Landscape Ecology Flashcards
What is a landscape?
a heterogenous ( diverse, mixed, varied) area consisting of distinct patches
- patches are known as landscape elements and are organized in a mosaic like pattern
What is landscape ecology?
a subdiscipline of ecology that examines the patterns and interactions between communities that make up relatively large areas
What is different about landscape ecology?
- involves knowledge from multiple disciplines
- spans across multiple scales
- often focused on humans and our influence
What are the factors that shape landscapes?
- geological processes (volcanism, sedimentation, erosion)
- organism activity (humans, beavers)
- climate ( ice ages, global warming)
- fire ( lighting caused, fire suppression )
Glacial ages
periods of variable cool and warm global temperatures that can last for millions of years
What is the most recent glacial age referred to as
the pleistocene
What are some landscape elements created by glaciers
- moraine
- esker
- kame
- drumlin field
Moraine
any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till
Esker
long, winding ridge of stratified sand and gravel
Kame
an irregularly shaped hill or mound composed of sand, gravel and till that accumulates in a depression on a retreating glacier and is then deposited on the land surface with further melting of the glacier
Drumlin Field
an enlongated hill in the shape of an inverted spoon or half buried egg formed by glacial ice acting on underlying unconsolidated till or ground moraine
What are Corries?
- bowl shaped hallows on the side of a mountain
- they form then the glacial deepens an existing hollow through freeze-thaw action and plucking
What is the difference between glacial river erosion?
- u-shaped valley = glacier
- v- shaped valley = stream
Glacial Refugia
regions that occurred adjacent to the extent of the glacial landscape and remained unglaciated
Nunataks
- a type of glacial refugia
- mountain peaks
- isolated peaks of a mountain area projected above a surface of ice/snow
Human-driven Glacier Melt-off (years and whats happening)
- 2000-2019
- glaciers globally lost a mass of 267 +/- 16 gigatonnes year
- greenland and antartic ice-sheets lost 205- and 143 gigatonnes year respectiveley
Beavers as Ecosystem Engineers
- at one time, beavers could shape the landscape of entire continents
- pre-colonization beavers ranges extended from the arctic tundra to the chihuhan and sonoran deserts
- almost driven to extinction bc of fur trade
- from 1927 to 1988, beavers transformed landscape from one dominates by forest to a diverse patchwork of several ecosystems
Example of humans as drivers of Landscape change
Veluwe Region, Netherlands
- pre-human: forest
- 800-1100 CE: heathlands and agriculture
- raising sheep were abandoned
- mostly due to inexpensive sheep from australia
- lack of grazing, alongside deliberate planting of pines, returned the landscape to forest
1800-present: forest plantation
How does fire (fire suppression) drive landscape change?
- fire produces a mosaic of plant communities or different ages and composition throughout landscapes
- the intensity of fire can change w terrain, across wind patterns, how much biofuel available on forest floor
What does landscape structure describe?
the size, shape, composition, number and position of patches (landscape elements) within a landscape
What is a Patch
a relatively homogenous area that differs from its surroundings
What is a Matrix
- element within the landscape that is most spatially continuous (interconnected)
- aka the background of the mosaic of patches
What kinds of processes do landscape structure influence?
processes such as flow of energy, materials, and species distributions across a landscape
How to quantify landscape structures?
habitat quality - GIS tools to assess habitat for wildlife or plant-based research objectives
Edge Effect
impacts to the adjacent ecosystem caused by changes in the physical environments along its edge
impacts of the edge effect
- reduced habitat area
- change in abiotic and biotic properties
- decrease in isolation
Edge effects in the Amazon Rainforest
- environment along forest edges hotter and drier, with higher intensity of solar radiation
- tree mortality higher at edges and overstory decreases while understory vegetation increases
- decreased diversity of many animal groups
Habitat fragmentation
the division of previously intact habitat into several isolated patches typically due to human development and resource extraction
Movement of Small Organisms
animals in small patches may be more isolated relatively from the metapopulation than those in larger patches
Corridors
some sort of strip of habitat connecting similar habitat types patches across landscape
