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Cited by 236Ecology and Vegetation Dynamics StudiesWildlife Ecology and ConservationConservation, Biodiversity, and Resource Management

The Diversity-Weighted Living Planet Index: Controlling for Taxonomic Bias in a Global Biodiversity Indicator

Open access
McRae, Louise, Deinet, Stefanie, Freeman, Robin·2017·PLOS ONE
DOI 10.1371/journal.pone.0169156PMC PMC5207715
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Abstract

As threats to species continue to increase, precise and unbiased measures of the impact these pressures are having on global biodiversity are urgently needed. Some existing indicators of the status and trends of biodiversity largely rely on publicly available data from the scientific and grey literature, and are therefore prone to biases introduced through over-representation of well-studied groups and regions in monitoring schemes. This can give misleading estimates of biodiversity trends. Here, we report on an approach to tackle taxonomic and geographic bias in one such indicator (Living Planet Index) by accounting for the estimated number of species within biogeographical realms, and the relative diversity of species within them. Based on a proportionally weighted index, we estimate a global population decline in vertebrate species between 1970 and 2012 of 58% rather than 20% from an index with no proportional weighting. From this data set, comprising 14,152 populations of 3,706 species from 3,095 data sources, we also find that freshwater populations have declined by 81%, marine populations by 36%, and terrestrial populations by 38% when using proportional weighting (compared to trends of -46%, +12% and +15% respectively). These results not only show starker declines than previously estimated, but suggests that those species for which there is poorer data coverage may be declining more rapidly.

AI snapshot

Written from the paper’s full text.

TL;DR

The paper develops a diversity-weighted Living Planet Index (LPI-D) to correct taxonomic and geographic bias in the Living Planet Index by weighting species trends according to estimated species richness across realms and taxa. It estimates a 58% global vertebrate population decline from 1970 to 2012, compared with 20% under the unweighted LPI.

Key findings

  • The global LPI-D declined by 58% (95% CI: -48.3 to -66.0) between 1970 and 2012, an average annual decline of 2%, versus a 19.7% decline (95% CI: -6.6 to -30.9) and 0.52% annual decline for the unweighted LPI-U.
  • System-level LPI-D declines were 81.5% for freshwater (95% CI: -68.5 to -89.3), 35.6% for marine (95% CI: -19.5 to -48.8), and 37.9% for terrestrial (95% CI: -20.4 to -51.5); Table 1 gives LPI-U 2012 index values of 0.544 for freshwater, 1.125 for marine, and 0.848 for terrestrial.
  • For the Palearctic realm, LPI-U showed a 38.4% increase (95% CI: 12.7–66.2), while LPI-D showed a 30.3% decline (95% CI: -1.4 to -50.2).
  • The database contained 14,152 populations of 3,706 species from 3,095 data sources; representation was biased toward temperate birds and mammals, with under-representation of most tropical realms and marine fishes, and Afrotropical herps representing less than 1% of known species.

Methods

  • Data came from the Living Planet Database: time series of population size, density, abundance, or abundance proxies for vertebrate species from 1970 to 2012, requiring at least two years of data, consistent methods, and traceable sources.
  • The LPI-D weighted trends by estimated known species richness across systems, biogeographic realms, and taxonomic groups (birds, mammals, fish, and combined herps), producing 57 subsets; systems were weighted equally, realms were weighted by species proportions within systems, and taxa were weighted by species proportions within realms.
  • Population trends were modeled with Generalized Additive Models for series with six or more data points and the chain method otherwise; population lambdas were averaged to species trends, and 95% confidence intervals were generated with 10,000 bootstrap iterations. Binomial tests assessed taxonomic over- or under-representation.

Limitations

  • Stated: the approach relies on reasonable species lists, which change over time and may be lower quality for less studied groups and regions; estimates of undescribed species (57% amphibians, 13% reptiles, 22% fish) suggest these groups could receive even greater weight and that declines may be steeper than estimated.
  • Stated: LPI-D addresses broad geographic bias but not smaller-scale coverage gaps, such as Palearctic data being largely from Europe, Afrotropical data being better represented in eastern and southern Africa, and marine data clustering near coasts.
  • Stated and evident: manual data entry is a critical limitation for growing the database; some abundance records are confidential and cannot be made publicly available, and incomplete IUCN assessments for fishes (745 of 1,369 species unassessed, plus 40 Data Deficient) limit the threatened-species representation analysis.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1371/journal.pone.0169156

Cites

37 of 37 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 37 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    The proportion of terrestrial LPD sites in protected areas is more than the expected 13%.

    “Our comparison to a study on geographic bias in terrestrial ecological sites revealed that 63% of the terrestrial sites in the LPD occur in a protected area which is the same proportion as found in Martin et al. (χ2 = 0.004, df = 1, p = 0.95), and more than the expected 13% (χ2 = 883.83, df = 1, p = 0.00).”
    Quote in the paperNot a substantial claim
  • Findingown data

    The unweighted Living Planet Index (LPI-U) estimates a global decline of 19.7% (95% CI: -6.6 to -30.9) in vertebrate populations between 1970 and 2012.

    “Based on a proportionally weighted index, we estimate a global population decline in vertebrate species between 1970 and 2012 of 58% rather than 20% from an index with no proportional weighting.”
    • Also stated in: § Applying the LPI-D approach to the global living planet index · plain
      “This result shows a greater rate of decline than the index calculated using the LPI-U approach which has an average annual decline of 0.52% per year and an overall decline of 19.7% (95% CI: -6.6 –-30.9), over the 42-year period.”
    Quote in the paperSubstantial claim
  • Findingown data

    Freshwater populations declined by 46% under the unweighted Living Planet Index between 1970 and 2012.

    “From this data set, comprising 14,152 populations of 3,706 species from 3,095 data sources, we also find that freshwater populations have declined by 81%, marine populations by 36%, and terrestrial populations by 38% when using proportional weighting (compared to trends of -46%, +12% and +15% respectively).”
    Quote in the paperSubstantial claim
  • Findingown data

    The proportion of terrestrial LPD sites in protected areas is the same as found in Martin et al.

    “Our comparison to a study on geographic bias in terrestrial ecological sites revealed that 63% of the terrestrial sites in the LPD occur in a protected area which is the same proportion as found in Martin et al. (χ2 = 0.004, df = 1, p = 0.95), and more than the expected 13% (χ2 = 883.83, df = 1, p = 0.00).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Martin et al.

      Not checked in the free run.

  • Findingown data

    Freshwater populations declined by 81% under the diversity-weighted Living Planet Index between 1970 and 2012.

    “From this data set, comprising 14,152 populations of 3,706 species from 3,095 data sources, we also find that freshwater populations have declined by 81%, marine populations by 36%, and terrestrial populations by 38% when using proportional weighting (compared to trends of -46%, +12% and +15% respectively).”
    Quote in the paperSubstantial claim
  • May combine two claims. 42
  • Classified as probably not a substantial claim. 18

  • May combine two claims.

    Findingown data

    Global vertebrate richness overlaid with locations of populations currently recorded within the Living Planet Index shows biases towards temperate regions, which the Living Planet Index over-represents, and under-representation of tropical regions.

    “Global vertebrate richness overlaid with locations of populations currently recorded within the Living Planet Index shows biases towards temperate regions, which the Living Planet Index over-represents, and under-representation of tropical regions (Fig 2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Afrotropical amphibians and reptiles represent less than 1% of known species and South temperate and Antarctic reptiles are currently not represented at all in the LPI database.

    “Afrotropical amphibians and reptiles (‘Afrotropical Herps’) represent less than 1% of known species and South temperate and Antarctic reptiles are currently not represented at all in the LPI database (0%, of a possible 3 species; not shown in figure).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The terrestrial index shows a 37.9% decline (95% CI: -20.4 to -51.5) from 1970 to 2012, averaging a 1.13% decline per year.

    “The terrestrial index shows a 37.9% decline (95% CI: -20.4 –-51.5) from 1970 to 2012, averaging at a 1.13% decline per year.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    In the marine system, the highest representation of species is for Pacific north temperate reptiles (100%, 2 species).

    “In the marine system, the highest representation of species is for Pacific north temperate reptiles (100%, 2 species).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The freshwater index shows an 81.5% decline (95% CI: -68.5 to -89.3) over 1970-2012, averaging a 3.94% decline per year.

    “The freshwater index shows a decline of greater magnitude, 81.5% (95% CI: -68.5 –-89.3) over the 42-year period and an average annual decline of 3.94% per year.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The pattern of representation in wealthy countries was similar to Martin et al. but overall results were mixed with over- and under-representation of high and low income countries compared to the number of sites expected.

    “The pattern of representation in wealthy countries was similar to Martin et al. but overall results were mixed with over- und under-representation of high and low income countries compared to the number of sites expected (S4 Table).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Martin et al.

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    The highest terrestrial and freshwater representation is for Nearctic birds (68%, 492 species out of a possible 725 species) and the lowest is for Afrotropical reptiles and amphibians (0.7%, 18 species of a possible 2,480 species).

    “The highest terrestrial and freshwater representation is for Nearctic birds (68%, 492 species out of a possible 725 species) and the lowest is for Afrotropical reptiles and amphibians (0.7%, 18 species of a possible 2,480 species).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    For the marine system, 6 subsets represent between 1 and 10% and 16 subsets represent 10% or more of known species.

    “For the marine system, 6 subsets represent between 1 and 10% and 16 subsets represent 10% or more of known species (S6B Table).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The taxonomic groups that are significantly under-represented in each terrestrial and freshwater realm are amphibians and reptiles, as well as fishes, the exception being Nearctic species which are all over-represented.

    “The taxonomic groups that are significantly under-represented in each terrestrial and freshwater realm are amphibians and reptiles, as well as fishes, the exception being Nearctic species which are all over-represented.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    The rate with which new data are incorporated into the LPD is relatively constant.

    “The rate with which new data are incorporated is relatively constant (S1 Fig), as a wealth of data remains available in the literature.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The diversity-weighted Living Planet Index (LPI-D) shows a greater decline than the unweighted LPI (LPI-U) for each of the terrestrial, freshwater and marine system indices.

    “The results of the LPI-D approach on the three system indices reveal that each show a greater decline than the LPI-U approach (Fig 6).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For marine realms, the significant results for birds, mammals and reptiles show they are over-represented in all realms with the exception of South temperate and Antarctic reptiles where there is no representation of the three species.

    “For marine realms, the significant results for birds, mammals and reptiles show they are over-represented in all realms with the exception of South temperate and Antarctic reptiles where there is no representation of the three species (S8 Table).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The effect of using proportional weighting means that the influence of the over-represented groups such as birds and mammals has been reduced by over half and almost a fifth respectively, whereas the influence of fishes has been increased by over three-fold and amphibians/reptiles by over two-fold.

    “The effect of using proportional weighting means that the influence of the over-represented groups such as birds and mammals has been reduced by over half and almost a fifth respectively, whereas the influence of fishes has been increased by over three-fold and amphibians/reptiles by over two-fold.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Each index shows a greater decline when groups with less than 1% representation are removed, but the difference is not significant.

    “Each index shows a greater decline when these groups are removed, which is most noticeable in the Terrestrial LPI-D index but it is not significantly different.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    At the global level, the LPI-U suggests a decline of 19.7%, while the LPI-D suggests a significantly larger decline of 58%.

    “The difference is also notable at the global level where the LPI-U suggests a decline of 19.7%, compared to a significantly larger declines of 58% in the LPI-D.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The LPI-D suggests that, on average, species populations within the Palearctic may have declined by 30.3%, whereas the LPI-U suggests an increase of 38.4%.

    “This weighted approach (LPI-D) suggests that, on average, species populations within the Palearctic may have declined by 30.3% as opposed to increasing in abundance by 38.4% (Fig 4) in the unweighted index (LPI-U).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The geographic and taxonomic representation of species in the LPI is varied with 12 subsets representing between 1 and 10% and 7 subsets representing over 10% of known species in the terrestrial and freshwater systems.

    “This representation is varied with 12 subsets representing between 1 and 10% and 7 subsets representing over 10% of known species in the terrestrial and freshwater systems (S6A Table).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The LPD data tend to be over-represented for temperate bird and mammal species, and under-represented for most species groups in tropical realms and for marine fishes.

    “The data tend to be over-represented for temperate bird and mammal species, and under-represented for most species groups in tropical realms and for marine fishes.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Findingnone given

    In the Afrotropics, eastern and southern Africa are better represented than western and central Africa.

    “Likewise in the Afrotropics, eastern and southern Africa are better represented than western and central Africa.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    For the marine system, data tend to be clustered near the coasts, which are areas of high human impact and higher species richness.

    “For the marine system, data tend to be clustered near the coasts which is where most known impact from human activity occurs [41] but also the areas of higher species richness [42].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [41] BS Halpern, 2008, A Global Map of Human Impact on Marine Ecosystems, Science source

      Not checked in the free run.

    • cites [42] DP Tittensor, 2010, Global patterns and predictors of marine biodiversity across taxa, Nature source

      Not checked in the free run.

  • May combine two claims.

    Findingnone given

    Amphibians, which are not significantly over-represented by threatened species, along with reptiles, are given the highest weighting among terrestrial species and the second highest weighting among freshwater species.

    “For example, amphibians, which are not significantly over-represented by threatened species, along with reptiles, are given the highest weighting among the terrestrial species and the second highest weighting among freshwater species.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Compared to the expected number of sites across biomes, the LPI over-represents Tropical deciduous woodland and under-represents Tropical evergreen woodland.

    “Compared to the expected number of sites across biomes, the LPI over-represents Tropical deciduous woodland and under-represents Tropical evergreen woodland (S3 Table).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The data from the Palearctic realm is largely from Europe, with much less coverage in Asia.

    “For example, the data from the Palearctic realm is largely from Europe and there is much less coverage in Asia (Fig 2).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    When compared to the expected diversity of species across realms, the significant results for birds and mammals show over-representation within terrestrial and freshwater realms with the exception of Afrotropical birds which are under-represented.

    “When compared to the expected diversity of species across realms, the significant results for birds and mammals show over-representation within terrestrial and freshwater realms with the exception of Afrotropical birds which are under-represented (Binomial test of proportions, see S7 Table).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The terrestrial data portion of the LPD has a geographic bias towards protected areas, tropical deciduous woodland and some wealthy countries, and under-representation of tropical evergreen woodland biomes.

    “We also find a geographic bias in the terrestrial data portion of the LPD towards protected areas, tropical deciduous woodland and some wealthy countries, at the same time as under-representation of tropical evergreen woodland biomes.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Findingnone given

    The majority of fish species (745 out of 1,369 species) have not yet been assessed by the IUCN Red List, and a further 40 species are assessed as Data Deficient, so these species were not included in this analysis.

    “What is also important to note is that the majority of fish species (745 out of 1,369 species) have not yet been assessed by the IUCN Red List and a further 40 species are assessed as Data Deficient so these species were not included in this analysis.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For values derived from an equal distribution of sites by global area, all other biomes except Tundra are over-represented while results are less clear by an assumed equal distribution among biomes.

    “For values derived from an equal distribution of sites by global area, all other biomes except Tundra are over-represented while results are less clear by an assumed equal distribution among biomes (S3 Table).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Fishes are a significantly under-represented group in the tropical and south temperate marine realms but are significantly over-represented in the Pacific north temperate.

    “Fishes are a significantly under-represented group in the tropical and south temperate marine realms but are significantly over-represented in the Pacific north temperate.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The marine index shows a 35.6% decline (95% CI: -19.5 to -48.8) over 1970-2012, averaging a 1.04% decline per year.

    “The marine index shows a similar decline of 35.6% (95% CI: -19.5 –-48.8) over the same period, with an average annual decline of 1.04% per year.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The LPI-D index for the Palearctic realm shows wider confidence intervals than the LPI-U index as well as a more undulating trend.

    “The LPI-D index for the Palearctic realm shows wider confidence intervals than the LPI-U index as well as a more undulating trend.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    These types of bias are a common feature of other global biodiversity databases, usually with a noticeable gap in data from tropical regions.

    “These types of bias are a common feature of other global biodiversity databases [10,11], usually with a noticeable gap in data from tropical regions [12].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [10] EH Boakes, 2010, Distorted Views of Biodiversity: Spatial and Temporal Bias in Species Occurrence Data, PLoS Biol source

      Not checked in the free run.

    • cites [11] C Yesson, 2007, How Global Is the Global Biodiversity Information Facility?, PLoS ONE source

      Not checked in the free run.

    • cites [12] B Collen, 2008, The tropical biodiversity data gap: addressing disparity in global monitoring, Tropical Conservation Science source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The performance of biodiversity indicators such as the LPI can be compromised by the presence of bias in the data and limited in effectiveness as tools in measuring progress towards specific policy targets.

    “Furthermore, the performance of biodiversity indicators such as the LPI can be compromised by the presence of bias in the data and limited in effectiveness as tools in measuring progress towards specific policy targets [1,14].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [1] B Collen, 2014, Taking the measure of change, Science source

      Not checked in the free run.

    • cites [14] E Nicholson, 2012, Making Robust Policy Decisions Using Global Biodiversity Indicators, PLoS ONE source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Other indicators based on species abundance are developed for a selected group of species using a systematic monitoring protocol, so the indicator is spatially and taxonomically representative of the region and taxa in question.

    “Other indicators based on species abundance (e.g. [15,16]) are developed for a selected group of species using a systematic monitoring protocol to collect the data used, so the indicator is spatially and taxonomically representative of the region and taxa in question.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [15] RD Gregory, 2005, Developing indicators for European birds, Philosophical Transactions of the Royal Society of London B: Biological Sciences source

      Not checked in the free run.

    • cites [16] CAM van Swaay, 2008, Butterfly monitoring in Europe: methods, applications and perspectives, Biodiversity and Conservation source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The Living Planet Index (LPI) is one in the suite of global species indicators used to track progress towards Aichi Target 12 and focuses on monitoring population trends of vertebrate species.

    “The Living Planet Index (LPI) [7–9], one in the suite of global species indicators used to track progress towards Aichi Target 12, focusses on monitoring the population trends of vertebrate species.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [7] WWF (2016) Living Planet Report 2016: Risk and resilience in a new era WWF International, Gland, Switzerland.

      Not checked in the free run.

    • cites [8] B Collen, 2009, Monitoring Change in Vertebrate Abundance: the Living Planet Index, Conservation Biology source

      Not checked in the free run.

    • cites [9] J Loh, 2005, The Living Planet Index: using species population time series to track trends in biodiversity, Philosophical Transactions of the Royal Society of London B: Biological Sciences source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    The Living Planet Database contains a number of abundance records that have been provided in confidence, which are used to calculate the presented trends and statistics but cannot be made publically available.

    “The Living Planet Database contains a number of abundance records that have been provided in confidence. These are used to calculate the presented trends and statistics, but cannot be made publically available.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    The year 2012 is chosen as the cut-off point for the index because at present there are insufficient data to calculate a robust index after this point due to publication time-lag.

    “The year 2012 is chosen as the cut-off point for the index because at present there are insufficient data to calculate a robust index after this point due to publication time-lag.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The LPI includes available published data from scientific and grey literature taken from the Living Planet Database and records trends in 14,152 populations of 3,706 species.

    “The LPI includes available published data, primarily in the scientific and grey literature (e.g. government/NGO reports) taken from the Living Planet Database (LPD) and records trends in 14,152 populations of 3,706 species.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [7] WWF (2016) Living Planet Report 2016: Risk and resilience in a new era WWF International, Gland, Switzerland.

      Not checked in the free run.

    • cites [8] B Collen, 2009, Monitoring Change in Vertebrate Abundance: the Living Planet Index, Conservation Biology source

      Not checked in the free run.

    • cites [9] J Loh, 2005, The Living Planet Index: using species population time series to track trends in biodiversity, Philosophical Transactions of the Royal Society of London B: Biological Sciences source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    Weighting by species diversity is only one of a number of potential weightings that could be applied to make trends more representative.

    “We note that weighting by species diversity is only one of a number of potential weightings that could be applied to make the trends more ‘representative’.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    Improving the coverage of Data Deficient species might introduce negative trends if these species are likely to be threatened.

    “Improving the coverage of Data Deficient species, as categorised by the IUCN Red List, might introduce negative trends if these species are likely to be threatened, as has been predicted for terrestrial mammals [43].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [43] LM Bland, 2015, Predicting the conservation status of data-deficient species, Conservation Biology source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Because tropical regions tend to have higher richness and a greater proportion of threatened species, the LPI-D method may introduce another bias by placing a high proportion of weight on groups that may be less well monitored, under-represented, or more likely to be categorized as threatened.

    “However, tropical regions tend to have higher richness and a greater proportion of threatened species [34], so this method may introduce another bias by placing a high proportion of weight on groups that may be less well monitored, under-represented, or more likely to be categorized as threatened.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [34] R Grenyer, 2006, Global distribution and conservation of rare and threatened vertebrates, Nature source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Species threatened under other criteria may be experiencing population declines but sufficient data are not available to contribute to the Red Listing assessment.

    “Furthermore, species threatened under other criteria may be experiencing population declines but sufficient data are just not available to contribute to the Red Listing assessment.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Estimates for the number of as yet unidentified birds and mammals are small (~10-15 species), but the number of unidentified amphibians, reptiles and fish are much larger, with respective estimates of 57%, 13% and 22% undescribed.

    “Estimates for the number of as yet unidentified birds and mammals are small (e.g. ~10–15 species), but the number of unidentified amphibians, reptiles and fish are much larger with respective estimates of 57%, 13% and 22% undescribed [44].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [44] BR Scheffers, 2012, What we know and don’t know about Earth's missing biodiversity, Trends in Ecology & Evolution source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Other approaches have been used to account for the differing proportion of a species' total population across different countries.

    “Other approaches have been used, for example, to account for the differing proportion of a species’ total population across different countries [15].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [15] RD Gregory, 2005, Developing indicators for European birds, Philosophical Transactions of the Royal Society of London B: Biological Sciences source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    A limitation of the LPI-D approach is that it is reliant on reasonable species lists, which are known to change over time and may be of lower quality for less studied groups and regions.

    “A limitation of our current approach is that it is reliant on reasonable species lists, which are known to change over time and may be of lower quality for less studied groups and regions.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S1 (asserted), S3 (load-bearing), S4 (based).

    Interpretationreasoning

    The bias towards data from protected areas might suggest the LPI would show a greater decline if counterfactuals from unprotected sites were equally monitored.

    “For example, the bias towards data from protected areas might suggest the LPI would show a greater decline if counterfactuals from unprotected sites were equally monitored, on the assumption that protection has a positive effect on population trends.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: Protection has a positive effect on population trends.

  • May combine two claims.

    Premisecitation

    Trends in abundance of species populations are a crucial indicator of biodiversity and can provide early warnings of declines prior to species qualifying for high levels of extinction risk.

    “Trends in abundance of species populations are a crucial indicator of biodiversity [28,29] and can provide early warnings of declines prior to species qualifying for high levels of extinction risk [30].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [28] L Santini, Assessing the suitability of diversity metrics to detect biodiversity change, Biological Conservation

      Not checked in the free run.

    • cites [29] ST Buckland, 2011, The geometric mean of relative abundance indices: a biodiversity measure with a difference, Ecosphere source

      Not checked in the free run.

    • cites [30] B Collen, 2011, Predicting how populations decline to extinction. Philosophical Transactions of the Royal Society B, Biological Sciences source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The metric of abundance trends has been recommended as an Essential Biodiversity Variable, and its use in geometric mean abundance indicators such as the Living Planet Index is part of the mechanism to monitor biodiversity and assess progress towards the Aichi Targets.

    “Consequently, this metric has been recommended as an Essential Biodiversity Variable [31], and, its use in geometric mean abundance indicators such as the Living Planet Index (LPI), is part of the mechanism to monitor biodiversity and assess progress towards the Aichi Targets.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] HM Pereira, 2013, Essential Biodiversity Variables, Science source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationreasoning

    Declines may be exacerbated by a prevalence of coastal marine data, areas of high human impact and where many heavily exploited commercial fish stocks are monitored.

    “Alternatively, declines may be exacerbated by a prevalence of coastal marine data; areas of high human impact and where many heavily exploited commercial fish stocks are monitored.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    As threatened species assessed under Criterion A are significantly over-represented in all groups except amphibians, the LPI has a bias towards negative population trends.

    “As threatened species assessed under Criterion A are significantly over-represented in all groups except for amphibians, we can infer that the LPI has a bias towards negative population trends.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    These latter groups would therefore be given even greater weight, suggesting that vertebrate populations may be declining, on average, even more rapidly than currently estimated.

    “These latter groups would therefore be given even greater weight, suggesting that vertebrate populations may be declining, on average, even more rapidly that we currently estimate.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    As the weighted index places more weight on less monitored groups in more species-rich regions, we might be exaggerating the declines in abundance, as these groups might be declining more.

    “We might expect that as the weighted index places more weight on less monitored groups in more species-rich regions, we would be exaggerating the declines in abundance–as we might expect these groups to be declining more.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Amphibians are threatened with a greater risk of extinction than mammals or birds.

    “For example we know that tropical vertebrate populations are in worse decline than those in temperate regions [45] and that amphibians are threatened with a greater risk of extinction than mammals or birds [46].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [46] SN Stuart, 2004, Status and Trends of Amphibian Declines and Extinctions Worldwide, Science source

      Not checked in the free run.

52 of 52

  • The authors state this as an assumption.

    Protection has a positive effect on population trends.

    “on the assumption that protection has a positive effect on population trends.”
1 of 1

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Freshwater vertebrate populations declined by 83% between 1970 and 2012.

    “Freshwater ecosystems have suffered the strongest decline of global biodiversity, while their vertebrate populations alone have declined by 83% between 1970 and 2012 [4], with maximum values of 94% in the Neotropics [5].”

    From Urban Stream and Wetland Restoration in the Global South—A DPSIR Analysis (2019) · cites this paper as [4]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Abstract reverses the unweighted terrestrial trend

    Major

    The abstract reports a 15% increase for the unweighted terrestrial index, but Table 1 gives its 2012 value as 0.848 relative to a 1970 baseline of 1-a decline of about 15%.

  • Marine group with zero representation contradicts removal rationale

    Minor

    The paper identifies a marine reptile group with 0% representation, then says no marine groups have less than 1% representation.

2 of 2

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Related

Authors
McRae, L., Deinet, S., & Freeman, R.
Affiliations
Zoological Society of London (GB)
Corresponding author
McRae, Louise
ORCID
Venue
PLOS ONE
Publisher
Public Library of Science (PLoS)
Published
2017-01-03
Volume
12
Issue
1
Pages
e0169156
ISSN
1932-6203 (ISSN-L)
DOI
10.1371/journal.pone.0169156
PMC
PMC5207715
OpenAlex
W2493835817
Cited by
236
References
37
Citations by year
2026: 13 · 2025: 26 · 2024: 22 · 2023: 42 · 2022: 42 · 2021: 22 · 2020: 36 · 2019: 15 · 2018: 13 · 2017: 5
FWCI
15.55
Type
journal article
Language
en
Open access
Licence
Locations
  • PLoS ONE (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • UCL Discovery (University College London) (submittedVersion)
  • Figshare (submittedVersion, cc-by)
Funders
WWF International
Topics
  • Physical Sciences › Environmental Science › Nature and Landscape Conservation › Ecology and Vegetation Dynamics Studies
  • Physical Sciences › Environmental Science › Ecology › Wildlife Ecology and Conservation
  • Physical Sciences › Environmental Science › Global and Planetary Change › Conservation, Biodiversity, and Resource Management
Keywords
Living Planet Index, biodiversity indicators, taxonomic bias, geographic bias, vertebrates, freshwater biodiversity, marine biodiversity, terrestrial biodiversity, biogeographical realms, data coverage, biodiversity monitoring
MeSH terms
Animals, Conservation of Natural Resources, Fresh Water, Geography, International Cooperation, Marine Biology, Science, Species Specificity, Time Factors, Vertebrates, Databases, Factual, Ecosystem, Earth, Planet, Biodiversity

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-07.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-07.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

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