Preface

Introduction

Welcome to Introduction to Ecology. This book introduces you to Ecology, the branch of biology that deals with the relations of living organisms, including humans, to one another and to their physical surroundings. Interactions between organisms and the environment are considered at the organismal, population, community, ecosystem, and biosphere level. You will gain insights into how field, lab, and modeling experiments are utilized by Ecologists to reveal the nature of these interactions and develop an appreciation for the interconnectedness of life on Earth. You will discover how ecological relationships are changing under the immense pressure and demands of the human population and the growing need to conserve ecosystems from excessive rates of extinction and the erosion of ecological interactions.

Audience

This book is an introductory text for those with little or no experience with biology or ecology. It is intended to support general education courses in biology, ecology, and conservation biology at the level of a freshman or sophomore college student. This book covers key concepts in science and biology, (such as the scientific method and evolution) that will serve as the foundation for understanding more advanced ecological concepts. This book is intended to guide students to understanding the importance of ecological study in the face of the wide variety of ways that humans affect ecological systems.

Chapter Outline

The text is organized into fourteen chapters that follow the levels of Ecological understanding.

Chapter 1-3 are introductory and include information which introduces students to the science of ecology and patterns and processes found on planet Earth.

• Chapter 1: Introduction to Ecology - In this chapter we introduce the science of ecology including; the levels of study, the experimental nature of ecology and how the scientific method is utilized, and covers the broad applications of ecological study.
• Chapter 2: The physical Environment - This chapter covers patterns and processes which govern Earths climate including the green house effect, atmospheric, and oceanic circulation and emphasizes why an understanding of the physical environment is key to understanding all ecological phenomena.
• Chapter 3: Terrestrial and Aquatic Biomes - Basic patterns in the distribution and abundance of life on earth are covered. Emphasis is placed on how tolerance to the physical environment determines which types of organisms and ecosystems are found in various locations on Earth.

Chapters 4-6 focus on the biotic and abiotic factors which drive adaptations of individual organisms (organismal level of Ecology).

• Chapter 4: Natural Selection and Evolution - Students are introduced to the theory of natural selection, processes of microevolution (such as mutation, genetic drift, and sexual selection) and the macroevolutionary process which drive speciation.
• Chapter 5: Adaptations to the Environment - This chapter focuses on how tolerance to environmental variables (such as temperature, water, and nutrients) and evolutionary trade offs drives the adaptation of organisms to their physical environments. Also covered within this chapter are the diverse roles organisms play in their environments by acting as producers, consumers, and detritivores.
• Chapter 6: Life History and Reproductive Strategies - The concept of evolutionary trades-offs in again highlighted in this chapter by examining the many different ways organisms allocate energy over their life time to events important for an organism's fitness such as growth, reproductive development, lifespan, finding a mate, and raising offspring.

Chapters 7-11 cover increasing levels of ecology and the associated complexity.

• Chapter 7: Population Ecology - In this chapter students will learn how characteristics of populations (such as density or age structure) can inform us about the distribution of resources or population change. Population growth models and regulation is discussed while emphasizing how population studies hold the key to solving practical problems such as saving endangered species, controlling pest populations, and managing fish and game populations.
• Chapter 8: Species Interactions - Populations rarely, if ever, live in isolation from populations of other species. This chapter coverers the diverse ways that different species interact (such as a predator and its prey) and how the outcomes of such interactions can be positive, negative, or neutral for the species involved. The theme of the chapter focuses on how such interactions drive evolutionary outcomes such as competitive exclusion and resource partitioning.
• Chapter 9: Community Structure and Dynamics - Communities are complex systems that can be characterized by community structure (the number and size of populations and their interactions) and community dynamics (how the members and their interactions change over time). The role of species in their community, trophic interactions, disturbance, and succession are discussed.
• Chapter 10: Ecosystems - The chapter focuses on the transfer of energy and matter among living and non-living components within and between ecosystems. Productivity of ecosystems measured by the efficiency of energy transfer between trophic levels in discussed as well as the cycling of matter by biogeochemical cycles. The varied ways ecosystems provide benefits to humans (Ecosystems services) and concepts of Ecosystem stability are also discussed.
• Chapter 11: Landscape Ecology and Island Biogeography - This chapter introduces students to the new and emerging field of landscape ecology and its increasing importance in a human dominated global landscape. Concepts such as habitat fragmentation, edge effects, and species-area relationships are introduced. The chapter has an underlying theme which emphasized the links between landscape ecology and conservation biology.

Chapters 12-14 focus on conservation biology by emphasizing human impacts and the importance of protecting biodiversity.

• Chapter 12: Biodiversity and the Extinction Crisis - This chapter introduces students to the current biodiversity crisis on Earth. Measures of biodiversity loss, increasing extinctions rates, and the value and importance of biodiversity is discussed.
• Chapter 13: Threats to Biodiversity - The core threat to biodiversity on the planet is the combination of human population growth and the resources used by that population. This chapter covers the five main threats to biodiversity which are habitat loss, pollution, overexploitation, invasive species, and climate change.
• Chapter 14: Protecting Biodiversity - This final chapter of the text focuses on the many tools and solutions with which we may combat threats to biodiversity. It emphasizes how protecting biodiversity is key for maintaining the ecosystem services (food and clean water) and environmental stability that humans rely on for survival.

For the Student

Each chapter in this text begins with an attention grabbing case study, a chapter summary, and a list of relevant learning objectives. Found at the top of each section is a table of contents for ease of navigation. Chapter sections may also include green boxes with definitions of the most important ecological terms, supporting videos, and interactive concept checks. To get the best learning experience you should begin by reading the learning objective and chapter summaries,and use the concept checks to test your understanding. Pay close attention to (or make flashcards for) terms in the green boxes and bold text. Use the videos to enhance your understanding of challenging concepts.

For the Instructor

A Chapter Summary and Learning Objectives can be found at the beginning of each chapter and can be used to identify which chapters to include or omit for a course other than Introductory Ecology. Of course the chapters are intended to be viewed in order by the student, but some sections may stand alone as units. For instance, a general biology instructor covering ecology may choose to utilize chapters 7-10, while any instructor intending to cover the concept of conservation biology may want to include chapters 12-14.

Each chapter begins with specific example or case study to grab the students attention and highlight an application of the ecological concept covered within the chapter. Throughout each chapter are green boxes with definitions of the most important ecological terms, supporting videos, and interactive concept checks.