Landscape Metrics for Analysis in SD

1
Landscape Metrics for Analysis in SDG

• Eastern Ontario Pilot
• NAESI Biodiversity Theme
• Erin Neave

2
A Tiered Approach

• Provides set of tools to assess biodiversity
  condition at a variety of scales depending on
  resources available
• Provides checks/balances on each approach
• Considers ongoing work in region
• Results should identify what types of habitat of
  what quality are needed to ensure the long term
  survival of key components of biological
  diversity
• It is likely that there will not be one simple
  answer, only a range of solutions with associated
  risks

3
A Tiered Approach

• Tier 1 how much habitat is enough guidelines
• Tier 2 refined patch definitions (age class/
  cover type) and existing species/habitat
  relationships and conservation direction
  (thresholds, targets, guidelines) from the
  literature
• Tier 3 dynamic landscape models (plant
  communities and habitat requirements of surrogate
  species)

4
Existing Information

• Literature search on thresholds, targets,
  guidelines for conservation applicable to Eastern
  Ontario for
• Habitat types (consider habitat loss, total
  cover, patch size, buffer width, corridor width,
  proximity of patches, road density, patch
  attributes)
• Species (specific information on individual
  species response to habitat availability)
• Three main themes
• Representation of ecosystem types
• Landscape Configuration
• Habitat features (patch level)

5
Existing Landscape Analysis

• Eastern Ontario Model Forest State of the Forest
  Criteria and Indicators Reporting
• How much habitat is enough? A Framework for
  Guiding Habitat Rehabilitation in the Great Lakes
  Areas of Concern (CWS Ontario Region)
• Updated data and expanded focus

6
Representation/Ecosystem Diversity
7
Landscape Configuration
8
Example Total Forest Cover

• How much habitat is enough
• Percent forest cover At least 30 of the AOC
  watershed should be in forest cover

• Species-based thresholds
• Consider areas of forest cover at 40, 50 and 60
• White throated sparrow 40 forest cover for
  probability of occurrence
• White-breasted nuthatch rapid decrease in pairing
  success at 40-60 remaining forest cover
• Ovenbird populations breeding in moderately
  fragmented landscapes with lt60 forest cover
  within a 100 km radius are generally not viable
  in the long term

0
100
land base in native/ semi native cover
of land base modified for agriculture
0
100
9
Example Forest Patch Size

• How much habitat is enough
• A watershed or other land unit should have at
  least one 200 ha forest patch which is a minimum
  500 m in width
• Other broad habitat targets
• blocks greater than 30 ha likely to support a
  range of area-sensitive species (OMNR 2001 -
  SWHTG)

• Species-based thresholds
• Wood Thrush manage forests to maintain supply of
  upland deciduous or mixed forest with dense
  understorey preferably in patches of 100 ha or
  greater
• Red Shouldered Hawk protect extensive tracts
  (gt100 ha) of mature forest with wetland or
  riparian features
• Canada Warbler protect mature mixed swamp forest
  with dense understorey within extensive forest
  tracts (gt400 ha)
• (BCR 13 Habitat Objective 2005)

10
Example Riparian and Wetland Buffers

• How much habitat is enough
• Minimum guidelines for Critical Function Zone /
  Protection Zone bog the total catchment area,
  Fen 100 m or as determined by hydrogeological
  study, which ever is greater, marsh and swamp
  100 m)
• Percent of stream naturally vegetated 75 of
  stream length should be naturally vegetated 30
  m minimum buffer on both sides

• Other habitat and species-based thresholds
• Buffer widths for biodiversity values are
  generally greater than those listed for water
  quality concerns
• 150-300m from edge of aquatic site for
  amphibians and reptiles
• 150-175 m total width for corridor to include
  90-95 of bird species
• gt50 m for mammals
• 50 m for detrital input, bank stabilization
• gt30 m for invertebrates and fish
• 25 m for nutrient and pollutants
• 16 m grass or woody buffer removed 97 of
  sediment

11
Example Pollinator Services for Agriculture
How much habitat is enough No guidelines for
habitats such as grassland, hedgerows, old field
which provide important resources for many species

• Other habitat and species-based thresholds
• Consider
• 10 natural/semi-natural habitat within 1-2.5 km
  of crop field to retain pollination services to
  field (Kremen et al. 2004)
• similar results for predators/ parasitoids 1-3
  km (Hickman and Wratten 1996 Tscharntke et al.
  2005)

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Habitat features (patch level)

• Examples (Forest)
• Cavity tree density 6/ha of at least 25 cm
  dbh, 1/ha gt40 cm dbh (OMNR 2000)
• Snags 4 small (lt 50 cm dbh) and 1 large (gt50
  cm dbh) totally 5/ha (OMNR 2000)
• Canopy closure and density of large trees
  70 and 80/ha to expect complete assemblage of
  forest bird species (Guenette and Villard 2005)
• Mast tree density 8/ha gt25 cm dbh (OMNR 2000)
• protection of vernal pools