Conservation at a slow pace: terrestrial gastropods facing fast-changing climate Annegret Nicolai, Armelle Ansart To cite this version: Annegret Nicolai, Armelle Ansart. Conservation at a slow pace: terrestrial gastropods facing fast-changing climate. Conservation Physiology, Oxford University Press, 2017, 5 (1), pp.cox007. 10.1093/conphys/cox007. hal-01510690 HAL Id: hal-01510690 https://hal-univ-rennes1.archives-ouvertes.fr/hal-01510690 Submitted on 20 Jun 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Volume 5 • 2017 10.1093/conphys/cox007 Perspective Conservation at a slow pace: terrestrial gastropods facing fast-changing climate Annegret Nicolai1,* and Armelle Ansart2 1UMR CNRS 6553 EcoBio/OSUR, Station Biologique Paimpont, Université Rennes 1, 35380 Paimpont, France 2UMR CNRS 6553 EcoBio/OSUR, Université Rennes 1, 35042 Rennes cedex, France *Corresponding author: UMR CNRS 6553 EcoBio/OSUR, Station Biologique Paimpont, Université Rennes 1, 35380 Paimpont, France. Tel: +33 29961 8174. Email: [email protected] .............................................................................................................................................................. The climate is changing rapidly, and terrestrial ectotherms are expected to be particularly vulnerable to changes in tem- perature and water regime, but also to an increase in extreme weather events in temperate regions. Physiological responses of terrestrial gastropods to climate change are poorly studied. This is surprising, because they are of biodiversity significance among litter-dwelling species, playing important roles in ecosystem function, with numerous species being listed as endangered and requiring efficient conservation management. Through a summary of our ecophysiological work on snail and slug species, we gained some insights into physiological and behavioural responses to climate change that we can organize into the following four threat categories. (i) Winter temperature and snow cover. Terrestrial gastropods use different strategies to survive sub-zero temperatures in buffered refuges, such as the litter or the soil. Absence of the insulating snow cov- er exposes species to high variability in temperature. The extent of specific cold tolerance might influence the potential of local extinction, but also of invasion. (ii) Drought and high temperature. Physiological responses involve high-cost processes that pro- tect against heat and dehydration. Some species decrease activity periods, thereby reducing foraging and reproduction time. Related costs and physiological limits are expected to increase mortality. (iii) Extreme events. Although some terrestrial gastropod communities can have a good resilience to fire, storms and flooding, an increase in the frequency of those events might lead to community impoverishment. (iv) Habitat loss and fragmentation. Given that terrestrial gastropods are poorly mobile, landscape alteration generally results in an increased risk of local extinction, but responses are highly variable between species, requiring studies at the population level. There is a great need for studies involving non-invasive methods on the plasticity of physiological and behavioural responses and the ability for local adaptation, considering the spatiotemporally heterogeneous climatic land- scape, to allow efficient management of ecosystems and conservation of biodiversity. Key words: Cold tolerance, dispersal, drought resistance, extreme events, habitat alteration, species at risk Editor: Steven Cooke Received 30 September 2016; Revised 26 December 2016; Editorial Decision 14 January 2017; accepted 9 February 2017 Cite as: Nicolai A, Ansart A (2017) Conservation at a slow pace: terrestrial gastropods facing fast-changing climate. Conserv Physiol 5(1): cox007; doi:10.1093/conphys/cox007. .............................................................................................................................................................. Introduction mean surface temperature is projected to increase by ~1°C, for the most optimistic scenario, to ~3.7°C, for the least optimistic Climate is one of the most important drivers of species’ distri- one. The global precipitation regime is expected to change, bution and abundance. Over the last decades, the earth’scli- increasing the contrast between seasons and between wet and mate has irrefutably warmed. For the coming century, global dry regions (Meehl et al.,2007). In temperate regions, snow .............................................................................................................................................................. © The Author 2017. Published by Oxford University Press and the Society for Experimental Biology. 1 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. Downloaded from https://academic.oup.com/conphys/article-abstract/5/1/cox007/3074430 by INRIA Rennes user on 20 June 2018 Perspective Conservation Physiology • Volume 5 2017 .............................................................................................................................................................. cover and snow events will decrease, and extreme events, such Johannes, 1995; Martin, 2000; Nyffeler and Symondson, as heat waves and drought, heavy precipitation and storms, 2001), and determining plant community structure (Hulme, are expected to occur more often (Stocker et al., 2013). Rapid 1996; Peters, 2007). Second, 1105 species worldwide appear variation of climate is expected to alter species’ life-history on the IUCN red list as extinct, critically endangered, endan- traits (for example, phenology, Fabina et al., 2010) and biotic gered or vulnerable (www.iucnredlist.org), and many more interactions (e.g. Wernegreen, 2012), which might lead to are listed regionally and nationally (Fig. 1A). Third, many range contractions or even extinctions (Thomas et al., 2004, species are serious pests that lead to crop damage and pesti- 2006). cide spreading (Barker, 2002) as well as negative impacts on natural habitats and native biodiversity (Cowie, 2011). Terrestrial ectothermic organisms may be particularly Fourth, some gastropods are pathogen vectors (Rowley fi affected by modi cations of local climate conditions, because et al., 1987; Graeff-Teixeira, 2007). body temperature and, subsequently, basic physiological functions, depend on environmental temperature (Gillooly Models of future distribution of gastropod species tend to et al., 2001; Deutsch et al., 2008). Among ectotherms, terres- predict range shifts and an increase of diversity with latitude trial gastropods (i.e. land snails and slugs) are particularly and altitude. These models are based on climate projections prone to climate change for the following reasons. First, their that predict higher temperatures and more precipitation at activity and physiology are highly sensitive to local tempera- high latitudes and altitudes compared with low latitudes and tures (Cameron, 1970; Bailey, 1975), and many species enter altitudes, where climate is expected to become drier (Willis a state of dormancy (aestivation and/or hibernation) when et al., 2006; Müller et al., 2009; Hof, 2011; Beltramino conditions are unfavourable for activity (e.g. Heller and et al., 2015). Although such models have a general interest, Ittiel, 1990; Iglesias et al., 1996). Second, their moist skin their reliability is limited. For example, most of the critically and the secretion of a mucus trail for locomotion make them endangered species live on islands (Oceania) or in Europe particularly sensitive to low hygrometric conditions (e.g. and North America, where the climate change will largely Young and Port, 1989). Third, moreover, their proverbial interact with anthropogenic pressures (Fig. 1B and C; slowness and high cost of movement strongly limit their abil- Gibson et al., 2009). In fact, it has been demonstrated that ity to escape a hostile environment actively (Denny, 1980). climate change could push gastropod species to the brink of Although widely used as witnesses of previous climate extinction, e.g. Rhachistia aldabrae was believed to be changes (Goodfriend, 1992), terrestrial gastropods have so extinct (Gerlach, 2007), but a few specimens were rediscov- far received little attention regarding the potential impact of ered in 2014 (Amla, 2014). Modifications in species’ distri- current rapid climate change on their distribution, compared bution and abundance without a northward shift of the with other taxa. This is surprising for the following reasons. range were also reported (Baur and Baur, 1993, 2013; First, with ~24 000 described species, inhabiting a large Peltanova et al., 2012; Pearce and Paustian, 2013). range of habitats, terrestrial