Biological Conservation 144 (2011) 989–997 Contents lists available at ScienceDirect Biological Conservation journal homepage: www.elsevier.com/locate/biocon Will climate change reduce the efficacy of protected areas for amphibian conservation in Italy? ⇑ Manuela D’Amen a, , Pierluigi Bombi b, Peter B. Pearman c, Dirk R. Schmatz c, Niklaus E. Zimmermann c, Marco A. Bologna a a Department of Environmental Biology, University of ‘‘Roma Tre’’, Viale G. Marconi 446, 00146 Rome, Italy b SPACE Environment, via Maria Giudice 23, 00135 Rome, Italy c Swiss Federal Research Institute WSL, Zuercherstrasse 111, 8903 Birmensdorf, Switzerland article info abstract Article history: Amphibians are an important and imperiled component of biodiversity. In this study we analyze the effi- Received 14 April 2010 cacy of Italian reserve network for protecting multiple amphibian species in a climate change scenario, Received in revised form 21 August 2010 considering both nationally designated areas and Natura 2000 sites. Our approach is based on ensemble Accepted 1 November 2010 niche modeling estimate of potential range shift under two carbon emission scenarios (A1FI and B1) and Available online 22 January 2011 two dispersal assumptions. The predicted distributions were used to perform gap and irreplaceability analyses. Our findings show that the current Italian reserve network incompletely represents current Keywords: amphibian diversity and its geographic pattern. The combination of the nationally designated protected Global warming areas and the Natura 2000 sites improves current representation of amphibians, but conservation targets Gap analysis Irreplaceability based on geographic range extent are achieved for only 40% of species. Under the future scenarios, Natura Conservation priorities 2000 sites become a crucial component of the protected areas system. Nonetheless, we predict that cli- mate change decreases for many species the amount of suitable range falling into reserves, regardless of our assumptions about dispersal. We identify some currently unprotected areas that have high irreplace- ability scores for species conservation and that maintain their importance under all the future scenarios we considered. We recommend designation of new reserves in these areas to help guarantee long-term amphibian conservation. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction tion of a relationship between increase in mean temperature, body condition decline, and decrease in fecundity (Reading, 2007). Amphibians are an important component of biodiversity that Extinctions of amphibians are projected to accumulate as climate has emerged as a global conservation concern because of recent warming increases in the decades to come, which suggests that worldwide declines (Stuart et al., 2004; Wake and Vredenburg, new strategies are needed to maximize the effectiveness of conser- 2008; D’Amen and Bombi, 2009). The extrinsic causes of their de- vation efforts for amphibians (IUCN, 2006). cline owe to many environmental conditions acting synergistically, Despite the imperilled status of amphibians, these vertebrates such as habitat loss and degradation, UV radiation, and disease are not as well represented in conservation studies as are other, (Alford et al., 2001; Daszak et al., 2003). In addition, recent changes less threatened taxonomic groups (Brito, 2008) and are often ne- in the global climate might impact adversely on amphibian popu- glected during conservation planning (Rodrigues et al., 2004; lations. A causative relationship can exist between amphibian pop- Pawar et al., 2007). However, the in situ conservation of viable pop- ulation reductions and climate anomalies (Daszak et al., 2005; ulations in natural ecosystems is a fundamental requirement for Whitfield et al., 2007). For example, wetland desiccation due to cli- the maintenance of amphibian biodiversity (Rodrigues et al., matic change is associated with amphibian declines in Yellowstone 2004). To this end the integration of the potential impacts of cli- National Park (McMenamin et al., 2008). Similarly, climate change mate change with selection of protected areas has recently gained is associated with population disappearances in Italy (D’Amen and attention (Heller and Zavaleta, 2009). Some species will likely Bombi, 2009). The potential mechanisms underlying these local become locally extinct in existing reserves as their suitability extinctions have become clearer in recently, with the demonstra- declines. Amphibians will require for long-term conservation access to other areas that are currently climatically unsuitable ⇑ Corresponding author. Mobile: +39 3396204708. but which will likely become suitable in the future (Hannah E-mail address: [email protected] (M. D’Amen). et al., 2002; Araújo et al., 2004; Heller and Zavaleta, 2009). In this 0006-3207/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.biocon.2010.11.004 990 M. D’Amen et al. / Biological Conservation 144 (2011) 989–997 light amphibian conservation strategies need to be re-examined in 2.2. Environmental data sets order to address lack of adequate species representation in existing reserves and to account for the anticipated risk of population Niche-based models were calibrated using climatic, land use, decline due to climate change (Hannah et al., 2002). and topographical predictors. Of 20 variables initially, we re- In the European context, Italy harbours a relatively diverse tained only those correlated at 0.70 or lower. Since the primary amphibian fauna (Gasc et al., 1997; Bologna, 2004; Temple and interest of this exercise is forecasting and not estimating model Cox, 2009). In Italy, studies have separately addressed the effec- parameters, this level of correlation is not of concern (Legendre tiveness of protected areas for terrestrial vertebrates and the po- and Legendre, 1998). We used seven bioclimatic predictors: (1) tential for detrimental climate change impacts on amphibians. annual mean temperature, (2) mean diurnal temperature range, Maiorano et al. (2006, 2007) evaluated the capacity of Italian na- (3) isothermality, (4) temperature annual range, (5) mean tem- tional and Natura 2000 protected areas to conserve vertebrate bio- perature of wettest quarter, (6) precipitation of warmest quarter, diversity under current climatic conditions. These authors found and (7) precipitation of coldest quarter. Current values for these that existing protected areas are often insufficient to conserve cur- variables were derived from the WorldClim database (Hijmans rent patterns of biodiversity in Italy. Similar results exist for other et al., 2005), which are climate grids for 1950–2000 with a res- European regions (Hopkinson et al., 2000; Dimitrakopoulos et al., olution of 30 arc-seconds (1 km). Potential future values for the 2004; Araújo et al., 2007). Finally, doubling current CO2 levels will time interval 2041–2070 were derived from the 10 arc-minute likely result in range contraction for those amphibian species that resolution climate grids of Mitchell et al. (2004) for the IPCC sce- occur in mountainous and Mediterranean areas (Girardello et al., narios A1FI and B1 and the HadCM3 circulation model, which is 2009). However, we know of no study that has focussed on Italy widely used for predicting climate change effects on fauna distri- to investigate how extinction risk of amphibians is associated with bution in Europe (e.g. Araújo et al., 2004, 2006). We chose A1FI the potential inadequacy of reserves systems under climate and B1 to capture some of the uncertainty surrounding future change. projections, since they are based on contrasting story lines cov- The goal of this paper is to analyze the efficacy of the Italian re- ering the range of possible demographic, socio-economic and serve network for protecting amphibian diversity in a climate technological changes thought to influence greenhouse gas emis- change scenario. We assessed how local amphibian biology and pat- sions. To produce high-resolution climate scenarios, the 10 arc- terns of predicted climate change could act together to affect minute grids were expressed as anomalies to the 1950–2000 extinction risk and protected-area effectiveness over the next cen- period of WorldClim, interpolated to 30 arc-seconds resolution tury. Moreover, we introduced a novel and flexible approach for and then recombined with the corresponding grids from the conservation target definition to consider complex factors sur- WorldClim data set. rounding the effects of climate change. In particular, we incremen- The effects of existing land use on habitat availability were ac- tally adjusted targets for amphibian species conservation in counted for by including two land cover variables, the percentage response to the predicted change in species range size. We used of forested surface and herbaceous vegetation (Corine Land Cover these targets to determine under current and future climatic condi- IV, SINAnet, 2008). Finally, topographic information was included tions the extent to which species are underrepresented in existing in the models as the prevalent exposition direction in a continuous protected areas. We determined whether the current system of pro- north–south gradient ranging between 1 and À1, derived from dig- tected areas matches the most-valuable sites, taking into consider- ital elevation model (75 m resolution). All variables were prepared ation the predicted effects of climate change on the distribution of in a geographical information