Nutrient Mobilization

Could spring be in the air? Well, if not at least we have a lot of seeds in the kitchen that we're sprouting.

Sprouting seeds are a phenomenon of nutrient mobilization that all plants use. The seeds are "programmed" to respond to a fairly precise range of moisture, light, and temperature. When the right combination of conditions is met, the seeds respond by germinating.

The process of germination is complex and it involves all the parts of the seed. As the embryo becomes activated it sends a hormonal message to the region just inside the seed coat, the aleurone layer, which is rich in proteins. Enzymes, which are a type of protein, are released from the aleurone layer. These enzymes digest the starch and other nutrients that make up the bulk of the seed, the endosperm.

Starch in the endosperm is broken down into glucose, which feeds the process of aerobic metabolism in the newly active embryo.

The first thing to emerge is the embryonic root, the "radicle." Nutrients from the soil are absorbed and along with the nutrients from the endosperm, the first leaves emerge from the seed.

The last stage in nutrient mobilization is the development of chlorophyll, a very complex molecule, which is also "expensive" for the new seedling to produce. It's no wonder that seeds are such a good source of nutrition. Everything the embryo needs to start life is stored there.

I wonder what these incredible self-contained structures can tell us about how to design more effective environments for ourselves.

Curves in Nature vs. Curves in the Built Environment

Back to the question of natural curves, which I touched on lightly the other day. Let's have some fun looking at a natural curve vs. a human-built curve. I just want to brainstorm about their characteristics, their functions, and their constraints.

Here's the natural curve of the day, the branches of a Saguaro cactus.

Characteristics: Acute angles, curve dominated by upward sweep of the branch.

Functions: Weight-bearing, growth upward, photosynthesis.

Constraints: Weight, tissue available for building, exogenous constraints like heat and dryness.

Let's see what I can find in a human-built shape that resembles this...

The arches seem like a kind of inverted branch. Obviously there are differences as well as similarities...let's explore.

Characteristics: Symmetrical, "branches" downward-facing.

Functions: Weight-bearing, decoration, shelter

Constraints: Weight, design, cost, others?

I'm not a structural engineer or an architect. Maybe you know someone who is. What kinds of comparisons would they make between these two curves? Is it worth discussing further?

Natural Curves

Most of the student designs I see and many of the professional ones as well seem to come up against the challenge of natural curves. Perhaps because we don't get enough of a chance to observe nature we don't understand how she produces curves. Here are a few pictures of natural curves from plant sources that might provide some inspiration for your next design.

Why Botany Without Borders?

The idea for this project is dedicated to my students at the Boston Architectural College (BAC). BAC students train to become architects, landscape architects, and designers. My course is required for the landscape architecture students at the BAC and it’s a science elective for the rest. BAC students are real problem solvers and the ideas in here are for problem solvers. I was recruited to teach at the BAC because I’ve been communicating about science to non-scientists for a long time. Perhaps in that way I’m a problem solver too, because I my specialty is making science understandable to people without formal scientific training. Most people are interested in what science can tell them about the world but most of my students come into class not necessarily “liking” science. So engaging people in scientific thought and analysis is a challenging goal.

Many of my BAC students are career changers, which I was, and they work very hard to accomplish their degrees, often at the expense of having a “life.” The BAC's concurrent educational program requires students to work in their discipline during the day and take classes at night. You can imagine that my students look and feel their best at five PM on a Wednesday night after battling traffic and finding a parking space on busy Newbury Street in Boston--all at the end of a long day's work. So the experience I have to share with you--an experience that made an indelible mark in my psyche as a teacher-- is an experience unique to the BAC and its students. These are "real" people whose feet are on the ground. Like I said, problem solvers. They're visual learners, quick studies with good brains, designers who grapple with the world of ideas and in particular, scientific ideas. Here's the story of my life-changing experience with my BAC students.

As a botanist I've pondered for years about chloroplasts, the photosynthetic bacteria that live in leaf cells and partner with plants. Chloroplasts, not plants, perform photosynthesis. Chloroplasts share the products of photosynthesis with the plant they dwell in, whose leaves are a kind of solar panel that house the chloroplasts. The plant leaf provides shelter, water, and proper exposure to light, but it’s the chloroplasts, actual separate organisms with their own DNA, that do the productive work of photosynthesis. We know what happens to leaves in the fall. But what happens to the millions of chloroplasts that live in each leaf? Do they die? Do their protein- and mineral-rich bodies (expensive to make and maintain) break apart into their component parts? Are they absorbed and stored somewhere, inactive, in the plant? And what happens in spring? How are chloroplasts recruited to take their place in the growing leaves? Are they somehow taken out of storage? Where do they come from? Are they put back together to function as photosynthetic entities? I've discussed these questions widely with my colleagues and even made inquiries to photosynthesis specialists. No one, especially me, has been able to come up with an answer. That is, until I brought the questions up one night to my BAC students.

It was the end of the semester, a warm night in May. It was time to go home. Time to call it a day. Instead, I insisted, unwisely I realized at the time, to continue class for a few more minutes. I asked the question, “What happens to chloroplasts in the fall?” And there was silence. Was it a trick question? Something I’d gone over in a flash, never coming back to? Was it something that would show up on the final? My students thought for a moment, quiet, which they always are. I perceived that their problem-solving apparatus had gone into gear and I didn’t break the silence, even after a long minute or two. Finally a student in the B-Arch program raised his hand and suggested, "Didn't you show us twigs last winter that were green under the bark?--I think you said that means they're doing photosynthesis....and if they're photosynthesizing doesn't that mean there are chloroplasts under the bark and in buds all winter?"

In a few simple sentences this student answered a questions that had bugged me for years. Practical, to the point, yet somehow inspired to think way outside of his design box. How he came up with the answer I don't know. How did he put his finger on the answer so effectively? So elegantly? Lecture notes? Field experience? Whatever, he cut through the complexities that had somehow hampered me from answering the question for so long. His answer made a statement pertinent to design—something we had been discussing all semester: Plants are structurally simple organisms that function in complex ways.

What magic motivates my students to think about plants as models for design? How is it that they use a science course as inspiration for their practice? How do they bridge the gap between academics and work, science and design, and how do they do it in a classroom when most of the world is relaxing with a glass of something red?

In these posts I explore botany for designers much as I do in class. With illustrations, questions, comparisons. To get the most out of my class I ask my students to observe, document, and analyze nature. If these pages inspire you to do the same, I will have achieved my goal.

Soil is Vital

The other day I wrote about insectiverous plants and their response to nutrient poor soils. Soil is vital in so many ways and every ecosystem has its own soils. Each soil carries a particular challenge to plants. And to survive in the ecosystem, they must be able to survive on each particular soil.


A few years ago I was playing hooky during a conference in Orlando, Florida. I was determined to find some natural habitats among the endless subdivisions, highways, and strip malls. So I pulled out a map and did my best. 

I found a postage-sized nature reserve, one of many, a typical spot for the Florida uplands, which were once a chain of sandy islands. The sandy soil at this reserve has two important characteristics that you can perceive just by bending down and picking up a handful of it. First, as sand, it is almost devoid of nutrients. There is almost no organic matter in the soil, nothing for a root to take hold of. Second, the sandy soil is super porous. Any rainfall (and they get about 60 inches a year) sinks right into the layers beneath the soil. The sand, with no organic matter, holds onto almost none of it. 


In a way, this is a desert. What kinds of plants would you expect here?

Amazing to see a cactus growing in Florida, perhaps more so to see it growing in the vicinity of palm trees on a piece of land that gets so much rain. Yet, to the plants that grow here the conditions are more like a desert than what we perceive as a piece of subtropical paradise.

The little bit of organic matter, for example leaves or wood that fall from the trees, are utilized immediately and abundantly by organisms like lichens and other fungi.

As a grad student at San Francisco State University I was fascinated with unusual soil types and their specialized plant types, for example "islands" of acidic soil that showed up in the otherwise alkaline California environment contained very special groups of plants, often native to the island alone.

Speaking of islands figurative and otherwise, Janet and I traveled to Puerto Rico a few years ago. I was eager to see the Unesco dry forest on the south side of the island. I got what I bargained for and lots more. Imagine seeing cacti like these growing right on the shore.

Plants seem almost infinitely adaptable to their environments. Part of the key to this is their incredible diversity. The more species there are, the more they are able to fill every possible niche with all its variables...rainfall, temperature, and soil. From a design perspective plants give us something to think about. 


How can we design environments, urban spaces, nature reserves, even buildings, with a diversity of forms and purposes?

Tajonal, The Secret Mayan Plant

We have traveled extensively in the Yucatan and as a botanist I'm always interested in local uses and cultural depictions of plants. One of the plants that really interests me is tajonal, the secret plant of the Mayans.

The tajonal plant covers the roadsides and empty fields all over the Yucatan. A large shrub covered with bright yellow flowers, it might be nothing more than pretty if it didn't have so much cultural significance.

The Pre-Conquest Mayans used two species of stingless bees to produce honey for them. The honey was important as a food, medication, and for religious sacrifice. Contemporary Mayan people still gather honey from these semi-domesticated bees.

Tajonal plants are abuzz with bees during the flowering season. These same bees are the descendants of the species used for thousands of years by the Mayans.

When you travel to archeological sites in the Yucatan you can see evidence of the value tajonal had to the ancient Mayans.

The design was picked up and used in colonial structures such as churches...

...and it was adopted in the 20th century in modernist designs like this:

I'm still looking for a photo I took of Tajonal shampoo that I bought in Carillo Puerto, but I can't seem to find it in my over 1500 flickr photos from Mexico!

Salt Kills

We’ve had a relatively warm and dry winter here in Boston. Now with snow threatening people are throwing rock salt onto the roads and sidewalks. Not just “people,” rather, the cities of Boston and Cambridge and the grounds people at Boston University where I work.

 Salt is a simple “solution” to the problem of snow and ice but unlike good solutions, this one comes along with plenty of problems.

 Salt kills. It penetrates the soil and changes its chemistry, destroying microorganisms that help plants grow.

 It changes the osmotic environment for plant roots so that water flows out of them instead of in.

 Salt corrodes public infrastructure and it destroys private vehicles.

 If you walk in the salt it ruins the soles of your shoes and boots.

And if you ride a bike like me you get it all over your tires, in your eyes, on your glasses, and in your mouth.

Salt may be the cheapest solution to de-icing our roads but it is far and away the worst way to do the job. These images  are from a photo essay I did for flickr a few years ago called “City of Salt.” I’d love to hear your comments.

Ecology Micro and Macro

There's so much to tell in a small plant like the sundew. Only a couple of inches across this plant holds a world of biological wonder.

Like humans, all plants need nitrogen. The same as us, they have all kinds of molecular structures that require nitrogen. A few examples: DNA, RNA, Amino Acids, ATP. 


Nitrogen is abundant in the atmosphere. About 78% of the air we breathe is composed of nitrogen. But that nitrogen is inert. It doesn't combine with other elements. So it can't be incorporated into the the molecules of life like DNA and amino acids.


Insect-eating plants like the sundew live in soils that are especially low in nitrogen. They have even less nitrogen available to them than plants that live in more favorable conditions. How have they responded to this environmental challenge?

Sundews, pitcher plants, and other insectivorous species capture and digest insects. The protein-rich insects (and sometimes larger animals) are broken down into their component molecules. The amino acids and other protein-rich molecules become available to the pitcher plant, which absorbs the nitrogen and uses it for its own purposes. 

The requirement for micronutrients reflects the nutrient-poor ecosystem. Our insectivorous plants create their own tiny ecosystem, passive, noiseless, emission-free. A simple, elegant response to a complex ecological problem.

Looking at a Plant

Southeast of London in the distant suburb of Down stands Downe House, the curiously named home of Charles Darwin. Standing In the garden at Down House, I learned that Darwin used to stoop and look at a flower for minutes on end, ten, fifteen minutes of rapt contemplation. The discovery of this anecdote was vindication for me. In crowded Cambridge, Massachusetts, my postage stamp garden with its sixty-odd plant families lies in the middle of a “village” of several family dwellings. Every time I study my plants someone is watching me, and since I don’t smoke or own a dog or water a lawn this makes me a little weird in the context of our neighbors. Standing in Darwin’s plant-loving shoes, or pretending to do so, somehow makes things a little easier.

Darwinian evolution (and all science) is based on a singular unifying principle: The Naturalistic Philosophy. Simply put, the Naturalistic Philosophy assumes that natural phenomena have natural causes. We can come to understand those causes through asking the right questions and studying nature in an appropriate manner. By “appropriate” I mean that we use our observations of nature as evidence for answering the questions we pose. This proviso simply means that nature is explained by nature, not by religious texts or belief systems. Corollary to the Naturalistic Philosophy is the Mechanistic Theory, which states that living (biological) systems are constrained by physical and chemical conditions. 

Water, light, nutrients, and temperature are some of the conditions that influence plants, and we’ll address all of them on these pages. But this is a space for designers, not scientists. When we look at plants, is it impossible to gain understanding without considering the Naturalistic Philosophy and the Mechanistic Theory? Do we have to reduce the plant to an evolutionary machine that eats, breathes, and reproduces? Of course, the answer is no, no more than we reduce humans to their separate parts, their functioning cells, or their molecular components. 

Plants are perhaps foremost things of great aesthetic beauty. Symmetry and asymmetry, modular growth patterns, rhythms of opening and closing, folding and unfolding, elongating, swaying, shading, creeping and standing; all of these define plants as well as any anatomic feature or molecular interaction. We are here to consider plants as design models. Always, and we want to keep in mind the aesthetic value of plants. Yet it makes sense that we want to understand something about their underlying function, because the evolution of functionality, in concert with beauty, grace, and harmony is the miracle of plants.

Looking at a plant we observe its outer facies, its shape and size, its visual nature, its place in the landscape. We may perceive its aroma, either of flowers or leaves, and perhaps we can hear it whisper in the breeze. But for design inspiration we want to go past “biomorphic” shapes. We don’t necessarily want to design leaf-shaped buildings, flower-shaped parks, or packaging that mimics plant ovaries, which grow into fruits. So I encourage my students to move beyond the popular concept of “biomimicry.” 

I assert that plants offer us something else, something much more valuable. Plants are radical living elements, the product of millions of years of evolution in the face of adversity. Plants offer us insights into how to make effective designs that have beauty, simplicity, and function. Beauty, simplicity, and function are wrapped up in the body of the plant. Darwin considered plant diversity--the array of physical patterns in plants--as an “abominable mystery.” Let’s harness that mystery for our own designs combine a study of botany with design.

Worms

A couple of days ago I hosted students who are studying in the Masters of Design for Sustainability at the Boston Architectural College. The students are involved in an online program that meets twice a year here in Boston for a weeklong “intensive,” with classes, fieldwork, and lots of group projects.

I bring the students to my house in Cambridge for breakfast or lunch and a walk around our historic, architecturally and socially diverse neighborhood of Cambridgeport. But after the meal and before the walk we check out Janet’s “vermiculture station” in the basement.

A few years ago we found heaps of worms in an abandoned, broken composter and brought them home. Since then they’ve expanded into a colony of thousands of worms. We feed these babies everything from coffee filters (with the grinds) to carrot peelings to paper egg cartons. Anything with a vegetable origin (but no fats, bones, or meats) is like candy to them.

As a biologist I’m super interested in how the worms function. Basically they are a tube full of bacteria. The worms ingest the vegetable matter and the bacteria break it down. This way the worms provide the bacteria with a steady diet and the worms make most of the food available to their host. The worms wouldn't be able to digest most of what they eat, and they need the bacteria to help them break it down. (We humans are the same. Without our "gut flora" we would be unable to digest most of what we eat. That's why you get an upset stomach when you take antibiotics...they kill the symbiotic "good" bacteria along with the "bad" that cause disease). 

When the worms defecate they send lots of bacteria back into the soil. These bacteria break down more of the nutrients in the soil and of course the worms re-ingest them as part of their ongoing diet. It’s a complex ecosystem with many different organisms all doing one thing- breaking down materials we would otherwise toss into the garbage.

Every now and then I pour a liter or so of water into the system and catch what drips out. It’s called “tea,” it smells like a farm, and it’s the best thing you can give your house or garden plants (watered down). Better than any artificially produced fertilizer.

No smell, no noise, no mess, just a colony of wriggly pets in the basement you can use to impress or alternatively, to gross out your guests.

Winter Survival

Collllld here in Boston. Last night it fell to about zero F. Our old wooden house was creaking in the wee hours as the structure shrank in the cold. I was alone in the house and sleepless as usual at about 3 AM, struggling in the cold and dark to fall asleep so I'd be ready for the 8 AM class meeting. Had spent the evening finding plant samples for my students at the Boston Architectural College...

...pines, firs, rhododendron, box, cypress, lavender, sage, rosemary, holly. Just a few of the plants that were, if not happy, at least looking alive as the temperature dipped far below freezing.

All were happy to be tucked into shopping bags and brought across the river for today's Masters in Sustainability class.

I know a bit about these plants and their strategies for winter survival. But it got me to thinking: How much is there about these winter survivors that we don't know?

Stay warm friends!

Tribute to Lynn Margulis

The amazing Lynne Margulis died on November 22, 2011. She probably thought “outside the box” more than any other scientist I knew.

I once had the opportunity to speak with her at the same meeting, a get together of New York State community college professors. Lynn was one of the leading scientists in the United States. I was just barely beginning my career. She gave all the enthusiasm to that small unassuming group that you would expect from a keynote speaker at a major conference.

Lynn Margulis was nothing if not egalitarian. And her social M.O. makes sense when you realize her scientific specialty was symbiosis, organisms helping one another to maximize their potential in a harsh environment.

I teach about symbiosis every semester, for example the fungal-plantroot symbiosis called mycorrhizae (fungus roots),

the legume-bacterial connection that stars nitrogen-fixing Rhizobium bacteria,

and of course my specialty, the lichen symbiosis.

But Lynn taught us more than just to think about partnerships. She championed the idea of endosymbiosis…the fact that all plant life depends on bacteria that live inside photosynthetic cells—the chloroplasts.

It took a long time for the scientific community to catch up with her, just like it’s taken us ages to catch the coattails of Darwin. But molecular research vindicated her hypothesis that chloroplasts are photosynthetic bacteria with their own bacterial genome hanging out inside of leaf cells.

Lynn’s depiction of the process of symbiosis is something I’ll never forget. Two one-celled organisms are riding a rocketship into outer space. As the rocketship goes faster and the conditions get worse, the two cells hug one another harder and harder, until at last one of them in inside the other. A better model for endosymbiosis was never imagined.