FW 404: Managing Reptile and Amphibian Habitat, 10/30

Managing Reptile and Amphibian Habitat

What are Herpetopauna?

  • Amphibians = frog, toad, salamander

    • permeable, moist skin

      • susceptible to contaminants

    • 2 phase life cycle (larvae and adults)

      • one or both is linked to aquatic systems

  • Reptiles = lizard, snake, turtle

    • dry, scaly skin

    • warm temperatures for egg incubation

  • both groups are exothermic, relying on environment to regulate body temperature

Southeast is Hotspot for Herps

  • ½ of North American herp species

  • 20% are endemic

  • 45% of southeastern vertebrates

  • Mountains and salamander speciation

Coastal Plain vs. Mountains

  • Disturbance more frequent in coastal plain

    • fire, wind, etc

  • Water table higher in coastal plain

  • Coastal plain herps evolved with frequent disturbance

Threats

  • Habitat loss/fragmentation (urbanization)

  • Roads

  • Air and water pollution

  • Disease (e.g. chytrid fungus, ranavirus)

  • Pet trade

  • Land management

  • NOT CLEARCUTTING according to Moorman

Effects of Timber Harvest

  • decrease canopy, increase light, increase soil temp, increase evaporation

  • increase and decrese CWM, decrease leaf litter, increase or decrease understory

Plethodontids

  • Stream salamanders

    • aquatic and semi aquatic

    • respire through skin (lungless)

    • sensitive to terrestrial and aquatic change

    • dominate clearcutting effects research vs reptiles like snakes and lizards

    • 2 lined salamander, 3 lined salamander are streamside

    • red-backed salamander, white-spotted slimy salamander are woodland

  • Woodland salamanaders

    • fully terrestrial

    • respire through skin (lungless)

    • require most micro-environments

Lungless Salamanders

  • High richness in Southern Appalachians

  • decrease after harvest

    • clearcut, shelterwood, and group selection

  • recovery time varied from 20-100 years

  • woodland salmanaders like northern red decline after clearcut

    • losers not winners

Amphibians in Coastal Plain

  • Some frogs and toads increase after harvests

    • heat tolerant and store water in bladder

    • southern toad and narrowmouth toad

  • Salamanders decrease after harvest

Reptiles and Timber Harvest

  • Generally increase

    • mimics severe fires

    • hotter, drier afterwards

    • thermo-regulation

  • Forest species decline

    • down wood/litter specialists

    • e.g. ring-necked snake

Salamander captures decreased in shelterwood harvests. Five-lined skink captures increased in shelterwood harvest.

Site Preparation

  • Differ whether mechanical or chemical

  • Mechanical

    • direct mortality?

    • decrease in cwm, litter, root channels

    • fossorial species decline?

Pesticides and Herps

  • Permeable skin makes some susceptible

  • Insecticide use = fewer Cali frogs

  • Roundup and frogs

    • herbicide and not insecticide

    • active ingredient or surfactant

  • with herbicides, follow label, esp in aquatic systems

Riparian buffers

  • decrease sedimentation for stream salamanders

  • limit increases in soil and water temps

  • refuge from adjacent harvests

  • buffer widths range up to 300 m

Isolated Wetlands

  • unique sites with high richness

    • anurans

    • ambystoma

  • predator free ephemeral pools

  • for semi aquatics, buffers up to 300 m

Downed Woody Material

  • Redistribute harvest debris into piles

  • Retain large dbh snags

  • Snags become downed logs

  • Fire interacts with CWM dynamics

Fire and Herps

  • Lack of fire causes some herp declines

    • woody encroachment of wetlands

    • promotes herbaceous cover

  • Removes litter, changes thermal condition

  • depends on historical exposure

  • fire prevalent on southwest aspects

Depends on Fire Characters

  • Few effects of fire on population documented

    • studies short-term

    • low intensity fire

  • Longer term

    • repeated fire

    • high severity

    • canopy mortality

    • need more research in these areas

Forest structure before and after repeated low-intensity dormant prescribed burns

Amphibians showed mixed response to treatment

Petranka et al. (1993)

  • 75-80% salamanders “die” after clearcut

  • 10,000 salamander/ha (4,000 acre)

  • NC USFWS clearcut 1709 ha/year

  • eliminated 13.7 million salamanders/year

    • about 0.34% of salamanders on national forest

  • Chronic reduction by 267 million

  • How do you respond to this research?

  • How would it influence your management?

Cookbook Recommendations

  • consider historical disturbance

  • consider management goals and target species

  • maintain snags and downed wood

  • use fire when appropriate

  • consider the scale of effects

  • Retain canopy during regen. harvests

    • group selection

    • two-aged stands

  • use small clearcuts, depending on objective

  • leave riparian buffers

  • protect isolated wetlands

TOPHAT

Which is true about reptile and amphibian response to disturbance?

A

salamanders tend to increase following shelterwood harvest

B

toads tend to decline following shelterwood harvest

C

lizards tend to increase following shelterwood harvest

D

all answers are correct

E

no answers are correct