Geoscience Reference
In-Depth Information
the.debate.(Colwell.et.al..2008;.Sekercioglu.et.al..2008),.and.further.such.research.
may. be. vital. to. assess. the. implications. of. climate. change. for. tropical. biodiversity.
(Chen.et.al..2009).
The.research.systems.described.in.this.chapter.will.allow.continued.monitoring.
of.shifts.in.species'.elevational.ranges.as.the.climate.warms..Indeed,.repeat.surveys.
of.alpine.plants.already.suggest.that.rates.of.upslope.shifts.have.increased.in.the.last.
two.decades.(Walther.et.al..2005;.Pauli.et.al..2007)..The.many.published.studies.of.
elevational.patterns.in.diversity.(e.g.,.Rahbek.1995;.Lomolino.2001;.McCain.2005).
provide.further.potential.sources.of.baseline.data.with.which.to.test.the.generality.
of. the. range. shifts. we. describe,. and. to. address. a. number. of. unresolved. questions..
Many.recent.studies.show.how.systems.with.data.on.the.past.and/or.current.eleva-
tional.ranges.of.species.present.the.opportunity.to.test.for.change.(see.Tingley.and.
Beissinger.2009)..Where.possible,.such.systems.should.continue.to.be.monitored.(or.
new.elevational.transects.should.be.established).to.provide.better.insight.into.pro-
cesses.such.as.metapopulation.dynamics.at.range.boundaries.(e.g.,.Epps.et.al..2004),.
changes.to.community.structure.(see.examples.in.Table 6.1),.or.the.biotic.interactions.
that.inluence.species.range.shifts.(e.g.,.Hodkinson.1999)..Suficient.data.do.not.yet.
exist.to.rigorously.analyze.differences.among.taxonomic.groups;.intraregional.stud-
ies.for.a.range.of.taxa.might.help.to.conirm.whether.uphill.shifts.are.faster,.more.
widespread,.or.more.predictably.uphill.(related.to.temperature).in.ectotherms.than.
endotherms,.or.whether.differential.shifts.in.the.distributions.of.interacting.species.
are.leading.to.host.release.from.natural.enemies.or.are.constraining.species.ranges.
relative.to.shifts.in.suitable.climate.space..Studies.of.the.elevational.ranges.of.the.
same.species.in.different.regions.may.help.to.determine.the.coherence.of.thermal.
associations.across.species.distributions,.and.hence.the.reliability.of.climate.enve-
lope. models. or. the. feasibility. of. assisted. colonization. programs. to. adapt. conser-
vation. to. climate. change. (which. requires. consideration. of. the. local. adaptation. of.
species.to.climatic.conditions;.Hoegh-Guldberg.et.al..2008)..Uphill.shifts.in.species.
distributions.caused.by.climate.change.appear.unwelcome.for.biodiversity,.yet.they.
present.an.opportunity.to.test.the.factors.governing.the.limits.to.species.ranges,.and.
thereby.to.plan.adaptive.measures.for.conservation..We.therefore.urge.further.eco-
logical.research.into.the.effects.of.climate.change.on.the.elevational.limits.and.extent.
of.species.distributions.
Observed.elevational.range.shifts.also.allow.some.general.recommendations.to.
be.drawn.about.approaches.to.conservation.in.the.face.of.climate.change..Species.
should.be.more.able.to.track.suitable.climates.over.elevational.rather.than.latitudinal.
gradients,. so. conservationists. must. ensure. that. suficient. favorable. habitat. is. con-
served.at.a.range.of.elevations.to.allow.them.to.do.so..In.this.context,.land.use.is.
critical..Species.such.as.plants.and.butterlies.associated.with.alpine.meadows.are.
threatened.by.land-use.changes.such.as.afforestation.and.the.abandonment.of.tradi-
tional.farming.(e.g.,.Tasser.and.Tappeiner.2002;.Van.Swaay.et.al..2006;.Becker.et.al..
2007)..Dense.forestry.can.reduce.rates.of.movement.between.populations.of.moun-
tain.butterlies.(Roland.et.al..2000).and.might.therefore.reduce.colonization.rates.in.
metapopulations.or.act.as.a.barrier.to.uphill.range.shifts..In.contrast,.whereas.graz-
ing.is.important.for.maintaining.open.habitats,.excessive.grazing.pressure.in.upland.
Britain. restricts. some. upland. plants. to. locations. inaccessible. to. sheep. (Thompson.
