Impacts of data quality on the setting of conservation planning targets using the species–area relationship

Abstract

International audienceAimThe species–area relationship (SAR) is increasingly being used to set conservation targets for habitat types when designing protected area networks. This approach is transparent and scientifically defensible, but there has been little research on how it is affected by data quality and quantity.LocationEnglish Channel.MethodsWe used a macrobenthic dataset containing 1314 sampling points and assigned each point to its associated habitat type. We then used the SAR-based approach and tested whether this was influenced by changes in (i) the number of sampling points used to generate estimates of total species richness for each habitat type; (ii) the nonparametric estimator used to calculate species richness; and (iii) the level of habitat classification employed. We then compared our results with targets from a similar national-level study that is currently being used to identify Marine Conservation Zones in the UK.ResultsWe found that targets were affected by all of the tested factors. Sample size had the greatest impact, with specific habitat targets increasing by up to 45% when sample size increased from 50 to 300. We also found that results based on the Bootstrap estimator of species richness, which is the most widely used for setting targets, were more influenced by sample size than the other tested estimators. Finally, we found that targets were higher when using broader habitat classification levels or a larger study region. However, this could also be a sample size effect because these larger habitat areas generally contained more sampling points.Main conclusionsHabitat targets based on the SAR can be strongly influenced by sample size, choice of richness estimator and the level of habitat classification. Whilst setting habitat targets using best-available data should play a key role in conservation planning, further research is needed to develop methods that better account for sampling effort

History of benthic research in the English Channel: From general patterns of communities to habitat mosaic description

“…Both studies Metcalfe et al, 2013) underlined the need to have a large database of good quality data for such exercises of MPA planning. Similar remarks were expressed by Robinson et al (2011) in the case of the HABMAP model used to predict the distribution of seabed biotopes in the southern Irish Sea: "the accuracy of predicted habitat maps is dependent on both quality and quantity of the input data".…”

“…The SAR approach to setting habitat targets provided an objective method for converting judgements of minimum species representation into a quantitative conservation target and provided an approach for distinguishing between different habitat types, thereby tailoring such targets to account for differences in patterns of species richness and turnover. Metcalfe et al (2013) showed that habitat targets based on the SAR had been mainly affected by sample size, choice of richness estimator, the amount and quality of biological survey data employed, and the level of habitat classification, i.e. the EUNIS classification levels 3 and 4 (see Coggan and Diesing, 2011, for the first map of EUNIS levels 3 and 4 at the scale of the whole English Channel).…”

“…4). All French sampling sites were sampled by 0.25 m 2 Hamon or 0.1 m 2 Van Veen grabs, while the British sampling was carried out either by 0.25 m 2 Hamon grab, by 0.1 m 2 Hamon grab or by 0.1 m 2 Day grab (a few stations) (see Metcalfe et al, 2013), and 2) to improve our knowledge of poorly characterized benthic sampling areas in the middle part of the EC.…”

“…In the same vein, Metcalfe et al (2013) used a large macrobenthic data set containing 1314 sampling stations to test the impact of data quality on the setting of conservation objectives using the speciesarea relationship applied to the presence/absence data for species. The SAR approach to setting habitat targets provided an objective method for converting judgements of minimum species representation into a quantitative conservation target and provided an approach for distinguishing between different habitat types, thereby tailoring such targets to account for differences in patterns of species richness and turnover.…”

Analysis of Progress Towards a Comprehensive System of Marine Protected Areas in Brazil

“…These objectives can be refined according to various criteria (e.g. Pressey et al 2003) and should be seen by conservation practitioners as temporary measures whilst objective-setting based on species-area relationships (Metcalfe et al 2013), rarity, threats and other criteria is underway. The 30% target is the "[...] average percentage of protected area recommended as necessary to conserve various aspects of biodiversity [...]" for evidence-based conservation assessments (Svancara et al 2005, p. 991).…”