Reading Essentials for Biology Glencoe, страница 9

When it cools, land forms, butthere are no living organisms in the new land. The first species tolive in such an area is called a pioneer species. Decaying lichens,along with bits of sediment in cracks and crevices of rock, makeup the first stage of soil development. Gradually, other life formstake hold. After some time, primary succession slows down andthe community becomes stable. Pioneer species eventually die.Once little or no change occurs, the community is called a climaxcommunity.

A climax community can last for hundreds of years.READING ESSENTIALSChapter 325NameDateClassSection3.1Communities, continuedWhat is secondary succession?3. Conclude After a flooddestroys everything growing on the land, whichtype of succession is mostlikely? (Circle yourchoice.)a. primaryb. secondarySecondary succession is the pattern of changes that takesplace after an existing community is destroyed. The destructioncan be caused by a forest fire or when a field is plowed over andnot replanted. During secondary succession, as in primary succession, organisms come into the area and change gradually. But,because soil already exists, the species involved in secondary succession are different from those in primary succession. Secondarysuccession may take less time than primary succession to reachthe stage of a climax community.◗ After You ReadMini Glossarylimiting factor: any biotic or abiotic factor thatrestricts the existence, numbers, reproduction, or distribution of organismsprimary succession: colonization of barren landby pioneer organismssecondary succession: sequence of changes thattake place after a community is disrupted bynatural disasters or human actionssuccession (suk SE shun): the orderly, naturalchanges that take place in the communitiesof an ecosystemtolerance: the ability of an organism to withstand changes in biotic and abiotic environmental factors1.

Review the terms and their definitions in the Mini Glossary above. Highlight the threeterms that deal with changes in an ecosystem. Then circle the term that refers to a situationin which there are few or no changes.2. Use the flowchart below to help you review what takes place after a volcanic eruption. Fill inthe blank box.Volcanic eruptionoccurs26Chapter 3Lava cools andnew land formsREADING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.climax community: a stable community thatundergoes little or no changeNameDateClassSection3.1Communities, continued3.

Column 1 lists new concepts that you learned about in this section. Column 2 gives anexample of each concept. Draw a line from each concept to its correct example.Column 1Column 21. limiting factorsa. the first organisms to grow on a new patch of cooled,hardened lava2. pioneer speciesb. weeds and wildflowers beginning to grow in a field aftera corn crop is harvested3.

tolerancec. ability of mosquitoes to survive in very different conditionsall over the world4. climax communityd. cold temperatures and high winds that prevent tree growthin mountain areas5. secondary successione. an old forest that has not had any fire damage in over200 yearsCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Visit the Glencoe Science Web site at science.glencoe.com to findyour biology book and learn more about communities.READING ESSENTIALSChapter 327NameDateClassSection3.2 Biomes◗ Before You ReadSC.G.1.4.1 The student knows of the great diversity and interdependence of living things.SC.G.2.4.4 The student knows that the world ecosystems are shaped by physical factorsthat limit their productivity. Also covers SC.F.1.4.2, SC.G.1.4.2, SC.G.2.4.6Deserts are very different from rain forests.

Each is home to species that can find everything theyneed to survive in their unique environment. This section discusses areas with their own specific setsof characteristics. Highlight each of the key terms that introduces one of these types of areas. Thenuse a different color to highlight important facts about each.◗ Read to LearnWhat is a biome?Aquatic BiomesApproximately 75 percent of Earth’s surface is covered withwater.

Most of that water is salty. Salt water is found in oceans,seas, and some inland lakes. Freshwater is found in rivers, streams,ponds, and most lakes.The oceans contain a large amount of biomass, or living material. Much of this biomass is made up of tiny organisms thathumans cannot see.

Large marine animals depend on these organisms for food.What is an estuary?1. What is an estuary?________________________________________________________________________28Chapter 3An estuary (ES chuh wer ee) is a coastal body of water partlysurrounded by land that forms where rivers meet the ocean.Freshwater and salt water come together in an estuary. The amountof salt in an estuary depends on how much freshwater the riverbrings into the estuary.Grasses that can grow in salt water can become very thick in anestuary.

Their stems and roots trap food material for small organisms like snails, crabs, and shrimp. These organisms feed on theREADING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Make Flash Cards Makeflash cards to help you learnsection material. Think of aquiz question for each paragraph.

Write the question onone side of the flash card andthe answer on the other side.Keep quizzing yourself untilyou know all of the answers.A biome is a large group of ecosystems that shares the sametype of climax community. All the ecosystems within the biomehave similar climates and organisms. Biomes located on land arecalled terrestrial biomes. Biomes located in bodies of water areknown as aquatic biomes.NameDateClassSection3.2Biomes, continuedtrapped, decaying materials. The nutrients in the food passthrough the food chain when these smaller organisms are eatenby larger predators, including birds.What are the effects of tides?Each day, the gravitational pull of the sun and moon causesocean tides to rise and fall. The area of shoreline that lies betweenthe high and low tide lines is called the intertidal zone.Many animals that live in the intertidal zone, such as snails andsea stars, have suctionlike adaptations.

These allow the animals tohold onto rocks when wave action is strong. Other animals maketheir own strong glue that helps them stay in place. Clams, worms,snails, and crabs survive by burying themselves into the sand.2. Why are planktonimportant?________________________________________________________________________Copyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Where do most marine organisms live?Most of the organisms that live in themarine (saltwater) biome are plankton.Plankton are tiny organisms that float inthe waters of the photic zone.

The photiczone is the area of the ocean that is shallow enough for sunlight to penetrate.Plankton include autotrophs (organismsthat make their own nutrients), diatoms,eggs, and very young marine animals.Plankton are important because they formthe base of the entire aquatic food chain.This means that every aquatic animaleither eats plankton or eats an animal thateats plankton.PlanktonPhoticzoneCrabsSnailsJellyfishesFishesWhat are freshwater biomes?Bodies of freshwater are another kind of biome. Lakes andponds serve as home to many organisms.

Plants grow around theshorelines and into the water. The shallow waters where theseplants grow are home to tadpoles, aquatic insects, worms, certainfishes, and many other living things. All the life forms are part ofthe local food chain.In deeper waters, it is colder and there are fewer species. Deadorganisms drift to the bottom. There, bacteria break down theorganisms and recycle the nutrients.

Organisms decay more slowlyat the bottom of a deep lake than in shallow water.READING ESSENTIALSChapter 329NameDateClassSection3.2Biomes, continuedTerrestrial BiomesTerrestrial biomes vary greatly. At the north pole, the weatheris very cold and there are no plants. As you move south, theweather gets warmer and there is a change in the size, number,and kinds of plants that cover the ground. As you continue south,the temperatures rise and you encounter forests. Still farthersouth are grasslands and deserts, with high summer temperaturesand little rainfall.

Near the equator, you find lush growth andmuch rainfall.How does climate affect biomes?________________________Climate is a group of abiotic factors that influences the kind ofclimax communities that develop in an area. Climate includes wind,cloud cover, temperature, humidity, and the amount of rain andsnow an area receives. The most common terrestrial biomes thatresult from differences in climate are tundras, taigas, deserts,grasslands, temperate forests, and tropical rain forests.________________________What is the tundra biome?________________________________________________________________________The biome that circles the north pole is called the tundra.Because it is so cold, only a few grasses and small plants grow.A thin layer of soil may thaw in the summer, but the soil underneath stays frozen.

The cold causes any organisms that die thereto decay slowly. As a result, nutrients are recycled slowly. Thiscauses a lack of nutrients in the soil. The lack of nutrients limitsthe types of organisms the tundra can support.The short growing season in the tundra limits the types ofplants found in this biome, but the plants that do grow there livea long time and are resistant to drought and cold. These includegrasses, dwarf shrubs, and cushion plants. Animals that live on thetundra include arctic foxes, weasels, lemmings, hares, snowy owls,hawks, musk oxen, caribou, and reindeer.What is the taiga biome?South of the north pole is the taiga (TI guh). The climatehere is warmer and wetter than the tundra and forests of trees,such as fir and spruce, are found.

Animals such as elk, deer, moose,squirrels, voles, weasels, and a variety of birds call the taiga home.The taiga stretches across much of Canada, northern Europe,and Asia.30Chapter 3READING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.3. What five abiotic factorsdoes climate include?NameDateClassSection3.2Biomes, continuedWhat is the desert biome?The driest biome is the desert biome. A desert is an arid regionwith little to no plant life. The plants that do grow there arewell adapted to these dry areas.