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Landscape Ecology and
# Biogeography
Autecology
Populations
Communities
Landscape
Global Landscape Ecology Basic Definitions
Habitat -physical and
biological
surroundings of an
organism
Landscape -large area
that comprises more
than one type of
habitat distributed in
numerous patches
(Danielson 1999)
Legacy Effects
(importance in
restoration ecology) Landscape Ecology and
Biogeography Biogeography -
The study of
patterns in the
geographic
distribution of
species
Historical
Biogeography -
changes through
time;
evolutionary
history
Ecological
Biogeography -
dist. of extant
species given
current
environmental
conditions
Where a species has been and where it is going
drivers of that change Realms and Biomes Realms large
regions across the
globe where
organisms share
common
geological and
evolutionary
history
Realms are
composed of
Biomes
Biomes
identified by
dominant
vegetation types
on land; or by
dominant physical
processes in
aquatic habitats PATTERN 1: The Relationship of
## Area and Species Richness Deriving the Species -Area Curve
S = cA z
log S = z log A + log C (takes on the form of y = mx +b)
S = # species, A = Area, c = constant
Logarithmic plot - straight line
where c = y intercept and z = slope
most values of z = 0.20 -0.35
> Applied Ecology and
> Conservation Why do
> Species -Area Curves
> matter?
Robert MacArthur and E.O. Wilson
(1967)
An application / extension using the
species -area curve theory
Equilibrium theory of island
biogeography
VARIABLE 1: immigration rate and
distance to a source population
VARIABLE 2: extinction rate and the
level of species richness
Remember SA curve relates area to
species richness
PATTERN 2: Island Biogeography Extinction rates linked to #of species present; smaller habitats
accommodate less species less resources, less eco. niches to fill
Compression hypothesis - as more species are packed into the
landscape, each niche becomes smaller; competition increases
Why is Extinction Linked to Size of the Habitat Patch? Application: Habitat Loss, Isolation, and
Fragmentation Habitat Loss The
complete elimination
of habitat; along with
their biological
communities and
ecological function
Isolation Potential
barriers to gene flow
Habitat
Fragmentation
Process by which
larger, continuous
habitats become
subdivided into a
greater number of
small patches Announcements
## 8 April 2025
HW9 Ecology will be available by tomorrow,
Wednesday, April 9 th : DUE: Thursday, April 17 th
TOPICS: Measuring Biodiversity (Biodiversity Indices)
and Biogeographic Patterns of Diversity
Quiz 10 Today: Measuring Biodiversity and
Biogeographic Patterns of Diversity
Quiz 11 Thursday: All material in Lecture 10 covered
through the end of today
Exam 3: Tuesday, April 15: Material begins with Part 2 of
Lecture 6: Trophic Levels and Food Chains and will end
with any material that we complete today in Lecture 10 Edge Effects
>
Examples:
>
Water rgimes (hydrology)
>
Soil moisture
>
Predation, parasitism, herbivory
modifications
Suite of physical and biological changes
that tend to occur at habitat patch edges;
can potentially negatively impact diversity Tigrosa helluo
> Pardosa milvina
Species Vary in
Their
Response to
Edge Habitats Ex. Habitat Edges and Social Parasitism PATTERN 3: Latitudinal Patterns in Species Diversity Latitudinal Patterns in Species Richness
Examining Five Hypotheses:
- 1. The Area Hypothesis
- 2. The (Evolutionary) Time Hypothesis
- 3. Spatial Heterogeneity Hypothesis (Diverse Niches)
- 4. Productivity Hypothesis
- 5. Favorable Climate Hypothesis
https://www.yo
utube.com/wat
ch?v=YLt0 -
yoOKvw PATTERN 4: Extinction The
Death of Species
Forms of Extinction:
1. Linnean Extinction
undocumented
2. Local Extinction
3. Ecological Extinction (loss of
function; genetic loss; loss of
interactions)
4. True Extinction Alert
phase, Monitoring Phase,
Contemporary extinction
-How long does it take to declare
a species officially extinct Extinction Patterns through Geologic Time
Extinction as a Natural Process What makes a species
vulnerable to extinction?
Seven Forms of Rarity
(Rabinowitz et al. 1986)
The more
specialized a
species is; the
more prone it is
to extinction
Modern
Extinction
Risk Determining Current Extinction Risk - IUCN Red List
> https://www.youtube.com/watch?v=VukyqMajAOU
## The 6 th Mass Extinction?
REASONS: H.I.P.P.O. + Rapid Anthropogenic Climate Change Extinction
risk for
various taxa
in the U.S.
Wilcove and
Master (2005)
https://www.youtu
be.com/watch?v=
Vm8112Ab0qg&t=
2s Biogeography and Conservation:
## Designating Protected Areas General
Rules of
Reserve
> Design
## Setting Conservation Priorities
## Based on Biogeography
Hotspots High endemism (1,500
endemic plants), high level of threat
(>70% of original habitat lost)
High Biodiversity Wilderness Area High
richness, lower human impacts Biodiversity Hotspots
https://www.youtube.com/watch?v=RaQBaVeEbW8