Anthropogenic emissions of pollutants modify air quality and soil chemistry. Sulfur dioxide, nitrogen oxides, carbon oxide, fine particulate matter such as soot, dust and emissions from factories and diesel vehicles are the major air pollutants. The input of pollutants to the atmosphere has increased significantly since the middle of 20th century due to increased industrial activities all over the world. In Poland the highest levels of dust and gaseous pollutants were recorded in 1980s (
The observed anthropogenic impact on the environment causes change in the elemental composition of the atmosphere and the biosphere. It affected on major limiting factors that controlled the functioning of many ecosystems (Vitousek
The main objectives of this study were: to analyze (1) record of historic pollution in tree-ring and (2) biological adaptation to pollution of pine growing nearby chemical factories in Kędzierzyn-Koźle during the period of industrial development and pro-ecological policy implementation in Poland.
Trees can provide annual records of ecosystem changes connected with human activity over several decades. These changes can be recorded in the pattern of variation of tree-rings widths and in the variation in the elemental composition of wood. In the literature, there has been much discussion about yearly variation of heavy metals, micronutrients and macronutrients, stable isotopes and radiocarbon in tree rings and needles linked to a common anthropogenic source (Prohaska
Different methods of dendrochronological analysis were often used to evaluate the impact of pollution on the potential incremental trees (McLaughlin
It has been observed that trees intercept and absorb air pollution from the atmosphere (Nowak
Trees of temperate regions, such as Europe, usually form visible annual growth rings, which can be dated accurately. It is possible to collect wood samples of different age and analyze its heavy metal content in order to get a chronological record of trace element pollution in the tree environment (Nabais
The uptake of heavy metals by pine is a complex process and its efficiency depends on the soil pH, redox potential, soil texture, soil organic matter content, soil metal content and metal availability (Seregin and Ivanov, 2000; Baltrnait and Butkus, 2007). The acid rain may have a strong effect on specific element mobility in the soil and plant uptake (Padilla and Anderson, 2002). For example, Pb is absorbed by trees mainly on acid soils and not on basic soils (Leonelli
The consequences of soil contamination are risks associated with the migration of contaminants to other components of the environment — water and air. Introduction of potential harmful trace metals into the soil involves interaction with the biological processes occurring in the soil and their excessive uptake by plants (Baath, 1989; Chaney and Oliver, 1996), although there is considerable variation between metals in terms of the environmental impact of soil pollution. The industrial pollutant emissions could potentially influence tree ring width and elemental composition of wood and occurs during physiological processes responsible for plant growth.
Kędzierzyn-Koźle is one of the most industrialized cities of Opole province. Factories operating in the city are of strategic importance to the region and the country. In this urban area, heavy metals are emitted from numerous anthropogenic sources including industrial processes, such as production of fertilizers, cement-lime and refractory materials, fugitive emissions from pollutants and traffic. Kędzierzyn-Koźle is located near two complex factories: Blachownia Holding s.a. (ancient and common name: Blachownia Chemical Factory) and nitrogen factory Grupa Azoty ZAK (ancient and common name: Zakłady Azotowe Kędzierzyn-Koźle, ZAK).
Blachownia Chemical Plant was a remnant from the ancient tradition of the iron and steel rolling. However, chemical production began in 1941, when it commissioned the German army Oberschlesische Hydrierwerke company to build a factory producing synthetic liquid fuels (petrol and diesel aircraft). In 1957, a power plant was launched.
The nitrogen factory ZAK has been one of leaders in the group of Polish producers of nitrogen fertilisers and other chemical products. This company was built on the ruins of another factory destroyed by warfare and the production restarted in 1954.
In both factories, many different units and production facilities were constructed and added over a period of last 60 years. Since the 1980s, numerous projects dedicated to environmental protection were implemented in both factories. After many years of trying to minimize the negative impact of production processes on the environmental, these factories were struck off the list of the most environmentally noxious factories. In 2004, Waste Management Plan for the City of Kędzierzyn-Koźle set strategic objectives for 2015: the implementation of low and nonwaste technologies and best available techniques (BAT) and the introduction of the principles of “cleaner production”.
Scots pine (
Sampling site – geographical coordinates, elevation and forest type (FMB – fresh mixed broadleaved forest).Site code Lat. N; Lon. E Elevation (m) Forest site type A 50°19’; 18°15’ 192 FMB B 50°20’; 18°18’ 209 FMB C 50°20’; 18°19’ 218 FMB N 50°22’; 18°23’ 218 FMB S 50°18’; 18°20’ 215 FMB T 50°18’; 18°17’ 207 FMB
The examined specimens were healthy and grew in the similar habitat conditions. All tree sampling sites were classified as a fresh mixed broadleaved forest site. In order to avoid different dendroecological reaction of juvenile wood, an attempt was made to select pine stands aged 80–100 years which is the felling age of Scots pine.
Firstly, tree-ring widths were measured. Next, they were dated and rechecked using the Cofecha computer program (Holmes, 1983). Medium-time fluctuation in tree ring width can result from periodical variation of the influence of pollutants. To remove age-related trends in the radial growth rate, the use of any tree-ring detrending method is required. The negative exponential curve fitting can be used to model the variation in radial width of coniferous trees. To build the site tree-ring width chronologies, tree-ring width series were averaged for each sampling site. The negative exponential fit curves have been adjusted to each of the chronologies. Next, the RI (radial increment index) was calculated as the ratio of real annual increments and their model values. RI indicates the relative value of radial growth compared to model values of growth.
The long-term periods of reduction of radial growth of trees have been designated for each population. The reductions periods corresponds to the incremental indexes (RI) lower than 1. Lower and higher value corresponds to the reduction of tree ring width.
Changes of Index (CI) were calculated as the difference between the RI values in two consecutive years. The parameters (TRW, RI and CI) were averaged for three periods of time (1) – before reduction, (2) – during reduction, and (3) – for the recovery period.
The degree of similarity of short-term incremental reactions in trees of each partial population was evaluated by calculating the mean correlation of standardized series of trees (rbt). rbt indices measure the signal strength of the chronology. rbt can be used to calculate the index expressed population signal (EPS). EPS — the expressed population signal — is a statistic for examining the common variability in chronology and it is dependent upon the sample depth (Wigley
Cluster analysis was used to analyse similarity in radial growing of each pine population in the period of time between 1940 and 2012 (
The IT indicators (interval trend indices, expressed in %) were calculated for all the analysed tree-ring width series (Schweingruber
where: m – the number of trees in which TRW in current year is greater than TRW in the previous year, n – total number of investigated trees.
A higher value of IT corresponds to the degree of homogeneity of the incremental response of trees in a given year. IT equal to 100% means that all the trees increased the size of the radial growth compared to the previous year (Schweingruber
The current quantitative emission rate information for existing sources available from public sources has been reviewed. The emission data were obtained from Statistical Yearbooks of the Environmental Protection 1975–2012, and CDIAC date base (Boden
Tree cores (C_2013 and C1_12) of two healthy pines collected from the research area (site C) were analysed for the total concentration of the following elements: 23Na, 26Mg, 56Fe, 60Ni, 65Cu, 66Zn, 208Pb. One core was used as a comparative sample. The C_2013 covered the period of time since 1920s until 2012, whereas a part of comparative sample (C1_12) covered the period of time since 1995.
Radial trace-element profiles were determined by Laser Ablation Inductively Coupled Plasma-Mass Spectrometry (Laser ablation: New Wave Research UP-193 FX Fast Excimer, ICP-MS: Thermo Scientific X-Series2 with CCT -Collision Cell Technology) at Royal Museum for Central Africa (Belgium). LA-ICP-MS provides a repeatable, minimally destructive, sensitive method for determining many elements in wood tissue, with relatively high spatial resolution (Hall
Laser ablation system produces craters in the sample ranging in size 10 microns. The ablated material was then swept by an He-Ar flow from the sample cell directly into the plasma of the ICP-MS. The sample particles were then ionized and the ions are separated and detected by the mass spectrometer.
The measurement were made in continuous ablation with 100-μm line at a speed of 15 μm/s. The spatial resolution is 14 μm between each measurement. The laser was fired with energy of 10 J/cm2 and a repetition rate of 40 Hz. Before analysis, the operating conditions of LA-ICP-MS were optimized by ablation on the standard reference material NIST SRM 612 (from National Institute of Standards & Technology, US). Two certified reference materials (MACS-1 and MACS-3 (from United States Geological Survey)) were used for the calibration and also analyzed with each series of samples to control the instrumental drift. The precision was below 10% and the accuracy was better than 6%. Total elements blanks were negligible and below their limit of detection (0.7 μg g−1 for Na, 0.4 μg g−1 for Mg, 0.4 μg g−1 for Fe, 0.2 μg g−1 for Ni, 0.15 μg g−1 for Cu, 0.1 μg g−1 for Zn and 0.01 μg g−1 for Pb). The limits of quantification were calculated from the intensity and standard deviation measurements of 20 blanks. 13C was used as internal standard and assumed to be 45% (in concentration). The radial trace-element profiles were rechecked, smoothed for spike removal and fit to annual tree-rings width. The median was used in analysis, because a median is a more outlier-resistant measure of a distribution’s center than is the arithmetic mean.
The values of rbt index fell over the period 1962–1989 in relation to the entire period in question (
Selected dendrochronological statistics. MTRW (mean tree-ring width), MRI (mean relative radial increment), and MCI (mean change of index) were calculated for 3 periods: (a) before reduction, (b) during reduction, (c) during recovery; rbt – the mean between-tree series correlation, EPS – the expressed population signal is a statistic for examining the common variability in chronology; rbt and EPS were calculated for 2 periods of time: (d) 1940–2012 (total common period, n=73) and (e) 1962–1989 (common reduction period, n=28)Site MTRW (mm) MRI (%) MCI rbt EPS a / b / c a / b / c a / b / c d / e d / e A 3.91 / 1.50 / 0.37 100 / 61 / 138 0.24 / 0.13 / 0.26 0.417 / 0.361 0.935 / 0.918 B 2.77 / 0.93 / 1.61 100 / 56 / 164 0.16 / 0.14 / 0.31 0.532 / 0.421 0.958 / 0.935 C 1.92 / 0.69 / 1.36 97 / 53 / 183 0.18 / 0.13 / 0.44 0.499 / 0.355 0.952 / 0.916 N 2.41 / 1.31 / 1.43 98 / 78 / 132 0.17 / 0.15 / 0.27 0.397 / 0.319 0.930 / 0.903 S 1.61 / 1.40 / 1.52 97 / 94 / 119 0.17 / 0.19 / 0.22 0.436 / 0.424 0.939 / 0.937 T 3.02 / 0.91 / 1.36 98 / 58 / 188 0.18 / 0.13 / 0.42 0.497 / 0.371 0.952 / 0.921
In the investigated area the principal gaseous pollutants are particulate matter (PM), carbon oxides, nitrogen oxides and sulphur oxide. The average concentration of all pollutants levels remained on a downward trend (
Indexed chronologies show clearly that in the 60s, 70s and 80s on 4 sites (A, B, C and T) long-term reduction in radial growth has been observed in pines (
The most significant reductions were recorded and observed in the tree population closest to factories and in the windiest zone (site B, C, and T). The average radial growth of trees of these populations varied between 53 and 58% of the model growth (
In the period before the culmination of industrial emissions, pine radial growth was close to the model one, as evidenced by MRI indicators whose values were close to 100% (ranging from 97% to 100%) of the fitted curve value (
In the period when emission was at its highest, the sensitivity of trees to environmental conditions, changing from year to year, was also lowered. The biggest declines in the value of the MCI indicator concern the population whose growth reduction was highest (B, C, and T). In contrast, on site S, where no reduction in growth has occurred, the MCI indicator has increased (
In the early 1990s there was a strong, long-term increase in radial growth (
This phenomenon is most marked in the trees which in previous decades showed the greatest reductions (B, C, and T). In recent years, the average growth of pines in these populations has reached 300% of the model growth (
With the smaller influence of pollutants, the size of the radial growth and sensitivity of trees to short-term environmental impulses started to grow rapidly. The biggest increases in MCI were observed in populations where theirs rate in the previous period was lowest (B, C, and T) (
The grouping of the pine population is compatible with the size reduction of their radial growth in the 1960s, 70s and 80s. B, C, and T form a highly homogeneous population group, the radial growth of which during the reduction period was respectively 53%, 56% and 58% of the model growth (
In the years 1940–2012 (the common period for the chronology of all the populations), the homogeneity of year-to-year pine incremental response varied significantly (
On the basis of the IT values the positive and negative pointer years were determined in the investigated area (positive pointer years corresponds to IT>90%, and negative pointer years corresponds to IT<10%, respectively). This analysis showed short-term dynamics of Scots pine radial growth. The number of pointer years decreased significantly (
During the 1940–2012 period, pine pointer years occurred simultaneously in 6 populations during one year (
Analysis then was made of the variability in the element concentrations among rings within a core, and between cores taken from two trees to verify the results. Temporal variations of element concentration (median) in annual tree-rings of pines were compared with time series of wet deposition of pollutant and air pollutant concentration in the investigated area. For the statistical calculation, Statistica 10.0 software was applied. The analysis of the trace element concentration (
The similar trends of magnitudes (
Chemical wood composition data shows some large peaks in wood profile. The difference between the elements record of tree rings and elements deposition or concentration in the air is that the former represents yearly averages whilst the latter are single-day measurements. During a day concentration of some elements can change by 300% (Statistical Yearbooks of the Environmental Protection 1975–2012).
Pine had very low elemental concentrations in heart-wood and higher concentrations of analyzed elements in sapwood (since 1950s). Na, Fe, Cu, Zn have shown increasing gradient (
The determination of properties of tree-rings is crucial for many applications in the investigation of local and global environmental changes. Since the beginning of the 20th century, there has been much discussion about how external environmental factors, including anthropogenic effects, affect the physiological processes that control tree growth. In the last few decades, many scientists have studied spatio-temporal distribution of pollution by conducting a chemical wood composition analysis of different species to establish the impact of soil, air and water contamination.
The year-to-year variability of tree ring qualities is shaped largely by the climatic factor (Fritts,1976; Sensuła and Wilczyński, 2017). However, industrial pollution affects medium- and long-term changes in the incremental characteristics. This depends on the degree and time of the pollution, tree species, habitat conditions, orography of the area and the location of trees in relation to emitters (Wilczynski, 2006; Malik
The 1960s, 70s and 80s are a period of rapid growth of industrial production, which resulted in an increase in the emission of pollutants. The incremental changes in the reactions of Scots Pine which we have observed can be attributed to the impact of pollutants. In the years 1960–1990 there was a decline in the thickness growth of pines. At the same time, the uniformity of incremental reactions and sensitivity to short-term environmental impulses decreased. These developments, however, show a distinct spatial variability which results from the locations of sites in relation to the emitters and the direction of the prevailing winds. Site S was located on the side of industrial factories and away from the zone of the prevailing winds. Pines growing there showed no reduction in growth or decrease in sensitivity. On the N site reductions were very insignificant. This population was located far away from both ZAK factory and also outside the main zone of migration of pollutants from Blachownia company. Therefore the position of trees relative to the emitters and direction of winds that carry pollution is significant.
Pine belongs to a species which is susceptible to industrial pollution. Such pollution reduces the radial growth of pines. Increasing the heterogeneity in incremental response of pine trees also occurs (Wilczyński, 2006). The trees which we have we examined have a high vitality, produce large growth rings and show a high sensitivity to short-term impulses and high uniformity of incremental reactions. They have survived three difficult decades. These were the strongest specimens which in their radial increments have recorded information about the biological effects of pollution. Weaker trees were systematically removed from the population and this information has been lost.
Many elements (P, K, Ca, Mg, Fe, Na, Zn, Cu, Mo, Co, V) are essential elements to living organisms, but their excessive amounts are generally harmful to plants, animals and humans (El-Hasan
Scientific literature reviews shown that different elements are important in physiological functions of plants, and that the air pollution and soil contamination may be toxic to the trees. The degree of air pollution is associated with the amount and type of the substance in the atmosphere. Trace elements are removed from the atmosphere by wet and dry deposition, diffusion and retention on solid surfaces. As a consequence of atmospheric pollution, trace elements accumulate in forest ecosystems. Each of the pollutants studied here had some effect on the concentration of biochemical compounds in pines. The scientific literature reviews shown, that trees have been used to monitor heavy metal pollution (Pearson
The existence of chemical factories near the investigated sites may be related to the rather high levels of investigated elements concentrations in the wood, especially in the period of time between 1960s and 1980s. This higher concentration of elements linked also to the change in tree-ring width. Also the narrowest tree rings has been linked to the increase of air pollution emission. Dmuchowski and Bytnerowicz (2009) reported that very high levels of pollution and serious ecological effects occurred near the emission sources. The analysis of trace elements in the samples of soil in the areas situated close to the factories (Kusza
Natural and anthropogenic sources (Cutter and Guyette, 1993) may contribute to accumulation of metals in the ecosystem where trees grown. Most of the trace elements (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) are derived from mining, metal smelting, coal and petroleum combustion, oil burning, incineration of waste, cement production and other industrial activities (Magnavita, 1989; Lombardo
It has been observed that vegetation intercepts the aerosol and the concentrations of elements are high in samples of plants from industrial areas. The addition of lead to the Earth’s ecosystem has long been recognized on a global scale (Shotyk and Le Roux, 2005). Over the last decades the increased awareness of environmental issues had led to the recognition that anthropogenic Pb emission to the environment represents a serious health hazard because of toxicity of this metal (Tommasini
Trace elements measured in tree components may be used for biomonitoring of air pollution. Whereas, it has been reported that some elements can migrate within trees, example P and K have shown increasing gradient towards the boarded of xylem, whereas Ca decrease towards the inner portion of the xylem. Some other elements (example Zn, Al, Cu) have constant concentration in all parts of xylem (Myre and Camire, 1994).
The information on the effects of industrial pollution has been recorded by pine trees in short- and long-term incremental response changes — the size of growth in thickness, uniformity of incremental response, sensitivity of trees to short-term environmental impulses and the elemental composition of wood.
The pressure of industrial pollution is revealed in these trees in long-term reduction in the size of thickness growth, reduction in the level of homogeneity of shortterm incremental response and reduced susceptibility of trees to short-term environmental impulses. The reactions of pines after pollution subsided should be considered interesting — pine trees quickly and strongly increased their thickness growth. The homogeneity of their year-to-year incremental response and sensitivity to short-term impulses has also significantly increased. These can be seen as symptoms of regeneration of these trees. It turned out that the degree of regeneration was greatest in populations that have been most affected by pollution. The degree of industrial pollution pressure can be observed after many years in the strongest specimens which had survived this period. This record takes various forms and affects the size of incremental growth and disturbance in the incremental reaction of trees.
Each of the pollutants studied had some effect on the concentration of biochemical compounds in pines and tree ring width. Trees can be indirect indicators of changes in ecosystem, where trees growing in non-controlled field conditions.
The importance of these proxies is highlighted as an important record of environmental contamination in the past, when detailed emission information and possible deposition rates from pollutant sites are not available. The results show that trees can record environmental impacts, and thus preserve environmental pollution signals, and trees can be a source of information that can help in environmental monitoring.
Ring width and elemental composition of tree rings growing in field conditions can be indicative of past pollution effects. Strong industrial activities in Poland provide an opportunity to study the possible environmental effects of chemical factories.