问题详情

At 5:30 in the morning we are deep in a dark forest on an island in the midddle of the Panama Canal. We"ve been out walking for only 15 minutes, but I"m already soaked in sweat.
As a colleague and I plod along, my head lamp picks out the occasional trail marker, but mainly the light seems to operate as a major local landmark for insects. Several mosquitoes have already discovered the delights of the soft parts of my ears, while others are slowly working their way between my seeks and legs to be discovered later after much scratching. Suddenly a deranged roaring and barking starts 25m above my head and builds chaotically and intensity before slowly quieting after several minutes. Similar mad choruses respond from other areas of the forest. Hearing the dawn cacophony of howler monkeys always give me a deep sense of pleasure -- the joy of being back in the tropics. It may be a hot, humid place where insects, plants and fungi rule, but the phone and fax won"t find me here. I"m free to watch monkeys, collect data and try to tease out a tiny piece of the great puzzle of life"s diversity.
That diversity faces disaster, and every biologist has a horror story to tell. Each year many of us return to the field after a cold winter"s teaching to discover that our research sites have been destroyed and our experiments and study organisms have disappeared. We can see with our own eyes the mass extermination of the world"s animal and plant life as forests, savannas and wetlands give way to farmland, housing developments and shopping malls. If current rates of habitat destruction continue, it is likely that we will condemn from a quarter to half the world"s currently living species to extinction within the next 100 years.
Nowhere is life more diverse than in tropical rainforests, and nowhere is the assault on life more tragic. Scientists are only beginning to understand the complex webs of interdependencies among various species. Increasingly, ecological research in the tropics is revealing how dependent humans are on forests for a wide variety of important services, particularly regulation of the earth"s atmosphere and climate. We may owe as much to the residents of the rainforests as we do our cattle, corn and wheat.
Much of our understanding of tropical-forest biology comes from research on Barro Colorado Island, a 1,600-hectare dot in the middle of the Panama Canal. B. C. I., as the island is affectionately known to the biologists who work there, is covered with dense tropical forest, which was declared a nature reserve in 1923. The Smithsonian Tropical Research Institute facility on B. C. I., established in 1946, is a Mecca for tropical biologists, who work to uncover the complex links between the large variety of species that live in forests and to demonstrate the importance of these woodlands as sources for medicines and other products of incalculable value to humans.
The atmosphere at the research station is probably similar to that at Los Alamos, New Mexico, in the 1940s when a group of the world"s top physicists were cloistered together trying to design the atom bomb. The justified the creation of a nuclear weapon by assuming it would provide the ultimate deterrent that could be used to reinforce peace in a democratic world. Similarly, the longer-term future of human civilization on earth is dependent on the earth"s forests, which act as its lungs, livers and kidneys. That is why scientists on B. C. I. are struggling to unravel the mysteries of the forests before they disappear.
At first the forest in Panama just looks like a wall of green. Then you start to notice differences between plant species, and file sheer diversity seems suddenly overwhelming. Variations between plants are often subtle and only apparent for the short period of time that a species bears flowers or fruit. Slowly you begin to identify specific types and family groups such as the palms, heliconias and f
A．research into tropical-forest biology on Barro Colorado Island
B．how the whole ecosystems can depend on the survival of a single species
C．the life cycle of the fig wasp
D．the importance of forests to the human race