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Gaps in biodiversity occurrence information may hamper the achievement of international biodiversity targets: insights from a cross-taxon analysis


Species distribution data are critical information sources when it comes to implementing the multiple Aichi Targets set by the international Convention on Biological Diversity. Although there have been international-scale efforts to aggregate distribution data, the magnitudes and locations of the gaps in biodiversity knowledge remain unclear. In this study, we use a large database, including over 200 000 species occurrence records, to identify knowledge gaps in biodiversity inventories for nine animal taxa in a Mediterranean biodiversity hotspot. Spatial modelling methods were employed to relate the completeness of inventories to population, road and protected area density. The completeness of faunistic inventories was correlated with the amount of protected areas, roads and population density. Despite more than 200 years of faunistic sampling, knowledge of the distributions of most animal taxa is still limited, especially for invertebrates. As the window of opportunity for achieving Aichi Targets 11 and 19 begins to close, means of filling such knowledge gaps are required. We argue that a combination of quantitative tools and citizen science data collection programmes may help inform conservation decisions.

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*Correspondence: Dr Marco Girardello email:
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Ballesteros-Mejia, L., Kitching, I.J., Jetz, W. & Beck, J. (2017) Putting insects on the map: near-global variation in sphingid moth richness along spatial and environmental gradients. Ecography 40 (6): 698708.
Ballesteros-Mejia, L., Kitching, I.J., Jetz, W., Nagel, P. & Beck, J. (2013) Mapping the biodiversity of tropical insects: species richness and inventory completeness of African sphingid moths. Global Ecology and Biogeography 22: 586595.
Canova, L., Bertolino, S., Cagnin, M., Cagnolaro, L., Martinoli, A., Merli, E., Nieder, L., Prigioni, C., De Marinis, A.M., Meriggi, A. & Apollonio, M. (2004) Articoli teriologici nelle principali riviste pubblicate in Italia (1980-2003): analisi e tendenze. Hystrix, the Italian Journal of Mammalogy 15: 520.
Cardoso, P., Erwin, T.L., Borges, P.A.V. & New, T.R. (2011) The seven impediments in invertebrate conservation and how to overcome them. Biological Conservation 144: 26472655.
Chapman, A.D. (2005) Principles and Methods of Data Cleaning: Primary Species and Species-Occurrence Data. Copenhagen, Denmark: Global Biodiversity Information Facility.
Convention on Biological Diversity (2011) Conference of the Parties Decision X/2: strategic plan for biodiversity 2011–2020 [www document]. URL
Danko, D.M. (1992) The digital chart of the world project. Photogrammetric Engineering and Remote Sensing 58: 11251128.
Engemann, K., Enquist, B.J., Sandel, B., Boyle, B., Jørgensen, P.M., Morueta-Holme, N., Peet, R.K., Violle, C. & Svenning, J.-C. (2015) Limited sampling hampers ‘big data’ estimation of species richness in a tropical biodiversity hotspot. Ecology and Evolution 5: 807820.
Fattorini, S., Galassi, D.M., & Strona, G. (2016). When human needs meet beetle preferences: tenebrionid beetle richness covaries with human population on the Mediterranean islands. Insect Conservation and Diversity 9: 369373.
Fattorini, S. (2013). Regional insect inventories require long time, extensive spatial sampling and good will. PLoS One 8: e62118.
Ficetola, G.F., Cagnetta, M., Padoa-Schioppa, E., Quas, A., Razzetti, E., Sindaco, R. & Bonardi, A. (2014) Sampling bias inverts ecogeographical relationships in island reptiles. Global Ecology and Biogeography 23: 13031313.
Ficetola, G.F. & Padoa-Schioppa, E. (2009). Human activities alter biogeographical patterns of reptiles on Mediterranean islands. Global Ecology and Biogeography 18: 214222.
Gallego, F.J. (2010) A population density grid of the European Union. Population and Environment 31: 460473.
Gardiner, M.M., Allee, L.L., Brown, P.M., Losey, J.E., Roy, H.E. & Smyth, R.R. (2012). Lessons from lady beetles: accuracy of monitoring data from US and UK citizen-science programs. Frontiers in Ecology and the Environment 10: 471476.
Guillera-Arroita, G. (2017) Modelling of species distributions, range dynamics and communities under imperfect detection: advances, challenges and opportunities. Ecography 40: 281295.
International Union for Conservation of Nature (2001) IUCN Red List Categories and Criteria: Version 3.1. Gland, Switzerland: IUCN Species Survival Commission.
Isaac, N.J.B., van Strien, A.J., August, T.A., de Zeeuw, M.P. & Roy, D.B. (2014) Statistics for citizen science: extracting signals of change from noisy ecological data. Methods in Ecology and Evolution 5: 10521060.
Italian Ministry for the Environment (2013) Italy's Fifth National Report to the Convention on Biological Diversity. Rome, Italy: Ministry of the Environment.
Kissling, W.D. & Carl, G. (2008) Spatial autocorrelation and the selection of simultaneous autoregressive models. Global Ecology and Biogeography 17: 5971.
Meyer, C., Kreft, H., Guralnick, R. & Jetz, W. (2015) Global priorities for an effective information basis of biodiversity distributions. Nature Communications 6: 8221.
Meyer, C., Weigelt, P. & Kreft, H. (2016) Multidimensional biases, gaps and uncertainties in global plant occurrence information. Ecology Letters 19: 9921006.
Oksanen, J., Blanchet, F.G., Friendly, M., Kindt, R., Legendre, P., McGlinn, D., Minchin, P.R., O'Hara, R.B., Simpson, G.L., Solymos, P., Stevens, M.H.H., Szoecs, E. & Wagner, H. (2016) vegan: Community Ecology Package.
Riservato, E., Fabbri, R., Festi, A., Grieco, C., Handersen, S., Landi, F., Utzeri, C., Rondinini, C., Battistoni, A. & Teofili, C. (2014) Lista Rossa IUCN delle Libellule Italiane. Rome, Italy: Comitato italiano IUCN e Ministero dell'Ambiente e della Tutela del Territorio e del Mare.
Rodrigues, A.S.L. & Brooks, T.M. (2007) Shortcuts for biodiversity conservation planning: the effectiveness of surrogates. Annual Review of Ecology, Evolution, and Systematics 38: 713737.
Ruffo, S. & Stoch, F. (2006) Checklist and Distribution of the Italian Fauna. 10,000 Terrestrial and Inland Water Species. Verona, Italy: Memorie del Museo Civico di Storia Naturale di Verona.
Sánchez-Fernández, D., Lobo, J.M., Abellán, P. & Millán, A. (2011) How to identify future sampling areas when information is biased and scarce: an example using predictive models for species richness of Iberian water beetles. Journal for Nature Conservation 19: 5459.
Sindaco, R. (2006) Atlante degli Anfibi e dei Rettili d'Italia. Florence, Italy: Edizioni Polistampa.
Stropp, J., Ladle, R.J.M., Malhado, A.C., Hortal, J., Gaffuri, J.H., Temperley, W., Olav Skøien, J. & Mayaux, P. (2016) Mapping ignorance: 300 years of collecting flowering plants in Africa. Global Ecology and Biogeography 25: 10851096.
Trouwborst, A. (2011) Conserving European biodiversity in a changing climate: the Bern Convention, the European Union Birds and Habitats Directives and the adaptation of nature to climate change. Review of European Community & International Environmental Law 20: 6277.
Wood, S. (2006) Generalized Additive Models: An Introduction with R. New York, NY, USA: CRC Press.
Yang, W., Ma, K. & Kreft, H. (2013) Geographical sampling bias in a large distributional database and its effects on species richness–environment models. Journal of Biogeography 40: 14151426.
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