Download Drivers of landscape pattern

Drivers of landscape pattern
Four basic drivers of landscape pattern
1. Abiotic factors
2. Biotic factors
3. Human activities
4. Disturbance
Abiotic factors
Climate
Climate influences the distribution of
dominant vegetation types
Climate influences species distributions
Long-term climate change and species distributions
•  Species distributions have
changed with changing
climate, generally shifting with
glacial-interglacial periods.
•  In general, in response to
climate change, species
evolve, migrate, or go extinct.
•  Ecotones have shifted
drastically in response to long
term climate change, but
species respond
individualistically, not as
communities.
Lines represent extent of distribution at a given time.
Numbers are thousands of years before present.
Holocene changes in the Puget Sound region
13,500 YBP
Tundra-like conditions with
patches of trees (Englemann
spruce, lodgepole pine, mountain
hemlock, subalpine fir).
10,000 YBP
Open landscape with Douglas fir,
grasses, red alder, bracken fern.
Warmer, drier, frequent fires.
7,000-5,000 YBP
Beginning of modern vegetation
(western red cedar, western
hemlock, Douglas fir). This
community is unique in the pollen
record.
Brubaker 1989
Projected changes in species distributions
Historical Climate – MC1 Simulation
(With Fire)
Ron Neilson, USFS
HADCM3-A
Ron Neilson, USFS
Abiotic factors
Landform
Abiotic factors:
Landform effects on pattern and process
Elevation
Aspect
Geology
Slope
Solar radiation
Temperature
Moisture
Nutrients
Swanson et al. 1988
Abiotic factors:
Landform effects on pattern and process
Landforms affect the flow of energy,
nutrients, organisms, and pollutants
across landscapes.
Specific Conductance
Northern Lakes, Wisconsin
(Kratz et al. 1991)
Low
(Landscape Position)
High
Abiotic factors:
Landform effects on pattern and process
Landforms may affect the frequency and
spatial characteristics of fire, wind, and
grazing, as well as other natural and
anthropogenic disturbances.
Abiotic factors:
Landform effects on pattern and process
Landforms may affect the spatial patterns
and rates of geomorphic processes
that can alter biotic characteristics and
processes.
Abiotic factors:
Interactions among drivers
•  Biotic responses to aiotic factors
are not always predictable
•  Establishment rates
•  Growth rates
•  Mortality rates
•  Competition
•  Disease
•  Disturbance
Biotic factors
Competition
Predation
Facilitation
Keystone species and
ecosystem engineers
Biotic factors
Competition
Competitive
exclusion
Biotic factors
Competition
Fundamental
and realized
niches
Biotic vs.
abiotic
controls
Connell 1961
Biotic factors
Predation
Ripple and Bescheta 2007
Biotic factors
Facilitation
García and Ramón Obeso 2003
Biotic factors
Keystone species
Paine 1966, 1969
Biotic factors
Keystone species, ecosystem engineers
Estes and Duggins 1995
Human Activities
Land use
Climate change
Human Activities
Land use
Human Activities
Climate change
Human Activities
Climate change
Human Activities
Climate change
Parmesan et al. 1999. Nature 399: 579-583
Human Activities
Climate change
stable
expansion
contraction
Northern Flying Squirrel
Glaucomys sabrinus
Human Activities
Climate change
stable
expansion
contraction
Yellow-Banded Poison Dart Frog
Dendrobates leucomelas