Landscape Ecology Flashcards
ecology scales
until recently small scale , large scale recent development- based on aerial photography and satellite data
GIS
Geographical information systems
Put together geographical co-ordinates with info from satellites
Why do we need to consider landscape in ecology
landscape is not homogenous
what is constitutes a landscape from an ecological perspective
Landscape is a mosaic of interacting systems
;An area spatially heterogenous in a least one factor of interest
any scale
Landscape from an organism perspective
Spatial distribution of a suitable habitat
Same physical area may represent different ‘landscapes’
Dependent on different species
Landscape ecology allows understanding of the relationship between
connectivity and biodiversity:
species distribution maps a particular landscape
barriers to migration –> speciation
structure of genetic diversity
biodiversity dirvers
For landscape ecology we must
“abstract” what the real landscape looks like in terms of useful variables
How does GIS work
allows integration of data for use in landscape ecology
Data collection by satellites, filter
Integration of multiple variables
Computer storage, processing, and spatial analysis
How does data collected vary
different materials reflect light at different wavelengths
Vary in grain size and extent
grain size
min resolution of the data, defined by the cell or minimum polygon size
Extent
The scope or domain of the data, defined as the size of the landscape or study area under consideration
Types of variables
Raw and Transformed
Examples of raw variables
temp, altitude, reflectance
Examples of transformed variables
land cover as inferred from a combo of variables
Binary variable
eg see water vs not see water
yes or no
Categorical variable
combine measurements
Gradient variable
% likelihood that something is present in a given place
landscape heterogeneity affects
species richness
Other ways in which landscapes can be classified
- composition (types of habitat, %)
- configuration: patch size, patch shape, type of patch, shape of patch, connectivity between patches
3 ways to describe landscape structure
cover types, composition, configuration
Species richness and habitat diversity: there are 2 processes operating..
Species area curve explain relationship between patch size and species richness
Heterogeneity affects species richness
larger patch=
higher diversity
In real life, patch size is associated with
fragmentation
Landscape smaller areas
hold on to species more
degree to which composition matters depends on
the organism
If there is lots of habitat available
composition matters
if there is a medium amount of habitat available
there is an interaction between composition and configuration
delineating patches procedure
define rule for connectivity (4 neighbours, 8 or 12) depending on the organism
- Join cells to clusters
- Derive statistics
Edges are equivalent to
ecotones- might have higher diversity, different species from th ecore
edges may have different ecological properties eg
microclimate
reduced access to resources
more susceptible to invasion
Exposure to invasive species and diseases
Changes in patch size effects
relative proportion of edge core habitat
More complex shapes will have
more edge areas than core
