View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Springer - Publisher Connector Ecol Res (2016) 31: 853–867 DOI 10.1007/s11284-016-1395-2 ORIGINAL ARTICLE Andrzej Zawal • Iga Lewin • Edyta Ste˛pien´ Agnieszka Szlauer-Łukaszewska • Edyta Buczyn´ska Paweł Buczyn´ski • Robert Stryjecki The influence of the landscape structure within buffer zones, catchment land use and instream environmental variables on mollusc communities in a medium-sized lowland river Received: 2 February 2016 / Accepted: 2 September 2016 / Published online: 17 September 2016 Ó The Author(s) 2016. This article is published with open access at Springerlink.com Abstract The world’s freshwater molluscan fauna is pacted by several environmental variables that act to- facing unprecedented threats from habitat loss and gether at multiple scales. The landscape structure within degradation. Declines in native populations are mostly buffer zones, catchment land use and instream envi- attributed to the human impact, which results in reduced ronmental variables were all important and influenced water quality. The objectives of our survey were to the structure of mollusc communities. Therefore, they analyse the structure of the mollusc communities in a should all be taken into consideration in the future medium-sized lowland river and to determine the most restoration of the river, future management projects and important environmental variables at different spatial programmes for the conservation of biodiversity in scales, including landscape structure, catchment land use running waters. The results of this study may be directly and instream environmental factors that influence their applicable for the rehabilitation of river ecosystems and structure. Our survey showed that a medium-sized river, are recommended to stakeholders in their future deci- that flows through areas included in the European sion concerning landscape planning, monitoring species Ecological Natura 2000 Network Programme of pro- and their habitats, conservation plans and management tected sites, provides diverse instream habitats and ni- in accordance with the requirements of sustainable ches that support 47 mollusc species including Unio development. crassus, a bivalve of Community interest, whose con- servation requires the designation of a special conser- Keywords Mollusca Æ Landscape metrics Æ vation area under the Habitats Directive Natura 2000. Environmental factors Æ Endangered species Æ This survey showed that mollusc communities are im- Protected area Introduction A. Zawal Æ A. Szlauer-Łukaszewska Department of Invertebrate Zoology and Limnology, University The primary threats to streams and rivers are habitat of Szczecin, Wa˛ska 13, 71-415 Szczecin, Poland alteration, i.e. changes resulting from catchment land I. Lewin (&) use, including deforestation, intensive agriculture or Department of Hydrobiology, Faculty of Biology and urban development; contaminants, i.e. nutrient enrich- Environmental Protection, University of Silesia, ment from agriculture, acidification, salinisation, and 40-007 Katowice, Poland toxic metals, especially from hard coal mining, and E-mail: [email protected] municipal waste; and the occurrence of invasive species E. Ste˛pien´ (Allan and Castillo 2007). These anthropogenic impacts Department of Plant Taxonomy and Phytogeography, University in the catchment area and instream habitats result in the of Szczecin, Wa˛ska 13, 71-415 Szczecin, Poland alteration of energy inputs, increased delivery of sedi- ments and contaminants, elevated turbidity, higher E. Buczyn´ ska Æ R. Stryjecki Department of Zoology, Animal Ecology and Wildlife concentrations of nutrients, chlorides, sulphates, trace Management, University of Life Sciences, Akademicka 13, metals, and decreased dissolved oxygen concentration in 20-033 Lublin, Poland the water (Dodds 2002; Jarvie et al. 2008). Therefore, achieving good ecological potential and good chemical P. Buczyn´ ski Department of Zoology, Maria Curie-Skłodowska University, status of surface waters by 2015 as was required by the Akademicka 19, 20-033 Lublin, Poland Directive (2000/60/EC) were not possible. 854 At the landscape scale, human activities are a major which results in reduced water quality. The human im- threat to the ecological integrity of river ecosystems pact is mainly reflected in the regulation of rivers and because they impact the habitats, water quality, and the flow regimes, the fragmentation of suitable habitats, biota through numerous and complex pathways. Vari- gravel mining and other sources of mine waste pollution, ous types of land use impair the suitability of substrates organic pollution, acidification, salinisation, and urban for periphyton and biofilm production, decrease primary and agricultural development (Bogan 2008; Strong et al. production and food quality, which cause bottom-up 2008). In Europe, for example, the intensification of effects through food webs, accelerate litter breakdown, agriculture affects 36 % of mollusc species; urbanisa- and favour more tolerant or alien species over more tion, including poor sewage control, affects 29 % of sensitive or native species (Allan 2004; Allan and Cas- species; and the over-utilisation of water impacts 33 % tillo 2007). of freshwater species. In comparison, invasive species Intensive multiple land use severely affects the affect about 5 % of species (Cuttelod et al. 2011). In chemical, geomorphological, and, almost importantly, degraded rivers alien mollusc species tend to flourish and the biological aspects of freshwater ecosystems. Some usually outnumber the native mollusc taxa or occur studies have emphasised the close relationship between alone. biological communities and land use. For example, In the face of the problems that are highlighted above agriculture and urban-industry land use have been and the facts that are related to the degradation of shown to significantly reduce more sensitive macroin- lowland rivers and the unquestionable, functional role of vertebrate taxa such as Ephemeroptera while increasing Mollusca in freshwater ecosystems, the formulation the more tolerant taxa (Gao et al. 2014). The types of following objectives of the survey is justified. The catchment land use are usually correlated with the objectives of our survey were to analyse the structure of physical and chemical parameters of the water and mollusc communities in a medium-sized lowland river bottom sediments, which in turn affect the structure of and to determine the most important environmental lotic macroinvertebrate communities, including molluscs variables at different spatial scales, including the land- (Sponseller et al. 2001; Erba et al. 2015; Valle Junior scape structure, catchment land use and instream envi- et al. 2015). For example, Ciparis et al. (2012) found ronmental factors that influence their structure. To date, statistically significant relationships between catchment no study has been conducted using a broader, multi- land use and the concentrations of heavy metals in the scale approach and included the landscape structure bottom sediments and Mollusca tissues. within buffer zones, catchment land use, and instream In freshwater ecosystems molluscs play an unques- environmental variables that determine the composition tionably important role by participating in the circula- of mollusc communities in a lowland river. tion of organic matter and nutrients, in the self- purification processes of the water, and in the nutrient cycles (accumulation and release of nutrients), in addi- Materials and methods tion to accumulating heavy metals and increasing water clarity. Molluscs also constitute a food resource for Study area macroinvertebrates, fish, waterfowl and mammals (Øk- land 1990; Vaughn and Hakenkamp 2001; Strayer 2014). The Kra˛piel River has a total length of 70 km and a Among macroinvertebrates, freshwater molluscs, which catchment area of 640.2 km2 (a medium-sized river). It is are hololimnic organisms and have a limited capability a typical lowland river (<200 m a.s.l.) that partially of movement, are especially vulnerable to habitat alter- flows through a landscape park within a natural physi- nation including water pollution, drainage and changes co-geographical region, the West Pomeranian Lakeland, in the water regime (Cuttelod et al. 2011; Strayer 2014). which is part of the Central Plains (Ecoregion 14) Environmental factors that have a detrimental effect on according to the EU Water Framework Directive (EU mollusc populations, e.g. on their recruitment and life WFD) (Directive 2000/60/EC) (Fig. 1). The upper cycle, may work at different spatial scales, and usually course of the Kra˛piel River shares some coverage with include both the catchment areas of rivers and instream the special protected area ‘Ostoja In´ ska’ (PLB 320008), characteristics. Changes in the landscape structure and which has an area of 87,711.0 ha, and was established land use within riparian zones, even a change from a under the Bird Directive (2009/147/EC) and Polish leg- deciduous forest to a coniferous forest in the river islation. The valley of the lower course of the Kra˛piel catchment, can significantly reduce populations of River is included in the European Ecological Natura freshwater molluscs. Data concerning both instream and 2000 Network Programme of protected sites, that rep- riparian zone land use are useful tools for the evaluation resent areas with natural habitats of the highest value of the population status of freshwater molluscs, includ-