Past, present, and future of the Living Planet Index

As we enter the next phase of international policy commitments to halt biodiversity loss (e.g., Kunming-Montreal Global Biodiversity Framework), biodiversity indicators will play an important role in forming the robust basis upon which targeted, and time sensitive conservation actions are developed. Population trend indicators are one of the most powerful tools in biodiversity monitoring due to their responsiveness to changes over short timescales and their ability to aggregate species trends from global down to sub-national or even local scale. We consider how the project behind one of the foremost population level indicators - the Living Planet Index - has evolved over the last 25 years, its value to the field of biodiversity monitoring, and how its components have portrayed a compelling account of the changing status of global biodiversity through its application at policy, research and practice levels. We explore ways the project can develop to enhance our understanding of the state of biodiversity and share lessons learned to inform indicator development and mobilise action.


Citation search and data collection
Three online platforms of scholarly literature were selected for their complementary coverage of both academic and grey literature and to boost representation of non-English language texts which are often neglected from citation search tools 1 ; Scopus, Web of Science and Google Scholar (via the academic citation analytical program Publish or Perish).Keywords chosen for the search were kept as the 'Living Planet Index' across all platforms for consistency and the acronym 'LPI' was not included to reduce the number non-target citations.The timeframe for the search was limited to 1998-2020 to coincide with the development of the LPI and to avoid non-target results from literature prior to the LPI's existence.We note that excluding searches for variations of the 'Living Planet Index' in English and other languages will potentially reduce the representation of LPI use at national and subset levels.
• Data screening.The results of the three citation search platforms were combined into a singular database and screened for search return errors, duplicate entries, Living Planet Report publications and incomplete entries, which were removed from further analysis.Publications with authors from the Indicators and Assessments Unit were coded so they could be differentiated from external users in the future.
• Language classification and screening.The language for each entry was classified from International Organization for Standardization (ISO) language codes using the text within the publication title and two formulas within Google Sheets (ISO language detect and Google Translate functions).Language classifications were screened and erroneous allocations (misinterpreting author names, years, abbreviations and Latin) were corrected.

Random sample metadata coding
To explore patterns in usage and reach in more detail, a random sample of 341 English language texts were coded with metadata such as geographical scale of focus, how the source used the LPI, and source type (See supplementary Table 1).Originally, we aimed to use the excerpt of text which Publish or Perish extracts from each source publication from Google Scholar to categorise the use of the 'Living Planet Index' for that entry.However, these text 'snippets' were limited in character length, not available for every source and would only return the 1st time the search term was used within the source.To evaluate the use of the LPI within a publication it was determined that returning to the source publication would be necessary.
• Random sample.Given time limitations and time taken to access each source publication and interpret the text and code up fields of interest (informed by a time trial of coding 50 random entries) it was determined that a random sample of >320 English language entries would be selected to act as a representative sample for a week's worth of coding.
• Coding the sample.Fields selected to be manually coded from interpreting the source document were categorising the use of the LPI within the document, the type of document, document affiliation, whether the focus of the document was at a global scale or a focal country, whether the document was accessible online, and a notes field.Definitions for LPI use, document type and document affiliation can be found in Supplementary Table A 1. To keep the source document focal country field standardised and to avoid typos, a data validation tool was used with the IPBES country list.The associated IPBES region was then automated using VLOOKUP.
• Data screening.We recorded whether the source document was irretrievable, or the citation had been misattributed by citation search tool error or by author error and removed these entries from analysis.

Books and book chapters
Books and book chapters

IGO
Intergovernmental organisation/ international organisation -made from sovereign states (referred to as member states), or of other intergovernmental organisations

Method used
The LPI method is applied to other data

Policy statement
Specify which type in Author/Affiliation field PRI Private sector -for-profit businesses that are not owned or operated by the government

Data used
Data from the LPD is used but analysed using a different method

Report
Gov report, Stats report, Research report.Important to specify which Author/Affiliation type in that field

Method & data used
The LPI method is applied to data from the LPD

News or Media article
Published online on a news agency website, magazine, or organisations website

MISC
Miscellaneous -make a note about it in the notes field

Not named
Any of the main publications (Loh paper, Collen paper, LPRs) are cited but the LPI is not used by name.

Teaching material
Presentations, syllabus, Guides for Classroom, teacher, lecturer, Nonclassroom, documents for education purposes

Does not appear
The LPI/ Living planet Index does not appear in the texterroneous retrieval from search

Other
Not a research outputcould be; Surveys, Letters, Blog posts, Newsletters etc -make a note in the notes field

Error in use
The LPI is named but the authors are referring to something else -e.g., footprint analysis or LPR

Irretrievable
Cannot get access to the document to assess LPI use

Definitions for metadata coding of the citation search results by usage of the LPI, document type and document affiliation
Google Scholar via Publish or Perish Altmetric scores of the three key Living Planet Index methodology publications 2-4 and two policy target review papers 5,6 on the primary Y-axis.The percentage of high attention scores compared to outputs of the same age, and same age and source are plotted on the secondary Y-axis.All publications were classed as within the top 5% of all research outputs scored by Altmetric.
Data correct at the time of collection on 19 th February 2021.
A visualisation of the underlying data within the Living Planet Index Database.
The data have been grouped thematically (A-F) and the numbered subcategories cover the types of metadata entered for every population within the LPI database.For more information on the definitions and categories see the LPI website supporting documents section (https://www.livingplanetindex.org/supporting_documents).

Results of the citation search for 'Living Planet Index' within literature between 1998-2020
. *Unique entries refer those which have been through a data screening and cleaning process to remove duplicate entries, entries pre-1998, entries with no year and entries which contained the "Living Planet Report" in their title.