Geoscience Reference
In-Depth Information
suggested.that.changes.in.temperature.and.moisture.could.cause.physiological.stress.
in. amphibians,. affect. their. mobility. patterns,. change. the. timing. and. duration. of.
breeding,.and.affect.growth,.hibernation,.and.aestivation.patterns.
Changes. in. global. temperature,. precipitation,. and. levels. of. ultraviolet. radiation.
may. contribute. to. amphibian. population. declines.. Moreover,. contamination. from.
airborne.pollutants.and.other.chemicals.may.act.alone.or.in.conjunction.with.global.
climate. change. to. adversely. affect. amphibian. populations.. Finally,. a. number. of.
investigators. have. proposed. that. emerging. infectious. diseases. may. be. stimulated.
by.climate.change.and.changes.in.the.levels.of.UV-B.radiation.reaching.the.earth's.
surface.(e.g.,.Epstein.1997;.Kiesecker.et.al..2001).
ASSESSING THE EFFECTS OF CLIMATE CHANGE ON AMPHIBIANS
C
limaTe
C
hange
and
a
mphibian
p
opulaTion
d
eClines
There. is. some. evidence. that. climate. change. may. be. contributing. to. amphibian.
population. declines—either. directly. or. indirectly.. Several. authors. have. suggested.
that. unusual. weather. contributes. to. amphibian. population. declines.. For. example,.
McMenamin.et.al..(2008).described.how.increasing.temperatures.and.drought.have.
contributed.to.loss.of.amphibian.habitats.in.parts.of.western.North.America..They.
observed.severe.reductions.in.the.number.and.diversity.of.amphibian.populations.in.
northern.Yellowstone.National.Park.in.the.United.States.for.16.years..Moreover,.they.
documented.that.amphibian.declines.in.that.region.were.linked.to.regional.changes.
in.the.hydrologic.landscape.and.overall.groundwater.condition,.which.were.driven.
by.long-term,.large-scale.climatic.change..The.disappearance.of.several.amphibian.
species.in.southeastern.Brazil.in.the.late.1970s.was.attributed.to.unusual.frost.(Heyer.
et.al..1988)..Weygoldt.(1989).attributed.population.declines.of.Brazilian.frogs.in.the.
Atlantic.mountains.to.extremely.dry.winters..The.disappearance.of.the.golden.toad.
(
Bufo periglenes
).in.Costa.Rica.was.originally.attributed.to.unusual.weather.condi-
tions.including.warmer.temperatures.and.changes.in.precipitation.patterns.that.may.
have.affected.breeding.patterns.(Crump.et.al..1992).
D'Amen.and.Bombi.(2009).tested.the.effects.of.global.warming,.habitat.destruc-
tion,. and. ultraviolet. radiation. on. population. declines. of. amphibians. in. Italy.. By.
analyzing. spatial. patterns. they. found. that,. even. though. multiple. factors. are. likely.
involved. in. amphibian. population. declines,. climate. change. appeared. to. play. the.
greatest. role.. Climatic. shifts. were. often. associated. with. declines,. even. in. species.
experiencing.slow.rates.of.population.decline.
Pounds.et.al..(1999).illustrated.the.complex.interrelationships.among.global.envi-
ronmental.changes.and.amphibian.population.declines..They.found.that.changes.in.
water. availability. associated. with. changes. in. large-scale. climate. processes,. such.
as. the. El. Nĩo/Southern. Oscillation. (ENSO),. may. signiicantly. affect. amphibian,.
reptile,. and. bird. populations. in. the. Monteverde. cloud. forest. of. Costa. Rica.. They.
showed.that.dry.periods.associated.with.global.warming.are.correlated.with.amphib-
ian.and.reptile.losses.and.changes.in.the.bird.community..In.Costa.Rica.and.poten-
tially.in.other.high-altitude.tropical.sites,.global.warming.appears.to.have.resulted.
