Scots pine needles macronutrient (N, P, K, CA, MG, and S) supply at different reclaimed mine soil substrates—as an indicator of the stability of developed forest ecosystems
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- Pietrzykowski, M., Woś, B. & Haus, N. Environ Monit Assess (2013) 185: 7445. doi:10.1007/s10661-013-3111-9
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A main objective of restoration and afforestation at post-mining sites is establishing a long-term sustainable ecosystem which depends on adaptations of tree species and which in turn depends on the soil nutrient flux. The nutrient concentration (nitrogen (N), P, K, Ca, Mg, and sulfur (S)) of Scots pine needles was investigated in reclaimed mine soils (RMS) located at the following post-mining sites: a sand mine pit, spoil heap from a lignite mine, spoil heap from a S mine, and a carbonaceous spoil heap from an underground coal mine. The control plots were arranged on natural forest sites adjacent to the post-mining sites. A higher level of foliar nutrients was noted in the carbonaceous RMS, while lower levels were found in RMS on the spoil heap following lignite mining. The characteristics of the substrate were found to exert greater effect than mineral fertilization (performed at the onset of reclamation) on the tree stand characteristics, needle length and foliar nutrient concentration. While the soils and trees were most deficient in N, negative symptoms have not been noted to this date in tree stands at reclaimed mine sites. Trophic ratings were recommended based on statistical correlations and groupings between N and P contents in needles and needles length (mean length of 300 needles) while nutrient ratings were recommended from statistical differences and groupings of the RMS substrates.
KeywordsMining sites Reclamation Afforestation Ecosystem Pine Nutrient supply
Bełchatów (mine sites (facilities))
Piaseczno (mine sites (facilities))
Szczakowa (mine sites (facilities))
Smolnica spoil heaps and quarry (mine sites (facilities))
- BEL-Ql, BEL-Ns, PIAS-Qs, PIAS-QsNc, SCZ-Qs, SCZ-Qls, SMOL-Cf
Soil-substrate (parent rock) variants on post-mine sites, detailed description in Table 1
The trees diameter at a breast height of 1.3 m
Average mean of d.b.h.
Dry mass of 100 pairs of needles
Area of stand cross-section at breast height of trees
Top height of tree stand
Average height of tree stand
Mean length of 300 pine needles
Numbers of trees per hectare
Natural forest sites
Reclaimed mine soils
Reineke’s Stand Density Index
Total exchangeable bases
Mined lands are drastically disturbed landscapes in need of soil reclamation to re-establish vegetation. Successful reclamation of mined lands requires site-specific strategies (Wali and Freeman 1973; Daniels et al. 1992; Wali 1999; West and Wali 2002; Bradshaw and Chadwick 1980; Bradshaw and Hüttl 2001; Hüttl and Weber 2001; Pietrzykowski and Krzaklewski 2007). Afforestation is a potentially sustainable strategy for reclaiming mine lands to their former state (Parrotta et al. 1997; Filcheva et al. 2000; Singh et al. 2002; Dutta and Agrawal 2003; Pietrzykowski and Krzaklewski 2007). In central Europe, a large proportion of post-mining landscapes are reclaimed to forest (Katzur and Haubold-Rosar 1996; Hüttl 1998; Hüttl and Weber 2001; Kaar 2002; Knoche et al. 2002; Pietrzykowski and Krzaklewski 2007). In Poland, lands disturbed by mining and the power industry are estimated at around 70,000 ha, approximately 25,000 of which has been reclaimed and returned to forest (Krzaklewski 2001; Pietrzykowski and Krzaklewski 2007).
From an ecological point of view, the goal of restoration is to develop a long-term sustainable ecosystem native to the area mined (Chambers et al. 1994; Bradshaw and Hüttl 2001). The ecosystem, according to the traditional definition (Golley 1993), should consist of an integrated system of biotic and abiotic elements where all the trophic layers contain a complete set of species ensuring the circulation of matter and energy flow. A complete assessment of the reclamation and afforestation processes should take into consideration many ecological factors (Rodrigue et al. 2002). Of particular importance is the need to understand soils processes, element flux (Bradshaw 1983; Daniels et al. 1992; Li and Daniels 1994; Bendtfeldt et al. 2001; Schaaf 2001; Knoche et al. 2002; Pietrzykowski 2010a) and energy balance (Pietrzykowski and Krzaklewski 2007).
In recent years, interest in tree species selection and their adaptation to post-mining sites has grown (Baumann et al. 2006; Chodak and Niklińska 2010; Kuznetsova et al. 2010; Pietrzykowski 2010a; Pietrzykowski and Socha 2011). Scots pine (Pinus sylvestris L.) is one of the most important species used for reclaiming mined lands in central Europe (Baumann et al. 2006; Pietrzykowski 2010a; Kuznetsova et al. 2010). Scots pine is native to Europe and Asia and has a common range extending west to Great Britain and to Portugal, east to eastern Siberia, south to the Caucasus Mountains, and as far north as the Arctic Circle in Scandinavia. In its northernmost range, the Scots pine is found at altitudes ranging from sea level to 1,000 m, while in the south, it is a high-altitude tree found between 1,200 and 2,600 m (Farjon 2005). The pioneering character of Scots pines over such a vast area coupled with its tolerance of poor soils makes it an ideal species for reclamation and reforestation in central Europe. However, post-mining sites differ significantly from natural sites; water and nutrient limitations are the foremost impediments to tree stand growth and stability on disturbed lands (Howard et al. 1988; Katzur and Haubold-Rosar 1996; Knoche et al. 2002; Ochał et al. 2010; Pietrzykowski 2010a; Zipper et al. 2011). The adaptability of Scots pine to these environments must be studied further (Baumann et al. 2006; Pietrzykowski and Krzaklewski 2007; Ochał et al. 2010; Pietrzykowski 2010a).
The nutritional status of pines in different habitats is primarily assessed by the content and relative abundance of macronutrients in the needles (Ballard and Carter 1986; Braeke and Sahin 2002). This criterion can also be used to assess reclaimed mine soil (RMS) nutrient status (Pietrzykowski 2010a) based on the correlation between nutrient availability in the soil versus nutrient content in the foliage (Braeke and Sahin 2002), though these correlations between nutrient and foliar RMS are in need of further proofing (Heinsdorf 1999; Baumann et al. 2006; Ochał et al. 2010; Pietrzykowski 2010a; Pietrzykowski and Socha 2011). More traditional criteria assess the morphology of the needles (i.e., needle weight and length) and growth of tree stands (mean height and mean diameter at a breast height of 1.3 m) (Baule and Fricker 1970; Ballard and Carter 1986).
This study evaluated the afforestation of Scots pine on four reclaimed mine spoils. The main goal of the study was to analyze and compare nutrient supply from different RMS substrates to the foliar and tree stand characteristics on post-mining lands afforested with Scots pine. The results were compared with data from “natural” control plots adjacent to the RMS.
Materials and methods
Site and substrate variant characteristics
Bełchatów external slope (BEL)
Smolnica spoil heap (SMOL)
Szczakowa sand quarry (SCZ)
Piaseczno external slope (PIAS)
Natural forest site (NFS) - control plots
In the vicinity of post-mining sites
Mean annual precipitation (mm)
Mean annual temperature (°C)
Parent material (substrate variant)
Quaternary loamy sands, loam, and bouldery clay
Neogene sands with loam and clay, carbonated and sulfurized
Carboniferous rocks: mudstones, sandstones and carbonaceous shales
Fluvioglacial quaternary sands
Fluvioglacial quaternary loamy sands
Mixture of neogene Krakowiec Beds formation clays and mudstones from Pectene Beds horizons
Fluvioglacial and morainic quaternary sands and haplic podzols (soils sub-type according to WRB, 2006)
Reclamation treatments (only for mine lands)
Neutralization with bog lime (neogene strata); NPK fertilization (60 kg N ha−1, 70 kg P ha−1, 60 kg K ha−1); 1-year cultivation of grasses and leguminous plants (sowing 60 kg ha−1); planting of trees
NPK fertilization (100 kg N ha−1, 20 kg P ha−1, 20 kg K ha−1); planting of poplars (Populus sp.) and pines (Pinus sylvestris L.). Self-sown pine seedlings
Organic amendment addition (300 m3 ha−1 organic horizons from forest soil, approx. 1.0 % Corg content); liming (1.5 Mg ha−1); NPK fertilization (140 kg N ha−1, 130 kg P ha−1, 150 kg K ha−1); 2-year lupine (Lupinus luteus L.) cultivation (sowing 240 kg ha−1); planting of pine tree (0.7 × 1.5 m spacing)
NPK fertilization (80 kg N ha−1, 50 kg P ha−1, 60 kg K ha−1); 2-year papilionaceous (Papilionaceae) plants and grasses cultivation; planting of pine tree (0.7 × 1.5 m spacing)
Basic soil parameters
Silt-sized fraction (0.05–0.002 mm (%))
Clay-sized fraction (<0.002 mm (%))
Acidity (pH in 1 M KCl)
Total exchangeable bases (cmol(+) kg−1)
Organic carbon (g kg−1)
Total nitrogen (g kg−1)
Total sulfur (g kg−1)
Branches were sampled and collected during the autumn of 2007 and 2008 from treetops on a southwest exposure from three trees with mean parameters (d.b.h. and h) at each plot.
The youngest needles (from the sampling year) were separated from the collected branches in the laboratory and representative mixed samples for each research plot were prepared. Three hundred (300) pairs of needles (L300n) from the representative mixed samples were selected randomly and their length (at 0.0 cm accuracy) was measured. The L300n samples were then dried at 65 °C, weighed (at 0.0 g accuracy) to determine the dry mass of 100 pair of needles (DM100n), washed in distilled water, dried again, and prepared for chemical analyses.
The carbon (C), N, and S content of the needles was assayed on a “Leco CNS 2000” analyzer. Organic carbon (Corg) and total sulfur (St) content was measured by infra-red absorption, and total nitrogen (Nt) by thermal conductivity; Total Ca, Mg, K was determined by digestion in the mixture of HNO3 (d = 1.40) and 60 % HClO4 acid in a 4:1 ratio; element levels were determined by atomic absorption spectroscopy. Total phosphorus (P) was determined by photocolorimetry by the molybdate blue method of Ostrowska et al. (1991) from a 60 % HClO4 extract.
Soil pedons were sampled and analyzed (reported in Pietrzykowski 2010b), from 32 hand-dug pits to a depth of 110 cm for RMS and 150 cm for NFS controls. Full profile descriptions with detailed soil morphology were completed for each of the seven RMS substrates and the 4 adjacent NFS locations. The typical pedons were located on sites representative of the local relief and average tree growth of the stands. Additionally, five samples were collected from each plot by soil auger (Eijkelkamp set) on a grid. Boreholes were sampled at depths of 0–8, 8–50, and 50–110 cm. Bulk density was sampled from each soil horizon with 3 replications using 250 cm3 steel cores according to the method of De Vos et al. (2005). Soil analyses were conducted on <2 mm air-dried samples using the procedures of Ostrowska et al. (1991) and Van Reeuwijk (1995). Particle size distribution was determined by hydrometer and sand fractions by sieving. Soil pH was determined in a 1:2.5 1 M KCl solution, exchangeable cations (Ca2+, Mg2+, K+, and Na+) were extracted with 1 M NH4OAc and total exchangeable bases (TEB) were calculated. Corg and St content was determined by infrared absorption, and Nt by thermal conductivity with a “Leco CNS 2000.” P in a form assimilated by plants was assayed using the Egner–Riehm method in calcium-lactate extract ((CH3CHOHCOO)2Ca) acidified with hydrochloric acid to pH 3.6. Nutrient storage (Mg ha−1 110 cm−1 depth) was determined from the bulk density and nutrient concentrations (N, P, K, Ca, Mg, and S) (Pietrzykowski 2010b).
Data sets were statistically analyzed using the Statistica 8.1 program (StatSoft Inc. 2007). Pearson’s procedure was used to test the first correlations at P = 0.05 between: nutrient concentration and nutrient ratio in the needles; nutrient concentration, dry mass, and length of the needles; nutrient concentration and tree stands parameters (Dg and HL); and the biometric needle characteristics (L300n and DM100n). Tukey’s multiple comparison procedure was used to test the differences between mean values at P = 0.05. Regression residuals were tested for normality using the Shapiro–Wilkes test. Means were grouped according to statistically similar N and P ranges.
The RMS and NFS soils are generally coarse grained to skeletal with low nutrient contents. Large variations in physical and chemical properties are normal and can change drastically within the confines of a single mining facility. Soil pH ranged from extremely acid (3.6) to slightly alkaline (7.5) with large differences observed for similar RMS substrates given the same reclamation treatment (Table 1). Likewise, the exchangeable bases: Corg, Nt, and St, also varied drastically under similar RMS substrates given the same reclamation treatment. With the exception of SMOL, the RMS properties ranged from 2.3 to 13.2 g kg−1 for Corg, from 0.15 to 0.86 g kg−1 for Nt, and from 0.07 to 0.25 g kg−1 for St. The SMOL substrate is extremely acid with a high content of geogenic C which contains much higher levels of carbon, N and S than other RMS substrates. The NFS soils were sandy (>90 % sand), extremely acidic (pH 4.1) and contained low organic (10 and 0.5 g kg−1 of Corg and Nt) and inorganic (TEB of 0.91 cmol(+) kg−1) nutrients not dissimilar from many of the RMS substrates. In conclusion, the soils varied greatly due to properties inherited from the parent material substrate. The SMOL soils were the most nutrient rich but also the most acidic. The remaining, nutrient poor soils were markedly similar to the adjacent NFS soils (Table 1).
NFS mean nutrient storage at a depth of 110 cm was: 4.41 Mg N ha−1, 0.03 Mg P ha−1, 2.69 Mg Ca2+ ha−1, 0.69 Mg Mg2+ ha−1, 0.24 Mg K+ ha−1, and 1.8 Mg S ha−1. Comparatively, NFS nutrient storage was similar to the lower range of nutrients stored at RMS sites. The lowest RMS storage of macronutrients was: 3.10 Mg N ha−1 (BEL-Ns), 0.02 Mg P ha−1 (SCZ-Qs), 2.33 Mg Ca2+ ha−1 (SCZ-Qs), 0.12 Mg Mg2+ ha−1 (PIAS-Qs), 0.11 Mg K+ ha−1 (SCZ-Qs), and 1.17 Mg St ha−1 (SCZ-Qs). The highest macronutrient storage was: 62.3 Mg N ha−1 (SMOL-Cf), 0.48 Mg P ha−1 (BEL-Ns), 26.24 Mg Ca2+ ha−1 (PIAS-QsNc), 3.10 Mg Mg2+ ha−1 (SMOL-Cf), 0.97 Mg K+ ha−1 (SMOL-Cf), and 69.6 Mg St ha−1 (SMOL-Cf). Although the storage of some nutrients is considerably higher especially at the Smolnica spoil heap, the majority of these nutrients are bound in geogenic materials such as shale and thus not available for plant uptake.
Tree stand characteristics
Characteristics of tree stand parameters
N (pcs ha−1)
G (m2 ha−1)
Needle biometric parameters
Nutrients (N, K, Ca, P, Mg, and S) concentrations in needles of Scots pine growing on reclaimed post-mining sites and natural forest sites (NFS)
Length (L300n; cm)
49.8 ± 7.6
48.3 ± 5.1
51.0 ± 2.0
53.0 ± 5.0
42.3 ± 9.9*
56.8 ± 4.0
54.8 ± 3.6
59.3 ± 5.3
Dry mass (DM100n; g)
2.37 ± 0.43
2.56 ± 0.27
1.75 ± 0.17*
3.10 ± 0.72
3.47 ± 0.82
2.66 ± 0.33
2.15 ± 0.13*
3.53 ± 0.72
N (g kg−1)
9.88 ± 0.49*
10.73 ± 0.86*
15.25 ± 0.35
12.14 ± 0.78*
11.52 ± 0.60*
14.23 ± 0.47
12.63 ± 0.49*
14.35 ± 1.06
K (g kg−1)
4.89 ± 0.33*
6.08 ± 0.19
7.60 ± 0.55
5.02 ± 0.14*
4.53 ± 0.29*
5.59 ± 0.44*
7.28 ± 0.49
5.17 ± 0.52*
Ca (g kg−1)
2.25 ± 0.38*
3.29 ± 0.17*
3.41 ± 0.33*
4.90 ± 0.49
4.63 ± 0.29
3.89 ± 0.87
3.74 ± 0.74*
3.27 ± 0.88*
P (g kg−1)
1.03 ± 0.03*
1.12 ± 0.04*
1.48 ± 0.03
1.16 ± 0.04*
1.14 ± 0.09*
1.31 ± 0.07
1.27 ± 0.04
1.32 ± 0.10
Mg (g kg−1)
1.05 ± 0.16*
0.89 ± 0.07*
1.26 ± 0.03
0.98 ± 0.04*
0.98 ± 0.04*
0.98 ± 0.10*
0.90 ± 0.02*
0.96 ± 0.11*
S (g kg−1)
0.75 ± 0.07*
1.06 ± 0.16
1.25 ± 0.06
0.84 ± 0.06*
0.73 ± 0.07*
0.97 ± 0.04*
0.89 ± 0.07*
0.85 ± 0.05*
Needle nutrients and relationships
The needle N and P contents had the greatest deviation from the nutrient content found in the NFS needles, while Mg and S contents in the needles were the most likely to be similar to needle contents in NFS. The needle N content for the RMS ranged from: 9.88 (BEL-Ql) to 15.25 g kg−1 (SMOL-Cf) with 14.35 g kg−1 found on the NFS. Excluding SMOL-Cf and PIAS-QsNc, needle N contents on RMS sites were significantly lower (at P = 0.05) than the NFS (Table 3). Needle P was also significantly lower (at P = 0.05) in the RMS needles which ranged from 1.03 (BEL-Ql) to 1.48 g kg−1 (SMOL-Cf), with the exception of SMOL-Cf, PIAS-QsNc, and PIAS-Qs which were statistically similar to the NFS needle P content of 1.32 g kg−1. Contrarily, the needle Mg content in the NFS needles (0.96 g kg−1) was statistically similar (at P = 0.05) to needle Mg content on RMS sites (with the exception of SMOL-Cf), with a range of 0.89 (BEL-Ns) to 1.26 g kg−1 (SMOL-Cf). Similarly, needle S contents on RMS (range of 0.73 (SCZ-Qs) to 1.25 g kg−1 (SMOL-Cf)) and NFS (0.85 g kg−1) were statistically similar (at P = 0.05) with the exception of BEL-Ns and SMOL-Cf which had slightly higher levels of needle S (Table 3).
Needle nutrient ratios
Nutrient (N, K, Ca, P, Mg, and S) ratios (by weight concentration in dry mass) of Scots pine needles grown on reclaimed mine soils (RMS) and natural forest sites (NFS)
The needle K/Ca, K/Mg, and Ca/Mg ratios were much more comparable to the NFS needle ratios. The K/Ca ratio of the NFS needles was 1.7 and only the Szczakowa sites (1.0) were significantly lower (P = 0.05). The K/Mg ratio was significantly higher on the Piaseczno S mine external heap (8.1) than the NSF (5.4) but otherwise there was little change in the K/Mg ratio between the NFS and the RMS needles. There were no significant differences in the Ca/Mg ratios of the RMS and NFS needles.
Previous studies on coal spoils in Lusatia, Germany, have assigned soil fertility ratings to Scots pine (Heinsdorf 1999). Accordingly, the RMS at SMOL-Cf, SCZ-Qls, PIAS-QsNc, and PIAS-Qs have low N levels and BEL-Ql, BEL-Ns, and SCZ-Qs have very low N levels. The range of needle N for the RMS and NFS control was low compared with a needle N range of 11.7–29.1 g kg−1 for pines in the same climatic zone (Fober 1993). RMS are often deficient in N (Li and Daniels 1994), which is frequently a limiting factor for tree growth. Despite the low content of N in the soils and needles of this study, no clear visual indications of N deficiency, such as chlorosis were reported. P is also a deficient nutrient in the majority of RMS (Marrs and Bradshaw 1993). In this study however, the P content in RMS at BEL-Ql, BEL-Ns, SCZ-Qls, and SCZ-Qs was medium and even high at SMOL-Cf, PIAS-QsNc, and PIAS-Qs (according to the above-mentioned fertility ratings at Lusatia, i.e., Germany). As a result, the needle P in this study was given a medium rating in comparison to a natural needle P range of 0.3–5.2 g kg−1 (Fober 1993). S, on the other hand, was low at BEL-Ns, and at SMOL-Cf, and found to be very low at BEL-Ql, SCZ-Qls, SCZ-Qs, PIAS-QsNc, and PIAS-Qs (Heinsdorf 1999). Such low S content in the needles of pines growing in areas heavily impacted by numerous coal-burning power plants and other industries is surprising. It is possible that the low needle S is a symptom of lower SOx emissions which have reduced atmospheric S deposition in this part of Europe. The reduction of S emissions from coal combustion in power plants is primarily the result of the installation of flu gas desulphurization technologies (Klose et al. 2003). However, low needle S in the trees grown on RMS with sufficient to high levels of soil S may indicate inhibited uptake. The speciation of elements found in soils depends on geochemical and thermodynamic conditions such as element concentrations, pH, and sorption complex. In RMS, these relationships are not yet stable and may be frequently disturbed which can affect the availability of nutrients uptake (Katzur and Haubold-Rosar 1996; Heinsdorf 1999; Knoche et. al. 2002; Pietrzykowski 2010a). Such is likely the case with the low needled S in the “sulfurized soils” of Bełchatów (BEL-Ns) and Smolnica (SMOL-Cf) where high soil S is likely not found in the form of plant available sulfate. The remaining macronutrients K, Ca, and Mg were at sufficient or higher levels for all RMS sites (Heinsdorf 1999).
It should be stressed that the soils and the reclamation technologies, in particular, that were applied in this study differed significantly from the conditions found at the Lusatia coal spoil heaps where the above-mentioned fertility ratings were derived. In Lusatia, soils were intensively fertilized by the addition of as much as 160 Mg ha−1 of lignite ash (Katzur and Hauboldt-Rosar 1996). Presently, the only reclaimed soils fertilized are those that are considered severely deficient in nutrients. Intensive fertilization of soils, a former reclamation practice, has been phased out because maximizing tree growth is no longer considered the chief aim (Knoche et al. 2002).
It is crucial that a balanced supply of macronutrients exist in RMS which usually necessitates fertilization (Knoche et. al. 2002; Pietrzykowski 2010a). Prior to fertilization, the relationship of macronutrients in a stable ecosystem must be defined (Baule and Fricker 1970). The balanced soil macronutrient content will, in turn, affect the supply and quantity of macronutrients in needles as well as the health (physiologic functioning) and stability of the tree stand (Baule and Fricker 1970). Macronutrients in the tree biomass display a certain natural variability, and therefore it is inappropriate to define precise quantitative relations. However, a comparison of results from mine sites and control plots on NFS (Table 3) shows that macronutrient ratios in biomass have been disturbed at mine sites, particularly the relationship of N to other nutrients. The nutrient imbalance shows that conditions in reclaimed soils are completely different from natural sites, necessitating the adaptation of a “tree-nutrient strategy” (Hüttl 1998; Pietrzykowski 2010a). As previously mentioned, although no negative symptoms in tree growth have been found, imbalanced nutrient supply may lead to physiological and growth problems in the future (Baule and Fricker 1970). Recently, tree stands in the Lusatian Mine District suffered significant damage due to infections from the pathogen Heterobasidion annosum (Fr.) Bref. after the RMS had been intensively fertilized and ameliorated with ash (Knoche and Ertle 2010).
In this study, tree growth significantly correlated with N (R = 0.70 for Dg and R = 0.66 for H100) and P contents (R = 0.59 for Dg and R = 0.55 for H100). Forestry management often assesses the productivity of a site by measuring the height of the dominant and codominant tree species to determine the site index (SI). Ideally, the average heights of various evenly aged tree stands are measured to determine species-specific SI models (Monserud et al. 1990). SI is dependent on tree species, stand density, soil, and forest habitat thereby providing valuable information about the economy and stability of tree stands that aid in determining the management strategies on afforested mine sites (Heinsdorf 1996; Torbert and Burger 2000). However, this approach is restricted to even-aged monocultures (e.g., Vanclay 1994). In the Appalachian Mine District (USA), SI is applied to define the potential productivity of White pine (Pinus strobus) plantations (Torbert et al. 1990; Torbert and Burger 2000). In the cited studies, a significant correlation was found between SI, electrical conductivity (by soil solution extract) and the content of available forms of P and K (deficient elements in the soils of the Appalachian region) (Torbert et al. 1990). However, growth features were largely dependent on tree stand age. Moreover, there was an important correlation with the N and P content (R = 0.41 and R = 0.36, respectively) and needle length (L300n), which in turn positively correlated with tree growth characteristics (Dg, R = 0.44 and H100, R = 0.50, respectively). Based on these findings, the L300n can be used as a simplified trophic condition assessment index for Scots pine on mine sites. The trophic rating and corresponding L300n range for this study are: (1) high (L300n > 57.0 mm), (2) medium (L300n from 42.0 to 57.0 mm), and (3) low (L300n < 42 mm).
The results of comparison of the nitrogen content in pine needles from reclaimed mine soils by RIR Tukey’s test
Statistical grouping of reclaimed mine soils according to the nitrogen content in the pine needles
Mean for variant (g kg−1)
The results of comparison of the phosphorus content in pine needles from reclaimed mine soils by RIR Tukey’s test
Statistical grouping of reclaimed mine soils according to the phosphorus content in the pine needles
Mean for variant (g kg−1)
Pine trees grown on fertilized RMS at the Smolnica spoil heap (SMOL-Cf) were found to have the highest level of nutrients whereas those grown on the Bełchatów spoil heap (BEL-Ql) had the lowest nutrient levels. The soil substrate exerted the greatest influence on the uptake of macronutrients in tree biomass. The results of fertilization (especially N) carried out during the initial reclamation process were not evident after about 12 years. The most deficient nutrients in the soil were N and P, which is in accordance with the literature for other RMS. However, no distinct symptoms to indicate nutrient deficiency in trees were found. The soil fertility ratings for pine trees grown in the waste dumps of the Lusatian Mine District and in NFS should only be treated as approximate. This is due to the fact that each post-mining site is specific, and moreover, that the Scots pine has a large adaptation capability. In case of N and P, appropriate soil levels and degrees of nutrient supply for pines were defined for specific RMS in this study. These ratings may be applied to assess the fertilization requirements in the investigated RMS.
This study was financially supported by the Polish Ministry of Science and Higher Education Grant No. 309 013 32/2076 and partly by statutory financial support of the Ministry of Science and Higher Education RP (DS-3420 in 2012, Department of Forest Ecology University of Agriculture in Krakow). This paper was developed during the 60th anniversary of the University of Agriculture in Krakow, Poland.
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