phil hurvitz avian conservation lab meeting 8. march. 2002

FocalPatch Extension

Phil Hurvitz 2002 1

Phil HurvitzAvian Conservation Lab Meeting

8. March. 2002

The FocalPatch Extension


Phil Hurvitz 2002 2

Overview

• Landscape Ecology• Landscape Configuration• Landscape Ecology Metrics• Fragstats• Focal Functions in GIS • The FocalPatch Extension• Patch Metrics and Utilization Distributions• Fragstats Revisited


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Overview



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Landscape Ecology

• Background

Landscape ecology emphasizes the interaction between spatial pattern and ecological process -- that is, the causes and consequences of spatial heterogeneity across a range of scales. Two important aspects of landscape ecology distinguish it from other subdisciplines within ecology.

First, landscape ecology explicitly addresses the importance of spatial configuration for ecological processes. Not only is landscape ecology concerned with how much there is of a particular component but also with how it is arranged.

Second, landscape ecology often focuses upon spatial extents that are much larger than those traditionally studied in ecology. Landscape ecology offers new concepts, theory and methods that are revealing the importance of spatial patterning on the dynamics of interacting ecosystems.

http://ravel.zoology.wisc.edu/mgt/ (Monica G. Turner)

http://ravel.zoology.wisc.edu/mgt/


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Landscape Ecology

• Background, continued• Effect of spatial configuration on ecological

process• Ecological process across large spatial scale

• GIS must be a central (tool = language = environment) for investigation of landscape ecology issues


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Overview



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Landscape Configuration• Varying configurations occur in both

managed and unmanaged areas

east of SeattleYakima area

near Hanford

(images from Terraserver)


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Landscape Configuration

• Different configurations can have very different effects on ecological function• Movement of plants & animals (enhancement

or inhibition)• Edge/interior effects, isolation


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• Understanding landscape configuration and composition is a central problem in management of ecosystems

• Loss or maintenance of “natural” (“sustainable”?) ecological functionality

• Configuration and composition affect ecological processes


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• Varying scale of landscape configuration can have varying effects on different species

(image from Fragstats manual)



Overview




Landscape Ecology Metrics

• Patterns and differences are immediately recognized by the eye + brain

• Landscape Ecology Metrics allow these patterns in space to be described quantitatively



Landscape Ecology Metrics

• Quantification of patch configuration on the landscape

• Central quantitative basis for much analysis & understanding in Landscape Ecology

• Attempt to quantify either individual patches, classes, or the entire landscape

• Assess continuity, contiguity, or fragmentation of landscape elements



Overview




Fragstats

• Developed by Kevin McGarigal & Barbara Marks, OSU 1994

• Computer program for calculating a number of patch, class, and landscape ecology metrics

• Integrated with ESRI GIS• fragstats.aml from McGarigal & Marks• ArcView Extension Patch Analyst (Rob

Rempel)



Fragstats L.E. Metrics: Classes

• Area• Patch density, patch size & variability• Edge• Shape• Core area• Nearest neighbor• Diversity• Contagion & interspersion



Fragstats

• Patch metrics




Fragstats

• Class metrics




Fragstats

• Landscape metrics




Fragstats L.E. Metrics: Examples

• Landscape Similarity Index (LSIM)

• For each patch type, LSIM is the proportion (percentage) of the landscape in that class

• Indicates the relative dominance of each different class




• Edge Contrast Index (EDGECON)

• Edge contrast values [0, 1] are specified for each combination of patch types

• EDGECON is the sum of (patch perimeters * edge contrast values)

• Indicates a “weighted” perimeter




• Fractal Dimension

• Indication of the convolution of shape for each patch

• R: 1 FRACT 2• Approaches 1 for simple shapes (circle, square)• Approaches 2 for highly convoluted shapes



Overview




Focal Functions in GIS

• Processing occurs on a central cell in conjunction with the values associated in its neighborhood

• “Moving window”• “Kernel”




• Example of the focal mean function

7.186

8) 44 6 16 21 16 22 8 (27




• ArcInfo & ArcViewfocal functionsare all “basic”statistical



Overview





• Application of focal processing on land cover grids

• Instead of using ArcInfo focal statistics, calculates Fragstats Landscape Ecology metrics on a focal basis




• New ArcView 3.x extension




• Creates point features




• Creates CWED file




• Runs on points




• Output files




• On a cell-by-cell basis• Creates a point feature at the cell center• Extracts the region in a user-specified radius

around the point• Calculates landscape metrics for that circle• Places metrics back into point attribute table




• Extract circle from habitat grid at user-defined radius




• Calculate landscape metrics

Rempel’s interface Rempel’s batch script




• Calculateslandscape metrics

• Values represent the landscape metrics for the focal region around the central cell




• Points can be used for interpolation of surfaces

• Surfaces can represent any of the landscape metrics



Overview




Patch Metrics and Utilization Distributions

• Some animal species respond to large regions of landscapes

• Typical animal-landscape relationships are explored either by point processes or by land cover types

• Is there a relationship between landscape metrics and actual animal usage of landscape?

• Which landscape characteristics do animals respond to ?




utilization distribution (UD)limit processing to UD




contrast-weighted edge surfaceutilization distribution




• Regression techniques will be used to determine strength of relationship between utilization and landscape metrics• Multiple regression• Raster regression within GRID



Overview




Fragstats Revisited

• Version 3 of Fragstats: “ Analysis Type.–Chose between “standard”

and “moving window” Moving Window.--If moving window mode

is selected, then FRAGSTATS will conduct a moving window analysis and output a separate grid for each metric selected.”



Fragstats Revisited

• Does Fragstats v.3 actually perform moving window analysis?



Final Question

• Given that Fragstats v.3 might perform focal analysis of landscape data, is it worth it to continue development of an ArcView 3.X interface for focal Fragstats analysis?

• What are the benefits of having this within the ArcView environment?

• Can this be considered original work?

phil hurvitz avian conservation lab meeting 8. march. 2002

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