Tuesday, May 21, 2013

Using Water the American Way

Every year when I teach environmental science my undergraduates kind of roll their eyes when I talk about the Ogallala Aquifer and our misuse of water. Yesterday's New York Times featured a front-page story about the dangers the aquifer water supply faces. What is the Ogallala and why does it matter?

Aquifers are groundwater. In some places they rest close to the surface and in other places they are deeper down. Even deserts have aquifers under them. There is an aquifer under Cape Cod. Aquifers form when freshwater from any source, for example rain, snowmelt, and glacial melting, seeps through porous layers of soil and rock and is stored underground. The water in the Ogallala Aquifer (or the High Plains Aquifer as the New York Times labelled it) is ancient. We call it "fossil water" because it originated during and after the last ice age, when water west of the 100th parallel was abundant, thanks to melting ice and moist climatic conditions. The Aquifer runs roughly north and south for hundreds of miles, from South Dakota to parts of west Texas. The region gets about 8-15 inches of rain per year so very little of the today's rain reaches the aquifer. In that sense it is a finite, non-renewable resource. 

For several decades farmers have withdrawn water from the aquifer in enormous quantities. It was cheap and easy to withdraw and with it, they irrigated millions of acres. Incidentally they made enormous profits and of course, fed millions of people. The crop circles that you see in this photo are irrigated with water from the Ogallala Aquifer. Each circle is a mile across.

The next photo is even more amazing. It is a satellite image from NOAA's Earth Observatory site. This photo really provides a sense of the extent of irrigated land that depends on the Ogallala Aquifer.

Courtesy of NOAA Earth Observatory

Most of the water that is drawn from the aquifer is used for farming in conditions that are semi-arid to arid. And most of the crops that are raised are grain or fodder that is fed to cattle and other livestock. Livestock is raised to provide meat for the millions of people in the United States and elsewhere who choose to depend on it as part of their daily diet. So the critically low levels of water in the Ogallala Aquifer are attributable to our hunger for meat. 

The article in the New York Times touted the "miracle" of providing so much food grown in a dry but fertile place, and one commentator declared the problem of the aquifer to be "economic" at its heart. Draining the Ogallala Aquifer for meat is an economic problem but its scope is much larger. It threatens our ability to feed ourselves in the coming decades.

I have a student who stated that human inventiveness would find a way around this problem. But there is a certain bottom line. Where meat consumption and water consumption continue to grow, and where resources are finite, the end result transcends what we can invent our way out of. Either we must move away from meat consumption (we can't seem to break our habit and the rest of the world is following suit), move to exploit other localities and water sources (we have already done this at tremendous, ongoing, global ecological cost to places like Amazonia, where the rainforest was cleared for pasture). Or we will continue down the road to a system of food production and consumption that is ever more inequitable as we lose control over the right to feed ourselves. 
As the right to eat becomes a privilege, the devastating results are pretty horrible to imagine.

Human cultures have thrived for hundreds of thousands of years without the gross consumption of meat that has become the norm for us. Human ingenuity from diverse cultures has come to the fore in managing water, collecting water, and storing water in ways that we are only beginning to learn. 

Back to the classroom. When I teach environmental science I inevitably discuss the demise of the Aral Sea, an example of mid-20th century ecological mismanagement by the former Soviet Union. The death of the Aral Sea was a slow motion disaster that unfolded over several decades. Abundance eventually gave way to disaster. In the United States we are seeing the end of abundance within our lifetimes. With potential disaster on the horizon, isn't it time we Americans took a lesson from the rest of the world on how to manage our resources more responsibly?

Friday, May 17, 2013

Hard and soft

When I take my landscape architecture students from the Boston Architectural College for a walk in the city I ask them what the plants are "doing." Inevitably they tell me that plants growing along the building, shrubs in front, vines growing up the wall, or green or flowering things are "softening" the architecture. I see their point. The curvaceous volume of the plants contrasting with the flat, angular spaces of the building are providing a kind of visual softness.

But if we look at soft and hard and hard and soft in another way, maybe we can come to understand things a little differently. This concept started to clarify itself for me when I visited Sri Lanka. There at the top of a mountain at the magnificent Kudimbigala Forest Monastery stood an ancient stupa made of bricks pummeled by the wind. The stupa looked solid against the sky and high clouds. All around it grass bent deep in the strong wind. In the distance the Indian Ocean, flat, impassive, and ethereal laid itself out toward the horizon. A vision of nature as soft and gossamer as could be against the strength and architectural determination the solid brick stupa.

The grass nothing, the stupa "something." But the stupa had areas where the bricks had loosened or fallen out. Countless pilgrims had walked up the hewn steps of the mountain with bricks for the stupa. All around the large structure they had built small cairns of brick and rock, insignificant piles that represented quantities of devotion. The cairns were small but they were numerous. It occurred to me that they represented the spiritual life of the people who assembled them. A life ongoing, flowing, growing. The grass and sky and ocean and wind all around the stupa also were eternal. It was structure itself that was constrained by materiality, by bricks and mortar, by its temporality, and by its hardness. It was there at Kudimbigala that I began to question the juxtaposition of monument versus moment.

Back here in the highly developed built environment of north America the same questions emerge. Azaleas flutter like clouds against a hard brick wall. In front of them the heavy metal of gigantic vehicles, a hot paved roadway. All of these built things will rot and rust over time. The soft flowers of the shrub will turn to seed and continue onward with species for longer than the wall will stand.


It seems so late in the season, racing past the middle of May, but the last frost date just sailed by so in a sense, the growing season here in Boston is just taking off. One signal of this is that the leaves of some plants are still unfolding.

The leaf, this wonderful structure that supports the mechanism for photosynthesis. Countless protein-laden chloroplasts inside, the dynamos that convert solar energy into chemical energy. The plant can't risk losing them, and the soft body of the leaf can't withstand frost.

So as the growing season goes into full swing we finally see the unfurling, the unfolding, the exploding of the photosynthetic universe. Its geometric forms are as amazing as the biochemical processes they enable.

Wednesday, May 15, 2013

Landscape: A birds-eye view

When we think about a "birds-eye view" we generally think about the view from above. I've been talking to my friend Neil Gore and I got some new perspectives on the way birds see things from him. Neil has been watching the birds for many years. Whenever we get together I ask him how the migration is going and he always has some very specific things to tell me.

For example, last week there was a zone of intense high pressure off the East Coast of United States. The heavy descending air acted as a barrier to birds who would have migrated up from the south. The ridge of high pressure extended roughly from east to west forming an invisible atmospheric wall. This kept the weather cool up here in New England but more important the prevailing wind blowing off the ocean slowed down the progress of the northward migration. So things have been pretty quiet for Neil during what is normally the busiest season of birdwatching. Right after I last saw him last week a frontal boundary moved north, and with it I'm sure came the birds.

I spend a lot of time in my diverse garden, which boasts almost 60 plant families in a small space. There are all sorts of plant forms and insects to go with them, which I expect would be a smorgasbord for our feathered friends. I'm curious why I don't see more birds there. I see some sparrows, some cardinals, some bluejays, some juncos, some chickadees, some robins, and some mockingbirds. But I don't see the amazing kind of diversity that Neil talks about; wrens and warblers and all kinds of little surprises. Neil doesn't just look for birds in his garden but the diversity he sees right by his house is remarkable. I asked him if he could look at my garden and diagnose why there aren't more bird species there. He explained what should've been obvious to me, that the birds need some very specific kinds of conditions. Not too much shade and not too much light. Not too much closed in area but not too much right out in the open. A way to escape from potential predators. All of these subtle, almost intangible factors add up to a landscape where birds can thrive or a landscape that at least some birds will avoid. Of course it may be that I'm not looking effectively. It could also be that horrible yapping dog next door.

So the birds-eye view of the landscape is perhaps more complicated than we thought. It involves movement and activities and process in three dimensions. There is a spatial aspect and a temporal aspect, which involves timing. Atmospheric conditions are important and the basic landscape, its contours, and plants make a difference. The birds are looking for specific features in which to nest as well as specific kinds of food, insects, seeds, or whatever.

The migration is something like 10,000 years old. At least as old as the last ice age. Yet every year and in every place there are subtle complexities that determine which bird will be in which spot and when. For the birds, just like for us, the landscape is a dynamic entity. It's a lived-in space, one that accommodates our activity and one that is altered by our activity. For the birds evolution or extinction may be determined by landscape. We humans depend on landscape too, something to think about and study.

Monday, May 13, 2013

Nutrient Flow

When we teach environmental science to our students there's a basic principle that energy flows through the biosphere while nutrients cycle. This is true in terms of global ecology but the facts on the ground are different.

The cold hard fact struck me last year when I was working in an organic dairy farm in upstate New York. Simply put, a hayfield gathers energy and nutrients all season. When we harvest the hay we remove those nutrients. On a macro scale we can acknowledge that the goats cycle the nutrients etc., but the fact is that the hayfield is the poorer after harvest.

I saw this fact at work again when I visited Sri Lanka this year. I had thought that rice paddy ecosystems were "balanced" because of microorganisms in the water that provide nutrients. To an extent this is true, but rice consumes enormous quantities of nutrients. The fields are a one-way flow of nutrients (out). The irrigation ponds (wewas), rich in aquatic life, are the source of nutrients that nourish the rice.

So as I obsessively remove snails from my postage-stamp sized garden in Boston I wonder, what if anything do these creatures do to cycle nutrients at the micro level? By removing them from the garden (I realize there are millions more I never find), how do I impact the nutrient content of my garden? If I were able to remove all the snails, what would the impact be?

Sunday, May 12, 2013

Intoxicating Wall of Aroma

Every year it happens, the moment we anticipate for months. The lilacs in full bloom spread their aroma with generous abandon, part their inflorescences just enough for us to bring them close and inhale. The lilacs are a thing of wonder. They bring back memories while enfolding us in a present that is wondrous to live in.

The lilac shrubs are large and you can't have them in every garden here in Cambridge, where we live together cheek to jowl. So they are a semi-public thing, marking street corners and creating a landscape of scent. As much as I love the lilacs and their aroma there's something else in the garden this time of year, something more pungent, something even shorter-lasting, but a plant unsurpassed in the olfactory sensation it provides.

Searching at ground level for snails I encounter the close landscape of the garden surface. Down there, rising about a foot in the morning stillness, the lilies of the valley pour their scent into the immediate atmosphere. You have to love them or hate them, but for less than a week in May they are the stars of the garden. Their aroma is truly a wall, something you run into and dazed, can't leave. As a mass they are incredible, individually less exotic-smelling.

And they are invasive. As the years go by they expand their aromatic territory like the solid underground biomass they comprise. Every year I take out a few shovelfuls, just to open a little space in between the troops. Trying to stop their march seems impossible, at least to a human. I leave it to the other plants to block their advance. But stopping them is not part of my agenda, at least not this week as they favor the garden with their enveloping aroma.

Saturday, May 11, 2013

Pregnant Silence of Full Humidity

Only vague bird call distracted in predawn deep humidity. A cloud hovers the air is still. There is no "awakening" or "non-awakening" in the garden as the apparatus of photosynthesis proves itself in silent exchange of electrons motivated and mediated by increasing light intensity. No "encouragement" from light as it simply is, in ever larger packets, delivered exogenously over tens of millions of miles, not "intended" for any leaf any more than the drop of rain, condensed around dust, is "intended" to reach the ground or the blade of grass.

Life is apparent though in this transparent ephemeral landscape, a machinery silent, dimensioned, passive in its force, programmed for increase under the regime of light and moisture.

This rareness is a May morning, floating on lufts of atmosphere. Shimmering newgreen in the abundance of photons. Attached to an ancient soil and climbing in fluid air.

Friday, May 10, 2013

The Tangled Bank

Looking at this famous passage written by Darwin over 100 years ago we can still ponder the depth of meaning he perceived in a humble landscape. Learning contemplatively is one of great challenges we face. Whatever the setting or the subject, I think it is worth it to keep Darwin's words in mind. 

It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us. . .There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone circling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.” 

Thursday, May 9, 2013


This strange world of ours where we strive for perfection and overlook or seek to destroy the imperfect. From a botanical standpoint, there is nothing that can be described as a weed. From any other perspective, a weed is something growing where you don't want it to grow. It's easy to find the weed in this photograph. But in a forest this maple seedling would be right in place.

Weeds seem to pop up where we don't want them but in the urban environment weeds can be a thing of beauty. I am drawn to the healthy form of "specimen" weeds that propagate at the sides of buildings, from cracks in the sidewalk, or where pavement meets wall. 

But it's not just the illicit pestiness of weeds that makes them beautiful in the eye of this beholder. Maybe it's because they can thrive on very little, in corners, on gravel, in hot, dusty, shady or overly sunlit spots. Weeds take on the environment and do with it what they can.

Most of our crop plants originated as "weeds." They are opportunistic fast growers that like disturbed soil and can withstand bright sunlight and dry conditions. At least that's how they started out. Today's pampered crop plants need plenty of attention, water, fertilizer, and pesticide for them to perform. Maybe when we've pampered them to extinction we'll find new crop plants from the hardy weeds that survived. Here are a couple of examples of "weedy" plants that we treasure as horticultural landscape elements. Would you believe the magnificent tree fern and water lilies could be considered as weeds?

I was in Sri Lanka for five wonderful weeks, a world with a very different concept of "perfection" from our own. One day I visited the ancient miniature stupas of Kantharodai, in the far north of the country. The keeper of the site was busy weeding the monuments.

Wednesday, May 8, 2013

Patterns in Nature

As a biologist I'm aware that few characteristics evolve more than once. We can uncover the relationships of “unrelated” species by looking at their DNA or more simply, by finding homologous anatomical features that have been inherited from a common ancestor. 

The world of plants, my area of study, is so rife with morphological similarities I wonder sometimes if there are any real differences among its species. For example I see patterns of fern-like growth (circinate vernation) in emerging shoots and flowers of many unrelated species, plants that evolved long after their fern ancestors. 

And we humans share so much in common with the rest of the living world that our common ancestry with plants, insects, and even fungi and bacteria, is a moot point. Even though we are only distantly related to say, sharks, we share an inherited vertebrate body plan, not to mention cellular, metabolic, and molecular features in common. 

Tuesday, May 7, 2013

Nature is the Teacher

I've been thinking about why it's so cold so late in the spring, and what the effect is on the plants. The explanation for the cold is easy, a region of high-pressure near New England has set up a clockwise flow of air that features winds from the Atlantic ocean. Since the ocean is cold this time of year, still in the 40s, the steady breeze off the water keeps Boston cool, even cold this time of year.

The cold and its effects on the plants is a little more complicated. First, plants that are close to the ground probably experience quite warm conditions this time of year. The soil is steadily heated from the sun and at night, because temperatures are relatively mild (influenced by the steady ocean temperature), there is not drastic cooling. So plants near the ground, which experience little wind, experience warm conditions. This may explain the abundant growth of groundcover plants and the exuberant bulb activity this time of year.

The higher plants grow off the ground the more cool breezes they experience. In general, we see a lot of flowers and the flowers, which don't have highly developed vascular systems (at least not as highly developed as the leaves...flowers are temporary after all), benefit from the cool temperatures. So this year we had a mighty showing of our star magnolia that lasted longer than usual. It also helped that the delicate flowers weren't caught in a downpour, which seems to happen most years. 

The young leaves of trees and shrubs benefit from cool weather because they have not hardened off yet. Their vascular systems are still developing. Because they are not fully open yet other systems, such as cells that block loss of water, are also not fully developed. And most leaves have not yet formed a well-developed cuticle layer, which would also protect them from desiccation. So while we don't necessarily enjoy the "air conditioning" off the ocean the young leaves and plants generally benefit from it.

This year has been a bit unusual in that we haven't had any significant moisture for a few weeks. We expect some in a day or so and it should last for several days. When this happens there is increased danger for the plants of invasion by fungi and other organisms that damage the young leaves. One example of this is anthracnose of sycamore, a disease that strips the first flush of leaves from the trees. Anthracnose is severe here in Boston, where sycamores (Platanus) are near the northern edge of their range. 

This is the time of year when other pathogens may enter the leaf, either through the open stomata that provide gas exchange for the leaves, or through the partially developed epidermis that has not yet "hardened." Some of these pathogens will remain dormant or slow-growing within the leaves and will not become apparent until late in the season when the leaves have begun to senesce in the late part of their annual life cycle. 

It's just amazing to have a chance to observe the responses of plants to the seasons. Nature teaches us so much about itself through simple observation. This light-infused time of May is to me, the most inspiring of all. If only it would warm up!

Monday, May 6, 2013

Patterns on the Ground

April was promising with emergence from the ground, from the branches, and sometimes, from the house. Cold turned tolerable and the soil warmed, plants emerged, magnolias flowered and finished, and we got ready, greedily, for May.

May is the problem child in Boston. A series of sunny days with a steady east wind off the ocean. Temperatures should climb to the 60s but stay in the low 50s with wind chills much colder. You can stand in the sun or you can stay behind a wall but this morning, riding a bike in the light fog my ears felt like they do on a cold October day. Or worse. 

So here's a little celebration of what happened in April, the halcyon days when things looked like they might get steadily better. The new growth took on patterns of its own and interacted delicately with bits of dead plants from the year before. 

Patterns of leaves emerged boldly or subtly from ground cover plants, and each day brought what seemed like it would be a continuous stream of wonders. Well, there's always June.