Is the human population a large-scale indicator of the species richness of ground beetles?
Article first published online: 30 MAR 2010
© 2010 The Authors. Journal compilation © 2010 The Zoological Society of London
Volume 13, Issue 5, pages 432–441, October 2010
How to Cite
Barbosa, A. M., Fontaneto, D., Marini, L. and Pautasso, M. (2010), Is the human population a large-scale indicator of the species richness of ground beetles?. Animal Conservation, 13: 432–441. doi: 10.1111/j.1469-1795.2010.00363.x
- Issue published online: 30 MAR 2010
- Article first published online: 30 MAR 2010
- Received 5 October 2009; accepted 19 February 2010
- conservation biogeography;
- Mediterranean hotspot;
- scale dependence;
- urbanized ecosystems;
- Western Palaearctic
Empirical evidence has often shown a large-scale positive co-occurrence of biodiversity-rich and densely populated regions. This biogeographical pattern has important implications for conservation biology. Previous studies have supported two of the potential mechanisms behind this pattern: the distributions of biodiversity and of human beings tend to match climatic patterns, and human beings have settled in regions of higher habitat heterogeneity or they may have increased it. There has been little testing and evidence for an artefactual explanation: more populated regions may show more species only because of a more thorough sampling. Using a new country-wide dataset, we tested whether the human population density correlates with the species richness of ground beetles in Italy's regions, provinces and 10 × 10 km (UTM) grid cells. As expected, the observed and estimated (Chao index) number of species increases significantly with increasing human population density for regions, while there is no significant variation for provinces. But this is not the case when controlling for sampling effort. Variations in observed and estimated species richness are primarily associated with the available number of records, which is in turn well correlated with human population size. These results were confirmed for endemic and widespread species richness. At the UTM level, when controlling for sampling effort and area, there was a significant positive correlation between the total/widespread species richness and variation in the human population size, while the correlation was negative for endemic species. We found no significant role of habitat heterogeneity in the above relationships. The available distributional data of Carabidae in Italy suggest (1) that the species richness of bio-indicators may not be a reliable measure for regional biological assessment; (2) that some broad-scale human population–biodiversity correlations can be artefactual.