Flora of spoil heaps after hard coal mining in Trzebinia (southern Poland): effect of substratum properties

Abstract

-The aim of the present study was to investigate the composition of spontaneous plant cover and the physicochemical properties of the substratum of spoil heaps of the Siersza hard coal mine in Trzebinia (southern Poland) abandoned in 2001. Floristic and soil analyses were performed in 2011. The substratum was very diverse in terms of texture (sand: 55-92 %, clay: 6-38 %), nutrient content (total C: 1.3-41.0 %, total N: 0.05-0.49 %, total Ca: 0.5-7.3 %) and pH (3.7-8.7). Moreover, total thallium concentration in the substratum was high, ranging from 6.0 to 14.6 mg kg -1 . Plant cover varied from 50 to 95 %. The number of plant species per 4 m 2 varied from 6 to 29 and correlated negatively with total carbon content (r = -0.85, p < 0.01), and positively with sand content in the substratum (r = 66, p < 0.05). The highest number of species per area unit was observed on a humus substratum, where initial soil has developed on the part of carboniferous waste rock spoil under 20-30 year old trees, and the lowest on carbon shale with coal and culm. Among 197 plant species, most belong to Asteraceae, Fabaceae, Poaceae and Rosaceae families. Hemicryptophytes (49%) and terophytes (18%) predominated. The investigated area was primarily colonized by native species spread by the wind. However, invasive alien species also had a significant share (8%) in the plant cover.

Effects of Calamagrostis epigejos, Chamaenerion palustre and Tussilago farfara on nutrient availability and microbial activity in the surface layer of spoil heaps after hard coal mining

“…Concentrations of Olsen P, N-NO 3 and exchangeable Ca were much lower than those characterizing agricultural soils (Barker and Bryson, 2007;Morari et al, 2008) and, generally, lower than the concentrations in soils developed on waste produced by the coal industry (Dutta and Agrawal, 2001;Juwarkar and Jambhulkar, 2008;Woch et al, 2013) or in soils affected by metal ore mining and smelting (Álvarez et al, 2003;Lorenc-Pluci nska et al, 2013;Stefanowicz et al, 2012). Only amounts of exchangeable K and N-NH 4 were similar, or higher, compared with the values recorded for soils of other industrial sites Dutta and Agrawal, 2001;LorencPluci nska et al, 2013;Mummey et al, 2002;Stefanowicz et al, 2012;Woch et al, 2013).…”

“…The pH values of the spoil material varied largely, from acidic to alkaline. Such variability has been commonly recorded for spoils left by hard and brown coal mining (Frouz and Nováková, 2005;Woch et al, 2013;Wo zniak, 2010). Spoil pH was expected to be reduced by plants and decrease with the age of the spoil heaps.…”

“…This material consists mainly of carboniferous minerals of gravel consistency, and minor quantities of low-grade coal. It is characterized by high compaction, low water retention, considerable thermal activity (due to susceptibility to self-ignition), extreme pH values (both low and high), high salinity, a deficiency of nutrient elements, and sometimes, elevated concentrations of heavy metals (e.g., thallium) and other pollutants (Bian et al, 2010;Bradshaw, 1997;Li et al, 2014;Woch et al, 2013). Such properties make it an extremely hostile habitat for biota.…”

“…Calamagrostis epigejos, Chamaenerion palustre and Tussilago farfara are examples of such species in the present study. These plants are commonly found on different types of industrial sites, including those left by coal mining (Abakumov and Frouz, 2014;Frouz et al, 2011;Rosta nski and Wo zniak, 2007;Woch et al, 2013;Wo zniak, 2010). Since they tend to occur in high numbers in these places, they should be examined for their usefulness in reclamation practices.…”

Leaching of selected metals from a landfill of the closed down Siersza coal mine in Trzebinia (S Poland)

“…For instance, the impact of mercury and some other elements on the water and soil environments was dealt with by Klojzy-Karczmarczyk andMazurek (2010, 2014). In the surface part of the landfill, natural succession has taken place [Woch et al 2013] and currently the site has already its top part reclaimed.…”