1. Landscape Connectivity and Permeability
Jeff Haight
Landscape Ecology (BIO 521)
October 16, 2018
20 minutes in total for each student presentation
12 minutes for presenting the objectives, research questions, methods, major findings and conclusions of the study
8 minutes for questions and discussion. The presenting graduate student must prepare 2 to 3 questions ahead of time.

2. Why do we care about connectivity?
Connectivity affects populations, communities, and ecosystems
Connectivity affects people

3. Landscape Connectivity and Permeability
Landscape connectivity can be evaluated as structural or functional, but it is typically refers to linkages between patches
Landscape Permeability:
“the degree to which whole landscapes, encompassing a variety of natural, semi-natural and developed land cover types, are compatible with wildlife needs and sustain ecological processes” (landscope.org)
Key aspects of landscape permeability
Edge permeability
Matrix permeability
When quantifying ability to move across landscapes, we often talk about permeability

4. I. Edge Permeability
Nams, V. O Tortuosity of habitat edges affects animal movement. Landscape Ecology 29:655–663.

5. Edge Permeability (Nams 2014)
Edge structures and animal responses to them are hierarchical
Tortuosity is a high-level property of edge structure
Research Question:
Can an individual’s simple (low-level) behavioral responses to edge manifest as response to high-level edge structure, such as edge tortuosity?
Objectives:
Investigate whether the permeability of habitat edges is a function of edge tortuosity at a range of scales
Explore how the effect of tortuosity on edge permeability changes with variable behavioral responses to edge

6. Edge Permeability (Nams 2014)
Methods:
Simulation models of individual animal movements within patches with variable edge tortuosity and edge-crossing probability (matrix favorability)
Edge permeability = number of crossings, standardized by edge length and mean distance from edge
Animals behave variably in response to edge: Attraction, Neutral, or Avoidance
Figure 1

7. Edge Permeability (Nams 2014)
Major Findings:
Edge tortuosity does affect permeability, regardless of edge length
For neutral and avoidance edge behaviors, tortuosity mattered more when edge-crossing probabilities were low (a less favorable matrix)
The location of edge crossings depended on edge behavior
Figure 2

8. Edge Permeability (Nams 2014)
Conclusions:
Edge tortuosity can affect permeability even when animals are not attracted to or repelled by edges
Permeability is predicted to be largest when the scale of the individual’s perception matches the scale of tortuosity
Figure 5

9. II. Matrix Permeability
Caryl, F. M., K. Thomson, and R. van der Ree Permeability of the urban matrix to arboreal gliding mammals: Sugar gliders in Melbourne, Australia. Austral Ecology 38:609–616.

10. Matrix Permeability (Caryl et al. 2013)
Research Question:
What landscape characteristics influence the movements of species into and through the matrix?
Objectives
Determine which key urban matrix characteristics are associated with functional connectivity for sugar gliders in an urban landscape
Demonstrate the importance of functional connectivity for conservation
Figure 1

11. Matrix Permeability (Caryl et al. 2013)
Methods:
Four reserves with glider habitat selected. Gliders trapped and radio-collared
Buffer around each reserve used to characterize matrix urbanization and tree cover (high or low)
Matrix permeability = maximum distance traveled into the matrix
Edge permeability = proportion of occurrences in the matrix
Figure 1

12. Matrix Permeability (Caryl et al. 2013)
Major Findings:
Locations within the matrix (i.e. edge permeability) were not significantly affected by urbanization or tree cover
Matrix permeability was higher at lower degrees of urbanization, but not when tree cover was higher
Figure 2

13. Matrix Permeability (Caryl et al. 2013)
Conclusions:
When managers seek to increase landscape permeability, structural connectivity alone may not be adequate for conservation
Effective facilitation of permeability needs to consider the behaviors and needs of the species being targeted
Management of the urban matrix to decrease its contrast with natural habitat patches can enhance functional connectivity

14. Thank You!
Questions?
20 minutes in total for each student presentation
12 minutes for presenting the objectives, research questions, methods, major findings and conclusions of the study
8 minutes for questions and discussion. The presenting graduate student must prepare 2 to 3 questions ahead of time.

15. Questions for Discussion
Of the landscape metrics that we have learned about in class, which do we think most influence landscape permeability?
How would the importance of those landscape metrics vary depending on the spatial scales at which animals perceive the world?
When assessing permeability, how can we better account for heterogeneity within the matrix and its patches?