How to deal with plant personalities.

Some are type V (vertically assertive), some less competitive. To best motivate and stimulate them, show them the light.

Trees are vertically assertive plant personalities. Access to sunlight is a key to success in plant competition, so trees concentrate on growing bigger and taller each year - a strategy that has allowed them to so dominate other vegetation that they now account for 80 percent of the 49 trillion tons of green plants living on our planet.

If trees could transfer their competitive success to human society, they would be running Congress, occupying the White House, managing most large organizations, and holding most of the property and money in the world. Placed in our society, trees would tend to associate with folks like Newt Gingrich, Nelson Mandela, and Barbara Bush.

Trees developed their go-for-the-power approaches because they must have power (sun power) in order to operate. We operate on sun power too but get it second-hand, after plants have processed it into a form we can use. To understand the power of trees, imagine that you are a tree:

As a tree, your basic role is: Green side up toward the sun; brown side down in the soil. You're stuck in the ground like a fencepost. You can grow taller and you can grow wider, but your center stays fight where it started. Others around you also are immobilized. If you grow taller and wider than they do, you collect the most sunlight and win. If they grow taller and wider, you lose.

Sunlight is key to your survival because it's the power you operate on. Catching sunlight is easy: Just stick a leaf into the flood of light energy streaming down from the sun. (Light - traveling at 186,281 miles per second in a vacuum - is the fastest thing in the universe. It can go around our planet three times in the blink of a human eye.)

The tricky part of running on sun power is that you have to be more than a speed-of-light-fastball catcher. You have to catch the light without stopping it completely, because you're going to use its forward motion a bit later. And you have to select out the red and blue spectrums because they have exactly the right energy levels - not too much, not too little.

Simultaneously with shagging the correct speed-of-light line drives from the sun, you must keep a flow of water and minerals coming up from the soil to mingle with carbon dioxide from the air. The elements in the water will be "split" by light energy, separating out the hydrogen, which will be combined with the other materials to make the essentials for life.

Here comes a photon of light, smoking along at the cosmic speed limit. You (remember - you're a tree) snag the red/blue spectrums and bunt their energy into the electrons that encircle the hydrogen and oxygen atoms in water. The electron movement causes hydrogen and oxygen atoms that were bound together as water to fly apart. You catch the hydrogen and let the oxygen sail away into the air. You'll use the hydrogen, minerals, carbon dioxide, and the energy fall-out from moving electrons in a series of chemical reactions to make complex molecules called sugars. The sugars are the food you live on.

The sugars are stored energy, fuel that you can move and use now or later. The sugar-fuel allows you to move power to areas of your trunk and limbs not in the sun, and store power for use when the sun is obscured. You can also use these sugars to store energy for next year's leaves and to build a thicker stem, and you can put some power away in seeds for the next generation.

The process just described is called photosynthesis. The term combines two Latin words that mean "putting together with light." Actually, as just described, photosynthesis starts when light energy is used to take water apart; then chemical energy puts various atoms together in new combinations.

The mechanisms for photosynthesis are formed in leaves by chlorophyll molecules, which create particles with very intricate arrangements of membranes. It's in these complex particles, called chloroplasts, that photosynthesis takes place. We see leaves as green because chloroplasts absorb the blue and red light spectrums for their work, leaving green visible to us.

Photosynthesis is the power-gathering, fuel-making system for green plants. It's good competitive strategy to get first crack at the sunlight powering this process. You do that by keeping your photosynthetic devices (leaves) above the competition. And you do that by continually growing taller and wider.

Okay, imagination aside, you're not really a tree - even if you put on green clothes, dig your toes into the earth, and stand in the sun all day. You will not photosynthesize - but you can help trees and other green plants do it.

We need to encourage healthy trees for all the good things that they do for our environment and our society, but if we're going to grow the functioning layers of greenery that best utilize land (the subject of the next article in this series), we need to know how various trees and plants get along with each other in their competition for light. We need to know this whether we're dealing with two trees and some grass or 2,000 acres of trees and a myriad of other plants and animals.

Trees and other green plants use all sorts of strategies to compete for sunlight. If you know a tree's strategy, you can give it what it needs to lead a long, productive life.

Dogwoods, for example, have a strategy of sun economy (foresters call this shade-tolerance). Check out their leaves. Their leaves are broad, thin, well-spaced, and carefully placed so as to collect partial sun without shading each other. A dogwood chugs along in the shade of other trees, reaching its maximum rate of growth at 30 percent of full sunlight.

Loblolly pine, on the other hand, is a light-grabbing racer. The twigs are crammed with shiny round little leaves (needles). They shade each other and reflect light on each other. This tree will keep increasing its rate of photosynthesis (and growth) all the way up to 100 percent full exposure to sunlight. Give it the sun and it will leave the sun-economy models far behind. Shade it and it will stall out and die. It's strategy is: Stay on top or go under.

Come out in my backyard to see how you might apply these ideas. Step up as you walk out the back door - we added a raised deck here last year. Follow me across a narrow strip of lawn with flower gardens around the fringe. Here's the edge of my woods (if you can call less than an acre of trees a woods). Sixteen species of trees and 40 species of other green plants live together here. Layers of working green leaves are staggered from ground level to 70 feet up - some in sunlight, some in shade. There's a variety of shapes, colors, and sizes of plant forms throughout the changing seasons and a variety of wildlife as well.

It's quite different today from the scene my family saw 11 years ago when we bought the house and a little plot of Virginia red clay, grass, weeds, brush, and trees. Our backyard view was pleasant but wall-like. Virginia pines were in charge of the area; their closely spaced stems and shade-killed lower branches knitted together a gray-brown barricade at the edge of the lawn. A canopy of dark green pine needles topped the "brownery" and shaded everything below.

From 15 feet on up, pine needles lived sumptuous lives, lolling in the sun, buzzing on a sugar high. Below 15 feet, slow starvation was the rule for any chlorophyllic thing except the most shade-tolerant ferns.

I knew that eventually bugs, blights, and storms would rip holes in the monotony and new life would invade again at ground level, but by the time that happened I might be in the ground myself, and the various low-growing plants that I could see lurking in the shade would likely be dead and buried as well.

What were those not-so-tall green plants fading away in the shade? Just below the 15-foot-high roof-line of dominant pine foliage there were dogwoods, hollies, and redcedars; at ground level there were ferns and spring wildflowers.

The dogwoods weren't getting enough light to build blossoms or add much size, but their low-tight-adapted leaves were still collecting enough sun energy to stay alive (barely).

The hollies were likewise holding on, their shiny evergreen leaves waiting in dark green domes. Redcedars raised green exclamation points here and there in the shade. A look at the tips of their branches showed that they were barely growing in the muted light.

Mid-level, sun-economy trees like hollies and dogwoods can generally operate on the sunlight that slips through the leaves of the tall tree monopolists up above. But there are times (and this was one of them) when the tall trees close ranks so completely that the shorter plants below gradually starve.

In May I noticed scattered ladyslippers, trilliums, jack-in-the-pulpits, bluebells, and various other attractive herbaceous plants sprouting, but their anemic growth indicated that they too were being over-shaded.

These plants are "springers": they pop up in spring before most other plants open new leaves. They live in a precarious balance between too much light and too little. Early spring sprouting gives them access to sunlight that will disappear in a few weeks as new leaves come out on hardwoods and other plants. They must soak up the available sun power quickly and store it in seeds and roots; then they die back to the ground as new tree leaves spread and intercept the sun.

Thinning was called for on our land because the pines had interlocked foliage, intercepting sunlight too effectively for any of the plants below to do well. But I would have to thin carefully to avoid over-lighting the forest floor and encouraging so much low-growing vegetation that the wildflowers couldn't compete.

My solution was a combination of actions over several years. In some areas I pruned branches up into the tree crowns to allow more light to filter through. I removed quite a few pine trees, especially those that were crowding hardwood trees or over-shading hollies, dogwoods, and red-cedars. I moved some of the small plants to locations that offered them better conditions.

In the next article in this series, we'll come back to exactly what I did on my little suburban forest. I'll discuss how to prune, thin, and place trees and plants so as to grow working layers of green from the ground up into the sky 100 feet or more. We'll use clippers, shovel, felling saw, pruning saw - and the knowledge of plant functions and requirements. It'll be full spring, a delightful time to be in a woods of any size.

RELATED ARTICLE: Different Goods for Different Woods

It's possible - and fun - to get up close and personal with most of the plants on less than an acre of backyard. It's quite different to interact with more than 200 acres of living things located a full day's drive from where you live. That's my situation with owning 200 acres of Maine hills, swamps, old fields, and mixed forests.

I planted pines on 30 acres of my old fields 30 years ago. We've thinned and pruned a little over the years, but basically the pines have been allowed to do what pines do best - take over the site and out and monopolize the sunlight. The forest floor beneath them looks like a russet carpet in a room with the shades drawn. The trees have interlocked foliage and grown tall and straight because tallness is an advantage in dense crowds of pines.

It doesn't sound like a diverse woodland, but the pines are surrounded by diversity. There are swampy areas with arborvitaes, fir trees, and moose. On the rocky uplands are hardwoods of many species and deer browsing on sprouts. There are zones of mixed growth in between: young, naturally seeded forests from past cuttings; remnants of old apple orchards; and fields. On my old farm, layers of fungi, ferns, mosses, trees, herbaceous plants, and animals of many kinds live, reproduce, and die in a constantly renewing, changing, sunpowered, tree-dominated metamorphosis of tons of natural chemicals.

My pine area is changing, and I'm speeding up the changes. The carpet beneath is becoming sun-dappled and spotted with low green plants. We are harvesting, removing every fourth row and thinning out the crowded trees in between. The smaller thinned wood will go for energy production or paper; some of the larger trees will become lumber, some will be holding up telephone lines next year. The remaining pines will grow faster and will attempt to close in and monopolize the sunlight again, but a variety of other plants will invade now that we've created openings.

Forester Alan Page, owner of Green Diamond Systems in Belchertown, Massachusetts, takes a different approach from my "pine-crowd" strategy. He uses the trees' "flex-defense" to encourage them to concentrate less on tallness and more on strong, thick stems.

Page says "A tree is not particularly in the business of growing wood; rather it is primarily designed for survival and reproduction. Growth occurs only when the tree has adequate resources. As they get larger, trees need increasing amounts of growing space for access to sunlight. Once a tree has found adequate space, it will grow in the region of the lower main stem in response to flexing (bending), caused by the wind, during the growing season. In response to this bending, the tree must add wood to its stem to stabilize itself and increase its chances of survival.

"In an unthinned forest, little wind penetrates. The trees are partially supported by each other. They don't need thick stems - they need tall stems to compete for light.

"In addition," he continues, "tree growth occurs only when there is adequate water. Growth will stop when the soil becomes so dry that the tree runs out of water. In the northeastern U.S., this usually occurs within two months of the start of spring growth."

According to Page, if you want to grow wood-producing trees, keep your trees widely spaced by frequent thinning, for the following benefits:

1) Giving full sun power to each tree.

2) Allowing wind access to those trees that are strong enough to take continual buffeting. If trees have been grown close together in the past, thin around groups of trees to start flexing from the wind; later, select trees in the group that have grown strong enough to stand alone, and thin around them.

3) Redistributing the available water to fewer trees. This stretches the supply so that trees are less likely to run out water in the midst of the growing season.

Page thins his trees by one-third, on average, every three to five years to achieve maximum growth. He also prunes to produce at least one clear foot log on each crop tree. He grows primarily white pines, as they're well suited to his area and the treatments he uses.

Alan Page's trees respond to the space he gives them by growing lots of wood, producing lots of oxygen, and absorbing lots of carbon dioxide. My Maine woods does those things and produces rich diversity in plant and animal life. And my little suburban Virginia wood-lot, now freed up and growing lushly, is doing its bit to add to the mix of essential molecules needed for life on earth.

In each of these wooded places, applied knowledge of the needs and preferences of the things that grow there improves the vitality of the area and the functioning of our planet.

RELATED ARTICLE: Questions for Young People (Reading "Green Side Up" will help you find the answers)

IF BARBARA BUSH BECAME A TREE, SHE WOULD BE A:

1) Loblolly pine 2) Dogwood 3) Hemlock 

A TREE GROWS TALL SO IT CAN:

1) play professional basketball 2) Produce wood for lumber 3) Keep its leaves in sunlight

ARE THESE STATEMENTS TRUE OR FALSE?

Photosynthesis is important only to green plants All animal life (including us) would die without functioning green plants All green plants would die without animal life There are no chemicals in a tree A tree is an assortment of chemicals Leaves need green light in order to operate

THE COSMIC SPEED LIMIT IS:

1) 55 miles per hour on the open highway 2) The speed of light (186,281 miles per second) 3) Warp speed 

MANY KINDS OF PLANTS GROW VIGOROUSLY IN DeCOSTER'S BACKYARD TODAY BECAUSE:

1) He left the area untouched. 2) He scattered many kinds of seed on the soil. 3) He thinned and pruned trees to let sunlight reach a variety of trees and plants.

SERIES AUTHOR LESTER DECOSTER - is president of The DeCoster Group, a Reston, Virginia, consulting firm offering expertise in writing, public relations, forestry, and environmental science.