the cleanest, will go into the soil container, to be re-mixed and used next spring for the new potted annuals. 

And some of the soil, the stuff I can't easily separate from tightly packed roots or stubborn stems, I'll throw back into the garden, whose surface seems to sink an inch or two every year. 

Cold soil in the pots reminds us that we're entering a time where everything, not just the house and not just the air, is readjusting for a new season.