Introduction To Ecology Chapter 1 Ecology: Evolution, Application, Integration Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Concepts 1.1 What Is Ecology? 1.2 What Important Ideas Will Emerge in Your Study of Ecology? Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Concept 1.1 Ecology is “The scientific discipline that is concerned with the relationships between organisms and their past, present and future environments, both living and non-living.” Official ESA Definition* *August 2000 Annual Meeting of the Ecological Society of America

What is Ecology? Ecology is the scientific study of the interactions between an organism and its past, present and future environments both living and non-living. Understanding these relationships will explain the patterns of distribution and abundance we see in nature.

Key words used to define Ecology Interactions - between everyone and everything Organisms - all taxa are fair game Environment - includes ABIOTIC and BIOTIC factors outside the organism Abundance - population sizes Distribution - where we find organisms

Environment Abiotic (physical) environment Temperature, water availability, soil, salinity, nutrients… Biotic (biological) environment Predators, prey, parasites, pathogens, symbionts…

Hierarchy in Nature

A Case Study: Snowshoe Hare Ecology Observations: Coat color of a snowshoe hare changes in spring and fall Color change is asynchronous among individuals Highest mortality is observed in spring and fall (compared to winter and summer) What drives coat color change? What makes this study an ecological study? Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

A Case Study: Snowshoe Hare Ecology What determines a change in snowshoe hare coat color? Proximate causes Ecological factors Direct effects of external stimuli; direct, immediate causes e.g., temperature and photoperiod Ultimate causes Evolutionary factors that led to appearance of certain traits e.g., selective pressure from predation

A Case Study: Snowshoe Hare Ecology Interaction is key in ecology Can you name abiotic and biotic factors affecting ecology of snowshoe hares? Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Snowshoe Hare Ecology: A Complex Story

Ecological Studies Often Encompass Several Levels of Organization Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Ecology Is Hierarchically Subdivided Organismal ecology: interactions between individuals and their environment Physiological ecology Behavioral ecology Population ecology: dynamics of a group of individuals of a single species Population genetics, demography Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Ecology Is Hierarchically Subdivided Community ecology: interactions among a group of coexisting species Ecosystem ecology: interactions between ecological communities and their abiotic environment Ecosphere or biosphere: sum of all Earth’s ecosystems Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Ecology Connections Natural history Observational study of plants and animals in their natural environment Popular in Victorian age for men and women of wealth to spend time walking and pondering gardens, etc. Darwin was essentially a Natural Historian who was observant and brilliant enough to see the patterns in his observations Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

How do Ecologists, Naturalists and Environmentalists Differ? Example: Consider the American Robin, Turdus migratorius Naturalist: Observes robins and paints/photographs/ writes/composes music about robins. Provides valuable “Natural History.” Ecologist: Asks, “What causes the robin’s singing behavior? Seeks to explain the Natural History. Environmentalist: Seeks action to preserve the habitat of the robin.

Ecology Connections Environmental science The study of the impact of humans on the environment Environmental studies includes knowledge from other fields such as history, political science, economics, philosophy Good Example: returning the wolves to Yellowstone National Park – keystone predator Lots of pros and cons; entrenched bias against predators Decision based not just on ecological science, but other issues such as reactions of cattle ranchers as well as public opinion were considered etc.

Ecology Connections Resource management sciences Sciences devoted to managing and husbanding resources important for human use Wildlife management Forestry Range management Fisheries biology Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Take Home Points Ecology is the study of the interactions between an organism and its biological and physical environment. Ecologists study interactions at multiple levels of organization: the organism, the population, the community, and the ecosystem. Natural history observations raise ecological questions and frame hypotheses. Other applied fields, such as environmental science and the management sciences, apply ecological principles to resources important to humans. Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

What Important Ideas Will Emerge in Your Study of Ecology? Fundamental ecological principles Application of the scientific method to answer specific ecological questions Ecology is a quantitative science Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Fundamental Ecological Principles Ecology-evolution connection Ecosystems are a product of evolution of species Ecological systems are often not in equilibrium No “ecological homeostasis” or “balance of nature” Both equilibrium and nonequilibrium ecological processes are important Human impact on the environment and on ecological processes

Fundamental Ecological Principals Ecology-evolution connection Ecosystems are a product of evolution of species Change in hare coat color is an adaptation Ecological theater and Evolutionary play

Subdisciplines of Ecology Physiological Ecology Genetic Ecology Evolutionary Ecology Behavioral Ecology Landscape Ecology Paleoecology Systems Ecology Theoretical Ecology Insect Ecology Bird Ecology Microbial Ecology Freshwater Ecology Marine Ecology Terrestrial Ecology Many more

Fundamental Ecological Principles Early ecological views: There is a “balance of nature” in which natural systems are stable and tend to return to an original state after disturbance. Each species has a distinct role to play in maintaining that balance.

Concept 1.2 Fundamental Ecological Principles Ecologists now recognize that natural systems do not necessarily return to their original state after a disturbance, and seemingly random perturbations can play an important role. Evidence suggests that different species often respond in different ways to changing conditions. Examples Food webs in ecological communities Flow of matter and energy through ecosystems Succession – climax is not a “constant” stable state to which communities return after disturbance.

Concept 1.2 Fundamental Ecological Principles Scientists now recognize that ecological interactions are more complex than previously thought. One view that has stood the test of time: Events in nature are inter-connected. A change in one part of an ecological system can alter other parts of that system. Emergent properties of communities and ecosystems Can’t rely on 2 species interactions Multiple species, multiple interactions – unexpected outcomes

Fundamental Ecological Principles Ecological systems are often not in equilibrium No “ecological homeostasis” or “balance of nature” Both equilibrium and nonequilibrium ecological processes are important Human impact on the environment and on ecological processes Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Ecology is a Science Ecology uses the Scientific method Uses tools such as Observation Experimentation Mathematical modelling Uses statistics to analyze data and arrive at A conclusion that is unbiased, based on the data; A mathematically derived level of confidence in that conclusion

01_p010.jpg Science is all about testing hypotheses and rejecting the false ones.

Ecology Is a Science It Uses Scientific Method Support the hypothesis Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

August Krogh Principle Which System to Choose to Study Ecological Questions? The concept of model system August Krogh Principle “For many problems there will be some animal of choice or a few such animals on which it can be most conveniently studied.” A. Krogh, 1874–1949, Nobel Laureate 1920 Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Which System to Study? The concept of a model system Basic biology and natural history of a species well known Possess specific features that allow addressing a specific question Amenable to experimental manipulation Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

Sarracenia purpurea Model system

Experimental Design, Statistics A huge part of ecology is about asking a good question and designing a study with the right kind of observations, experiments and statistics to get a reliable answer.

Experimental Design, Statistics Data interpretation requires the use of statistics Data sets are often very large and complex. Statistics allows us to express a mathematically tested level of confidence in the outcome of a study.

Ecology Is a Quantitative Science Statistical analysis of the data is required Statistics allows us to express a mathematically tested level of confidence in the outcome of a study. Traditionally accepted confidence level—95%, but can vary depending on the question Ecological modeling Statistical, mathematical, and computer models Ecology: Evolution, Application, Integration                                       David T. Krohne                                Copyright © 2015 Oxford University Press

What’s the overall aim? To recognize patterns in nature To explain or understand these patterns To predict what will happen to these patterns if conditions change To control or exploit populations

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