Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Cycles in Nature Section 1 The Cycles of Matter Section 2 Ecological Succession Chapter 19 Table of Contents

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Diagram the water cycle, and explain its importance to living things. Diagram the carbon cycle, and explain its importance to living things. Diagram the nitrogen cycle, and explain its importance to living things. Objectives

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 The movement of water between the oceans, atmosphere, land, and living things is known as the water cycle. How Water Moves During evaporation, * In the process of condensation, * The Water Cycle

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 * is called precipitation. Rain, snow, sleet, and hail are all forms of precipitation. Most precipitation falls into the ocean. The precipitation that falls on the land and flows into streams, rivers, and lakes is called runoff. Groundwater *. Groundwater slowly flows back into the soil, streams, rivers, and oceans. The Water Cycle, continued

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 The Water Cycle

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Water and Life Without water, there would be no life on Earth. All organisms, from bacteria to animals and plants, are composed mostly of water. Water helps transport nutrients and waste within an organism. Water helps regulate temperature. All water taken in by an organism is eventually returned to the environment. The Water Cycle, continued

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Besides water, the most common molecules in living things are organic molecules, or molecules that contain carbon. * is known as the carbon cycle. The Carbon Cycle

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Photosynthesis and Respiration During photosynthesis, plants use * Most animals get the carbon and energy they need by eating plants. * called respiration. Respiration uses oxygen and releases carbon dioxide and water back into the environment. The Carbon Cycle, continued

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Decomposition and Combustions * is called decomposition. For example, when fungi and bacteria decompose organic matter, carbon dioxide and water are returned to the environment. Combustion is the *. Combustion of organic matter releases carbon. The Carbon Cycle, continued

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 The Carbon Cycle

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Living things need nitrogen to build proteins and DNA. The movement of nitrogen between the environment and living things is called the nitrogen cycle. The Nitrogen Cycle

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Converting Nitrogen Gas Although about 78% of the Earth’s atmosphere is nitrogen gas. Most organisms cannot use nitrogen gas directly. * is called nitrogen fixation. Other organisms get the nitrogen they need by eating plants or animals that eat plants. The Nitrogen Cycle, continued

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Passing It On On When organisms die, decomposers break down the remains. Decomposition releases a form of nitrogen into the soil that plants can use. Certain types of bacteria in the soil convert nitrogen to a gas, which is returned to the atmosphere. The Nitrogen Cycle, continued

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 The Nitrogen Cycle

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 1 The Cycles of Matter Chapter 19 Other forms of matter on Earth also pass through cycles. Many of the minerals that living cells need, such as calcium and phosphorous, are cycled through the environment. Each of the cycles is connected in many ways. Living organisms play a part in each of the cycles. Many Cycles

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Ecological Succession Chapter 19 Describe the process of succession. Contrast primary and secondary succession. Explain how mature communities develop. Objectives

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Ecological Succession Chapter 19 Regrowth of a Forest Succession * is called succession. The regrowth of a forest after a forest fire is an example of succession. Succession takes place in all communities, not just those affected by disturbances such as forest fires.

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Ecological Succession Chapter 19 Primary Succession Sometimes, a small community starts to grow in an area where other organisms had not previously lived. *. This process is called primary succession.

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Ecological Succession Chapter 19

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Ecological Succession Chapter 19 Secondary Succession * called secondary succession.

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Ecological Succession Chapter 19

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Ecological Succession Chapter 19 Mature Communities and Biodiversity In the early stages of succession, only a few species grow in an area. As a community matures, it may be dominated by a well-adapted, slow-growing climax species. The variety of species that are present in an area is referred to as biodiversity. Having biodiversity helps communities *

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Section 2 Ecological Succession Chapter 19 Mature Communities and Biodiversity, continued Mature communities tend to have biodiversity. A mature community simply has organisms that are well adapted to live together in the same area over time.

ResourcesChapter menu Copyright © by Holt, Rinehart and Winston. All rights reserved. Chapter 19 Standardized Test Preparation