Links in the functional diversity between soil microorganisms and plant communities during natural succession in coal mine spoil heaps

Ecol Res (2015) 30: 1005–1014 DOI 10.1007/s11284-015-1301-3 O R I GI N A L A R T IC L E Anna Markowicz • Gabriela Woźniak Sławomir Borymski • Zofia Piotrowska-Seget Damian Chmura Links in the functional diversity between soil microorganisms and plant communities during natural succession in coal mine spoil heaps Received: 10 December 2014 / Accepted: 12 August 2015 / Published online: 1 September 2015  The Author(s) 2015. This article is published with open access at Springerlink.com Abstract The successful establishment of vegetation, soil development and biogeochemical cycling during the restoration process of mine tailings requires a diverse and metabolically active microbial communities. The objective of this study was to test whether there is any link between the functional groups of both the dominant plant species and soil microbial communities on unreclaimed coal mine spoil heaps of different age located in the Silesian Upland (Poland). At each sampling site the dominant plant species were recorded and characterised based on their Raunkiaer’s life form, socio-ecological group and their potential to form mycorrhiza. The functional diversity of the plantassociated microbial communities was assessed using the microbial carbon-utilisation guilds generated using the Biolog method. We observed no differences in the microbial functional diversity, but a gradual increase in the plant functional diversity with the age of the heap. Our results indicate that trees, plants with the potential to form ectomycorrhiza, and deciduous plants strongly affected Electronic supplementary material The online version of this article (doi:10.1007/s11284-015-1301-3) contains supplementary material, which is available to authorized users. A. Markowicz (&) Æ S. Borymski Æ Z. Piotrowska-Seget Department of Microbiology, University of Silesia, Jagiellońska 28, 40-032 Katowice, Poland E-mail: Tel.: +48 032 2009 357 S. Borymski E-mail: Z. Piotrowska-Seget E-mail: zofia G. Woźniak Department of Geobotany and Nature Protection, University of Silesia, Jagiellońska 28, 40-032 Katowice, Poland E-mail: D. Chmura Institute of Environmental Protection and Engineering, University of Bielsko-Biała, Willowa 2, 43-309 Bielsko-Biała, Poland E-mail: the carbon-utilisation profiles. The mean proportion of microbe guilds in dominant plant patches accounts for 60 % of the variance while the soil physicochemical parameters explained only 30 % of the variance. This suggest that in post-industrial habitats the biotic features of the soil substratum are more important for the vegetation development than the abiotic parameters. Keywords Vegetation development Æ Dominant plant species Æ Functional diversity Æ Microbial community Æ Community-level physiological profiles Introduction Coal mine spoil heaps are sites, where the stone material extracted together with the coal was stored. The spoil material does not contain organic carbon and the amounts of nitrogen and phosphorus are low (Ledin and Pedersen 1996). Moreover, these sites are also characterised by extreme abiotic conditions, e.g., lack of water, low nutrient availability, high temperature and high salinity (Bradshaw 2000; Mendez and Maier 2008; Woźniak 2010). Each of these limits biological activity and therefore the development of diverse microflora in this environment is very slow (Frouz et al. 2001; Urbanová et al. 2011). However, over time hard coal mine heaps, despite their adverse conditions, are effectively colonised by many plant and animal species, which promote the development of soil (Cohn et al. 2001; Woźniak et al. 2003; Rostański and Woźniak 2007; Chmura et al. 2011; Tropek et al. 2012). The spontaneous colonisation by living organisms on post-industrial sites represents a model situation of de novo ecosystem development. This provides opportunity for studying the structure of spontaneously established vegetation and relations between plants and rhizosphere microorganisms on coal mine heaps in succession process over a long period of time. The increase in plant diversity during vegetation development has been recorded in many studies 1006 (Whittaker 1965; Matthews 1979; Pineda et al. 1981) but the results of these studies did not show consistently how plant diversity changes during spontaneous succession. However, the species diversity of plant pioneer communities decreases with time because their composition is determined by chance in the initial phase of colonisation (Margalef 1968). The variety of plants that were recorded among the sites and over time causes difficulties and often makes it impossible to detect repetitive patterns and relationships between the organisms and/or the habitat. One solution is to implement the concept of functional groups that was introduced in order to reduce the variety of organisms into a ‘‘relatively continuous feature space’’ sensu Box (1996); Smith et al. (1997); Duckworth et al. (2000). In this study we used the functional concept for both plants and microorganisms. This approach allows a better explanation and understanding of changes in an ecosystem in time–space than an analysis that is solely based on species composition (Pokorny et al. 2005; Dzwonko and Loster 2007; Cadotte et al. 2011; Woźniak et al. 2011; Wang and Chen 2013; Piekarska-Stachowiak et al. 2014). The plant functional groups (PFGs) concept means, that the analysis of vegetation is based on the number and participation of species with similar morphological and ecological characteristics, representing the same ecological feature. Some studies have shown that the PFGs composition of certain plant species may strongly affect the microbial functional diversity (Milcu et al. 2006; Zhang et al. 2011). There is an increasing understanding that plant succession is closely connected with the diversity and activity of soil microbial communities due to positive and negative feedbacks (Ehrenfeld et al. 2005; Bezemer et al. 2006; Kardol et al. 2007). The study on plant–microbial relations were mostly focused on natural reclaimed postindustrial sites (Tscherko et al. 2003; Šourková et al. 2005). Our knowledge of changes in microbial functional diversity in relation to plant succession on coal heaps is limited. Therefore, in this study changes in plant functional groups (PFGs) in relation to microbial functional groups (MFGs) were assessed. The microbial metabolic potential can be studied by community-level physiological profiles (CLPPs) that reflect microbial functional groups (MFGs). In this paper, the MFGs refer to groups with an ability to degrade specific carbon sources: carbohydrates, carboxylic acids, amino acids, polymers, amines and amides and miscellaneous (Zak et al. 1994; Garcı́a-Palacios et al. 2011; Kenarova et al. 2014). The aim of the study was to find any relations between plant functional groups (features of the dominant species): (1) life span (tree, biannual, perennial), (2) socioecological group (coniferous forest, ruder (...truncated)