Thursday, December 10, 2009

TREES (PART 4): FLOWERS AND FRUITS



FLOWERS AND FRUITS

by

Chris Maser

The creation of a thousand forests is in one acorn. — Ralph Waldo Emerson

I find in every plant’s seed the miracle of its being, because each seed has already present, hidden within its coat, not only the size and shape of the tree but also the size, shape, color, odor, and season of bloom of its flowers, as well as the size, shape, color, odor, flavor, and season of maturation of its fruits. Thus, the pear tree in my garden looks like a pear tree and produces only pear blossoms and fruits, and the apple tree likewise produces after its kind, as do the maples. Like all other components of life, there is infinite variety in flowers and fruits.

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Some flowers are bright and showy, some drab and secretive; some are large while others are tiny; some transmit from place to place wonderful perfume on the pathways of the air, and others do not. Some flowers are pollinated by wind, some by insects, others by birds and bats. Brightly colored flowers always cheer me, regardless of circumstances. And some flowers scent the air in such a way that on smelling them I am transported to another world.

Some trees have both male and female flowers on the same individual plant, whereas others have them on separate plants. Some flowers contain both male and female parts in the same blossom; others have separate blossoms. Some flowers are self-fertilizing when cross-pollination fails, whereas other flowers accept pollinated only from different blossoms.

In addition, some male flowers, through their wind-borne pollen, have left a multi-millennial climatic record and through it given society a glimpse into its own evolution before language made recorded history possible. The time-encapsulated secrets of a world lay archived in the sedimentary strata of lake bottoms, peat bogs, and glaciers before humans even knew how to question their existence. Here is secreted the drama of migrating trees and forests, of great fires and raging floods, of glaciers and drought-ridden deserts. Here, too, resides the ancestral lineage of communities of trees whose pollen chronicled their comings and goings even as their blooms brightened the day with color and tinted the air with odor in their bid to bring forth fruit and seed—the trees of the future.

But most of all, I marvel that so small a cone, so tiny a seed as that of the western red cedar can produce the ancient trees I remember from my youth, when a fallen monarch was so big that I could not climb over it when it blocked the trail as I hiked along the Green River in western Washington State. And the coastal redwoods of northwestern California live even longer and grow larger than the cedar.

The first time I saw a redwood tree, I pressed my cheek against its bark in an effort to look up the straightness of its trunk to the place where its top and the sky met. I failed, however, because the tip of the redwood’s crown was far loftier than I had ever imagined. While I was awed by the sheer size and majesty of this ancient tree, I was comforted by it as well. This redwood, close to 3,000 years old, also arose, like the cedar, from a seed so fragile that I could squash the life out of it between my fingers.

As flowers provide food for such animals as honeybees, butterflies, hummingbirds, sunbirds and nectar-eating bats; fruits, seeds, and nuts offer food to others, such as squirrels, mice, deer, bear, and fruit bats, some of which have wingspans approaching four feet. The flowers and fruits eaten by animals are not, however, free of service to Nature.

Many species of trees in the tropical rain forests, especially those that germinate in the dark understory, have large seeds that carry enough stored energy to grow leaves and roots without much help from the sun. Such fruits and seeds are often so large that only proportionately sized birds and mammals can swallow or carry them. In Gabon, a republic of west-central Africa, for example, monkeys may disperse 67 percent of the fruits eaten by animals.

Seed-dispersing animals, such as large birds and monkeys, are critical in replacing the large trees and lianas (high-climbing vines) of the tropical forest canopy. By eating the fruits and defecating the seeds some distance from the parent plants, thereby improving the seeds’ chances of landing in a favorable place for germination, the birds and monkeys are helping the trees and lianas, as species, to survive. These animals are the first species to disappear, however, when humans hunt for food and, along with elephants, have already been hunted so heavily that they either have been drastically reduced in numbers or eliminated completely over vast areas of the African forest, as well as in the tropical rain forests of Central and South America.

For the most part, foresters have overlooked how the interdependency of plants and animals affects the biodiversity of a plant community. Elephants, for example, disperse the seeds of 37 species of trees in the Ivory Coast, a republic of western Africa. Of those, only seven species have alternate means of dispersal (by birds and monkeys). Of the 201 individual trees in one study area, elephants dispersed 83 species. In one forest, where humans had eliminated elephants a century earlier, few juvenile trees of the elephant-dispersed species were left, and the two major species had no offspring at all.

Once the large species of birds and mammals are gone, the stunningly rich tropical rain forests will change and gradually lose species of trees, lianas, and other plants. Smaller seeds dispersed by wind will replace large seeds dispersed by large animals. Those species of plants whose seeds grow in the shaded understory will not survive, and the land will gradually be forested by fewer, more common species.1

A similar, albeit simpler, phenomenon is taking place in my own garden with scrub jays. Each autumn, the jays bury hazelnuts, filberts (also a nut), and acorns and simply leave them over winter, forgetting where they are. But the jays are back in late spring and early summer searching for seedlings that germinated from their autumn caches. On finding a seedling, a jay digs down to the filbert or acorn, plucks it from the seedling, cracks it open, eats the remains, and flies away. The seedling, meanwhile, is well established and flourishes—until I pluck it out.

Some animal-fruit interactions, however, appear to have little or nothing to do with seed propagation. In mid-February 1972, I was in the canyon along the Crooked River near the town of Prineville in central Oregon. It was a clear, warm, sunny day. The ground was mottled with snow. A light breeze, blowing up the Crooked River, carried with it ever so faint a hint of spring. As I glanced toward the river, I saw a muskrat climb out of the water and search the bank for something to eat. Somewhere a Canadian goose called, then another. It was peaceful with the little sucking noises of the water against the banks and the voices of the animals.

What a perfect day! I was protected from the wind by juniper trees growing along the river and up the slopes to the massive rims of basalt, which capped the canyon’s walls. And just across the river, I could see more junipers marching out of sight into the distance. As I stood breathing deeply of the cold, clean winter air, I glanced toward the rim of the canyon, where part way up the slope was an incredible commotion. Birds were plummeting out of the trees for no apparent reason. My curiosity aroused, I found a place to cross the river and started up the slope.

It is common in this country for birds of different species to band together in winter, forming what is called a feeding flock. As I climbed toward the rim, the commotion, which until then had been silent with distance, became an awful din. Mountain bluebirds, evening grosbeaks, cedar waxwings, and robins, with a few birds of other species thrown in, were creating incredible pandemonium. There were hundreds of them, all seeming to squawk at once. In addition, I could see, even from a distance, that some of them were literally falling out of the trees and flopping around on the ground with their heads lolling this way and that, unable to fly. What on earth was going on?

I began walking a little faster, for it was now obvious that something was seriously amiss. I had seen birds act in a similar manner in years past when pesticides had been sprayed in an area. But who would be spraying pesticides in this isolated canyon country at this time of year, and what would they be spraying for? It just didn’t make sense.

I was still some distance from the birds, and slightly out of breath from my rapid climb, when I became conscious of just how sweet the juniper berries were that I had been plucking off the trees as I walked by. They had an unmistakable zing to them–the berries were fermenting because they had been frozen and warmed again by the sun only to be refrozen and warmed again.

I suddenly understood, and all I could do was laugh until my stomach and sides ached. The birds were drunk, very drunk, but dangerous mostly to themselves. They were just crashing into things, and once down, they simply could not get up again. No matter what they did, they could not become airborne. And there were hundreds of them, all in various stages of inebriation.

If birds get hangovers, I mused, there would be a bunch of miserable birds in the days ahead. Just then, a bluebird fell off a branch. Well, I thought, if they don’t get hangovers, they must certainly get bruises.

ENDNOTE

  1. The foregoing discussion of tropical rainforests is based on: Louise H. Emmons. 1989. Tropical rain forests: why they have so many species, and how we may lose this biodiversity without cutting a single tree. Orion 8:8-14.

© Chris Maser, 2006. All rights reserved.

I spent over 25 years as an active research scientist in natural history and ecology in forest, shrub steppe, subarctic, desert, coastal, and agricultural settings. Today I am an independent author as well as an international lecturer, facilitator in resolving environmental conflicts, vision statements, and sustainable community development. I am also an international consultant in forest ecology and sustainable forestry practices.

I Have Lived, Worked, Consulted, And/Or Lectured In: Austria • Canada • Chile • Egypt • France • Germany • Japan • Malaysia • Mexico • Nepal • Slovakia • Switzerland • and various settings in the United States.

If you want to contact me, you can visit my website. If you wish, you can also read an article about what is important to me and/or you can listen to me give a presentation.

[Via http://chrismaser.wordpress.com]

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