a bird’s eye view of habitat 04-17-07... · 2019-08-27 · a bird’s eye view of habitat putting...

A Bird’s Eye View of Habitat

Putting the pieces together

Restoration Ecology

• Using what science has learned about living things and their interactions with their environment to re-create habitats that have been lost due to human activities.

Revegetation

• Revegetation projects are classified as one of the following:– Reclamation: Returning disturbed land to a productive

state; The process of rehabilitating disturbed lands, or converting unproductive lands to productive uses.

• Productive?

– Restoration: The return of an ecosystem or habitat to its original community structure, natural complement of species, and natural functions

– How are these different?

Restoration Ecology

• The science (and art) of healing scars left by human activities such as– Mining– Grazing– Agriculture– Dams

Restoration Ecology

• In order to restore vegetation and animals we have to look at all the components of the biotic and abiotic conditions at a site– Soils, topography, water drainage, etc…

• This includes the overall landscape that surrounds the restoration and the spatial arrangement of the site and other similar areas

Restoration Ecology

• Any good restoration project must take landscape scale issues into consideration

• Also, must be monitored to determine success

• If we build it, will “they” come?

Landscape Ecology• Landscape =

– A large area or region that contains a patchwork (or mosaic) of different vegetation or ecosystem types

– A group of interacting ecosystems occupying adjacent geographical areas

• Examples:– The San Pedro River watershed– Yellowstone National Park– The Phoenix Metropolitan area

San Pedro River, SE Arizona

Yellowstone National Park

Landscape Ecology• Studies the influence of spatial arrangement of

ecosystems on ecological processes (and vice versa)– How do ecological processes determine landscape

pattern?• E.g., How does fire form patterns in vegetation?

– How does landscape pattern influence ecological processes?

• E.g., How does the composition and arrangement of patches affect the ability of a predator to find food?

• Often uses Geographic Information Systems (GIS) as a tool

Terms to Describe Landscape Pattern

• Patch– a contiguous area covered by one ecosystem or

vegetation type

• Matrix– the background or dominant ecosystem or land-use

type in a landscape

• Corridor– a linear strip of habitat that may link different patches

and act as a conduit for movement of organisms

Agricultural Matrix

Riparian Corridor

Woodland Patch

Effects of Land Use Change on Landscape Pattern

Human land use often fragments intact habitats

Ex: Cadiz township, Wisconsin (1831-1950)

(forest in green, cleared in white)

Restoration can connect fragments

Forest expansion with agricultural abandonment in a New England landscape

(forest in black)(from Foster 1992)

Effects of Land Use Change on Landscape Pattern

1830 1900

19651938

Edge vs. Interior Habitat• Fragmentation increases edge and

decreases interior habitat– Edge = the zone of habitat near the boundary

between one patch type and another– Interior = the zone of habitat that is on the inside of

a patch, far from the edge

What effects does forest fragmentation have on birds in the eastern US?

Landscape Maps for Exercise 1 40%

60%

20%

10%

80%

Gray cells = forest

White cells = cleared

KEY:

10% = % of forest cleared

40%40%

60%60%

20%20%

10%10%

80%80%

Gray cells = forest

White cells = cleared

KEY:

10% = % of forest cleared

Species rules for Exercise 1

Ovenbird• Edge-avoiding, forest interior species• Rule: only forest cells that do not

share a border with cleared cells

10% cleared, 90 forest cells remainX X X X X X X X XX X X X X XX X X XX X XX X X X X

X X X X XX X X X X X X

X X X X X X X XX X X X X X XX X X X X X X X X


Indigo Bunting• Forest edge exploiter• Rule: only forest cells that do

share a border with cleared cells

10% cleared, 90 forest cells remainX

X X XX X X XX X X X X

X X XX X X X

X XX X

X XX


Red-eyed Vireo• Area-sensitive forest species, no

edge response• Rule: forest patches composed of at

least 3 contiguous cells

50% cleared, 50 forest cells remainX X X

XXX X

X X X X XX X X X X X X X X

X X X X XX X X X X

X X X XX X X X X


Red-shouldered Hawk• Area-sensitive forest species, no

edge response• Rule: forest patches composed of at

least 9 contiguous cells

50% cleared, 50 forest cells remain

XX X

X X X X XX X X X X X X X X

X X X X XX X X

X X XX X X


Eastern Meadowlark• Open habitat (grassland) species, edge

avoider• Rule: only cleared cells that do not

share a border with a forest cell

50% cleared, 50 forest cells remainX

X XX

X

0

20

40

60

80

100

0% 20% 40% 60% 80% 100%

% of Landscape Cleared

# ce

lls o

f sui

tabl

e ha

bita

t

OvenbirdVireoHawkBuntingMeadowlark

Changes in Habitat Availability with Forest Fragmentation

0%

20%

40%

60%

80%

100%

0% 20% 40% 60% 80% 100%

% of Landscape Cleared

% F

ores

t Cel

ls S

uita

ble

OvenbirdVireoHawkBunting

% of Remaining Forest Cells that are Suitable Habitat

Implications• Species differ in response to fragmentation

based on their habitat preferences and other ecological characteristics

• Fragmentation reduces area of a particular habitat, but proportionally causes a much greater loss of interior habitat

• There may be thresholds of % habitat loss beyond which big changes in habitat suitability occur

50%

50%

50%50%

50%

50%

BA

DC

E F

Landscape Maps for

Exercise 2

Implications• The spatial pattern of habitat loss has a

strong effect on habitat suitability and populations of different species.

• How would you manage the forest to maintain the most habitat for all species?

a bird’s eye view of habitat 04-17-07... · 2019-08-27 · a bird’s eye view of habitat putting...

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