NAME _____________________________________________ CH. 3 COMMUNITIES, BIOMES AND ECOSYSTEMS STUDY GUIDE 1. 2. Name the pioneer species that begins primary succession on a rocky area? After a community is disrupted by a large-scale event, such as a forest fire, a new community is established through what succession process? 3. What determines whether a zone is photic or aphotic? 4. Name the terrestrial biome houses the greatest biodiversity. 5. What is the definition of a biological community? 6. What is the definition of secondary succession? 7. Describe the tundra biome? 8. What event is most likely to initiate primary succession? 9. Explain why secondary succession generally occurs more rapidly in an area than does primary succession? 10.What type of succession is most likely to occur after a burned forest or a flood? 11. At which stage in Figure 3-3 are the most pioneer species found? Stage A, B, C, or D 12. What single feature is primarily responsible for the variation of climate in different parts of the world? 13. If precipitation on a tropical savanna increased from 100 to 200 centimeters per year but temperature remained the same, what biome would replace the savanna? 14. What is the zone of tolerance? 15. Write the correct sequence in the primary succession of species colonizing a newly formed volcanic island. 16. Describe limiting factors. 17. Name the biome that has a forest with broad-leaf evergreen trees, mosses, and orchids, 20–25° C temperatures, and where the >200 cm of rainfall per year is seasonal. 18. The climates of Earth’s tropical, temperate, and polar zones are primarily determined by what? 19. What is the definition of a biological community? 20. What is the definition of weather? 21.Trees cannot take root in tundra biomes because of the existence of what? 22. Describe a boreal forest. 23. Describe a desert. 24. Describe a temperate forest. 25. Describe a tropical savanna. 26. Describe a tropical rain forest. 27. Describe how a range of tolerance works. 28. Biologists are surveying a biome with an average precipitation of 188 cm and an average temperature above 18°C. Identify the biome they are surveying. Answer: ___________________________________ 29. Identify several factors that determine the climate of a region. 30. Compare and contrast weather and climate. 31. Explain why there is a climatic difference between the cities of Anchorage, Alaska, and Kingston, Jamaica. 32. Much of the world’s original temperate grasslands have been destroyed by human activities. Infer why temperate grassland biomes have been dramatically affected by human activities. Read the following and then answer the questions. Epiphytes are plants that grow on other plants. In the rain forest, they sprout from seeds or spores carried by the wind or animals and take root on the trunks and branches of the canopy trees. Epiphytes are not parasitic: they gain nothing from the trees except support and access to sunlight. However, under favorable conditions, they may form dense, water-logged, tangled mats of roots and stems, weighing up to several thousand kilograms. This weight is often enough to break the limbs of the more fragile trees. Some tree species have developed adaptations to protect against the growth of epiphytes. Two known mechanisms are (1) the frequent shedding of bark layers that periodically removes young epiphytes, and (2) the presence of certain plant-manufactured chemicals that inhibit the growth of other plants. In his explorations of the Costa Rican rain forest, Donald Perry developed an apparatus consisting of a platform base built on one tree and connected to two other trees by means of ropes. From this base, a system of ropes and pulleys attached to a harness would allow an investigator to access previously unexplored areas of the canopy and to move relatively unrestricted with minimal contact or interference with rain forest organisms. During his studies, Perry noticed that some trees were completely free of epiphytes, although the species were known not to shed bark or to manufacture plant-inhibiting chemicals. Other scientists had speculated that the Azteca ants, which live mutualistically with certain species of rain forest trees, were responsible. These aggressive ants were known to swarm and attack other insects and mammals that might damage their trees. To test the effect of epiphytes on these trees, Perry tied some moss and other small epiphytes to the limbs of one such tree. Perry found that the ants did destroy epiphytes. 33. Why was the development and use of Perry's rope-and-pulley apparatus necessary in the testing of this hypothesis? 34. How might Perry's invention help scientists discover new species?