Contents

1 The Web of Life

Deformity and Decline in Amphibian Populations: A Case Study

Introduction

■ CONCEPT 1.1 Events in the natural world are interconnected.

Connections in Nature

■ CONCEPT 1.2 Ecology is the scientific study of interactions between organisms and their environment.

What Is Ecology?

■ CONCEPT 1.3 Ecologists evaluate competing hypotheses about natural systems with observations, experiments, and models.

Answering Ecological Questions

■ CLIMATE CHANGE CONNECTION Approaches Used To Study Global Warming

■ ECOLOGICAL TOOLKIT 1.1 Designing Ecological Experiments

■ ANALYZING DATA 1.1 Are Introduced Predators a Cause of Amphibian Decline?

I A CASE STUDY REVISITED Deformity and Decline in Amphibian Populations

■ CONNECTIONS IN NATURE Mission Impossible?

UNIT 1 Organisms and Their Environment

2 The Physical Environment

Climate Variation and Salmon Abundance: A Case Study

Introduction

■ CONCEPT 2.1 Climate is the most fundamental component of the physical environment.

Climate

■ CONCEPT 2.2 Winds and ocean currents result from differences in solar radiation across Earth's surface.

Atmospheric and Oceanic Circulation

■ CONCEPT 2.3 Large-scale atmospheric and oceanic circulation patterns establish global patterns of temperature and precipitation.

Global Climate Patterns

■ CONCEPT 2.4 Regional climates reflect the influence of oceans and continents, mountains, and vegetation.

Regional Climate Influences

■ ANALYZING DATA 2.1 How Do Changes in Vegetation Cover Influence Climate?

■ CONCEPT 2.5 Seasonal and decadal climate variation are associated with changes in Earth's position relative to the sun and the strength of atmospheric pressure cells.

Climate Variation over Time

■ CONCEPT 2.6 Salinity, acidity, and oxygen concentrations are major determinants of the chemical environment.

The Chemical Environment

I A CASE STUDY REVISITED Climate Variation and Salmon Abundance

■ CONNECTIONS IN NATURE Climate Variation and Ecology

3 The Biosphere

The American Serengeti—Twelve Centuries of Change in the Great Plains: A Case Study

Introduction

■ CONCEPT 3.1 Terrestrial biomes are characterized by the growth forms of the dominant vegetation.

Terrestrial Biomes

■ ECOLOGICAL TOOLKIT 3.1 Climate Diagrams

■ CLIMATE CHANGE CONNECTION Tropical forests and greenhouse gases

■ ANALYZING DATA 3.1 How Will Climate Change Affect the Grasslands Biome?

■ CONCEPT 3.2 Biological zones in freshwater ecosystems are associated with the velocity, depth, temperature, clarity, and chemistry of the water.

Freshwater Biological Zones

■ CONCEPT 3.3 Marine biological zones are determined by ocean depth, light availability, and the stability of the bottom substrate.

Marine Biological Zones

I A CASE STUDY REVISITED The American Serengeti—Twelve Centuries of Change in the Great Plains

■ CONNECTIONS IN NATURE Long-Term Ecological Research

4 Coping with Environmental Variation: Temperature and Water

Frozen Frogs: A Case Study

Introduction

■ CONCEPT 4.1 Each species has a range of environmental tolerances that determines its potential geographic distribution.

Responses to Environmental Variation

■ CONCEPT 4.2 The temperature of an organism is determined by exchanges of energy with the external environment.

Variation in Temperature

■ ANALYZING DATA 4.1 How Does Fur Thickness Influence Metabolic Activity in Endotherms?

■ CONCEPT 4.3 The water balance of an organism is determined by exchanges of water and solutes with the external environment.

Variation in Water Availability

I A CASE STUDY REVISITED Frozen Frogs

■ CONNECTIONS IN NATURE Desiccation Tolerance, Body Size, and Rarity

5 Coping with Environmental Variation: Energy

Toolmaking Crows: A Case Study

Introduction

■ CONCEPT 5.1 Organisms obtain energy from sunlight, from inorganic chemical compounds, or through the consumption of organic compounds.

Sources of Energy

■ CONCEPT 5.2 Radiant and chemical energy captured by autotrophs is converted into stored energy in carbon-carbon bonds.

Autotrophy

■ ANALYZING DATA 5.1 How Does Acclimatization Affect Plant Energy Balance?

■ CONCEPT 5.3 Environmental constraints have resulted in the evolution of biochemical pathways that improve the efficiency of photosynthesis.

Photosynthetic Pathways

■ ECOLOGICAL TOOLKIT 5.1 Stable Isotopes

■ CONCEPT 5.4 Heterotrophs have adaptations for acquiring and assimilating energy efficiently from a variety of organic sources.

Heterotrophy

I A CASE STUDY REVISITED Toolmaking Crows

■ CONNECTIONS IN NATURE Tool Use: Adaptation or Learned Behavior?

UNIT 2 Evolutionary Ecology

6 Evolution and Ecology

Trophy Hunting and Inadvertent Evolution: A Case Study

Introduction

■ CONCEPT 6.1 Evolution can be viewed as genetic change over time or as a process of descent with modification.

What Is Evolution?

■ CONCEPT 6.2 Natural selection, genetic drift, and gene flow can cause allele frequencies in a population to change over time.

Mechanisms of Evolution

■ CONCEPT 6.3 Natural selection is the mechanism for adaptive evolution.

Adaptive Evolution

■ CLIMATE CHANGE CONNECTION Evolutionary Responses to Climate Change

■ CONCEPT 6.4 Long-term patterns of evolution are shaped by large-scale processes such as speciation, mass extinction, and adaptive radiation.

The Evolutionary History of Life

■ CONCEPT 6.5 Ecological interactions and evolution exert a profound influence on one another.

Joint Effects of Ecology and Evolution

I A CASE STUDY REVISITED Trophy Hunting and Inadvertent Evolution

■ Trophy Hunting and Inadvertent Evolution

■ CONNECTIONS IN NATURE The Human Impact On Evolution

■ ANALYZING DATA 6.1 Does Predation by Birds Cause Evolution in Moth Populations?

7 Life History

Nemo Grows Up: A Case Study

Introduction

■ CONCEPT 7.1 Life history patterns vary within and among species.

Life History Diversity

■ CLIMATE CHANGE CONNECTION Climate Change and the Timing of Seasonal Activities

■ CONCEPT 7.2 There are trade-offs between life history traits.

Trade-Offs

■ ANALYZING DATA 7.1 Is There a Trade-Off between Current and Delayed Reproduction in the Collared Flycatcher?

■ CONCEPT 7.3 Organisms face different selection pressures at different life cycle stages.

Life Cycle Evolution

■ CONCEPT 7.4 Life history patterns can be classified along several continua.

Life History Continua

I A CASE STUDY REVISITED Nemo Grows Up

■ CONNECTIONS IN NATURE Territoriality, Competition, And Life History

8 Behavioral Ecology

Infanticide in Lion Packs: A Case Study

Introduction

■ CONCEPT 8.1 Evolution is the basis for adaptive behavior.

An Evolutionary Approach to Behavior

■ CONCEPT 8.2 Animals make behavioral choices that enhance their energy gain and reduce their risk of becoming prey.

Foraging Behavior

■ CONCEPT 8.3 Mating behaviors reflect the costs and benefits of parental investment and mate defense.

Mating Behavior

■ CONCEPT 8.4 There are advantages and disadvantages to living in groups.

Living in Groups

■ ANALYZING DATA 8.1 Does the Dilution Effect Protect Individual Ocean Skaters from Fish Predators?

I A CASE STUDY REVISITED Infanticide in Lion Packs

■ CONNECTIONS IN NATURE Behavioral Responses to Predators Have Broad

UNIT 3 Populations

9 Distribution and Abundance

From Kelp Forest to Urchin Barren: A Case Study

Introduction

■ CONCEPT 9.1 Populations are groups of individuals of the same species that vary in size over space and time.

Populations and Individuals

■ ECOLOGICAL TOOLKIT 9.1 Estimating Abundance

■ CONCEPT 9.2 Species vary in their distribution and abundance across their geographic range.

Distribution and Abundance Patterns

■ CLIMATE CHANGE CONNECTION Effects of Climate Change on the Geographic Distributions of Species

■ CONCEPT 9.3 Species are limited in their distribution and abundance by habitat suitability, historical factors, and dispersal.

Processes Important to Distribution and Abundance

■ ANALYZING DATA 9.1 Have Introduced Grasses Altered the Occurrence of

Fires in Hawaiian Dry Forests?

■ CONCEPT 9.4 In metapopulations, sets of spatially isolated populations are linked by dispersal.

Metapopulations

I A CASE STUDY REVISITED From Kelp Forest to Urchin Barren

■ CONNECTIONS IN NATURE From Urchins to Ecosystems

10 Population Dynamics

A Sea in Trouble: A Case Study

Introduction

■ CONCEPT 10.1 Populations are dynamic entities that vary in size over time.

Patterns of Population Growth

■ ANALYZING DATA 10.1 Does delayed density dependence produce cycles in blowfly populations?

■ CLIMATE CHANGE CONNECTION Collapsing Population Cycles and Climate Change

■ CONCEPT 10.2 The risk of extinction increases in populations that fluctuate in size and/or are small.

Population Extinction

I A CASE STUDY REVISITED A Sea in Trouble

■ CONNECTIONS IN NATURE From Bottom to Top, and Back Again

II Population Growth and Regulation

Human Population Growth: A Case Study

Introduction

■ CONCEPT 11.1 Populations can grow exponentially when conditions are favorable, but exponential growth cannot continue indefinitely.

Geometric and Exponential Growth

■ ANALYZING DATA 11.1 How Has the Growth of the Human Population Changed over Time?

■ CONCEPT 11.2 Population size is determined by a combination of density­dependent and density-independent factors.

Effects of Density

■ CLIMATE CHANGE CONNECTION Effects of Climate Change on Tree Mortality Rates

■ CONCEPT 11.3 The logistic equation incorporates limits to growth and shows how a population may stabilize at a maximum size, the carrying capacity.

Logistic Growth

■ CONCEPT 11.4 Life tables show how survival and reproduction vary with age or size structure, influencing population growth and size.

Life Tables

■ ECOLOGICAL TOOLKIT 11.1 Estimating Population Growth Rates in a Threatened Species

I A CASE STUDY REVISITED Human Population Growth

■ CONNECTIONS IN NATURE Your Ecological Footprint

UNIT 4 Species Interactions

12 Predation

Snowshoe Hare Cycles: A Case Study

Introduction

■ CONCEPT 12.1 Most carnivores have broad diets, whereas a majority of herbivores have relatively narrow diets.

Carnivore and Herbivore Dietary Preferences

■ CONCEPT 12.2 Predation results in a wide range of capture and avoidance mechanisms.

Mechanisms Important to Predation

■ ANALYZING DATA 12.1 Do Different Herbivore Species Select for Different Plant Genotypes?

■ CONCEPT 12.3 Predator populations can cycle with their prey populations.

Predator-Prey Population Cycles

■ CONCEPT 12.4 Predation can affect prey distribution and abundance, in some cases causing a shift from one community type to another.

Effects of Predation on Communities

■ CLIMATE CHANGE CONNECTION Climate Change and Species Interactions

I A CASE STUDY REVISITED Snowshoe Hare Cycles

■ CONNECTIONS IN NATURE From Fear to Hormones to Population Dynamics

13 Parasitism

Enslaver Parasites: A Case Study

Introduction

■ CONCEPT 13.1 Parasites typically feed on only one or a few host species, but host species have multiple parasite species.

Parasite Natural History

■ CONCEPT 13.2 Hosts have mechanisms for defending themselves against parasites, and parasites have mechanisms for overcoming host defenses.

Defense and Counterdefenses

■ ANALYZING DATA 13.1 Will a Defensive Symbiont Increase in Frequency in a Host Population Subjected to Parasitism?

■ CONCEPT 13.3 Host and parasite populations can evolve together, each in response to selection pressure imposed by the other.

Parasite-Host Coevolution

■ CONCEPT 13.4 Hosts and parasites can have important effects on each other's population dynamics

Host-Parasite Population Dynamics

■ CONCEPT 13.5 Parasites can alter the outcomes of species interactions, thereby causing communities to change.

Parasites Can Change Ecological Communities

■ CLIMATE CHANGE CONNECTION Climate Change and Disease Spread

I A CASE STUDY REVISITED Enslaver Parasites

■ CONNECTIONS IN NATURE From Chemicals to Evolution and Ecosystems

14 Competition

Competition in Plants That Eat Animals: A Case Study

Introduction

■ CONCEPT 14.1 Competition can be direct or indirect, vary in its intensity, and occur between similar or dissimilar species.

General Features of Competition

■ CONCEPT 14.2 Competing species are more likely to coexist when they use resources in different ways.

Competitive Coexistence

■ CONCEPT 14.3 Competitive interactions can be modeled using the logistic equation.

The Lotka-Volterra Competition Model

■ ANALYZING DATA 14.1 Will Competition with a Native Mosquito Species Prevent the Spread of an Introduced Mosquito?

■ CONCEPT 14.4 The outcome of competition can be altered by predation, the physical environment, and disturbance.

Altering the Outcome of Competition

■ CLIMATE CHANGE CONNECTION Climate Warming, Non-Native Species, and Competition

I A CASE STUDY REVISITED Competition in Plants That Eat Animals

■ CONNECTIONS IN NATURE The Paradox of Diversity

15 Mutualism and Commensalism

The First Farmers: A Case Study

Introduction

■ CONCEPT 15.1 In positive interactions, no species is harmed, and the benefits are greater than the costs for at least one species.

Positive Interactions

■ CONCEPT 15.2 Each partner in a mutualistic interaction acts in ways that serve its own ecological and evolutionary interests.

Characteristics of Mutualism

■ ANALYZING DATA 15.1 Does a Mycorrhizal Fungus Transfer More Phosphorus to Plant Roots That Provide More Carbohydrates?

■ CONCEPT 15.3 Positive interactions affect the abundances and distributions of populations as well as the structure of ecological communities.

Ecological Consequences of Positive Interactions

■ CLIMATE CHANGE CONNECTION Climate warming and extinction of plant­pollinator networks

I A CASE STUDY REVISITED The First Farmers

■ CONNECTIONS IN NATURE From Mandibles to Nutrient Cycling

UNIT 5 Communities

16 The Nature of Communities

“Killer Algae!”: A Case Study

Introduction

■ CONCEPT 16.1 Communities are groups of interacting species that occur together at the same place and time.

What Are Communities?

■ CONCEPT 16.2 Species diversity and species composition are important descriptors of community structure.

Community Structure

■ ANALYZING DATA 16.1 What Are the Effects of Invasive Species on Species Diversity?

■ CONCEPT 16.3 Communities can be characterized by complex networks of

direct and indirect interactions that vary in strength and direction.

Interactions of Multiple Species

■ ECOLOGICAL TOOLKIT 16.1 Measurements of Interaction Strength

■ CLIMATE CHANGE CONNECTION Context Dependence of Ocean Acidification

I A CASE STUDY REVISITED “Killer Algae!”

■ CONNECTIONS IN NATURE Stopping Invasions Requires Commitment

17 Change in Communities

A Natural Experiment of Mountainous Proportions: A Case Study

Introduction

■ CONCEPT 17.1 Agents of change act on communities across all temporal and spatial scales.

Agents of Change

■ CLIMATE CHANGE CONNECTION Volcanoes and Climate as an Agent of Change

■ CONCEPT 17.2 Succession is the process of change in species composition over time as a result of abiotic and biotic agents of change.

The Basics of Succession

■ CONCEPT 17.3 Experimental work on succession shows its mechanisms to be diverse and context dependent.

Mechanisms of Succession

■ ANALYZING DATA 17.1 What Kinds of Species Interactions Drive Succession in Mountain Forests?

■ CONCEPT 17.4 Communities can follow different successional paths and display alternative states.

Alternative Stable States

I A CASE STUDY REVISITED A Natural Experiment of Mountainous Proportions

■ CONNECTIONS IN NATURE Primary Succession and Mutualism

18 Biogeography

The Largest Ecological Experiment on Earth: A Case Study

Introduction

■ CONCEPT 18.1 Patterns of species diversity and distribution vary at global, regional, and local spatial scales.

Biogeography and Spatial Scale

■ CONCEPT 18.2 Global patterns of species diversity and composition are influenced by geographic area and isolation, evolutionary history, and global climate.

Global Biogeography

■ CLIMATE CHANGE CONNECTION Latitudinal Gradients in Diversity under Climate Change

■ CONCEPT 18.3 Regional differences in species diversity are influenced by area and distance, which determine the balance between immigration and extinction rates.

Regional Biogeography

■ ECOLOGICAL TOOLKIT 18.1 Species-Area Curves

■ ANALYZING DATA 18.1 Do Species Invasions Influence Species-Area Curves?

I A CASE STUDY REVISITED The Largest Ecological Experiment on Earth

■ CONNECTIONS IN NATURE Tropical Rainforest Diversity Benefits Humans

19 Species Diversity in Communities

Can Species Diversity Suppress Human Diseases? A Case Study

Introduction

■ CONCEPT 19.1 Species diversity differs among communities as a consequence of regional species pools, abiotic conditions, and species interactions.

Community Membership

■ CLIMATE CHANGE CONNECTION How are Species Invasions Enhanced by Climate Change?

■ CONCEPT 19.2 Resource partitioning is theorized to reduce competition and increase species diversity.

Resource Partitioning

■ CONCEPT 19.3 Processes such as disturbance, stress, predation, and positive interactions can mediate resource availability, thus promoting species diversity.

Resource Mediation and Species Diversity

■ ANALYZING DATA 19.1 How Do Predation and Dispersal Interact to Influence Species Richness?

■ CONCEPT 19.4 Many experiments show that species diversity affects community function.

The Consequences of Diversity

I A CASE STUDY REVISITED Can Species Diversity Suppress Human Diseases?

■ CONNECTIONS IN NATURE Managing Pathogens by Managing Biodiversity

UNIT 6 Ecosystems

20 Production

Life in the Deep Blue Sea, How Can It Be? A Case Study

Introduction

■ CONCEPT 20.1 Energy in ecosystems originates with primary production by autotrophs.

Primary Production

■ ECOLOGICAL TOOLKIT 20.1 Remote Sensing

■ ANALYZING DATA 20.1 Does Deforestation Influence Atmospheric CO2 Concentrations?

■ CONCEPT 20.2 Net primary production is constrained by both physical and biotic environmental factors.

Environmental Controls on NPP

■ CONCEPT 20.3 Global patterns of net primary production reflect climate constraints and biome types.

Global Patterns of NPP

■ CONCEPT 20.4 Secondary production is generated through the consumption of organic matter by heterotrophs.

Secondary Production

I A CASE STUDY REVISITED Life in the Deep Blue Sea, How Can It Be?

■ CONNECTIONS IN NATURE Energy-Driven Succession and Evolution in Hydrothermal Vent Communities

21 Energy Flow and Food Webs

Toxins in Remote Places: A Case Study

Introduction

■ CONCEPT 21.1 Trophic levels describe the feeding positions of groups of organisms in ecosystems.

Feeding Relationships

■ CONCEPT 21.2 The amount of energy transferred from one trophic level to the next depends on food quality and on consumer abundance and physiology.

Energy Flow between Trophic Levels

■ CONCEPT 21.3 Changes in the abundances of organisms at one trophic level can influence energy flow at multiple trophic levels.

Trophic Cascades

■ ANALYZING DATA 21.1 Does the Identity of Organisms Influence Energy Flow between Trophic Levels?

■ CONCEPT 21.4 Food webs are conceptual models of the trophic interactions of organisms in an ecosystem.

Food Webs

I A CASE STUDY REVISITED Toxins in Remote Places

■ CONNECTIONS IN NATURE Biological Transport of Pollutants

22 Nutrient Supply and Cycling

A Fragile Crust: A Case Study

Introduction

■ CONCEPT 22.1 Nutrients enter ecosystems through the chemical breakdown of minerals in rocks or through fixation of atmospheric gases.

Nutrient Requirements and Sources

■ CONCEPT 22.2 Chemical and biological transformations in ecosystems alter the chemical form and supply of nutrients.

Nutrient Transformations

■ ANALYZING DATA 22.1 Does Lignin Always Inhibit Decomposition?

■ CONCEPT 22.3 Nutrients cycle repeatedly through the components of ecosystems.

Nutrient Cycles and Losses

■ ECOLOGICAL TOOLKIT 22.1 Instrumenting Catchments

■ CONCEPT 22.4 Freshwater and marine nutrient cycles occur in a moving medium and are linked to terrestrial ecosystems

Nutrients in Aquatic Ecosystems

I A CASE STUDY REVISITED A Fragile Crust

■ CONNECTIONS IN NATURE Nutrients, Disturbance, and Invasive Species

UNIT 7 Applied and Large-Scale Ecology

23 Conservation Biology

Can Birds and Bombs Coexist? A Case Study

Introduction

■ CONCEPT 23.1 Conservation biology is an integrative discipline that applies the principles of ecology to the protection of biodiversity.

Conservation Biology

■ CONCEPT 23.2 Biodiversity is declining globally.

Declining Biodiversity

■ CONCEPT 23.3 Primary threats to diversity include habitat loss, invasive species, overexploitation, pollution, disease, and climate change.

Threats to Diversity

■ ANALYZING DATA 23.1 Do Nitric Oxide Emissions Differ Statistically between Plots with and without Kudzu?

■ CLIMATE CHANGE CONNECTION Impacts on Diversity

■ CONCEPT 23.4 Conservation biologists use many tools and work at multiple scales to manage declining populations.

Approaches to Conservation

■ ECOLOGICAL TOOLKIT 23.1 Forensics in Conservation Biology

■ CONCEPT 23.5 Prioritizing species helps maximize the biodiversity that can be protected with limited resources.

Ranking Species for Protection

I A CASE STUDY REVISITED Can Birds and Bombs Coexist?

■ CONNECTIONS IN NATURE Some Burning Questions

24 Landscape Ecology and Ecosystem Management

Wolves in the Yellowstone Landscape: A Case Study

Introduction

■ ECOLOGICAL TOOLKIT 24.1 Geographic Information Systems (GIS)

■ CONCEPT 24.1 Landscape ecology examines spatial patterns and their relationship to ecological processes.

Landscape Ecology

■ CONCEPT 24.2 Habitat loss and fragmentation decrease habitat area, isolate populations, and alter conditions at habitat edges.

Habitat Loss and Fragmentation

■ ANALYZING DATA 24.1 How Far Do Edge Effects Penetrate into Forest Fragments?

■ CONCEPT 24.3 Biodiversity can best be sustained by large reserves connected across the landscape and buffered from areas of intense human use.

Designing Nature Reserves

■ CONCEPT 24.4 Ecosystem management is a collaborative process with the maintenance of long-term ecological integrity as its core value.

Ecosystem Management

I A CASE STUDY REVISITED Wolves in the Yellowstone Landscape

■ CONNECTIONS IN NATURE Future Changes in the Yellowstone Landscape

25 Global Ecology

Dust Storms of Epic Proportions: A Case Study

Introduction

■ CONCEPT 25.1 Elements move among geologic, atmospheric, oceanic, and biological pools at a global scale.

Global Biogeochemical Cycles

■ ANALYZING DATA 25.1 How Much Will Ocean pH Drop in the Twenty-First Century?

■ CONCEPT 25.2 Earth is warming because of anthropogenic emissions of greenhouse gases.

Global Climate Change

■ CONCEPT 25.3 Anthropogenic emissions of sulfur and nitrogen cause acid deposition, alter soil chemistry, and affect the health of ecosystems.

Acid and Nitrogen Deposition

■ CONCEPT 25.4 Losses of ozone in the stratosphere and increases in ozone in the troposphere both pose risks to organisms.

Atmospheric Ozone

I A CASE STUDY REVISITED Dust Storms of Epic Proportions

■ CONNECTIONS IN NATURE Dust as a Vector of Ecological Impacts

Appendix

Answers

Glossary

Literature Cited

Index