Introduction to Ecology [BIO 3510]

Origin of the word “ecology” Greek origin OIKOS = household LOGOS = study of… Study of the “house/environment” in which we live.

Definitions the study of relationships of organisms to their environment and to one another. a branch of science describing, explaining and predicting where organisms live (distribution and abundance). literally means the study of ‘houses’, ‘home conditions’, ‘habitats or more broadly ‘environment’ of plants and animals. according to Crebs (1972), “Ecology is the scientific study of the interactions that determine the distribution and abundance of organisms” systems are dynamic, not static.

What is Ecology? The study of interactions that take place between organisms and their environment. It explains how living organisms affect each other and the world they live in. copyright cmassengale

Habitat & Niche Habitat is the place a plant or animal lives Niche is an organism’s total way of life copyright cmassengale

History of Ecology In 1859, a French Zoologist St. Hilaire, had employed the word ‘ethology’ for the study of organisms in relation to their environment. The term ‘ecology’ was first defined by a German biologist Ernst Haeckel in 1866. The term ‘ecology’ is derived from the Greek word ‘Oikos-meaning ‘house or dwelling place and ‘logos’ meaning discourse.

Ecology - A Science for Today! We have a great need for ecological understanding: what are the best policies for managing our environmental support systems -- our watersheds, agricultural lands, wetlands? we must apply ecological principles to: solve or prevent environmental problems inform our economic, political, and social thought and practice.

Ecology and Environmentalism Ecology is a science and is different from environmentalism. Ecology provides the science behind many questions related to human impacts on the environment but it is not the same as environmentalism. Environmentalism is an advocacy or concern for the environments. However, most ecologists would tend to support efforts to protect natural systems and restore degraded environments

Scopes of Ecology: Interactions determine distribution and abundance of organisms. Two main themes in ecology are: Where do organisms live? & Why? How many organisms are present? & Why? By understanding the principals of ecology we can then apply them to management of both plants and animals By studying ecology, we expect to be carried through the sequence i.e. observation, explanation, hypothesis, experiment and conclusion where we are now on the path to understanding. We are not only interested in the structure of the population or community but also how it functions. In other words, we are interested in “cause and effect”.

Divisions of Ecology: Divisions of Ecology Autecology- ecological study of individual species Synecology – ecological study of a population of a species growing together or communities.

How Ecologists Study the Natural World Ecologists, like other scientists, employ a scientific method: observation and description of natural phenomena development of hypotheses or explanations testing the predictions of these hypotheses We test hypotheses because many explanations are plausible (reasonable). Which is best?

Ecology Employs the Scientific Method Induction Observation Hypothesis or model Experiment Prediction Deduction

Observing Experimenting Modeling What species live here? How many individuals of species are there? Experimenting Used to test a hypothesis Ex - making artificial environments in the lab Modeling Making models to gain insight into complex phenomena Ex. - Global warming

What is an hypothesis? An hypothesis is an idea about how the world works: e.g., “Frogs sing on warm nights after periods of rain.” We often wish to understand two components of such a phenomenon: how? (encompasses physiological processes) why? (encompasses costs and benefits of the behavior to the individual)

Experiments test predictions. Hypotheses generate predictions: if observations confirm the prediction, the hypothesis is strengthened if observations fail to confirm the prediction, the hypothesis is weakened (or rejected) Best tests of hypotheses are experiments: independently manipulate one/few variables establish appropriate controls.

Methods to Study Ecology Theoretical Mathematical models Laboratory Highly controlled but lack realism Field Highly realistic but may lack control.

Mathematical models are powerful tools: researcher portrays system as set of equations model is an hypothesis and yields predictions that can be tested. examples include: models of disease spread models of global carbon

Field Study