6 Introduction to Ecology

Andrea Bierema

Ecology: The study of how organisms interact with each other and their environment.

Ecological Levels

Ecology is studied at different levels. For instance, it can focus on the interaction of individuals within the same species (population ecology) or individuals of different species (community ecology). See the figure below for all of the levels and click on the plus hotspots for definitions and more information.

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In this unit, we will examine ecology at these various levels. First, we examine biodiversity, which addresses all of the ecological levels. Next, we consider the broad levels of biosphere and ecosystem ecology by learning about nutrient cycling and climate change. Then we focus on community ecology, learning about the various ways that species interact with one another. We consider population ecology, focusing on how population sizes change over time and the factors that influence those changes.  We learn about evolution and modeling evolution using phylogenetic trees, which evolution occurs at the population level but is often influenced by biotic and abiotic factors. Lastly, we consider reproductive strategies.