Plant Lives - Strategies for Survival

Life on planet Earth began with bacteria and for two billion years they were its only inhabitants. From these humble beginnings arose the great diversity of plant, animal, fungi and bacteria that now comprise life on Earth. Through the process of adaptation and mutation, life evolved into new forms. In order to survive in an everchanging world, simple life forms changed into more specialized forms. Those able to adapt to change survived, those unable to adapt became extinct. Charles Darwin called this process "survival of the fittest."

In the process of adapting to myriad circumstances, plants have developed an enormous gene pool and the capability of surviving under all kinds of conditions. Life can he found from the deepest depths of the oceans to the summits of the Himalayas, ranging in size from the smallest virus to the largest fungus.

Different Strategies
Brilliant color and fragrance evolved in flowers to attract birds, insects and mammals that pollinate them. These are symbiotic relationships; the plants offer their partners nourishment, the animals transfer pollen and increase genetic diversity while helping the plants reproduce. Flowering plants are a relatively recent evolutionary form within the plant world. Plant life cycles can range from short to very long periods. The oldest known life form on Earth is the bristle cone pine of California's White Mountains. These remarkable trees have life cycles of more than 5,000 years. Trees living today are only one or two generations apart from the time when saber tooth tigers and mammoths roamed the plains and mountains of North America. Not many of these remarkable trees exist, and their environment is extremely hostile.

In that context, it is incredible to think that annuals must progress from seed to seedling, through vegetative growth, flowering, fruiting and finally the seed production stage - all within one year or less! Many annuals are primary commercial crops for today's farmers: tomato, pepper, lettuce, spinach, beans, melons and many flowers.

In extreme environments, seeds may lie dormant for many years awaiting a good rainfall before beginning a life cycle. Some plants take advantage of birds or rodents to transport seed far from its original home before germinating. The seed has evolved a tough outer shell that can go through the intestine of its vehicle without being destroyed. Lodgepole pine prefers for its seed to experience a burn in order to germinate - a natural survival strategy where forest fires sweep the land from time to time.

Plants and animals often develop powerful toxins to deter predators and pathogens that would otherwise decimate them. The tropical forests are practically a natural pharmacy where plants and animals use exotic chemistries to deter predators, or as a mechanism to subdue prey. Many wonders have yet to be revealed. Remedies for disease, new kinds of foods, dyes, fibers, fuels and a host of other useful products will be discovered if we can manage to protect our forests and their inhabitants. By managing natural resources instead of raiding them for short-term gain, we open the door to future cultivation of wonder plants and animals.

Population and Competition
Generally, life adapts to its environment. The objective is first to survive, and secondly, to procreate. Consider extreme environments. Many deserts tend to be hot and dry during summer days, often cold at night. Cactus need to preserve moisture. Their minimal surface area reduces transpiration, light is so abundant that a huge canopy of foliage is unnecessary to capture it. Thorns protect the cactus from animals that would devour them and the hard surface of the thorns helps prevent loss of moisture.

Thorns on cactus evolved from foliage and the body of the cactus, which is responsible for photosynthesis, is actually stem tissue. We can surmise that the desert of today's cactus was once more temperate. The cactus changed with its environment. In the rain forest, life is more abundant and competition intense. Many plants growing in rain forests have evolved large surface areas to help capture light and transpire moisture more efficiently in the humid air. The strategy of developing larger surface area to capture the subdued light on the forest floor is an adaptation to intense competition among forest plants.

Others compete by rapid upward growth. These are the giants whose tops form the canopy of the forest. There are layers in these densely populated forests where plants and animals have found a niche wherein is far lower in a given area. For they survive within unique ecosystems. Many animals never venture to the forest floor, others never ascend to the Amazon roof of the forest.

Some plants can only be found on the floor, others grow upon "hosts" high above the ground. Among these arc the epiphytes including beautiful orchids and bromeliads.

In tropical rain forests, due to the intensity of competition, the variety of species is many times greater than in temperate forests, while the number of individual plants of a given species is far lower in a given area. For example, rubber trees will not be found growing close together in the Amazon. A "seringuerio" or rubber tapper, will have to walk long distances from tree to tree to draw latex. In the conifer forests of the northern hemisphere there can be enormous numbers of trees of the same species growing in nearly continuous tracts.

This can be attributed in part to harsh winters which interrupt the life cycle of insects and diseases that prey upon the temperate forest inhabitants. Another reason for the limited number of species in temperate forests is the great ice ages which rapidly overran the northern hemisphere. Only those life forms that were able to outrun the progression of ice were able to survive.

The entire United States east of the Mississippi, but excluding southern Florida, contains only about 4,000 plant species. A single township in Brazil, an area of only 25 by 25 miles, contains more. On the other hand, the eastern United States is incredibly lush because the soil is fertile and rainfall fairly consistent.

A Delicate Balance
Attempts to grow huge tracts of rubber trees in the Amazon failed because the high density of trees attracted insects and diseases. By growing far apart in the wild, the tree frustrate those that prey on them. This is their stategy for survival. Closely planted populations of rubber trees do grow successfully in Malaysia where the British established large plantations to meet the great need for rubber in the industrial world. These plantations are successful because the rubber tree is not native to Malaysia and the insects and diseases that prey on them have not yet developed.

With time, you can be sure that insects and diseases will evolve that will decimate the huge tracts of rubber in Malaysia and the natural order of survival based upon dissipation of individual trees will again prevail. We can surmise that the extreme seasonal changes that occur in temperate climates help control insects and diseases and successful life forms like conifers are able to dominate. In the tropics, where seasonal changes are mild, the insects and diseases proliferate. Those life forms that are susceptible to infestation have to spread out to survive.

For man, the consequences of these survival strategies have led to reforestation of single species where it can be achieved. Monoculture of conifers in the northern hemisphere is an effective economic strategy for the timber industry and their success has resulted in the decimation of virgin forest areas. Today, we have at best only about 10 percent of the original wild forest remaining in the northwestern United States. Monoculture is generally not effective in tropical forests. When tropical forests are burned back to enable crop cultivation, the average lifetime of an agricultural endeavor is only about three years. After that the soil becomes so depleted that neither the forest nor agricultural crops can survive. The region becomes a wasteland.

It is imperative that we protect what little virgin forest we have left on our planet. We will soon regret the loss of genetic diversity if we allow further annihilation of our few surviving native forests.

Nature's Building Blocks
Using the tools of modern science we have learned to create new varieties of life. Luther Burbank generated over 200 new plant varieties through hybridization. A plant variety with a desirable characteristic was crossed with another plant with a different desirable characteristic in an effort to create a unique hybrid that carried both.

Now through "genetic engineering we are able to cross completely unrelated life forms, a tomato can have a gene from a chicken spliced into it to create a new tomato with unique properties. There is a great deal of controversy regarding genetic engineering. Will we create new miracle plants or will we create monsters? No one knows for sure.

The practitioners of gene splicing or genetic engineering need variety to work with. And although serious questions remain about genetic engineering as an appropriate technology, there is no question that destruction of the limited natural resources will greatly limit future possibilities.

A Strategy for Human Survival
For a modern farmer this may all seem a bit too esoteric, but on the other hand, the farmer will be most successful with an understanding of the unique characteristics of his crop and the circumstances under which it evolved.

Selecting an appropriate crop requires understanding. A farmer needs to know the appropriate range of temperature, humidity, light, fertilizer and proper cultural practices for a given crop.

We have learned a lot from a few thousand years of farming, but many questions remain. We have learned to grow plants in environments that are distant and radically different from that in which they evolved. And we have learned to manipulate plants to increase yield, change color and flavour, and to increase resistance to disease.

The key question is if we have learned to preserve original species and the environments in which they evolved. If we are not successful in this effort, we will likely find ourselves on the endangered species list because we failed to develop our own strategy for survival.

Personal Impact
All of this philosophy and insight means nothing unless we can begin to turn the tide of environmental destruction. All action begins at the personal level. That is where the impact really occurs. It is what we do, or don't do, as individuals that really counts. A giant snowball is built by beginning small and building through accumulation. You might think of it as the ultimate cliche - write your government representatives! We've heard it a thousand times, but how many times have you sat down and let anyone in power know how you feel about things? No doubt there are laws that you find absurd or offensive. Let them know that you are fed up with the status quo.

Write to the embassies of governments like the United States, Brazil and Australia that have populations of native peoples. The Indians and aboriginals may be the last human populations on Earth that are still in touch with nature. They will become our teachers if they survive our onslaught.

There are two ways to achieve immortality, through our children and through our work. Every time I hear Mozart, he proves that he's still alive. Likewise, affect change through your actions. By participating in a global effort to help save the planet, you help assure that it will remain alive. Every day more and more forests are destroyed, there is little left so we must act together now.