Chapter 7: Landscape Ecology Flashcards
This discipline addresses the relation of spatial variation to ecological processes
Landscape ecology
What are four focuses of landscape ecology?
Spatial landscape structure; Relationship between patterns and processes; Landscape formation processes; Effect of human activity on landscapes
These are spatially heterogeneous land areas
Landscapes
Of what are landscapes comprised?
Mosaic of interacting ecosystems
Landscapes vary in this
Spatial structure
What are the two basic components of landscapes?
Composition and configuration
This landscape component describes the types of landscape elements
Composition
This landscape component describes the size, shape, and arrangement of elements
Configuration
What are the two types of landscape elements?
Patches and mosaics
This is a homogeneous area that differs from its surroundings
Patch
What are four ways that patches can be quantified?
Number, size, shape, configuration
This is a spatial mix of patches
Mosaic
This landscape metric is the contribution of an element to the total area
Total patch cover
This landscape metric is the middle size of landscape elements
Median patch size
This landscape metric is the number of patches per area
Patch density
What shape is a patch if S=1?
Circular
What shape is a patch if S > 1?
Elongated
What is the equation for patch shape?
S = P / 2√𝜋A
These are the borders between adjacent ecosystems/patches
Boundaries
This is the ecosystem near the perimeter of a patch
Edge
This is the interior of a patch
Core
This is a transitional area between ecosystems
Ecotone
What are the two types of edge?
Inherent and induced
From what does inherent edge arise?
Differences in soils and landforms
From what does induced edge arise?
Disturbance
Which type of edge is relatively stable?
Inherent edge
Which type of edge is relatively transient?
Induced edge
What does edge contrast describe?
Transition between elements
Do small or large patches have more edge than core?
Small
Do irregular or square patches have more edge?
Irregular
These are effects of adjacent patches on habitat
Edge effects
What four forest conditions increase at edge?
Light, temperature, wind, noise
What two forest conditions decrease at edge?
Moisture and humidity
Are edge habitats less complex?
No
Do edge habitats support higher species richness?
Yes
This is a measure of landscape continuity
Connectivity
These are elements that link similar habitats
Corridors
This is the dominant element in a landscape
Matrix
What are six factors of landscape pattern creation?
Surface geology; Geomorphical processes; Topography; Natural disturbances; Animal activities; Human activities
What are three examples of surface geology processes that create landscape patterns?
Tectonic uplift; Volcanism; Sedimentation
This is the study of landforms
Geomorphology
This is the removal of material from the surface
Denudation
What are three types of denudation?
Weathering, erosion, mass wasting
This is how species change from lower to higher elevations
Altitudinal zonation
These two topographical effects impact microclimate and soils
Slope and aspect
This is the rate of incline of a landform
Slope
This is the direction a landform faces
Aspect
Altitude zonates species similarly to this
Latitude
Disturbance removes this
Biomass
What are three types of disturbances that can remove biomass?
Fire, floods, windstorms
What are three factors of disturbance regimes that determine how they affect landscape mosaics?
Frequency, intensity, and severity
What are six ways that animals can affect landscape generation?
Pollination; Seed dispersal; Pests; Disease vectors; Burrowing/wallowing; Vegetation removal
These animals play myriad roles in landscape generation and outbreaks can have large scale effects
Insects
These are organisms that create, maintain, or modify habitats
Ecosystem engineers
These ecosystem engineers modify habitats via their own physical structure and are “self-creating”
Autogenic engineers
What are two examples of autogenic engineers?
Trees and corals
These ecosystem engineers modify their habitat by changing the structure of materials
Allogenic engineers
What are three examples of allogenic engineers?
Beavers, termites, elephants
How much of the planet’s ice-free surface have humans altered?
50%
What are six ways humans have altered landscapes?
Urbanization, agriculture, channeling, drainage, right-of-ways (roads, powerlines, pipelines, etc.), forestry
This is the reduction of continuous habitat into fragments
Habitat fragmentation
Does patch number increase or decrease with habitat fragmentation?
Increase
Does patch size increase or decrease with habitat fragmentation?
Decrease
Does patch isolation increase or decrease with habitat fragmentation?
Increase
Does patch edge increase or decrease with habitat fragmentation?
Increase
Does core habitat increase or decrease with habitat fragmentation?
Decrease
How much of tropical forests in 10 countries has been lost to deforestation?
75%
How much tropical forest has been lost in Brazil to deforestation?
30%
What are four activities that have rapidly depleted Brazilian forests?
Large-scale ranching; Subsistence farming; Logging; Industrial farming
These forests have had the highest historical deforestation
Temperate forests
Forests used to cover this entire region and extended westward via river valleys
Eastern U.S.
By what year were most eastern U.S. forests logged?
1920
For what purpose were national forests established?
Timber reserves for logging
What are three ways humans impact forests?
Deforestation, fire management, and forest management
Deforestation rate in this region has slowed
Amazon
This continent has lost much of its tropical forests
Africa
In tropical forests, this is as much of a problem as the actual deforestation
Fragmentation
Fragmentation from deforestation greatly impacts this type of habitat
Core habitat
Land is often deforested in this pattern
Herringbone
Fire suppression alters this
Species composition
Fire suppression leads to this
Fuel accumulation
Fire suppression leads to increased risk of these
Large fires
This region has had large fires because of suppression
Baja/Southern California
This form of fire management impacts landscape patterns
Controlled burning
This type of forest management removes forest cover
Clear cutting
Clear cutting is not the same thing as this
Tree ‘mining’
In what country does most ‘tree mining’ happen?
Russia
Clear cuts vary in these three aspects
Size, shape, spacing
Small, irregular harvests create a landscape that is this
More ‘natural’
Harvest rotation affects this aspect of a forest
Forest age
What are two things on which rotation timelines depend?
Tree species and use
Forest plantations are these, with greatly reduced species diversity
Monocultures
These are similar to pine plantations
Natural pine forests
In natural forests, this weeds out weaker individuals and prevents other species from invading
Competition
These have the worst impact in forests
Forest roads
Forest roads do this to the landscape
Fragment