Ecology: Lecture 1

1
Ecology Lecture 1

• Introduction

2
Photo Stanford University News Service
3
(No Transcript)
4
(No Transcript)
5
(No Transcript)
6
What is ecology?

• Ecology works at characterizing the patterns
  seen in nature, studying the complex interactions
  among organisms and their environments, and
  understanding the mechanisms involved in
  biological diversity.

7
1. Characterizing the patterns seen in nature

• Example The River Continuum
• Many differences are seen between the upstream
  and downstream stretches of a river
• Different types of invertebrates
• Different species of fish

8
(No Transcript)
9
2. Studying complex interactions between
organisms and their environment

• Example What causes the differences seen between
  upstream and downstream sites?
• Possibilities???

10
3. Understanding the mechanisms involved in
biodiversity

• Why do some reaches of a river tend to have
  greater diversity than others? Why do some
  rivers have greater diversity than others?
• Why do tropical rain forests and coral reefs have
  relatively high species diversity compared to
  other ecosystems?

11
The absolute geographical boundaries of a species
are set by abiotic factors

• Global scale Adelie penguins would overheat in
  the tropics

12
The absolute geographical boundaries of a species
are set by abiotic factors

• Local scale Giant, green anemones are found in
  pooling water in the intertidal, but not on
  vertical rock faces

13
Within limits set by abiotic factors,biological
interactions affect the presence abundance of
species

• What are some of these biological interactions?

14
Why are there no polar bears in the Antarctic?
15
Shelfords law of tolerance

• What do the axes mean? What do different parts of
  the curve tell us about the species?

16
Seasonal or geographical shifts in tolerance

• What do the three different curves represent?
  (gt1 possibility)
• What does the arrow represent?
• What types of values belong on the x-axis?

17
Winter distribution of the Eastern phoebeBlue
line -4º isotherm, minimum average temp.
JanuaryBlue patches Deviation of phoebe
distribution from -4º isotherm.
18
How might natural selection affect a species
tolerance curve?

• Within a single generation?
• After several generations?

19
Global warming and species shifts

• Example malaria

Diagram from Bellarmine University website