Survival and growth of alders (Alnus glutinosa (L.) Gaertn. and Alnus incana (L.) Moench) on fly ash technosols at different substrate improvement

Ecological Engineering 49 (2012) 35–40

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Survival and growth of alders (Alnus glutinosa (L.) Gaertn. and Alnus incana (L.) Moench) on fly ash technosols at different substrate improvement Wojciech Krzaklewski, Marcin Pietrzykowski ∗ , Bartłomiej Wo´s Department of Forest Ecology, Forest Faculty, University of Agriculture in Krakow, Al. 29 Listopada 46, Pl. 31-425 Krakow, Poland

a r t i c l e

i n f o

Article history: Received 25 April 2012 Received in revised form 18 July 2012 Accepted 10 August 2012 Available online 29 September 2012 Keywords: Fly ash Biological stabilization Alders Afforestation

a b s t r a c t Difficulties in disposal of fly ash resulting from coal combustion at electric power plants are of increasing concern. Establishment of vegetation is often an effective means of stabilizing solid wastes. This paper presents an evaluation of adaptation based on survival, growth and nitrogen supply of black alder and grey alder introduced on the landfill fly ash resulting from lignite combustion in ‘Bełchatów’ Power Plant (Central Poland). The research was conducted at 3 substrate variants: control with pure fly ash (CFA), with addition (3 dm3 in planting hole) lignite culm (CFA + L) and Miocene, acidic and carboniferous sands from overburden of ‘Bełchatów’ Lignite Mine (CFA + MS). Before putting the experience uniformly on the whole surface sewage sludge (4 Mg ha−1 ) mixed with grass seedling (200 kg ha−1 ) and mineral fertilization (N – 60, P – 36 and K – 36 kg ha−1 ) were applied by hydroseeding. The results show the high adaptability of alders for extremely hard site conditions on the landfill ash. After 5 years of investigation the survival of black alder was from 61% (at CFA + MS) to 88% (at CFA + L), and grey alder from 81% (at CFA + MS) to 87% (at CFA). Black alder was characterized by higher growth parameters (diameter growth d0 and height h) compare to grey alder. The best substrate for fly ash enhancement was lignite culm. Therefore, if the goal of biological stabilization of fly ash landfill would be the greatest increase of tree biomass for example for energy plantations, the recommend solution for substrate improvement is using of lignite culm and Black alder. However, the introduction of alders directly on the fly ash using start up NPK fertilising and hydroseeding with seed sludge may be recommend mainly for economic reasons, especially when the introduced alders are to have primarily protective and phytomelioration functions and thus prepare the substrate for the afforestation and next generation of target species. © 2012 Elsevier B.V. All rights reserved.

1. Introduction Generation of electric power through the combustion of coal produces large amounts of waste, of which 70–75% is fly ash (Haynes, 2009). Its use amounts to little more than 30% worldwide, it is mainly utilised in the production of building materials, the rest is transported to various landfills (Asokan et al., 2005; Haynes, 2009). The impact of fly ash landfills results in a number of changes in the adjacent ecosystems as toxic substances are leached out and transported to the soil and groundwater (Juwarkar and Jambhulkar, 2008; Dellantonio et al., 2009; Haynes, 2009). Among the characteristics of having an adverse impact on the environment, increased content of heavy metals and radioactivity of ash are listed, as well (Tripathi et al., 2004; Haynes, 2009). These properties are characterized by high variability, however, depending on the type and origin of coal burned in power plants (Haynes, 2009). Furthermore,

∗ Corresponding author. Tel.: +48 12 6625302; fax: +48 12 4119715. E-mail address: [email protected] (M. Pietrzykowski). 0925-8574/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ecoleng.2012.08.026

ash from landfills is susceptible to wind erosion as it remains suspended in the air for a long time and thus becomes a major source of pollution. This negatively affects the health of the local population, causing irritation of the upper respiratory tract and a number of adverse health effects, including even lung cancer (Dellantonio et al., 2009; Pandey et al., 2009). The primary method of preventing erosion of ash landfills is technical and biological surface stabilization. Sealing lids made of bitumen emulsion, asphalt and other substances are used for technical stabilisation. These methods are, however, very expensive. Biological stabilization of ash landfills consists mainly of planting turf or trees after an earlier application of an insulating layer in the form of fertile sediment (Junor, 1978; Carlson and Adriano, ˇ 1991; Jusaitis and Pillman, 1997; Cheung et al., 2000; Cermák, 2008; Haynes, 2009). The introduction of vegetation directly on the ash, without the insulating layer, is however most advantageous due to low cost and labour input; it is also beneficial for the landscape and effective as anti-erosion protection (Gupta et al., 2002). The accumulation of heavy metals from fly ash in trees can be important to limit the migration of xenobiotics into the waters

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and adjacent ecosystems (Tripathi et al., 2004; Gupta et al., 2007; Malá et al., 2010). The introduced vegetation is also an important element which initiates the processes of soil formation and the process of ecological succession on completely anthropogenic postindustrial sites. Combustion waste deposited in landfills displays numerous properties which are unfavourable for plant growth, including mainly: high susceptibility to compaction, poor air and water ratio, excessively alkaline reaction, high EC variability, an almost complete absence of nitrogen and available phosphorus, and in some cases high content of heavy metals (Hodgson and Townsend, 1973; Adriano et al., 1980; Gray and Schwab, 1993; ˇ 2008; Haynes, 2009). In some Pillman and Jusaitis, 1997; Cermák, ´ landfill belonging to ‘Bełchatów’ lignite cases such as ‘Lubien’ power station (Central Poland), afforestation is planned in the future. This is a very challenging project due to the considerable size of the site (about 440 ha) and the necessity to recreate soil directly on an artificial substrate (fly ash), without the use of a mineral soil horizon. For these reasons it is necessary to develop effective methods of biological stabilization and reforestation allowing to recreate soils in situ on substrate and then to introduce the target tree species. This is possible primarily by improving physical and chemical properties of the deposited ash. In case of afforestation it is also necessary to test the adaptability of trees and shrubs to the conditions on fly ash landfills. In Europe in the course of experiments concerning tree planting of fly ash landfills the following species were introduced: Scots pine (Pinus sylvestris L.), Silver Birch (Betula pendula Roth), black locust (Robinia pseudoaccacia L.), red oak (Quercus rubra L.), common oak (Quercus robur L.), black alder (Alnus glutinosa (L.) Gaertn.) and willow (Salix sp.) ˇ (Pietrzykowski et al., 2010; Cermák, 2008). In addition, attention was drawn to Nitrogen-fixing tree species: silverberry (Elaeagnus angustifolia L.), bladder senna (Colutea arborescens L.), common seabuckthorn (Hippophae rhamnoides L.) and honey locust (Gleditsia triacanthos L.) which have fairly high tolerance to the conditions of fly ash landfill (Hodgson and Townsend, 1973). In the North America some investigation on pulverized coal ash was tested as a substrate for woody plant species, included Nitrogen-fixing species like alders and other like maples (Scanlon and Duggan, 1979). As reported in literature sweetgum (Liquidambar styraciflua L.) and American sycamore (Platanus occidentalis L.) grew acceptably on fly ash after coal burning, as well (McMinn et al., 1982; Carlson and Adriano, 1991). Previous experiments show a satisfactory growth of the introduced woody plants species, but it should be noted that they were conducted mostly after the ash was topped with mineral soil (Hodgson and Townsend, 1973; Junor, 1978; Scanlon and Duggan, 1979; Carlson and Adriano, 1991; Cheung et al., 2000; ˇ Cermák, 2008; Haynes, 2009; Pietrzykowski et al., 2010). Such a practice in addition to substantial costs also entails the risk of root system deformation due to the fact that it develops primarily in ˇ the surface horizons containing mineral soil (Cermák, 2008). This is very important for the stability of the introduced afforestation in later phases of development. As mentioned above this technology is very expensive, and stocks of more fertile soil are limited. Therefore, at present, research is needed on the introduction of trees directly on to the ash. The optimum method of afforesting post-industrial sites, which are highly difficult from the point of view of biological reclamation should be to stimulate natural succession by introducing first pioneering species which also have phytomelioration functions. Only after habitats are prepared and the initial soil formation process is dynamized by the pioneering species (improvement of air–water properties, accumulation of organic matter and nutrients) should species with higher habitat requirements (such as oaks) be introduced. In Central Europe different species of alders (Alnus sp.) have potential significance as, owing to their

capability of atmospheric nitrogen fixing by symbiotic bacteria of genus Frankia sp., they play an important phytomelioration role (Kuznetsova et al., 2010). This paper presents the results of experiments on the introduction of alders (A. glutinosa (L.) GAERTN. and Alnus incana (L.) MOENCH) to a landfill containing fly ash generated by lignite combustion. In the experiment, enhancing substrates were applied (lignite culm and Miocene acidic sands) available in the immediate vicinity of the site and a variant in which trees were introduced on to the ash with no insulating layer was also included. The survival and growth rate of trees within 5 years of staring the experiment were assessed. This period is crucial for survival of introduced tree species and first phase of biological stabilization. 2. Materials and methods 2.1. Study site ´ combustion waste land‘Bełchatów’ power plant and ‘Lubien’ fill which belongs to it are located in Central Poland (N 51 27; E 19 27), in temperate climate zone with precipitation ranging from 550 to 600 mm annually and an average annual temperature of around 7.6–8 ◦ C. The vegetation period lasts from 210 to 218 days ´ landfill has been in operation since 1980 (Wo´s, 1999). The ‘Lubien’ and currently takes up approximately 440 ha. of land. Combustion waste containing about 85% ash and 15% slag is deposited there with the use of hydro-transport. The main component of combustion waste are thermally processed aluminosilicates. The average content of Al2 O3 and SiO2 compounds is from about 60 to 70%, and calcium oxide CaO about 20%. The content of trace elements generally do not exceed the average reported for natural soils. In the ash deposited on the tested landfill radioactivity determined by the concentration of isotopes K40 , Ra226 and Th228 is low and does not constitute a threat to the environment (Kobus and Ostrowicz, ´ adverse envi1987; Stolecki, 2005). In the case of landfills, ‘Lubien’ ronmental impact is caused mainly by leaching sulfate, chloride and calcium, which in turn affects the growth of concentrations of these ions, increased mineralization and increased the overall hardness and alkalinization of ground water (Stolecki, 2005). Previously introduction of vegetation was conducted mainly in parts of slopes, using an insulating layer of mineral soil (Pietrzykowski et al., 2010). 2.2. Description of the experiment The experiment stared in September 2005 in a part of a sedimentation tank flat shelf set up between 2003 and 2004. Before the start of the experiment and the planting of trees on the entire surface, it was first subject to hydro-seeding with seed sludge of 4 Mg ha−1 (dry mass) mixed with the seeds (200 kg ha−1 ) of Cock’s-foot grass (Dactylis glomerata L.) and Italian ryegrass (Lolium multiflorum Lam.). Next NPK start up mineral fertilising was applied with N – 60, P – 36 and K – 36 kg ha−1 . Afterwards 24 plots measuring 6 m × 13 m were laid out. They were separated using 2-m-wide buffer strip. On the plots 50 seedlings each of black alder or grey alder were planted in holes of 40 cm × 40 cm × 40 cm in 3 variants (with 4 replications for each variant): control (fly ash – CFA), with a bedding layer of Miocene acidic sand (CFA + MS) and with a bedding layer of lignite culm (CFA + L). 2.3. Soil sampling and laboratory tests In the spring of 2006 in order to determine the output characteristics of the deposited substrate (fly ash), a soil stick from an Eijkelkamp set was used to collect soil samples from 0 to 40 cm

18.4 ± 3.7a 17.5 ± 3.0a 16.3 ± 2.9a 0.9 ± 0.3a 1.0 ± 0.3a 1.1 ± 0.3a 17.4 ± 2.1a 16.5 ± 2.3a 17.5 ± 2.3a 20.3 ± 3.3a 17.3 ± 3.2a 20.7 ± 3.2a *

Mean and SD; letters (a, b) indicate significant differences between mean values of properties of the combination of substrates after 2 years of investigations.

45.0 ± 6.4a 45.8 ± 6.6a 43.8 ± 6.9a 8.6 ± 6.4a 9.7 ± 8.0a 7.6 ± 4.5a 526.8 ± 162.9a 472.3 ± 152.4a 629.4 ± 227.6a 99.06 ± 0.27a 98.70 ± 0.48a 98.38 ± 0.42a 61.50 ± 18.06a 53.98 ± 17.46a 62.43 ± 15.94a 0.82 ± 0.23a 0.78 ± 0.17a 0.89 ± 0.19a 59.92 ± 17.77a 52.38 ± 17.20a 60.32 ± 15.56a 0.12 ± 0.02a 0.11 ± 0.03a 0.11 ± 0.03a 493.2 ± 156.0a 478.8 ± 141.5a 550.6 ± 174.7a Characteristics of substrates after 2 years of investigation

Sturt up characteristic Acidic miocene sand Lignite culm

CFA CFA + MS CFA + L

7.93 ± 018a* 7.89 ± 0.16a 7.69 ± 0.17a

0.13 ± 0.04a 0.12 ± 0.03a 0.15 ± 0.03a

272.25 317.0 4800.0 45.17 3.74 104.47 0.94 0.61 78.81 954.5 255.0 162.0 9.57 3.38 5.49

0.19 0.46 26.17

0.12 0.20 2.30

Ca2+ K+ (cmol(+) kg−1 )

Na+ EC (␮S cm−1 ) pH Substrate

Data sets were statistically analyzed using the Statistica 9.1 programme (StatSoft Inc., 2009). Significant differences between mean values of basic soil characteristics (Table 1), survival and growth characteristics of alder sp. from differing groups (e.g. substrate variants) (Table 2) were tested by RIR-Tukey multiple comparison procedure (at p = 0.05). Distribution conformity of the investigated features was compared to normal distribution using the Shapiro–Wilk test. The average values of analyse characteristic for

Table 1 Some characteristics of substrates tested in plot experiment on fly ash landfill.

2.5. Statistical procedures

43.86 40.3 1624.0

2.4. Assessment of survival, growth and nitrogen supply in the trees In each experimental plot the survival rate was assessed (as a percentage of live trees in comparison to the total number of trees introduced), diameter at root collar was measured (d0 ) with an accuracy of 0.1 cm and height (h) of all trees with an accuracy of 0.01 m (Table 2). Tree measurements were conducted in the autumn of the first year (2006) and 5 years after planting (2011), later based on these measurements the current annual growth was calculated for tree collar diameter (d0 ) and height (h). Additionally, samples of leaves to determine nitrogen content (the main deficient element in the ash substrate) were collected in autumn, from 5 trees regularly distributed along the diagonal of each plot, from the top of the crown of the exposition SW (Baule and Fricker, 1970). Nitrogen content in leaves was determined using ‘Leco CNS 2000 (Ostrowska et al., 1991).

99.90 55.84 84.92

(mg kg−1 ) (%)

Mg2+

CEC

BS

Nt

P

1.05 1.4 4.6

Zn

57.8 0.7 5.9

Cu

22.3 4.7 0.1

Pb

10.1 3.2 2.3

Cd

0.8 0.0 0.0

Cr

horizon and 16 points regularly distributed along the diagonal of the plot intended for the experiment; eventually four mixed samples were made out of them. Additionally, one sample was collected from each mixed enhanced substrate from piles (Miocene acidic sand and lignite culm) brought to the site for the experiment (Table 1). In 2008, samples were collected again to determine the properties of substrates formed after using the combination of (CFA, CFA + MS, CFA + L) from seeding holes. For this purpose, in each plot, samples were collected from 0 to 40 cm horizon in 5 points which were regularly distributed along the diagonal of each plot in close proximity to tree root collar. 24 mixed samples representative of individual plots were selected from them. Mixed samples of technosols were taken (1.0 kg mass of fresh sample) to determine basic soil properties. In the lab, soil samples were dried and sieved through a 2.0 mm sieve. The basic soil parameters were determined in the soil samples using soil laboratory procedures: particle size distribution was determined by hydrometer analysis method and sand fractions by sieving. Soil pH was determined in 1 M KCl at a 1:2.5 soil:solution ratio; electrical conductivity (EC) by conductometric methods at a 1:5 soil: solution ratio with 21 ◦ C temperature; total nitrogen (Nt) using the thermal conductivity method with the ‘Leco CNS 2000’; exchangeable acidity (Hh ) in 1 M Ca(OAc)2 ; basic exchangeable cations (Sh ) Na+ , K+ , Ca2+ , Mg2+ in 1 M NH4 Ac by AAS; phosphorus (P) in a form available by plants was assayed in calcium lactate extract ((CH3 CHOHCOO)2 Ca) acidified with hydrochloric acid to pH 3.6 (by the Egner–Riehm method) and in total form using the molybdate blue colorimetric method. CEC was determined by the sum of alkaline cations (Sh ) extractable in 1 N NH4 OAc and exchangeable acidity (Hh ) (Van Reeuwijk, 1995). The content of some metallic elements (close to the total forms): Zn, Cu, Pb, Cd and Cr were determined after digestion in the mixture of HNO3 (d = 1.40) and 60% HCl04 acid in 4:1 proportion, using the AAS method (Ostrowska et al., 1991).

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19.9 9.0 5.7

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W. Krzaklewski et al. / Ecological Engineering 49 (2012) 35–40

Table 2 Survival and growth of alders at the different substrate variants. Species

Variant

Survival [%] 2006

2011

2006

2011

2006

2011

Black Alder

CFA CFA + MS CFA + L

82 ± 5a * 73 ± 6a 93 ± 4b

76 ± 11a 61 ± 3a 88 ± 4b

0.97 ± 0.26a 0.98 ± 0.28a 1.23 ± 0.36b

5.17 ± 1.52a 4.81 ± 1.67a 5.92 ± 1.80b

90.36 ± 22.25b 82.68 ± 26.01a 90.33 ± 27.89b

302.61 ± 80.14b 251.36 ± 86.52a 349.87 ± 81.45c

Grey Alder

CFA CFA + MS CFA + L

91 ± 4a 85 ± 17a 88 ± 7a

87 ± 4a 81 ± 20a 82 ± 13a

1.04 ± 0.32a 1.14 ± 0.34b 1.02 ± 0.30a

4.26 ± 1.78a 4.73 ± 1.93b 4.61 ± 1.77ab

76.94 ± 22.70a 77.81 ± 22.60a 74.27 ± 16.32a

233.47 ± 70.17a 264.06 ± 78.03b 258.00 ± 76.71b

*

d0 [cm]

h [cm]

Mean and SD; letters (a, b) indicate significant differences between mean values of trees characteristics after 2 years on different substrate combination.

substrate were compared using ANOVA preceded by Leven’s variance homogeneity test. 3. Results 3.1. Substrate characteristics The output properties of fly ash were very unfavourable for the introduced vegetation and tended to be a strongly alkaline with pH amounting to 9.57; hight EC with an average of 954.5 ␮S cm−1 , low nitrogen content (Nt) (272.25 mg kg−1 ) and trace amounts of phosphorus (P) (1.05 mg kg−1 ). The content of heavy metals concentration was respectively: Zn 57.8 mg kg−1 , Cu 22.3 mg kg−1 , Pb 10.1 mg kg−1 , Cd 0.8 mg kg−1 and Cr 19.9 mg kg−1 (Table 1). The properties of Miocene acidic sand used as an enhancing substrate included acidity and pH of 3.38, EC of 255.0 ␮S cm−1 as well as low nitrogen (317.0 mg kg−1 ) and phosphorus content (1.4 mg kg−1 ), CEC of 3.74 cmol(+) kg−1 , and BS of 55.84%. The content of heavy metals concentration was respectively: Zn 0.7 mg kg−1 , Cu 4.7 mg kg−1 , Pb 3.2 mg kg−1 , Cd 0.0 mg kg−1 and Cr 9.0 mg kg−1 (Table 1). Lignite culm used as enhancing substrate exhibited pH of 5.49, EC of 162.0 ␮S cm−1 , nitrogen content (mainly geogenic) of 4800 mg kg−1 and phosphorus content of 4.6 mg kg−1 , CEC of 104.47 cmol(+) kg−1 , and BS of 84.92%. The content of heavy metals concentration was respectively: Zn 5.9 mg kg−1 , Cu 0.1 mg kg−1 , Pb 2.3 mg kg−1 , Cd 0.0 mg kg−1 and Cr 5.7 mg kg−1 (Table 1). Two years after the experiment was begun the properties of the applied substrate combinations at tree root collar were equalised and amounted to: pH from 7.69 to 7.93; EC from 478.8 to 550.6 ␮S cm−1 ; Nt from 472.32 to 629.4 mg kg−1 and P from 7.6 to 9.7 mg kg−1 ; CEC from 53.98 to 62.43 cmol(+) kg−1 , and BS from 98.38 to 99.06%. The content of heavy metals concentration was respectively: Zn from 43.8 to 45.8 mg kg−1 , Cu from 17.3 to 20.7 mg kg−1 , Pb from 16.5 to 17.5 mg kg−1 , Cd from 0.9 to 1.1 mg kg−1 and Cr from 16.3 to 18.4 mg kg−1 (Table 1).

Fig. 1. The average diameter growth (d0 ) of alders after 4-year vegetation periods (autumn 2006–spring 2011) on the different substrate variants (CFA – control; CFA + MS – fly ash with acidic Miocene sand addition; CFA + L – fly ash with lignite culm addition).

with added lignite culm (CFA + L) (5.92 cm) (Table 2). An average diameter growth (d0 ) in the 4-year period (autumn 2006–spring 2011) was from 0.79 cm yr−1 (CFA + MS) to 0.94 cm yr−1 (CFA + L), and these differences were not statistically significant (Fig. 1). The height (h) of black alder on control plots (CFA) was on average 302.61 cm which is considerably higher in comparison to the variant with an addition of acidic sand (CFA + MS) (251.36 cm) and considerably lower in comparison to the variant with an addition of lignite culm (CFA + L) (349.87 cm) (Table 2). The average height increase (h) was from 33.50 (CFA + MS) to 53.63 cm yr−1 (CFA + L), and these differences were statistically significant (Fig. 2).

3.2. Alders’ survival After 1 year of starting the experiment an average of 73% (CFA + MS) to 93% (CFA + L) black alder seedlings and from 85% (CFA + MS) to 91% (CFA) grey alder seedlings survived. After 5 years of starting the experiment, black alder survival ranged from 61% (CFA + MS) to 88% (CFA + L), while the grey alder survival from 81% (CFA + MS) to 87% (CFA) (Table 2). 3.3. Alders’ growth parameter Black alder root collar diameter (d0 ) after 5 years of setting up the experiment on control plots (CFA) was 5.17 cm. In the variant with added acidic sand (CFA + MS) it was 4.81 cm. These values were significantly lower than the ones obtained on the variant

Fig. 2. The average height growth (d0 ) of alders after 4-year vegetation periods (autumn 2006–spring 2011) on the different substrate variants (CFA – control; CFA + MS – fly ash with acidic Miocene sand addition; CFA + L – fly ash with lignite culm addition).

W. Krzaklewski et al. / Ecological Engineering 49 (2012) 35–40

Root collar diameter (d0 ) of grey alder on control plots (CFA) was 4.26 cm, which was considerably lower in comparison to variants CFA + MS (4.73 cm) and CFA + L (4.61 cm) (Table 1). The average diameter increase (d0 ) of grey alder was from 0.63 (CFA) to 0.72 cm yr−1 (CFA + MS and CFA + L), and these differences were not statistically significant (Fig. 1). The height of grey alder in CFA variant was on average 233.47 cm, which was considerably lower in comparison to variant CFA + MS (264.06 cm) (Table 1). The average height increase (h) was from 30.87 cm yr−1 (CFA) to 36.37 cm yr−1 (CFA + MS), and these differences were not statistically significant (Fig. 2).

3.4. Nitrogen supply Nitrogen (N) content in black alder leaves was on average 25.73 g kg−1 in CFA + MS variant, 28.55 g kg−1 in CFA + L variant up to 29.11 g kg−1 in CFA variant, and these differences were not statistically significant. Nitrogen (N) content in grey alder leaves was poorly diversified between the variants and ranged from 25.49 g kg−1 in CFA + MS variant, through 25.95 g kg−1 in CFA + L variant to 26.08 g kg−1 in CFA variant.

4. Discussion In biological stabilization of fly ash landfills the key issue is the selection of plant species with high tolerance to adverse site conditions (Carlson and Adriano, 1991; Cheung et al., 2000; Gupta ˇ et al., 2002; Pavlovic´ et al., 2004; Pietrzykowski et al., 2010; Cermák, 2008; Juwarkar and Jambhulkar, 2008; Haynes, 2009; Pandey et al., 2009; Bilski et al., 2011). Based on experiments described in literature, this group includes first of all the species belonging to the Brassicaceae, Chenopodiaceae, Fabiaceae, Leguminoceae and Poaceae families (Jusaitis and Pillman, 1997; Pandey et al., 2009). They are mainly herbaceous plants which may form turf and provide erosion protection. In the course of tree planting or afforestation of some ash landfills it is important to recognize the adaptability potential of trees and shrubs. As already mentioned, the main factors limiting plant growth in these conditions are primarily a deficit of nutrients (mainly N and P) and very high pH (Table 1). Therefore, in order to provide start up doses of nutrients in extreme conditions, uniform mineral NPK fertilization was applied with initial stabilization through hydroseeding with seed sludge uniformly on all surfaces. Application of the tested substrates was primarily aimed at lowering the pH. The rationale for testing the above substrates was also their availability in the vicinity of ‘Bełchatów’ opencast lignite mine. Miocene acidic sands widely present in the overburden of the mine usually have a high content of carbon and sulphur. They tend to have sulphur content higher >0.2%, geogenic carbon content >0.5% and low pH values (even <3.5). Soils formed on the Miocene deposits are referred to in the literature as the so-called ‘sulphurous mine soils’ from areas of Lusatian Mine District in Germany (Katzur and Haubold-Rosar, 1996). Hence, in the course of work on biolog´ landfill, a concept was developed of ical stabilization in ‘Lubien’ lowering the pH of excessively alkaline ash by mixing it with acidic sands. In the case of lignite the possibility has long been pointed out of using this substrate for the production of organic fertilizers (Kwiatkowska et al., 2008; Chassapis et al., 2009; Giannouli et al., 2009). Lignite may also be a valuable source of soil organic matter (SOM) due to a high content of humic acid. Humic acids enhance the physical properties of soil and increase soil fertility because of high content of nutrients (Chassapis et al., 2009). The above properties of lignite and its relatively low pH as well as hydrophilic character of

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humic acid may improve fly ash properties and growth conditions of vegetation introduced to fly ash landfills. Within 2 years of starting the experiment the properties of the applied substrate combinations in the seeding holes were uniform. With the applied amount of substrate (3 dm3 per hole) and after sampling was carried out no significant parameter differences were observed in substrates (Table 1). It was found however, that even such scarce NPK start up fertilising and hydroseeding with seed sludge uniformly on all surfaces had a positive impact on the substrate properties. The positive impact of the treatment was evident most of all in a significant lowering of fly ash substrate pH (from 9.6 to approx. 8.0) as well as in nitrogen content increase (N) (from 272.3 to 472.3–629.4 mg kg−1 ) and phosphorus (P) (from 1.05 to 7.6–9.7 mg kg−1 ) content increase. The contents of selected heavy metals in the fly ash substrates, before and during the experiment, does not exceed the average reported for non-contaminated soils (Kabata-Pendias and Pendias, 1992). Thus the literature data and data from technical reports were confirmed, that there is no specific threat to introduced vegetation by this factor in terms of ´ Despite uniform properties combustion waste landfills ‘Lubien’. in the combinations of substrates, it was found that the survival rate and dimensions attained by alders were diverse for different variants (Table 2). This indicates that the substrates used had the greatest impact on the studied tree species in the first year of the experiment. This period determines the most survival rate and further growth of seedlings planted in extreme habitat conditions of anthropogenic sites (Kuznetsova et al., 2011). This is confirmed by results of alder survival rate where the largest number is lost after the first year of the experiment (Table 2). After 5 years the survival rate of alders on the research plots was relatively high and ranged from 61 to 88% for black alder and from 81 to 87% for grey alder (Table 2). Similar survival rate results were obtained for other reclaimed for forestry post-industrial sites characterized by a substrate with a strongly alkaline reaction, such as: sediment tanks for waste generated by an acetylene and polyvinyl chloride factory (Oliveira et al., 2005) and shale oil mining sites (Kuznetsova et al., 2010). This demonstrates high adaptability potential and broad ecological amplitude of alders, which in natural conditions occur in habitats which are mostly fertile, constantly humid, or even periodically flooded (Ellenberg, 2009). Nutrient supply, especially nitrogen, which in these conditions is frequently ˇ the minimum factor (Adriano et al., 1980; Cermák, 2008; Haynes, 2009) is an important aspect of tree adaptability potential assessment to extreme conditions. Nitrogen content in the leaves of black alder (from 25.73 to 29.11 g kg−1 and grey alder (from 25.49 to 25.95 g kg−1 ) was within the ranges reported for the genus Alnus sp. in conditions of Central Europe (Uri et al., 2002, Kuznetsova et al., 2011). It indicates an absence of disturbance in the uptake and mineral nutrition with this nutrient and is another factor in confirming the adaptability potential of the tested alder species.

5. Conclusions The results of alder survival rate and growth assessment in the presented experiment indicate the species’ significant ability to adapt to habitat conditions in the combustion waste landfills. The obtained results of survival rate studies, especially of black alder, however, clearly indicate that the use of Miocene sand is not a good solution for improving ash substrate. Lignite culm addition impacted most beneficially the survival rate and attained dimensions of black alder. In plots where it was applied, the highest survival rate and bigger (considerably) average root collar (d0 ) as well as height (h) and bigger (insignificantly) annual growth d0 and h were reported. In the case of grey alder, the highest

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survival rate was reported in the control plots where no enhancing agents were used (CFA). In this variant the smallest dimensions of alders were reported (average root collar diameter d0 , height h, annual growth d0 and h) in comparison to other substrate variants (CFA + MS; CFA + L), where the assessed parameters were comparable. Comparing the growth of the introduced alder species and the applied experimental variants it was found that the best results were obtained in the case of black alder in the variant using lignite (CFA + L). This solution is important, e.g. when planning the production of trees to obtain biomass for energy generation purposes, where the objective is to maximize timber production. Close proximity of the site to the power plant indicates the validity of this approach and may affect additional benefits resulting from the use of biological stability. As follows from the conducted experiments, the introduction of two species of alders directly on the fly ash using start up NPK fertilising and hydroseeding with seed sludge may be recommend mainly for economic reasons. Especially when one considers the fact that the introduced alder species are to have primarily protective and phytomelioration functions, and thus prepare the substrate for the major and target species with higher habitat requirements (such as oaks). Acknowledgements The authors acknowledge and appreciate the efforts of parties representing mining firms: KWB ‘Bełchatów’ and Power Plant ‘Bełchatów’, and The State Forests National Forest Holding PGL ´ Lasy Panstwowe, Forest Districts: Bełchatów, who provided site ´ access permissions and assistance. Thanks to Iwona Skowronska MSc. from Lab of Department of Forest Ecology for laboratory analyses. This study was financially supported by the Polish Ministry of Science and Higher Education in frame of DS 3420 KEkL 2011, Department of Forest Ecology, Agricultural University of Krakow. References Adriano, D.C., Page, A.L., Elseewi, A.A., Chang, A.C., Straughan, I., 1980. Utilization and disposal of fly ash and other coal residues in terrestrial ecosystems: a review. J. Environ. Qual. 9 (3), 333–344. P., Saxena, M., Asolekar, S.R., 2005. Coal combustion Asokan, residues—environmental implications and recycling potentials. Resour. Conserv. Recycl. 43, 239–262. Baule, H., Fricker, C., 1970. The Fertilizer Treatment of Forest Trees. BLV, Verlagsgesellschaft, Munich. Bilski, J., Mclean, K., McLean, E., 2011. Revegetation of coal ash (FA) by selected cereal crops and trace elements accumulation by plant seedlings. Electron. J. Environ. Agric. Food Chem. 10 (6), 2337–2349. Carlson, C.L., Adriano, D.C., 1991. Growth and elemental content of two tree species growing on abandoned coal fly ash basins. J. Environ. Qual. 20 (3), 581–587. ˇ P., 2008. Forest reclamation of dumpsites of coal combustion by-products Cermák, (CCB). J. For. Sci. 54 (6), 273–280. Chassapis, K., Roulia, M., Tsirigoti, D., 2009. Chemistry of metal–humic complexes contained in Megalopolis lignite and potential application in modern organomineral fertilization. Int. J. Coal Geol. 78 (4), 288–295. Cheung, K.C., Wong, J.P.K., Zhang, Z.Q., Wong, J.W.J., Wong, M.H., 2000. Revegetation of lagoon ash using the legume species Acacia auriculiformis and Leucaena leucocephala. Environ. Pollut. 109 (1), 75–82. Dellantonio, A., Fitz, W.J., Repmann, F., Wenzel, W.W., 2009. Disposal of coal combustion residues in terrestrial systems: contamination and risk management. J. Environ. Qual. 39 (3), 761–775. Ellenberg, H., 2009. Vegetation Ecology of Central Europe. Cambridge University Press. Giannouli, A., Kalaitzidis, S., Siavalas, G., Chatziapostolou, A., Christanis, K., Papazisimou, S., Papanicolaou, C., Foscolos, A., 2009. Evaluation of Greek low-rank coals

as potential raw material for the production of soil amendments and organic fertilizers. Int. J. Coal Geol. 77, 383–393. Gupta, D.K., Rai, U.N., Tripathi, R.D., Inouhe, M., 2002. Impacts of fly-ash on soil and plant responses. J. Plant Res. 115, 401–409. Gupta, A.K., Dwivedi, S., Sinhi, S., Tripathi, R.D., Rai, U.N., Singh, S.N., 2007. Metal accumulation and plant growth performance of Phaseolus vulgaris grown in fly ash amended soil. Bioresour. Technol. 98, 3404–3407. Gray, Ch.A., Schwab, A.P., 1993. Phosphorus-fixing ability of high ph, high calcium, coal-combustion, waste materials. Water Air Soil Pollut. 69, 309–320. Haynes, R.J., 2009. Reclamation and revegetation of fly ash disposal sites—challenges and research needs. J. Environ. Manage. 90, 43–53. Hodgson, D.R., Townsend, W.N., 1973. The amelioration and revegetation of pulverized fuel ash. In: Chadwick, M.J., Goodman, G.T. (Eds.), Ecology and Reclamation of Devastated Land, vol. 2. Gordon and Breach, London, pp. 247–270. Junor, R.S., 1978. Control of wind erosion on coal ash. J. Soil Conservat. Serv. New S. Wales 34 (1), 8–13. Jusaitis, M., Pillman, A., 1997. Revegetation of waste fly ash lagoons. I. Plant selection and surface amelioration. Waste Manage. Res. 15 (3), 307–321. Juwarkar, A.A., Jambhulkar, H.P., 2008. Restoration of fly ash dump through biological interventions. Environ. Monit. Assess. 139, 355–365. Kabata-Pendias, A., Pendias, H., 1992. Trace Elements in Soil and Plants, 2nd ed. CRC Press, Boca Raton, London. Katzur, J., Haubold-Rosar, M., 1996. Amelioration and reforestation of sulfurous mine soils in Lusatia (Eastern Germany). Water Air Soil Pollut. 91, 17–32. Kobus, A., Ostrowicz, I., 1987. Effect of ash and slag disposal on the environment. In: National Conference on Science and Technology, Environmental Protection in the Bełchatów Industrial District, 17–18 September 1987, Bełchatów (in Polish). Kuznetsova, T., Rosenvald, K., Ostonen, I., Helmisaari, H.-S., Mandre, M., Lõhmus, K., 2010. Survival of black alder (Alnus glutinosa L.) silver birch (Betula pendula Roth.) and Scots pine (Pinus sylvestris L.) seedlings in a reclaimed oil shale mining area. Ecol. Eng. 36, 495–502. Kuznetsova, T., Lukjanova, A., Mandre, M., Lõhmus, K., 2011. Aboveground biomass and nutrient accumulation dynamics in young black alder, silver birch and Scots pine plantations on reclaimed oil shale mining areas in Estonia. For. Ecol. Manage. 262 (2), 56–64. Kwiatkowska, J., Provenzano, M.R., Senesi, N., 2008. Long term effects of a brown coal-based amendment on the properties of soil humic acid. Geoderma 148 (2), 200–205. ˇ Malá, J., Cvrˇcková, H., Máchová, P., Dostál, J., Síma, P., 2010. Heavy metal accumulation by willow clones in short-time hydroponics. J. For. Sci. 56, 28–34. McMinn, J.W., Berry, L.E., Horton, J.H., 1982. Ash basin reclamation with commercial forest species. Reclam. Reveg. Res. 1, 359–365. Oliveira, R.S., Castro, P.M.L., Dodd, J.C., Vosátka, M., 2005. Synergetic effect of Glomus intraradices and Frankia sp. on the growth and stress recovery of Alnus glutinosa in an alkaline anthropogenic sediment. Chemosphere 60, 1462–1470. Ostrowska, S., Gawlinski, S., Szczubialka, Z., 1991. Procedures for Soil and Plants Analysis. Institute of Environmental Protection, Warsaw (in Polish). Pandey, V.C., Abhilash, P.C., Singh, N., 2009. The Indian perspective of utilizing fly ash in phytoremediation, phytomanagement and biomass production. J. Environ. Manage. 90, 2943–2958. ´ P., Mitrovic, ´ M., Djurdjevic, ´ L., 2004. An ecophysiological study of plants Pavlovic, growing on the fly ash deposits from the Nikola Tesla—a thermal power station in Serbia. Environ. Manage. 33 (5), 654–663. Pietrzykowski, M., Krzaklewski, W., Gaik, G., 2010. Assessment of forest growth with plantings dominated by Scots pine (Pinus sylvestris L.) on experimental plots on a fly ash disposal site at the Bełchatów power plant. Environ. Eng. 137 (17), 65–74 (In Polish, English summary). Pillman, A., Jusaitis, M., 1997. Revegetation of waste fly ash lagoons II. Seedling transplants and plant nutrition. Waste Manage. Res. 15 (4), 359–370. Scanlon, D.H., Duggan, J.C., 1979. Growth and element uptake of woody plant on fly ash. Environ. Sci. Technol. 13 (3), 311–315. StatSoft, Inc. 2009. STATISTICA (data analysis software system), Version 9.1. Stolecki, L., 2005. The Influence of Combustion Waste Disposal in the Final Excavation Pit ‘Bełchatów’ on the Aquatic Environment. PhD Thesis, Wrocław University of Technology, Faculty of Geoengineering, Mining and Geology, Wrocław (in Polish). Tripathi, R.D., Vajpayee, P., Singh, N., Rai, U.N., Kumar, A., Ali, M.B., Kumar, B., Yunus, M., 2004. Efficacy of various amendments for amelioration of flyash toxicity: growth performance and metalcomposition of Cassia siamea Lamk. Chemosphere 54, 1581–1588. Uri, V., Tullus, H., Lõhmus, K., 2002. Biomass production and nutrient accumulation in short-rotation grey alder (Alnus incana (L.) Moench.) plantation on abandoned agricultural land. For. Ecol. Manage. 161 (1–3), 169–179. Van Reeuwijk, L.P., 1995. Procedures for Soil Analysis, 5th ed. ISRIC, FAO, Wageningen, Technical Paper 9. Wo´s, A., 1999. Polish Climate. PWN, Warsaw, pp. 1–301 (in Polish).