Fundamental ecological principles

Transcription

1 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 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 1

2 Subdisciplines of Ecology Physiological Ecology Genetic Ecology Evolutionary Ecology Behavioral Ecology Landscape Ecology Paleoecology Systems Ecology Theoretical Ecology Community Ecology Insect Ecology Bird Ecology Microbial Ecology Freshwater Ecology Marine Ecology Terrestrial Ecology Population Ecology Plant Ecology Many more Early ecological views: o There is a balance of nature in which natural systems are stable and tend to return to an original state after disturbance. o Each species has a distinct role to play in maintaining that balance. 2

3 Concept 1.2 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 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 o Can t simply rely on 2 species interactions o Multiple species, multiple interactions unexpected outcomes 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 3

4 Ecology is a Science Ecology uses the Scientific method Uses tools such as Observation Hypothesis formulation Hypothesis testing/experimentation Mathematical modelling = one way to test hypothesis 01_p010.jpg Science is all about testing hypotheses and rejecting the false ones. 4

5 Ecology Is a Science It Uses Scientific Method Support the hypothesis Ecology Is a Quantitative Science Data interpretation requires the use of statistics Data sets are often very large and complex. Uses statistics to analyze data and arrive at: A conclusion that is unbiased, based on the data; Statistics allows us to express a mathematically derived level of confidence in the outcome of a study. Traditionally accepted confidence level 95%, but can vary depending on the question 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. 5

6 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, , Nobel Laureate 1920 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 Sarracenia purpurea Inquiline Community Model system 6

7 Revised Map of Food Web Interactions 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 7

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