Download
1 / 65
650 likes | 665 Views
Explore the intricate relationships between organisms and their environments in ecosystems. Delve into biodiversity and the urgent need for conservation efforts. Learn about primary and secondary succession, food webs, and the impact of human activities on Earth's diverse habitats.
E N D
Chap.25 Biomes and Communities Life Science 2010 鄭先祐(Ayo) 製作
名詞定義 • Ecologists are those biologists who study ecology, the interrelationship of the organism and the environment. • An ecosystem (生態体系) is a group of interacting living things, together with all the environmental factors with which they interact. • A community (群落，群區、社區) is an assemblage of interacting living things that forms an identifiable factors. Life Science 2010
Fig. 25.1 The makeup of ecosystems. Life Science 2010
Fig. 25.2 The feeding zones of five species of North American warblers in spruce trees. • Habitat (棲息地) Niche (棲位；職位) Life Science 2010
Succession (演進、演替、演遞、消長) • Two kinds of succession • primary succession • secondary succession • climax stage, where the species, structure, and energy flow will remain relatively stable as long as the environment does not change markedly. Life Science 2010
Fig. 25.2 Mount St. Helens immediately after its eruption (a) Life Science 2010
Fig. 25.3 (b) nine months later Life Science 2010
Fig. 25.4 An example of primary succession. Life Science 2010
Fig. 25.5 An example of secondary succession. Fast-growing species begin to take over a cleared forest, the whole process requiring just 70 years. Life Science 2010
The Web of Life (生活網) • Producers • primary, secondary, tertiary, consumers • food chain food web Fig. 25-6 A carnivore is a secondary consumer that feeds on primary consumers such as these grazers. Life Science 2010
Fig. 25.7 The animals of a hypothetical food web. Life Science 2010
Fig. 25.8 The material that once made up this unfortunate animal is being recycled by decomposers. Life Science 2010
Fig. 25.10↓ Interdependency of ten theoretical species. • Fig. 25.9↑ interdependency of five theoretical species. Life Science 2010
Essay 25.1 Biodiversity -- A dwindling treasure • Scientists have estimated that there are about 8 to 10 million species in existence and that number is rapidly diminishing because of human behavior. • We known more about birds and flowering plants than we do about fungi. We know about roughly 69,000 kinds of fungi, but it is suspected that perhaps 1.5 million may actually exist. Life Science 2010
Essay 25.1 Biodiversity • We also don't known much about bacteria. About 48,000 species of bacteria have been identified and researchers think this is only a fraction of what's out there. • Probably 50 to 80 percent of the world's species live in the tropics and about half of those in rainforests. • However, most scientists live in temperate areas. Life Science 2010
Furthermore, we're cutting down the rainforests at an alarming rate. • We lose an area of rainforest the size of Florida every year. Life Science 2010
Extinction and Us • Should we care if thousands of species of animals have disappeared from the Earth in the last 50 years? • Should we care that some scientists calculate that until 2010, one species an hour will meet extinction? • Thousands of species whose very existence is presently endangered -- largely because of our activities? Life Science 2010
Fig. 25.11 The bald eagle is officially designated to a threatened species 我們只關注於我們所注意到的，或是所珍惜的，而忽略我們沒有看到的，或是其它的生物。 Life Science 2010
Essay 25.2subdue the Earth (征服地球) • Indian farmers are incessantly waging war on rats. • It has been calculated that the progeny of one pair of rats, in a year's time, can consume enough grain to feed five people. Life Science 2010
The killing is thereby justified. (真的嗎？) • 但我們也可以說，只要五個人一年的糧食就可以養活一對老鼠以及其所有的後代一整年。 • It is to our own best interest to place a higher premium on ourselves and, to carry it further, on those most like us. Life Science 2010
BiomesFig. 25.12 The world's biomes. (cf. Table 25.3) Life Science 2010
Fig.25.13 In tall mountains, the interaction between temperature and precipitation determines the distribution of biomes. Life Science 2010
Fig. 24.14 The prevailing wind directions are important in producing the biomes, which begin as rotating air cells. Life Science 2010
Fig.25.15 The interior of a tropical rainforest is often dark and quite open, permitting the Waorani hunter of Ecuador's Amazon Basin to pursue monkeys and parrots with a blowgun and poisoned darts. Life Science 2010
Essay 25.3 The destruction of tropical forests. • The tropical forests occupy only about 7 percent of the Earth's surface. • These incredibly productive areas probably harbor 50 to 80 percent of the Earth's species. • Every minute more than 100 acres of tropical forests are devastated or seriously degraded. • Every day more than 240 square miles were wiped out. Life Science 2010
Why don't we stop? The reasons stem from a shortsighted view of economics. Life Science 2010
The variation is essentially a storehouse we can call on for special genes or combinations of genes to help us solve our mounting agricultural problems. • The tropical forests absorb much of the Earth's carbon dioxide and provide, in turn, much of the Earth's oxygen. • There are the potential new foods, medicine, and other products that are found in the fragile tropical forests, products that we never had a chance to develop. Life Science 2010
Essay 25.3 the destruction of tropical forests • Recently, in one 3-acre plot that was being cleared to extend a jungle runway, four new species of trees were discovered. • Some experts have calculated that over the next 15 years we can expect the extinction of 100 to 200 species a day. Life Science 2010
Fig. 25.16 The thick jungle growth along the Conanaco River of Ecuador. Life Science 2010
Fig. 25.17a. Temperate deciduous forests are marked by distinct seasons. Life Science 2010
Fig. 25.17b. Temperate deciduous forests are marked by distinct seasons. Life Science 2010
Fig. 25.17c. Temperate deciduous forests are marked by distinct seasons. Life Science 2010
Fig. 25.18 The great evergreen forests of the taiga cover large area of the northern hemisphere. Life Science 2010
Fig. 25.19 Where bogs and marshes form, the taiga is interrupted. Life Science 2010
Essay 25.4 The redwoods • It was 390 feet tall. Nothing on earth could match it. • As the population of California grew, the trees began to be cut. • Some citizens tried to establish a national park to save some of them, but the lumber industry blocked it in congress. Life Science 2010
Essay 25.4 The redwoods • After World War II, California experienced a population surge of unprecedented dimensions. • The conservationists, led by the Sierra Club, pushed again for parks to be set aside. • By 1960, there were only two areas left that were relatively unscarred and of park caliber. Life Science 2010
While conservationists dickered among themselves over which area was the best, the lumber industry was busy in Sacramento and Washington, DC. • As the arguments continued, the trees kept falling. • Then, in the summer of 1965, the 390-foot giant was discovered by the lumber companies. • They worked quickly and the great tree was felled, cut into 20-foot lengths, and hauled away. Life Science 2010
Fig. 25.20 After the snow melts in the brief arctic summer, the tundra often reveals a variety of plants. Life Science 2010
Fig. 25.21 Grasslands may support a surprising number of animals. Life Science 2010
Fig. 25.22 The chaparral in southern California. These scrubby plants survive fire and annual drought that would discourage other plants. Life Science 2010
Fig. 25.23 Deserts are fascinating place with great temperature variation because the air is unbuffered by water. This puma tends to conserve water by behaving so as to minimize loss. Life Science 2010
The water environmentWe are so dependent on water that most of our great cities have developed along the water's edge. Life Science 2010
A cypress swamp in winter.The water in such swamps moves very slowly. Life Science 2010
Tules, or bulrushes(莞), which thrive on overflowed land in the American Southwest. Life Science 2010
A glacial lake in Banff National Park, Alberta.Such lakes may be exceptionally deep and cold with a predictable turnover rate as their upper reaches are heated or cooled by the air temperature. Life Science 2010
The Channel Islands off the California coast. Life Science 2010
A salt marsh estuary in South Carolina. Life Science 2010
Rivers of ice such as these harbor few forms of life (many of them microscopic) Life Science 2010
Highly oxygenated cold waters can be home to a variety of life, including vertebrates such as tout. Life Science 2010
