Amphibians and Forested Wetlands

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Amphibiansand Forested Wetlands
Washington Department of FISH AND WILDLIFE
Marc P. Hayes
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Forested Wetland Amphibians

• NO PNW amphibian studies have focused
  specifically on forested wetlands
• MAJOR DATA GAP
• Amphibian species richness and relative abundance
  among forested wetland categories virtually
  unknown

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Why the Data Gap?

• Wetland studies exist, BUT
• Estuarine and stillwater emphasis
• Foci - Open (non-forested) habitats estuaries
  saline most easily sampled habitat in
  freshwaters
• Biases Amphibians rare in bogs
• Ignorance of selected wetland types (e.g.,
  sloping fens)

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Truth?

• Amphibians
• and
• Forested Wetlands
• Diverse in PNW

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Amphibian Diversity
Based in part on use of reproductive habitat
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Reproduction ONLY
Part of Story
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Forested Wetland Amphibians

• 19 (76) amphibian species in Washington have a
  high likelihood of using forested wetland habitat
  for at least one of their life stages

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Forested Wetland Amphibians

• All 7 FFR amphibians in Washington have been
  documented using forested wetland habitat for at
  least one of their life stages

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(No Transcript)
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Forest WetlandSystems
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Potential Changesin Forested Wetlands

• Watered area or hydroperiod
• Succession
• Organic storage or nutrient inputs
• Exotic biota
• Other possibilities

Leads to changes in amphibian abundance or
species richness?
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Seep Area and Torrentor Seep Salamander Density
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Consequence of Watered Area or Hydroperiod Changes
Decreases in watered areas may reduce
available habitat (temporary?)
number of habitat units (local extirpation?)
Increases in watered areas may
increase available habitat reduce
distinguishable habitat unit Decreases in
hydroperiod may eliminate
longer-hydroperiod requiring species
alter refuge habitat quality for some species
Increases in hydroperiod may add
longer-hydroperiod requiring species
increase accessibility of fish and exotics
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Consequence of Successional Changes
Increased shading of stillwater forested
wetlands (i.e., bogs and fens) may reduce
diversity of stillwater-breeding
amphibians. Decrease shading may do the reverse
assuming all else is equal Increased shading
of flowing water forested wetlands may reduce
the relatively abundance of grazing
amphibian Decrease shading of flowing water
forested wetlands may do the reverse assuming
all else is equal
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Consequence of Organic Storage or Nutrient Changes
Increased nutrient loading may accelerate
succession in bogs or fens, which could alter the
diversity stillwater-breeding amphibians
If a bog was pH limited (3.8 or below), such
loading may at least initially increase
stillwater- breeding amphibians
diversity. If a bog was not pH limited,
such loading may decrease the stillwater
amphibian diversity. Increased woody
debris/slash may favor stillwater- breeding
amphibians that use such for reproduction or
refuge
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Life History Larvae grazers in flowing
water Juveniles and adults insectivorous, can
use aquatic or terrestrial habitats Adults
reproduce in moderate to high flow habitats
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Tailed Frogs Habitat Picture
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Life History Larvae, Juveniles and Adults
insectivorous, use wet or saturated habitats Repr
oduction in low flow habitats
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Torrent or Seep Salamanders Habitat Picture
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Life History Juveniles and Adults
insectivorous, use saturated or dripping wet
habitats No larval stage (direct
development), reproduction in moist terrestrial
site female parental care
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Van Dykes Salamander Habitat Picture
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Life History Juveniles and Adults
insectivorous, use moist stream margin
habitats No larval stage (direct
development), reproduction in moist terrestrial
site female parental care
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Dunns SalamanderHabitat Picture
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Life History Larvae, Juveniles and Adults
insectivorous Larvae streams Juveniles and
Adults moist terrestrial habitats Reproduction
streams female parental care
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Life History Juveniles and Adults
insectivorous, use moist terrestrial habitats No
larval stage (direct development), reproduction
in moist terrestrial site female parental care
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Life History Larvae pond grazers Juveniles/Adul
ts insectivorous-carnivorous Larvae
ponds Juveniles and Adults moist terrestrial
or aquatic habitats Reproduction
open stillwater habitats
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Life History Larvae pond grazers Juveniles/Adul
ts insectivorous-carnivorous Larvae
ponds Juveniles and Adults moist terrestrial
habitats Reproduction open stillwater habitats
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Life History Larvae/Juveniles/Adults insectivor
ous-carnivorous Larvae ponds Juveniles and
Adults moist terrestrial habitats Reproduction
stillwater habitats
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Key Needs

• Life-stage specific diversity of amphibians
  across forested wetlands types needs to be
  understood.
• For FFR amphibian taxa, the biggest gaps in
  potential significant use of forested wetlands is
  as active-season or overwintering habitat
• Selected potentially high sensitivity forested
  wetlands categories (e.g., sloping fens) need
  study to address their importance to selected FFR
  species (e.g., Van Dykes salamander).