Tree Growth and Climate Relationship: Dynamics of Scots Pine (Pinus Sylvestris L.) Growing in the Near-Source Region of the Combined Heat and Power Plant During the Development of the Pro-Ecological Strategy in Poland

The Impact of Urbanization on Tree Growth and Xylem Anatomical Characteristics

In the context of the intensification of global urbanization, how urbanization (urban heat island effect and air pollution) affects urban tree growth is not fully understood. In this paper, the radial growth and xylem anatomical characteristics of three different tree species (Quercus mongolica, Fraxinus mandshurica, and Pinus sylvestris var. mongolica) in urban and rural areas of Harbin were compared by means of tree-ring anatomy. The results showed that there were significant differences in the growth of both broadleaf trees and conifers between urban and rural areas. The vessel number, cumulative area of vessels, and theoretical hydraulic conductivity of all tree species in rural areas were higher than those in urban areas, indicating that urbanization may have the effect of slowing down growth. However, broadleaf trees in urban areas had higher vessel density and a greater percentage of a conductive area within xylem and theoretical xylem-specific hydraulic conductivity. The thickness of cell walls and cell wall reinforcement index of P. sylvestris var. mongolica were strongly reduced by air pollution, implying that it may be more sensitive to urbanization. Compared to Q. mongolica, F. mandshurica showed less sensitivity to urbanization. Warming and drying climate in Harbin may be an important factor affecting tree growth.

Effect of warming on ground vegetation in Carpathian Norway spruce stands, exemplified by European blueberry (Vaccinium myrtillus L.) nutrient stoichiometry

Despite its small share of total forest biomass, ground vegetation plays an important role in biogeochemical cycles, being able to modify carbon (C) and nutrients fluxes. Global climate warming may affect plant nutrient uptake and the carbon:nitrogen:phosphorus (C:N:P) stoichiometry, the release of nutrients from the soil and soil organic matter, as well as significantly influence the tree stand nutrient supply. In this context, the response of Norway spruce (Picea abies (L.) H.Karst) stands' ground vegetation to warming is uncertain. An open-top chamber soil-warming simulation, lasting two growing seasons, was conducted in a spruce forest. At the end of each of the two growing seasons, before leaf senescence, European blueberry (Vaccinium myrtillus L.) aboveground biomass (leaves and stems) and mineral topsoil samples were collected from the plots. The C, N, P, micronutrient, and macronutrient concentrations were estimated in the samples. Warming caused significant decreases in C, N, and P in the soil. Warming also decreased the C:P and N:P stoichiometric ratios in the soil and increased the C:P ratio in plant stems. Significant increase in foliar C and decrease in foliar P in warmed plots were observed. The most evident effect was reduction of N and P in the soil, which directly affected the plant C:P and soil N:P stoichiometry. Our results show that warming has caused a significant decrease in the content of some nutrients in the aboveground plant tissues of blueberries. Given that N is a limiting factor of ecosystems productivity, its reduction in the soil caused by warming may be a serious threat to proper nutrient uptake and cause disruption of biogeochemical cycles. The decrease in nutrient content in aboveground tissues due to warming can result in disruptions to physiological processes.

Dynamics Changes in Basal Area Increment, Carbon Isotopes Composition and Water Use Efficiency in Pine as Response to Water and Heat Stress in Silesia, Poland

Trees can be used as archives of changes in the environment. In this paper, we present the results of the analysis of the impact of water stress and increase in air temperature on BAI and carbon stable isotopic composition and water use efficiency of pine. Dendrochronological methods together with mass spectrometry techniques give a possibility to conduct a detailed investigation of pine growing in four industrial forests in Silesia (Poland). Detailed analysis-based bootstrap and moving correlation between climatic indices (temperature, precipitation, and Standardized Precipitation-Evapotranspiration Index) and tree parameters give the chance to check if the climatic signals recorded by trees can be hidden or modified over a longer period of time. Trees have been found to be very sensitive to weather conditions, but their sensitivity can be modified and masked by the effect of pollution. Scots pine trees at all sites systematically increased the basal area increment (BAI) and the intrinsic water use efficiency (iWUE) and decreased δ¹³C in the last century. Furthermore, their sensitivity to the climatic factor remained at a relatively high level. Industrial pollution caused a small reduction in the wood growth of pines and an increase in the heterogeneity of annual growth responses of trees. The main factors influencing the formation of wood in the pines were thermal conditions in the winter season and pluvial conditions in the previous autumn, and also in spring and summer in the year of tree ring formation. The impact of thermal and pluvial conditions in the year of tree ring formation has also been reflected in the isotopic composition of tree rings and water use efficiency. Three different scenarios of trees' reaction link to the reduction of stomata conductance or changes in photosynthesis rate as the response to climate changes in the last 40 years have been proposed.

Wood Biomass Resources in Poland Depending on Forest Structure and Industrial Processing of Wood Raw Material

(1) Wood is a widely available raw material on the market, which satisfies the industrial demand and which is used both as a source of biomass for the wood materials industry in a broad sense and for energy-supplying purposes. These areas prove the functional values and the possibilities of the directional use of low-quality wood products. One of the factors influencing the overall balance of the wood biomass is the form and quality of the wood material that cannot be further processed mechanically. This study was conducted to determine the influence of this material by presenting the dependence between the level of wood biomass resources and the conditions of wood acquisition and processing in Poland. (2) The basic directions of biomass acquisition were verified in correlation with the level of its acquisition from forest areas and with the form of by-products generated by sawmills. The research was based on the data from reference publications and analysis of the processing of raw wood in sawmills. The research was conducted on raw hardwood and softwood from coniferous and deciduous forests in Poland. (3) The research confirmed the influence of the processing method on the form and share of by-products. It also showed that the form of the wood biomass obtained was influenced by the region of Poland. (4) The research showed that the regionalisation and wood processing directions were correlated with the structure of the wood biomass acquired.

The Strength of Pine (Pinus sylvestris L.) Sawn Timber in Correlation with Selected Wood Defects

Pine timber of Polish origin intended for structural purposes is characterized by significant variability in the quality parameters. Technological suitability determined on the basis of relevant international classifications is based on the assessment of both selected mechanical and physical properties of wood. Moreover, the description of visual properties is also a valuable indicator regarding defect distribution. In the group of quality features playing a crucial role in the classification of sawn timber, there are knots, disruptions of grains, cracks, etc. Thus, the aim of the research was to determine the correlation between the presence of selected defects and the strength properties of individual timber pieces. This type of study is based on a nondestructive test method that allows for high optimization of sawn materials processing. In the case of sawn timber of Polish origin, the modulus of elasticity (MOE) determined using the sonic test is commonly used as a criterion. The research material was harvested from southern Poland. The results of the conducted studies confirmed a correlation between an increasing occurrence of particular types of defects and the results of MOE. Furthermore, as a result of the performed investigations, no significant effect of narrow surface cracks on strength properties was observed.

Environmental Factors at Different Canopy Heights Had Significant Effects on Leaf Water-Use Efficiency in Cold-Temperate Larch Forest

It is of great significance to study short-term water-use efficiency (WUEs) at different canopy heights for accurately evaluating the adaptability of cold-temperate larch (Larix gmelinii) forest to climate change. The stable isotope method combining data of gradient meteorology, photosynthetic properties and leaf structure were used to assess the influence of different canopy heights on short-term water-use efficiency (WUEs) in larch forests in the northern Da Hinggan Mountains. The results show that: (1) The rank of leaf WUEs at different canopy heights was upper canopy > middle canopy > lower canopy. The leaf WUEs in upper canopy was significantly higher than those in the middle and lower canopy (p < 0.01), and no significant difference was found between the middle and lower canopy (p > 0.05). (2) The environmental factors, the photosynthetic characteristics, the specific leaf weight (LMA) and stomatal density (SD) had significant impact (p < 0.05) on leaf WUEs at different canopy heights of larch forest. (3) The results of the weighted random forest analysis show that the main factor affecting WUEs in larch forests at different canopy heights was vapor pressure deficit (VPD), followed by relative humidity (RH) and net photosynthetic rate (Pn), while LMA and SD made relatively small contributions. This indicates that the variation of leaf WUEs at different canopy heights is mainly due to environmental factors. Our results highlight that the difference of environmental factors at different canopy heights should be considered in the future study of leaf WUE. Our results contribute to a better understanding of water utilization strategies and carbohydrate relations in the boreal forest ecosystems, which is of great significance for improving the sustainable management measures and strategies of boreal forest resources.

The Impact of Air Pollution on the Growth of Scots Pine Stands in Poland on the Basis of Dendrochronological Analyses

The aim of this study was to evaluate Scots pine stand degradation caused by the pollutants emitted from Zakłądy Azotowe Puławy, one of the biggest polluters of the environment in Poland for over 25 years (1966–1990). To assess the pollution stress in trees, we chose the dendrochronological analysis We outlined three directions for our research: (i) the spatio-temporal distribution of the growth response of trees to the stress associated with air pollution; (ii) the direct and indirect effects of air pollution which may have influenced the growth response of trees; and (iii) the role of local factors, both environmental and technological, in shaping the growth response of trees. Eight Scots pine stands were selected for study, seven plots located in different damage zones and a reference plot in an undamaged stand. We found that pollutant emission caused disturbances of incremental dynamics and long-term strong reduction of growth. A significant decrease in growth was observed for the majority of investigated trees (75%) from 1966 (start of factory) to the end of the 1990s. The zone of destruction extended primarily in easterly and southern directions, from the pollution source, associated with the prevailing winds of the region. At the end of the 1990s, the decreasing trend stopped and the wider tree-rings could be observed. This situation was related to a radical reduction in ammonia emissions and an improvement in environmental conditions. However, the growth of damaged trees due to the weakened health condition is lower than the growth of Scots pine on the reference plot and trees are more sensitive to stressful climatic conditions, especially to drought.

The Influence of Habitat Conditions on the Properties of Pinewood

This article starts a series of articles on dependences between the conditions of the growth of trees in forests and the technical aspects and directions of using the raw material obtained from these trees. This is a key feature for wood purchasers because it determines the efficiency of production and directly affects the final financial result of their activity. Wood represents an environmentally sustainable and renewable material, which is a widely available raw material on the market and must meet specific quality and strength requirements. These parameters indicate the utility values of wood and the possibilities of its use. One of the factors influencing the properties of wood is the type of the forest habitat it comes from. In order to determine this influence, tests were carried out to show how tree growth conditions affected changes in the density and strength of raw wood. The assumption (hypothesis) about the correlation between the static bending strength of Scots pine (Pinus sylvestris L.) wood and the forest habitat was verified on four forest types, i.e., fresh coniferous forest (FCF), fresh mixed coniferous forest (FMCF), fresh mixed forest (FMF) and fresh forest (FF). The properties depend largely on the wood structure, its origin on the cross section and the length of the stems. The raw material selected for the study came from Scots pine trees growing in forests in central Poland. The study confirmed the influence of the habitat on changes in the density and strength of pinewood. There was a correlation between the habitat FMCF and the quality parameters of the raw material, which reflected the wood structure r = 0.775; p < 0.05.

Environmental factors exert strong control over the climate-growth relationships of Picea abies in Central Europe

The growth response of trees to changing climate is frequently discussed as increasing temperatures and more severe droughts become major risks for forest ecosystems. However, the ability of trees to cope with the changing climate and the effects of other environmental factors on climate-growth relationships are still poorly understood. There is thus an increasing need to understand the ability of individual trees to cope with changing climate in various environments. To improve the current understanding, a large tree-ring network covering the whole area of the Czech Republic (in 7×7km grids) was utilized to investigate how the climate-growth relationships of Norway spruce are affected by 1) various geographical variables, 2) changing levels of acidic deposition, 3) soil characteristics and 4) age, tree diameter and neighbourhood competition. The period from 1930 to 2013 was divided into four, 21-year long intervals of differing levels of acidic deposition, which peaked in the 1972-1993 period. Our individual-based, spatiotemporal, multivariate analyses revealed that spruce growth was mostly affected by drought and warm summers. Drought plays the most important negative role at lower altitudes, while the positive effect of higher temperature was identified for trees at higher altitudes. Increased levels of acidic deposition, together with geographical variables, were identified as the most important factors affecting climate-growth association. Tree age, tree size and soil characteristics also significantly modulate climate-growth relationships. The importance of all environmental variables on climate-growth relationships was suppressed by acidic deposition during periods when this was at a high level; growth was significantly more enhanced by spring and summer temperatures during these periods. Our results suggest that spruce will undergo significant growth reduction under the predicted climate changes, especially at the lower altitudes which lie outside of its natural range.

The Impact of Climate, Sulfur Dioxide, and Industrial Dust on δ18O and δ13C in Glucose from Pine Tree Rings Growing in an Industrialized Area in the Southern Part of Poland

The mass spectrometric analysis of the impact of sulfur dioxide and dust emission on carbon and oxygen stable isotopic compositions of glucose hydrolysed from α-cellulose samples extracted from Scots pine growing in the vicinity of "Huta Katowice" steelworks was the main aim of this study. The annual rings covered the time span from 1975 to 2012 AD. The relationships between climatic conditions, sulfur dioxide, and industrial dust emission and oxygen and carbon isotopic compositions were analyzed using correlation function methods. This study shows the first analysis of carbon and oxygen stable isotopes in glucose as the bio-indicators of CO₂, sulfur dioxide, and industrial dust emission. The anticoincidence trend of δ¹⁸O and δ¹³C and dust and sulfur dioxide confirms that the decreases of dust and sulfur dioxide industrial emission increase δ¹⁸O and δ¹³C values in glucose.

δ13C and Water Use Efficiency in the Glucose of Annual Pine Tree Rings as Ecological Indicators of the Forests in the Most Industrialized Part of Poland

In this study, stable carbon isotope ratios in the glucose samples were extracted from annual pine tree rings as bio-indicators of contemporary environmental changes in heavily urbanized areas. The sampling sites were located in close proximity to point source pollution emitters, such as a heat and power plant "Łaziska" and steelworks "Huta Katowice" in Silesia (Poland). The analysed samples covered the time span from 1975 to 2012 AD, the time period of the development of industrialization and the modernization in the industrial sector in Poland, similarly as in Eastern Europe. This modernization was connected with EU legislation and the implementation of restrictive governmental regulations on emissions. The carbon isotope discrimination has been proposed as a method for evaluating water use efficiency. The measurements of carbon isotopes were carried out using the continuous flow isotope ratio mass spectrometer coupled to the elemental analyser. The δ¹³C values were calibrated relative to the C-3 and C-5 international standards. Diffuse air pollution caused the variation in δ¹³C and iWUE (the ratio between CO₂ assimilation and stomatal conductance) dependency on the type of emitter and some local effects of other human activities. In this study, the first results of water use efficiency in glucose are presented. In the period of time from 1975 to 2012, the water use efficiency values increased from 98 to 122 μmol/mol.

Spatial and Short-Temporal Variability of δ13C and δ15N and Water-Use Efficiency in Pine Needles of the Three Forests Along the Most Industrialized Part of Poland

In this study, stable carbon and nitrogen isotope ratios in the samples of pine needles collected in 2013 and 2014 from heavily urbanized area in close proximity to point-source pollution emitters, such as a heat and power plant, nitrogen plant, and steelworks in Silesia (Poland), were analyzed as bio-indicators of contemporary environmental changes. The carbon isotope discrimination has been proposed as a method for evaluating water-use efficiency. The measurement of carbon and nitrogen isotopes was carried out using the continuous flow isotope ratio mass spectrometer. The isotope ratio mass spectrometer allows the precise measurement of mixtures of naturally occurring isotopes. The δ15N values were calibrated relative to the NO-3 and USGS34 international standards, whereas the δ13C values were calibrated relative to the C-3 and C-5 international standards. The strong year-to-year correlations between the δ13C in different sampling sites, and also the inter-annual correlation of δ15N values in the pine needles at each of the investigated sampling sites confirm that the measured δ13C and δ15N and also intrinsic water-use efficiency (iWUE) trends are representative of the sampling site. Diffuse air pollution caused the variation in δ 13C, δ15N, and iWUE dependent on type of emitter, the localization in the space (distance and direction) from factories and some local effect of other human activities. The complex short-term variation analysis can be helpful to distinguish isotopic fractionation, which is not an effect explainable by climatic conditions but by the anthropogenic effect. Between 2012 and 2014, an increase in iWUE is observed at leaf level.