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CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT

CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

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Page 1: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT

Page 2: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH

• Sustaining life on Earth requires more than individuals

• Life is sustained by interactions of many organisms functioning together in ecosystems

• Physical and chemical environments

Page 3: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

6.1.1 BASIC CHARACTERISTICS OF ECOSYSTEMS

• Structure

• Made up of two major parts; living (ecological community)and non living (physical chemical enviro)

• Processes

• Cycling of chemical elements and flow of energy

• Change

• Undergo development through succession

Page 4: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

BASIC CHARACTERISTICS OF ECOSYSTEMS

• For complete recycling of chemical elements to take place, several species must interact.

• Photosynthetic organisms produce sugar from carbon dioxide and water

• From sugar and inorganic compound they make other organic compounds (protein, woody tissue)

• Need decomposers to get back to inorganic compounds

Page 5: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

BASIC CHARACTERISTICS OF ECOSYSTEMS

• At its simplest a community will have

• At least one species that is a producer

• Another species that is a decomposer

• Plus a fluid medium

Page 6: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

6.1.2ECOLOGICAL COMMUNITIES

• Ecological community defined in two ways

• A set of interacting species found in the same place and functioning together to maintain life.

• Operational definition= all the species found in an area, whether or not they interact.

Page 7: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

6.1.2 FOOD CHAINS

• Energy, chemicals and some compounds are transferred from creature to creature along food chains (food webs).

• The linkage of who feeds on whom

• Grouped by trophic level

• # of feeding levels away from original source of energy

Page 8: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

TROPHIC LEVELS

• First trophic level• Use energy from the sun and carbon dioxide from the air to

photosynthesizes

• Green plants, algae and certain bacteria

• Called autotrophs

• Second trophic level• Organisms that feed on autotrophs

• Called herbivores

Page 9: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

TROPHIC LEVELS

• Third trophic level• Feed directly on herbivores

• Called carnivores (meat eaters)

• Forth trophic level• Carnivores that feed on third-level carnivores

• Decomposers- feed on waste and dead organisms of all trophic levels

Page 10: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life
Page 11: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

• Example: North American Temperate Woodland• 1st level- grasses,

herbs and trees• 2nd level- mice, pine

borer and deer• 3rd level- foxes,

wolves, hawks and other predatory birds and insects

• 4th level- humans

A TERRESTRIAL FOOD CHAIN

Page 12: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

• Tend to have more trophic levels

• 1st level- planktonic algae and planktonic bacteria

• 2nd level- zooplankton and some fish

• 3rd level- fish and invertebrates feed on herbivores, baleen whales

• 4th+ levels- killer whales, predatory fish

AN OCEANIC FOOD CHAIN

Page 13: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

• Harp seal (shown at 5th level)

• Feeds on flatfish (4th level)

• But also feed on foods from 2nd – 4th

• A species that feeds on several levels placed in a category one above the highest level it feeds on.

THE FOOD WEB OF THE HARP SEALFood webs are complex because most species feed on several trophic levels.

Page 14: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

6.2 THE COMMUNITY EFFECT

• Indirect and more complicated community wide affects species have on one another.

• Sea otter of the Pacific Ocean• Came close to extinction because of over hunting

for fur

• Feed on shellfish (abalone, sea urchins)

• Where sea otters abundant kelp beds abundant and few sea urchins

• Otters affects the abundance of kelp

Page 15: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

6.2 THE COMMUNITY EFFECT

• Sea otters have community level effect

• Where more kelp is present more habitat for many species

• Keystone species

• A species that has a large effect on its community or ecosystem

• Holistic view

• Ecological community is more than the sum of its parts

Page 16: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life
Page 17: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life
Page 18: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

6.3 HOW DO YOU KNOW WHEN YOU HAVE FOUND AN ECOSYSTEM?

• An ecosystem is the minimal entity that has the properties required to sustain life.

• Vary greatly in structural complexity and clarity of their boundaries.

• Differ is size, composition, proportion of non-biological constituents and degree of variation in time and space.

Page 19: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life
Page 20: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life

6.3.1 WATERSHED

• Watershed

• Commonly used practical delineation of the boundary of an ecosystem

• Determined by topography

• United in terms of chemical cycling

Page 21: CHAPTER 6: ECOSYSTEMS AND ECOSYSTEM MANAGEMENT. 6.1 THE ECOSYSTEM: SUSTAINING LIFE ON EARTH Sustaining life on Earth requires more than individuals Life
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6.4 ECOSYSTEM MANAGEMENT

• Ecosystem can be natural or artificial

• Can also be managed

• Agriculture

• Wildlife preserves

• Ecosystem concepts lies at the heart of the management of natural resources.