Ecology

Introduction to Ecology

Why are you here?

Teaching children about the natural world should be treated as one of the most important events in their lives.

--Thomas Berry

Global and Local Environmental Issues• Human Population Growth

• Water Quality and Supply– Surface– Ground

• Degradation of Soils

• Air Quality

• Species Diversity

• Invasive Species

• Land Use

• Post-911 Ecology

Hierarchy of Biological Systems

Krohne, D.T. General Ecology. 2nd Edition.Pacific Grove, CA. Brooks/Cole. 2001. p. 8

What is ecology?• Ecology – a study of the interaction

between organisms and their environment.

• Branches:– Molecular – Physiological– Genetic– Autoecology– Population– Community– Ecosystem*– Systems / Landscape

Allied Sciences• Natural Science (qualitative

descriptions)

• Environmental Toxicology – chemistry and physiology of pollution

• Conservation biology – maintain biodiversity

• Environmental Science – ecological effects of human activities on the environment

Allied Sciences• Environmental Science involves

understanding:– Ecology– Chemistry– Geology– Physics– Meteorology– Cultural anthropology– Sociology– Psychology– Cartography– Economics

Objectives of Ecology• Understand how the natural world

works

• Understand how human systems are interacting with natural systems

• Accurately assess the status and model the trends of crucial natural systems

• Promote and follow a long-term, sustainable relationship with the natural world

Your WORLD

vs.

Your CHOICE

Conceptual Framework for Ecological Research•Scientific Process•(aka Scientific Method)

–There are various ways to represent the scientific method, but all share these basic characteristics:

observe

Question

Research

Conduct Experiments

Collect and Analyze Data

Draw Conclusions

Hypothesize

Conceptual Framework for Ecological Research1. Garbage in—Garbage out

2. All Scientific Conclusions are tentative (no vs. maybe)

3. Understanding how to do science is far more important than memorizing ephemeral facts.

Conceptual Framework for Ecological Research• Science proceeds by the falsification

of alternate explanations of an observed effect. (Krohne, 2001)

• One of these alternative explanations (hypotheses) must be the Null Hypothesis (H0) which states that the observed effect is the result of chance (No statistically significant difference between data).

Conceptual Framework for Ecological Research•Example: Do bats prefer to munch on a certain size moth?

vs.

MothsMoths

Conceptual Framework for Ecological Research•Observations of the bats in the field show that they prey more on big moths than little moths.

Study of Bat Insectivory

1 2 3 4

Moth Size Ranking

Fre

qu

ency

Moths Eaten

Conclusion?

Conceptual Framework for Ecological Research•Now let’s gather some more data…

Interaction of Moth Demographics and Bat Insectivory

1 2 3 4

Moth Size Ranking

Fre

qu

ency

Moths Present

Moths eaten by bats

Conclusion?

H1= Bats prefer smaller moths

H2= Bats prefer large moths

H0= Bat do not demonstrate a moth size preference

Reductionism vs. Holism• Reductionism – a process in which a

system is reduced to its component parts for the purpose of study.

• Holism – a process in which a system is kept intact for the purpose of studying the interaction of its parts.

• The trick in ecological research is to be as holistic as possible while maintaining the reductionism needed to be quantitative and empirical.

Reductionism vs. Holism•Example 1:

predationWolf Deer

Reductionism vs. Holism•Example 2:

competition

predation

predation

predation grazing

grazing

grazingcompetition

Moose

Deer

Hares

Wolf Vegetation

Reductionism vs. Holism• Most modern ecological research

attempts to be as quantitative as possible.

• The higher up the hierarchy you go, the more difficult it is to make inferences.

• This is why comparative studies are so valuable to ecologists.

Reductionism vs. Holism•Emergent Properties – Phenomena that are observable only in the complete, intact system.

Statistical Analysis• Various statistical tools are useful to

test the accuracy and validity of, and correlation between collected data.– Regression– T-tests– ANOVAs

• Lab: Stats and Data Sets.

• Discussion of Results

Mathematical Modeling• Mathematical models are used in an

attempt to formulate equations that reflect the operation of a system.

• These models are fueled by general assumptions about the basic operation of the system that affect the validity of the final mathematical model.