How must conservation efforts for amphibians in the Mediterranean evolve with climate change?
Conservation biology is particularly considerate of amphibians because of the widespread decline of many species in this class, a direct and indirect consequence of human activities. (Wake & Vredenburg, 2008). Climate change brings with it a new set of circumstances affecting the ecology of amphibian territory, and thus raises the question of how conservation efforts must be adapted to cope with this adjustment.
The Mediterranean is witnessing a general downward trend in precipitation over the past few years (Longobardi & Villani, 2010). This has implications on the persistence of many amphibian species that rely on the existence of "temporary ponds". "Temporary ponds" are shallow bodies of water that are flooded during the wet season but are intermittent because of a yearly dry season (Zacharias & Zamparas, 2010). They allow the growth of many semi-aquatic flora and fauna (Dimitriou et al. 2006), also housing numerous endangered amphibians (Zacharias & Zamparas, 2010). It is important to note that permanently flooded bodies, such as rivers, do not provide alternative breeding habitats for these amphibians (Ferreira & Beja, 2013). A decrease in rainfall would cause shallower temporary ponds to dry out faster. Shortened hydroperiods may degrade many of the ponds that acted as breeding grounds for amphibian species.
The behavioral processes of many amphibians may be sensitive to changing temperatures because they are ectotherms (Blaustein et. al., 2001). Studies present a trend of increasing average annual temperatures in the Mediterranean (Blaustein et. al., 2001). Many temperate-zone anuran populations are breeding earlier in the year because of these increased average temperatures. Temperature changes are expected to not only impact the breeding times of amphibians, but also period of hibernation, ability to obtain food, and indirectly, the spread of diseases (Blaustein et. al., 2001). How exactly this influences the survival of many species requires investigation on a species-by-species basis.
There is no single answer for how conservation should co-evolve with climate change. Experts in the field should employ a zoning methodology. Using local data, they can plot out areas within their jurisdiction that are expected to remain significant for the survival of many amphibian species, even after projected climate changes (Garcia-Munoz et al., 2013). Focus can be placed on protecting these sites. For example, they may choose to protect temporary ponds that are larger, with lower runoffs, because these are expected to have a suitable hydroperiods even with lower rainfall. They can also emphasize conservation during periods of the year that are critical for amphibian survival (e.g. closing reserves during breeding periods, which are subject to change due to warmer climates). This situational planning provides the tools needed to protect amphibians more successfully and also allows conservation authorities to direct their resources more efficiently.
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Dimitriou, E., I. Karaouzas, N. Skoulikidis, and I. Zacharias. 2006. Assessing the environmental status of Mediterranean temporary ponds in Greece. International Journal of Limnology 42:33-41.
Ferreira, M., and P. Beja. 2013. Mediterranean amphibians and the loss of temporary ponds: are there alternative breeding habitats? Biological Conservation 165:179-186.
Garcia-Munoz, E., F. Ceacero, M. A. Carretero, L. Pedrajas-Pulido, G. Parra, F. Guerrero. 2013. International Journal of Ecology 49:45-52.
Longobardi, A., and P. Villani. 2010. Trend analysis of annual and seasonal rainfall time series in the Mediterranean area. International Journal of Climatology 30:1538-1546.
Wake, D. B., and V.T. Vredenburg. 2003. Are we in the midst of the sixth mass extinction? A view from the world of amphibians. Proceedings of the National Academy of Sciences of the United States of America 101:7646–7650.
Zacharias, I., and M. Zamparas. 2010. Mediterranean temporary ponds: A disappearing ecosystem. Biodiversity and Conservation 19:3827-3834.