Interfacing Vegetation Databases with ecological theory and practical analysis'

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Interfacing Vegetation Databases with ecological
theory and practical analysis.

• Mike Austin, Margaret Cawsey and Andre Zerger
• CSIRO Sustainable Ecosystems
• Canberra Australia

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Examples of Current Vegetation Databases

• PurposeVegetation classification
• TurboVeg Phytosociological relevees
• Vegbank General vegetation classification
• Purpose Vegetation Analysis
• Minimalist minimum data set
• Biograd Regional prediction and mapping

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Purpose and Product
Statistical methods model
Ecological theory model
Data Measurement model
Relational Database
Geographic Information System (GIS)
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Topics

• Interface between vegetation databases theory and
  analysis
• Interface between data and practical applications
  for conservation evaluation

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Biograd Database

• Grew from minimalist database
• Location, plot data, co-occurrence of canopy
  species, slope, aspect, elevation.
• Current size 10027 plots.
• Used software packages and GIS to derive
  environmental variables
• Temperature, rainfall, radiation, soil
  properties.
• Predicted potential vegetation from species
  environmental models

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Application to Theory

• Pattern of Species Density in relation to climate.

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Questions

• What is a suitable statistical method for
  species/environment modelling
• What environmental variables predict species
  density?
• What is their relative importance?
• Does their importance vary with mean annual
  temperature?
• What does this say about models of species
  density determinants?
• What are the Database requirements for this type
  of analysis?

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Some Suggested Answers

• Statistical modelling using Generalized Additive
  Modelling (GAM)
• Predictors use both climatic and local variables
  ( 7 variables used)
• Importance GAM gives relative measure
• Hypothesis Behaviour of tree species density
  differs above and below 12ºC - split data.

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4gully
1ridge
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relative heat load and lithology are not included
in this model
lithology
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Purpose and Product
Statistical methods model
Ecological theory model
Data Measurement model
Relational Database
Geographic Information System (GIS)
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Application to conservation evaluation

• Problem of aggregating data into classes for
  inclusion in a data base
• How many soil types should be recognised?
• What are the implications for predicting species
  distribution?

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Predicting Spatial Distribution of Acacia pendula

• Acacia pendula occurs on floodplain soils under
  low rainfall conditions (lt600mm mean annual
  rainfall) in the Central Lachlan region of New
  South Wales, Australia.
• GAM models of 135 tree and shrub species
  including A. pendula were used to predict
  potential vegetation on cleared areas in the
  region.

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The central Lachlan region
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Selected study area
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An integrated approach to vegetation mapping
Data Collectionand Management
Survey
Classificationand Mapping
Products
Relational Database
Plot location environmentaldata
Plotvegetationdata
Statisticalmodelling ofindividual species
Vegetationplot data
Soil landscapedata frommanuals
Plant speciesdata
Survey
Spatial allocation tovegetation communities
Geographical InformationSystems (GIS) data
EnvironmentalStratification
DigitalElevationModel (DEM)
Climaticattributes
PredictedVegetation
DigitalTerrainModels (DTM)
Soil landscapes
Drainage
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Individual species predictions
MeanTemperature
Plot Data
Species Models
TemperatureSeasonality
Annual Mean Rainfall
S-Plus Grasp
RainfallSeasonality
ArcView Grasp script
Topographic Position
Geology
Great Soil Group
Soil Depth
Soil pH
Soil Fertility
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Spatial Prediction of Acacia pendula using
original Great Soil Groups
Masked mean annual rainfall gt 568mm
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Spatial Prediction of Acacia pendula using
reaggregated Great Soil Groups
Masked mean annual rainfall gt568mm
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Spatial Prediction of Acacia pendula Difference
between model predictions
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Conclusions

• Small changes in attribute classification can
  have a marked impact on outcomes
• Attributes in a database should be kept at as
  disaggregated a level as possible
• How cost-effective are databases where numerous
  attributes are kept which may not be used?
• Is this best done with in-house or commercial
  software

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Predicted vegetation map for the central Lachlan
region
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Current remnant distribution of predicted
vegetation communities
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Remaining area for different communities
(based on M305 mapping of woody vegetation)
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Final
Purpose and Product
Statistical methods model
Ecological theory model
Data Measurement model
Relational Database
Geographic Information System (GIS)
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Vegetation plots in good condition
(Good condition is defined as greater than 50
native plant cover in the lower vegetation layer)
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Area and condition estimates for communities
Red lt 10 in modest condition
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COMMUNITY AS AN AREAL CONCEPT
RECOGNITION OF COMMUNITIES DEPENDS ON THE
FREQUENCY OF ENVIRONMENTAL COMBINATIONS IN THE
LANDSCAPE
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Frequency of species co-occurrences as a function
of landscape
Topographic distribution of communities as
indicated in previous slide
Altered topographic distribution of communities
with the lowest bench at 170m and the highest
bench at 430m