Biodiversity change is uncoupled from species richness trends: consequences for conservation and monitoring

TY - JOUR

T1 - Biodiversity change is uncoupled from species richness trends: consequences for conservation and monitoring

AU - Hillebrand, Helmut

AU - Blasius, Bernd

AU - Borer, Elizabeth T.

AU - Chase, Jonathan M.

AU - Downing, John

AU - Eriksson, Britas Klemens

AU - Filstrup, Christopher T.

AU - Harpole, W. Stanley

AU - Hodapp, Dorothee

AU - Larsen, Stefano

AU - Lewandowska, Aleksandra M.

AU - Seabloom, Eric W.

AU - Van de Waal, Dedmer B.

AU - Ryabov, Alexey B.

N1 - 6320, AqE; Data Archiving: data archived at Dryad

PY - 2018

Y1 - 2018

N2 - * Global concern about human impact on biological diversity has triggered an intense research agenda on drivers and consequences of biodiversity change in parallel with international policy seeking to conserve biodiversity and associated ecosystem functions. Quantifying the trends in biodiversity is far from trivial however, as recently documented by meta-analyses, which report little if any net change of local species richness through time. * Here, we summarize several limitations of species richness as a metric of biodiversity change and show that the expectation of directional species richness trends under changing conditions is invalid. Instead, we illustrate how a set of species turnover indices provide more information content regarding temporal trends in biodiversity, as they reflect how dominance and identity shift in communities over time. * We apply these metrics to three monitoring data sets representing different ecosystem types. In all data sets, nearly complete species turnover occurred, but this was disconnected from any species richness trends. Instead, turnover was strongly influenced by changes in species presence (identities) and dominance (abundances). We further show that these metrics can detect phases of strong compositional shifts in monitoring data and thus identify a different aspect of biodiversity change decoupled from species richness. * Synthesis and applications: Temporal trends in species richness are insufficient to capture key changes in biodiversity in changing environments. In fact, reductions in environmental quality can lead to transient increases in species richness if immigration or extinction have different temporal dynamics. Thus, biodiversity monitoring programs need to go beyond analyses of trends in richness in favour of more meaningful assessments of biodiversity change. This article is protected by copyright. All rights reserved.

AB - * Global concern about human impact on biological diversity has triggered an intense research agenda on drivers and consequences of biodiversity change in parallel with international policy seeking to conserve biodiversity and associated ecosystem functions. Quantifying the trends in biodiversity is far from trivial however, as recently documented by meta-analyses, which report little if any net change of local species richness through time. * Here, we summarize several limitations of species richness as a metric of biodiversity change and show that the expectation of directional species richness trends under changing conditions is invalid. Instead, we illustrate how a set of species turnover indices provide more information content regarding temporal trends in biodiversity, as they reflect how dominance and identity shift in communities over time. * We apply these metrics to three monitoring data sets representing different ecosystem types. In all data sets, nearly complete species turnover occurred, but this was disconnected from any species richness trends. Instead, turnover was strongly influenced by changes in species presence (identities) and dominance (abundances). We further show that these metrics can detect phases of strong compositional shifts in monitoring data and thus identify a different aspect of biodiversity change decoupled from species richness. * Synthesis and applications: Temporal trends in species richness are insufficient to capture key changes in biodiversity in changing environments. In fact, reductions in environmental quality can lead to transient increases in species richness if immigration or extinction have different temporal dynamics. Thus, biodiversity monitoring programs need to go beyond analyses of trends in richness in favour of more meaningful assessments of biodiversity change. This article is protected by copyright. All rights reserved.

KW - biodiversity loss

KW - diversity

KW - dominance

KW - richness

KW - species composition

KW - species turnover

KW - time series

KW - monitoring

KW - human impact

KW - biodiversity change

KW - international

UR - http://dx.doi.org/10.5061/dryad.1sd59

U2 - 10.1111/1365-2664.12959

DO - 10.1111/1365-2664.12959

M3 - Article

SN - 1365-2664

VL - 55

SP - 169

EP - 184

JO - Journal of Applied Ecology

JF - Journal of Applied Ecology

IS - 1

ER -