Tuesday, June 25, 2013

The Sad Strange Waste of AC

Here in Boston we experience a handful of days each year with high heat and humidity. Yesterday was one of them. I guess you could call it uncomfortable. But really, most of the year here is bone cold. As if by reflex the air conditioners have roared into action.

It's a strange thing in the morning to walk outside and hear the steady crash of the AC, window units, central units, each with a distinctive unpleasant growl. Each gobbling electricity, wasting resources in the dewy cool morning. Meanwhile the garden sends up its moist aroma after last night's thunderstorms, shoulder high plants cooling the air passively through photosynthesis.

At night when it cools down we like to keep our windows open. Everyone could. No one does. Our reward for letting in a breeze is the mechanical thunder of air conditioners, the stupidest solution to making a comfortable house/neighborhood/city.

I know I sound like a throwback. People will complain that AC is a lifesaver, allowing them to sleep, preventing allergies, enabling work and play. But really, in this cold city where we live by the weather, would it hurt to turn off the motors and relish the tropical warmth?

Thursday, June 20, 2013

A collaborative effort

The plant body is a complex system of cells and tissues. It appears to be structurally simple but it is functionally complex. There are so many activities the plant body has to accommodate. Think about it: Circulation of water and nutrients, collection of solar energy, reproductive activities, growth and the production of useful molecules. These are but a few of the multiple functions of the plant body. How can we teach this complicated stuff to undergraduates?

All plant activities require the coordinated effort of many components. How is this coordination accomplished? What controls these activities? How are activities initiated and how are they truncated? What is plant "process?" What is learning "process?"

As I plan my classes for next fall I am excited by the prospect of new innovative lab activities. I just received a grant from the Boston University provost's office, part of the Boston University Arts Initiative. The grant will allow me to buy fun, new and interesting supplies for my students to use. More important, the grant has provided me with encouragement to move ahead combining arts and science in the undergraduate learning environment.

I was just looking at some cool construction toys that I want to introduce. Partly they will be for used when we build enzymes as part of our discussion of protein structure and function. Partly we will use the toys in our broad exploration of form. But perhaps the most interesting opportunity will be to have the students collaborate in building things together. Proteins are built by the collaboration of innumerable processes. On a larger scale plant form is the result of tremendous collaborative activity. Ecosystem evolution is an extremely complex collaborative process. So is learning. Maybe the best way to get this across to students is to have them build things together. In the learning environment, hands on collaboration should prove to be a super interesting interdisciplinary experience.

Thursday, June 13, 2013

Ancient Plants, Ancient Ecologies

It's the 20th anniversary of Jurassic Park. Pretty amazing how our imaginations got caught up in the images, real or not, from that movie. I have a survivor of the Jurassic growing in my garden, a lovely, lively Gingko biloba, the ancient maidenhair tree. Gingko is an antique gymnosperm, older than the other gymnosperms like pines, firs, yews, and cypresses. It has no extant relatives, a deciduous gymnosperm without cones, a real oddity.

The smelly fruits of Gingko biloba are edible

The gingko in my garden taught me something about ancient forests and their ecology. We think of the gingko as a large, upright, stately tree, a significant addition to the landscape. But the other day I saw it in a different light. Last fall I trimmed the main stem of my gingko, which was growing toward the second floor of my house and threatening to shade out the rest of the garden. As much as I love the form of this tree I love the light more, so I had to sacrifice height for light. I stuck some of the branches I trimmed into the cold damp soil of autumn, and this spring they were sprouting new leaves. I learned that you could clone a gingko, something I would never have expected. The main tree itself also thrived. In return for its severe trim, the gingko grew lushly this spring, several long branches competing for dominance, the whole thing like a large graceful shrub, long, cascading limbs heavy with leaves, nearly touching the ground.

Graceful low-slung branches

After a few days of heavy rain the tall new branches had joined the others in a downward sweep, threatening again to shade out the garden. Knowing how well this tree responds to a trim I went ahead and pruned. Four foot, five foot branches fell to the clipper. What amazed me was the texture of those new, fast growing branches. Instead of being super woody they were super soft and supple, something you might predict for new fast-growing tissue but still, in a gingko

It got me thinking about ancient forest ecology. Then suddenly this morning it occurred to me. Maybe gingkos weren't the dominant tree in their ancient forests. They were vying for space among giant ferns, selaginellas, and horsetails that were hundreds of feet tall. Early in its evolutionary history gingko was a newcomer on the block. A very shady block. A block with lots of established competitors. It had to think on its feet and act energetically, with stealth and a little bit of cunning.

Ancient horsetails were huge

My guess is that in its early history, gingko was an opportunistic plant that could take advantage of scarce forest light. And it was a fast grower that could use gaps in the forest, temporarily flooded with light, as a way to establish and grow. We have lots of contemporary forest plants that behave this way. And some ancients too. Consider the tree ferns of New Zealand, fast-growing "weeds" that grow when temporary gaps in the forest canopy let in light. But unlike the tree fern, gingko can sprout new branches all along the old branches. There is meristem tissue wherever the leaves emerge that can mobilize vertical growth and become a new branch. 

Imagine light through a temporary opening in the forest canopy

How does this connect to ancient forest ecology? So imagine the dark, dense, damp forests of old. Imagine a smallish gingko growing among towering giants. It survives but does not thrive in the shade. Now imagine one of the giants dying, being struck by lightning, or being felled by the wind. A little light comes through the canopy. Gingko responds by fast vertical growth. The faster it grows the weaker (softer actually) its branches, so with heavy rainfall or perhaps when something falls on them, the branches cascade toward the soil, eventually coming into contact with it. Still in touch with the mother plant, the branches get nutrients, vital perhaps as they find themselves shaded out by nearby giants. Eventually they establish themselves in the soil and by lateral growth and cloning the gingko claims an ever-larger part of the forest. More light becomes available and the gingko responds by renewed vertical growth. The process continues and gingko survives and thrives. 

I am always amazed by how much I can learn in the confines of my small garden. Gingko was discovered by western science only quite recently. Before that all we had was fossil evidence of this amazing tree. And it's no coincidence that I'm writing about a "living fossil" today, my 60th birthday!

Gingko in its glory

Sunday, June 9, 2013


What is the true meaning of sequestering? You may be surprised. It's not a poisonous Republican euphemism concocted to neglect social responsibilities. It has nothing to do with ripping off the people of the United States in the guise of "fiscal responsibility." Botanists have used it for years as a scientific term.

This little beach plant, Salicornia, lives in the salty environment of marshes at the edge of the ocean. Living in salt marshes is beautiful but harsh, because salt is a toxic compound. Cells can't function in a matrix that's too salty. So plants like Salicornia, with its roots in brackish water, had to evolve ways to deal with salt.

Salicornia and many other plants sequester salt in specialized thick-walled cells where it won't do damage. Salt is shunted into these cells by various mechanisms that bypass physiologically functional cells. In plants like Salicornia sequestering is a way of putting toxins aside, "hiding" them behind a protective barrier. So when you hear or read the term "sequestering" in its political, non-botanical sense, challenge the source. Are they putting aside toxins or spreading them?