Miller LITE 4ce PPT Ch04 accessibleV1...Title: Miller LITE 4ce_PPT_Ch04_accessibleV1 Author: Maria Morlin Created Date: 1/3/2020 6:03:26 PM

1/3/20

Copyright © 2017 by Nelson Education Ltd. 1

Copyright © 2017 by Nelson Education Ltd.

NETA PowerPoint® Slidesto accompany

Fourth Canadian Edition, Living in the Environment

prepared byIan Dawe


Chapter 4

Ecosystems:What Are They, and How Do They Work?

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Key Concepts

• Ecology and learning about ecosystems• Earth’s life support systems

• Ecosystem components and energy flows

• Soils and biogeochemical cycles

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What Is Ecology?

The study of connections in nature• How do organisms interact with

each other?• In what ways are they connected?

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Levels of Organization in Nature

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Known Species on Earth

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Cellular Diversity of Life

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What Species Rule the World? Small Matters!

• Microorganisms are the key to life on earth.

• Microbes, for example, help you digest food.

• Microbes clean water.• Microbes act as natural pesticides.• Microbes are essential for life.

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Populations

• Populations are groups of organisms of the same species living in the same habitat.

• Populations have genetic diversity.

• This sets the stage for natural selection.

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Communities and Ecosystems

• A group of populations is a community.

• Ecosystems add in all the non-living elements (abiotic).

• The earth can be understood as a system.

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Example: A Freshwater Ecosystem

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Major Parts of Earth’s Life-Support Systems

• Atmosphere• Troposphere• Stratosphere

• Geosphere• Crust

• Lithosphere• Upper mantle

• Asthenosphere• Lower mantle• Core

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What Sustains Life on Earth?

• One-way flow of high-quality energy, with energy loss due to heat

• Cycling of essential forms of matter, such as water, carbon, and nitrogen

• Gravity

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How Does the Sun Sustain Life on Earth?

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Major Components of an Ecosystem

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Major Components of an Ecosystem: Producers

Art: From RUSSELL/WOLFE/HERTZ/STARR. Biology, 1E. © 2010 Nelson Education Ltd. Reproduced by permission.www.cengage.com/permissions

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Major Components of an Ecosystem: Detritivores

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Energy Flow in Ecosystems

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Food Web

• Represents energy flow in a real ecosystem

• Webs are a better model than “chains,” as the system is not necessarily linear.

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How Tolerant Are Organisms to Environmental Conditions?

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What Factors Limit Population Growth?

Limiting factor principleToo much or little of a single abiotic factor can limit or prevent growth of a population.• Precipitation• Dissolved oxygen (DO)• Salinity Source: Data from U.S. Department of

Agriculture and the Canadian Forest Service

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What Is Biodiversity?

• Genetic diversity• Species diversity

• Ecological diversity• Ecosystems

• Functional diversity• Biological and chemical processes

• Structural diversity• Physical characteristics of a habitat

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What Are Biomes and Aquatic Life Zones?

• Biomes• Terrestrial component • Distinct climate and specific species

• Aquatic life zones• Freshwater life zones• Marine life zones

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Major Biomes Along the 49th Parallel in Canada

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Primary Productivity of Ecosystems

• NPP limits population of all consumers

• Humans consume majority of NPP• 27% of total• 10 - 55% terrestrial

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Net Primary Productivity (NPP)

Source: Data from Communities and Ecosystems, 2nd ed, by R.H. Whittaker, 1975. New York: Macmillan.

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What Is Soil?

• Thin covering over most land• Minerals, eroded rock, decaying organic

matter, water, air, microscopic organisms…• Renewable at slow rate• Critical nutrients for plant growth• Earth’s primary filtration system• Water storage and recycling

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Major Layers in Mature Soil

Art: From Derek Elsom, Earth: The Making, Shaping and Workings of a Planet, 1992. Copyright © 1992 by Marshall Editions Developments Limited. New York: Macmillan. Used by permission.

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Ecology of a Compost Heap: Making Soil

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Soil Types in Major Biomes

Variations in Soil• Soil texture• Soil porosity• Soil permeability

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Matter Cycling in Ecosystems

Biogeochemical cycles of nutrients• Water• Carbon• Nitrogen• Phosphorus• Sulfur

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The Hydrologic (Water) Cycle

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The Carbon Cycle

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How Are Human Activities Affecting the Carbon Cycle?

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Source: Data from UN Environment Programme, British Petroleum, International Energy Agency, and U.S. Department of Energy

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The Nitrogen Cycle

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The Phosphorus Cycle

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The Sulphur Cycle

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Geographic Information Systems (GIS)

• Complex data analysis• Remote sensing data• Field studies• Satellite data• Geographic coordinates

• Landscape ecology• Effects of spatial patterns

on ecological systems

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Systems AnalysisSystems Measurement involves

Define objectivesIdentify and inventory variables Obtain baseline data on variables

Data analysis involves

Make statistical analysis of relationships among variables Determine significant interactions

System modelling involves Construct mathematical model describing interactions among variables

System simulation involves Run the model on a computer, with values entered for different variables

System optimization involvesEvaluate best ways to achieve objectives

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Systems Measurement

Lead toData Analysis

Lead toSystem Modelling

Lead toSystem Simulation

Lead toSystem Optimization

Source: Modified data from Charles Southwick


Conclusion

• Ecology is the study of interactions between living things, and between biotic and abiotic parts of the ecosphere.

• Nutrients cycle, energy flows• Living things are restricted by their

environmental conditions and trophic level.

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Documents

Miller LITE 4ce PPT Ch04 accessibleV1...Title: Miller LITE 4ce_PPT_Ch04_accessibleV1 Author: Maria Morlin Created Date: 1/3/2020 6:03:26 PM