Environmental Protection and Natural Resources Vol. 31 No 4(86): 8-16 Ochrona Środowiska i Zasobów Naturalnych DOI 10.2478/oszn-2020-0013 Wojciech Gotkiewicz*, Krzysztof Wittbrodt**, Ewa Dragańska* The Dynamics of Changes in the Amphibian (Amphibia) Population Size in the Masurian Landscape Park Monitoring Results of Spring Migration Monitoring from the Years 2011–2019 * Faculty of Environmental Management and Agriculture, University of Warmia and Mazury in Olsztyn; ** Masurian Landscape Park in Krutyń; e-mails: [email protected]; [email protected], [email protected] Keywords: Biodiversity, amphibians, threats, Masurian Landscape Park Abstract The study presents the results of nine-year-long monitoring of the population size of amphibians (Amphibia) as one of the indicator communities used to assess the biological diversity level. The study was conducted in the Masurian Landscape Park located in Warmińsko-MazurskieVoivodeship. The obtained results demonstrated that 13 out of the 18 domestic amphibian species occurred in the area selected for research activities, including the species entered in the IUCN Red List. No clear correlation was found between the dynamics of population changes and the environmental, primarily climatic, determinants. © IOŚ-PIB 1. INTRODUCTION 2. FACTORS REPRESENTING A THREAT TO In Poland, 18 amphibian species live in Poland. They AMPHIBIANS represent two orders, namely, salamanders – Caudata and frogs – Anura, and six families: true frogs (Ranidae), As regards amphibians, the greatest threat is the loss of true toads (Bufonidae), true salamanders and newts habitats, which affects a total of 76 species. Contaminants (Salamandridae), European spadefoot toads (Pelobatidae), are the second major threat that affects 62 species. They Firebelly toads (Bombinatoridae) and Tree frogs (Hylidae). are followed by invasive alien species, which pose a All of them are subject to species protection and, with threat to almost half of the European amphibian species. the exception of the common toad and smooth newt, to These invasive species include predators, such as the protection under the EU Habitats Directive (Table 1) [Sura salmonids, and pathogens, such as a fungal disease P., Głowaciński Z., 2018; Herczek A., Gorczyca J., 2004]. chytridiomycosis, which is associated with a reduction in Amphibians are among the most endangered vertebrate the amphibian population numbers, and the extinction species worldwide. At the European level, nearly 23% of of amphibians in many parts of the world1 [Todd B. et al., the amphibians have been recognised as endangered, of 2009; Woodhams D.C. et al., 2003; Rollins-Smith L. A., 2017]. which 2.4% as critically endangered, 7.2% as endangered As far as amphibians are concerned, it is the loss of wetland and 13.3% as vulnerable. A similar situation is observed habitats that is of particular importance, as many species throughout the EU-27 (22.0% endangered, including use shallow or periodically flooded wetland habitats for 2.4% critically endangered, 6.1% endangered and 13.4% reproduction [Ray A. M. et al., 2016; Mollov I.A., 2018]. vulnerable). In general, almost a quarter of amphibians Another serious threat is the uptake of water resources are regarded as endangered on the European continent. (particularly for agricultural purposes), which changes the Further, 16.9% of the amphibians are regarded as near hydrology of surface waters of the habitats inhabited by threatened. By way of contrast, 19.4% of the reptiles, amphibians [Mathwin R. et al., 2002]. The fragmentation 15.2% of the mammals and 13% of the European birds are of habitats, which contributes to the loss of biological endangered [Temple, H.J., Cox, N.A., 2009]. diversity worldwide, is also of extreme importance. The 1 ec.europa.eu/environment/nature/conservation/species/ redlist/amphibians/major_threats.htm 8 Wojciech Gotkiewicz, Krzysztof Wittbrodt, Ewa Dragańska fragmentation implies a reduced gene flow, an increase in that there is little evidence of climate change being lethal the inbreeding levels, the loss of diversity in populations, to amphibians. These authors believe that the information an increased differentiation between populations and the on thermal tolerance of amphibians, their thermal increased risk of extinction and the dispersion (i.e. from preferences and the actual temperature and humidity the site of birth to the reproduction in other population) ranges in which amphibians live is too limited. [Pabijan M. et al., 2020; Winter M. et al., 2016; Testud G. et The examples provided above have resulted in eight out al., 2020]. of 18 species having been awarded the UI (unfavourable- One of the factors contributing to the fragmentation inadequate) status in the European Union. These species of habitats is the network of roads, particularly the include: European common spadefoot (Pelobatesfuscus), local ones. Amphibians are dependent on the complex European fire-bellied toad (Bombinabombina), landscape structure when moving between breeding and European tree frog (Hylaarborea), Northern crested newt feeding habitats. Roads act as barriers: they increase the (Trituruscristatus), pool frog (Pelophylaxlessonae), moor imperviousness of habitats and mortality of amphibians. frog (Rana arvalis), common frog (Rana temporaria) and Unfortunately, the mass mortality of amphibians on the Carpathian newt (Triturusmontandoni).23 roads increases with the development of infrastructure In Poland, all amphibian species are subject to legal and occurs faster than mitigating measures [Kolenda K. protection, of which three species are under strict et al., 2019]. Consequently, the fragmentation of habitats protection, while for six species, active protection was results in the fragmentation of population, modification proposed (Table 1). of animals’ behaviours and a reduction in gene flow [Puky M., 2006; Sillero N. et al., 2019; Wittbrodt K., 2011; Sjögren- 3. SELECTED PREVENTIVE MEASURES Gulve P., 2020]. In addition, the roads, due to the need for maintaining them (e.g., sand or salt spreading on icy The unfavourable situation in the context of changes in roads), change and pollute the habitats located in the populations of individual amphibian species necessitates immediate vicinity, which can have a lasting effect on the taking remedial measures such as the development biology of organisms, the population dynamics and the of programmes for construction/reconstruction of distribution of species [Grzybowski M., Glińska-Lewczuk, water bodies, which increase the diversity of plants and 2019]. The fragmentation of habitats in the form of road invertebrates as well as amphibians, programmes for infrastructure development has an adverse effect on: Eurasian beaver reintroduction and the construction - an amphibian’s individual characteristics within the of road-crossing tunnels for amphibians in the road same species (certain individuals, especially females, infrastructure [Downie J.R. et al., 2019; Klimaszewski K. et mature earlier, while others do it later), al., 2015; Dalbeck L. et al., 2020]. - ecological and hydrobiological differences, even It is very important to create natural buffers between between neighbouring water bodies in which wetlands and the surrounding areas, which will amphibians mate, consequently have a positive effect on water quality - differences in meteorological conditions, taking place and biological diversity. Buffer zones are contact zones primarily during the growing periods of individual between aquatic and terrestrial ecosystems, which help years (dry, wet, warm and cold growing periods) regulate the ecological functions of both systems. As [Juszczyk W., 1987]. regards the amphibians, an effective buffer zone should be approximately 50 m wide [Lind L. et al., 2019; GuzyJ.C. It is believed that it is the climate change that is of et al., 2019]. significance in the shaping of amphibian population. However, the research conducted in Canada, the United Ectothermic animals such as amphibians and reptiles States and Italy showed that the guidelines concerning are particularly sensitive to the rapidly rising global the protection of true frogs (Ranidae) and true toads temperature [Bodensteiner B.L., 2020; Taylor E.N. et al., (Bufonidae) in agricultural landscapes should focus on 2020]. According to Bucciarelli G.M. et al. [2020], although the protection of terrestrial habitats at the landscape the amphibians have developed life strategies in order to level, and not on the maintenance of narrow buffers in mitigate the adverse consequences of varying precipitation wetlands [Sawatzky M.E. et al., 2019; FicetolaG.F., 2009; patterns, their ability to adapt to the simultaneous Semlitsch R.D. et al., 2003]. Such a strategy, however, drought and rapid increased in the temperature as well requires the cooperation between naturalists with as the greater environmental variability in general, may broadly understood local communities and professional be insufficient to maintain viable populations, given the groups due to the emerging conflicts of interest [Preisser rate and intensity of these changes. A study by Cohen E. et al., 2000]. Further measures to protect amphibians J. M. et al. [2018] demonstrated that global warming may have consequences for the amphibians adapted 2 nature-art17.eionet.europa.eu/article17/species/report/?pe- to relatively cold conditions, which are most vulnerable riod=5&group=Amphibians&country=PL&region= to the interactions between an increase in the average 3 Council Directive 92/43/EEC