Assessing the utility of direct and indirect methods for estimating tropical tree age in the Western Ghats, India

The knowledge of tree age is important for understanding tree growth and forest dynamics. It may be estimated by ‘direct’ methods involving growth ring counts, or by ‘indirect’ methods involving field measurements of growth rates. Direct methods are considered more accurate, but it is not clear if they are appropriate for all species, notably from the humid tropics. In this paper we assess the occurrence of annual growth rings and their utility for age estimation in three tropical tree species, Acrocarpus fraxinifolius, Dalbergia latifolia (Fabaceae) and Syzygium cumini (Myrtaceae), growing in traditional shade coffee plantations of the southern Western Ghats, India. These species previously were described as having “indistinct or absent” growth rings. We used anatomical studies, field measurements and computational methods to characterise growth rings and assess similarities between directly and indirectly estimated tree ages. Our study revealed that annual growth rings were characterised by different sets of anatomical features per species and were most distinct in the fast-growing deciduous A. fraxinifolius. Growth rates measured in the field showed annual periodicity in all three species, and reflected annual rainfall-drought cycles in D. latifolia and S. cumini. Direct age estimates were most similar to indirect estimates in D. latifolia, and least so in S. cumini. The results of direct age estimation by counting rings are consistent with them being annual in nature in tropical species with distinct and reliable annual growth ring formation. However, for species with poorly defined growth rings, indirect age estimation methods might be more useful.     

Detecting invisible growth rings of trees in seasonally dry forests in Thailand: isotopic and wood anatomical approaches

We measured radial variation of carbon isotope composition and vessel traits in tree species in seasonally dry forests of Northeast Thailand to explore a more reliable and amenable method of tropical dendrochronology for trees that lack visually detectable and consistent growth rings. Six Dipterocarpaceae species (3 Shorea, 2 Dipterocarpus, and 1 Hopea species) with indistinct or irregular growth rings and teak (Tectona grandis), a species which forms distinct growth rings, were examined. The δ¹³C value variations in all species showed annual cyclicity. Dipterocarpaceae species usually marked the lowest values of δ¹³C in the middle of the growing season, whereas teak had the lowest values at nearly the end of the growing season. Since the growing season of the species examined almost corresponds to the rainy season in the study area, the δ¹³C variation was likely caused by the change in moisture availability. The different variation pattern of teak was attributable to its stronger dependence on ¹³C-enriched reserved material early in the growing season. Changes in tree vessel traits for all species examined also showed annual cyclicity. Dipterocarpaceae species showed significant correlation between δ¹³C values and vessel measurements. Vessel lumen (mean area, tangential and radial diameter, and proportion of total area) had a negative correlation, whereas vessel frequency showed a positive correlation. The correlations indicated that changes in vessel traits were caused by the seasonal variation of moisture available to the trees. Thus, we concluded that methods using wood anatomy, as well as δ¹³C, have great potential for use as tools in tropical dendrochronology within the context of seasonal climate.     

Millipede (Diplopoda) communities in an arboretum: Influence of tree species and soil properties

The paper deals with the influence of tree species on millipede communities (Diplopoda). The research was carried out in nine sites in the Borová hora arboretum (Zvolen town, Central Slovakia). Each studied site represents a monoculture of one of nine tree species: Betula pubescens Ehrh., Pinus sylvestris L., Larix decidua Mill., Carpinus betulus L., Abies alba Mill., Picea abies (L.) Karst., Alnus incana (L.) Moench, Populus nigra L., Ulmus laevis Pall. Millipedes were collected by pitfall trapping during vegetation periods in 2008-2011. In total, 1064 individuals of 17 species and 7 families were obtained. The results of research confirmed (i) an influence of tree species on the composition of millipede communities, (ii) a significant influence of soil nitrogen on the species richness and biodiversity, and (iii) an impact of soil pH on the species composition of these terrestrial invertebrate communities. In terms of total dynamic activity and species richness of millipedes, the most favourable conditions were revealed in the forest stands of Alnus incana, Populus nigra, Ulmus laevis and Carpinus betulus. On the contrary, the least favourable biotopes were (from both points of view) the forest stands of Betula pubescens and Larix decidua.     

How a measure of tree structural complexity relates to architectural benefit‐to‐cost ratio,light availability,and growth of trees

Aboveground tree architecture is neither fully deterministic nor random. It is likely the result of mechanisms that balance static requirements and light‐capturing efficiency. Here, we used terrestrial laser scanning data to investigate the relationship between tree architecture, here addressed using the box‐dimension (D_b), and the architectural benefit‐to‐cost ratio, the light availability, and the growth of trees. We detected a clear relationship between D_b and the benefit‐to‐cost ratio for the tested three temperate forest tree species (Fagus sylvatica L., Fraxinus excelsior L., and Acer pseudoplatanus L.). In addition, we could also show that D_b is positively related to the growth performance of several tropical tree species. Finally, we observed a negative relationship between the strength of competition enforced on red oak (Quercus rubra L.) trees and their D_b. We therefore argue that D_b is a meaningful and integrative measure that describes the structural complexity of the aboveground compartments of a plant as well as its relation to structural efficiency (benefit‐to‐cost ratio), productivity, and growing conditions (competition or availability of light).     

Seasonal variation of growth and development of the roots of five second year conifer species in the nursery

Every other week over their second growing season, stem height, collar diameter, shoot and root dry masses, number of lateral roots and length of the tap root were measured on nursery grown seedlings ofAbies balsamea L. Mill.,Pinus banksiana Lamb.,Pinus resinosa Ait.,Picea mariana Mill. BSP andPicea glauca Moench Voss. Root elongation, branching and mycorrhizal development were also recorded.Given species showed distinct seasonal growth patterns. The rate and timing of maximum root growth (mg/dry weight/week) differed markedly between species.Except for the increase in height ofPinus banksiana, root and shoot growth were not negatively correlated.The results are discussed in relation to the performance of tree seedlings in the nursery.     

Discrete versus continuous analysis of anatomical and δ13C variability in tree rings with intra-annual density fluctuations

Intra-annual density fluctuations (IADFs) are anomalies of tree rings where wood density is abruptly altered after sudden changes in environmental conditions. Their characterisation can provide information about the relationship between environmental factors and eco-physiological processes during tree growth. This paper reports about the variability of anatomical traits and stable carbon isotopic composition along tree rings as resulting from the application of two different methodological approaches: (a) the separation of each ring into different regions (earlywood, latewood and IADF) and the comparison of anatomical and isotopic parameters measured in those specific sectors and (b) the analysis of such features in continuum along ring width. Moreover, different parameters of vessels (i.e. ecd—equivalent circle diameter, elongation, sphericity and convexity of vessel lumen) were considered to identify those more appropriate for the representation of intra-annual anatomical variations. The analysis was conducted on Arbutus unedo L. growing on the Elba Island (Italy); tree rings of this species form IADFs with features clearly responsive to the environmental conditions experienced during plant growth. Results showed that the first approach, although more suitable to obtain data for subsequent statistical comparisons and for the calculation of correlations with environmental parameters, suffers from elements of subjectivity due to the size and position of the selected tree-ring regions. The in continuum method allows a clearer identification of the variation of tree-ring properties along ring width. Regarding anatomical parameters, shape indexes were not suitable indicators of intra-annual variability. The overall analysis suggested that using both methodologies in synergy helps to gain complete information and avoid misleading interpretations of IADFs in tree rings.     

Planting of different-sized tree transplants on arable soil

On the arable land of the Rosovka Stream alluvium in the Czech Republic, a windbreak containing native woody species, was planted within a restoration project. This study evaluates the effect of that planting of three different tree sizes, on the rate of growth. The sizes of transplants employed in this study included small (1.0–1.5 meters tall), medium-sized (2.0–2.5 meters tall) and large (with a trunk circumference of 0.1–0.12 meters). The following native tree species, from the Eurosiberian region, were used: Quercus robur L., Carpinus betulus L., Fraxinus excelsior L., Acer campestre L., Acer pseudoplatanus L., Tilia cordata Mill., and Prunus avium L. Growth rates were monitored over a five-year period. Small transplants had the highest growth; they grew approximately 0.4 meters more than transplants from the other size categories. Our results show that the selection of the size of transplant has a significant impact on development and growth. However, differences in the post-transplant responses of individual species were found.     

Age and Long-term Growth of Trees in an Old-growth Tropical Rain Forest, Based on Analyses of Tree Rings and 14C1

In an old‐growth tropical wet forest at La Selva, Costa Rica, we combined radiocarbon (¹⁴C) dating and tree‐ring analysis to estimate the ages of large trees of canopy and emergent species spanning a broad range of wood densities and growth rates. We collected samples from the trunks of 29 fallen, dead individuals. We found that all eight sampled species formed visible growth rings, which varied considerably in distinctiveness. For five of the six species for which we combined wood anatomical studies with ¹⁴C‐dates (ring ages), the analyses demonstrated that growth rings were of annual formation. The oldest tree we found by direct ring counting was a Hymenolobium mesoamericanum Lima (Papilionaceae) specimen, with an age of ca. 530 years at the time of death. All other sampled individuals, including very large trees of slow‐growing species, had died at ages between 200 and 300 years. These results show that, even in an everwet tropical rain forest, tree growth of many species can be rhythmic, with an annual periodicity. This study thus raises the possibility of extending tree‐ring analyses throughout the tropical forest types lacking a strong dry season or annual flooding. Our findings and similar measurements from other tropical forests indicate that the maximum ages of tropical emergent trees are unlikely to be much greater than 600 years, and that these trees often die earlier from various natural causes.     

黄土高原子午岭林区典型树种叶片N、P再吸收特征

为揭示黄土高原子午岭林区不同演替阶段和植被类型主要树种养分再吸收特征,研究选取4种次生植被树种(白桦、山杨、辽东栎和油松)和2种人工植被树种(刺槐和侧柏),测定其成熟叶、凋落叶和林下土壤碳(C)、氮(N)、磷(P)含量,研究了叶片N、P再吸收率及其与养分指标的关系。结果表明:(1)不同树种叶片养分和林下土壤养分含量存在显著差异,土壤C、N含量和C∶N∶P计量比均表现为演替后期林地(辽东栎和油松)演替前期林地(山杨和白桦)人工林(侧柏和刺槐);(2)不同树种叶片N、P再吸收率分别为17.18%—43.34%和27.13%—58.12%,均表现为演替后期林地人工林演替前期林地,且P的再吸收率总体高于N的再吸收率;(3)不同树种叶片N、P再吸收率与叶片养分指标的关系强于土壤,与养分计量比的相关性大于养分含量的相关性。说明子午岭典型植被会通过叶片N、P再吸收来适应养分限制环境,尤其是演替后期植被再吸收能力更强,研究可为黄土高原植被恢复提供理论依据。     

Species-Specific Growth Responses to Climate Variations in Understory Trees of a Central African Rain Forest

Basic knowledge of the relationships between tree growth and environmental variables is crucial for understanding forest dynamics and predicting vegetation responses to climate variations. Trees growing in tropical areas with a clear seasonality in rainfall often form annual growth rings. In the understory, however, tree growth is supposed to be mainly affected by interference for access to light and other resources. In the semi-deciduous Mayombe forest of the Democratic Republic of Congo, the evergreen species Aidia ochroleuca, Corynanthe paniculata and Xylopia wilwerthii dominate the understory. We studied their wood to determine whether they form annual growth rings in response to changing climate conditions. Distinct growth rings were proved to be annual and triggered by a common external factor for the three species. Species-specific site chronologies were thus constructed from the cross-dated individual growth-ring series. Correlation analysis with climatic variables revealed that annual radial stem growth is positively related to precipitation during the rainy season but at different months. The growth was found to associate with precipitation during the early rainy season for Aidia but at the end of the rainy season for Corynanthe and Xylopia. Our results suggest that a dendrochronological approach allows the understanding of climate–growth relationships in tropical forests, not only for canopy trees but also for evergreen understory species and thus arguably for the whole tree community. Global climate change influences climatic seasonality in tropical forest areas, which is likely to result in differential responses across species with a possible effect on forest composition over time.     

Allelopathic Effects of Tree Species on Some Soil Microbial Populations and Herbaceous Plants

The allelopathic potential of four tree species on soil microbial populations and some herbaceous plants (two understory species and one general biotest species) was investigated. Effects of three nonindigenous tree species, Eucalyptus globulus Labill, Pinus radiata D.Don and Acacia melanoxylon R.Br., on microorganisms participating in the cycle of nitrogen were evaluated, comparing them with those produced by the autochthonous Quercus robur L. Influence of the trees on Lactuca sativa L., Dactylis glomerata L. and Trifolium repens L. was also checked in bioassays. Cell numbers of Nitrosomonas sp. were negatively affected by Acacia and Eucalyptus stands, mainly during spring, when flowers are especially abundant on the ground. Proteolytic microorganisms were also negatively affected by Eucalyptus and Pinus stands, whilst Quercus stand did not show any toxicity. Soil bioassays showed clear inhibitory effects on germination and growth of understory plants, particularly soils from Eucalyptus and Acacia stands. The greatest effects had the soil from Acacia stand, which was phytotoxic during the whole period of germination and growth of understory plants. Allelopathic phenomena could be, at least partially, responsible of the low species diversity in the understory of the nonindigenous tree stands.     

Wood anatomy and hydraulic architecture of stems and twigs of some Mediterranean trees and shrubs along a mesic-xeric gradient

Woody species populating the major Mediterranean ecosystems in the world are characterized by different levels of adaptation to the seasonal Mediterranean climate conditions. Many species of these ecosystems show wood features that allow high efficiency of transport when water is available, while maintaining hydraulic safety during drought periods. This study focuses on the anatomy of juvenile and mature wood of some species representative of continuous sequences of Mediterranean vegetation formations according to gradients of water availability, from xeric to relatively mesic: Cistus monspeliensis L., Rhamnus alaternus L., Myrtus communis L., Pistacia lentiscus L., Olea europaea L., Quercus ilex L., Fraxinus ornus L. and Ostrya carpinifolia L. Twigwood collected in Southern Italy was anatomically compared with the stemwood of the same species represented in the reference slide collection of the National Herbarium of the Netherlands (Lw). The “hydraulic distance” between the wood of main stems and twigs was estimated on the basis of suites of anatomical features related to water efficiency/safety. Although some attributes (i.e. porosity and type of imperforate tracheary elements) were similar in young twigs and older rings, other traits (i.e. vessel frequency and size) evidenced the different hydraulic properties of twig and stemwood. The difference between juvenile and mature structures was large in the species of the mesic end of the gradient while it was relatively small in those more xeric. This tendency is in agreement with the habit gradient from medium-sized trees to small evergreen/drought deciduous shrubs according to decreasing water availability in Mediterranean vegetation types.     

Drought impact on water use efficiency and intra‐annual density fluctuations in Erica arborea on Elba (Italy)

Erica arborea (L) is a widespread Mediterranean species, able to cope with water stress and colonize semiarid environments. The eco‐physiological plasticity of this species was evaluated by studying plants growing at two sites with different soil moistures on the island of Elba (Italy), through dendrochronological, wood‐anatomical analyses and stable isotopes measurements. Intra‐annual density fluctuations (IADFs) were abundant in tree rings, and were identified as the key parameter to understand site‐specific plant responses to water stress. Our findings showed that the formation of IADFs is mainly related to the high temperature, precipitation patterns and probably to soil water availability, which differs at the selected study sites. The recorded increase in the ¹³C‐derived intrinsic water use efficiency at the IADFs level was linked to reduced water loss rather than to increasing C assimilation. The variation in vessel size and the different absolute values of δ¹⁸O among trees growing at the two study sites underlined possible differences in stomatal control of water loss and possible differences in sources of water uptake. This approach not only helped monitor seasonal environmental differences through tree‐ring width, but also added valuable information on E. arborea responses to drought and their ecological implications for Mediterranean vegetation dynamics.     

Parameter-specific hydroclimatic sensitivity of a low-elevation network of living and historical tree-ring series from north-eastern Austria

Compared to the alpine regions of Austria, the eastern part of the country is overall warmer and drier with some tree species growing at the dry limit within their ecological range. This suggests that tree rings may be a valuable proxy for hydroclimatic variability. In this study, we develop ring-width, earlywood-width and latewood-width chronologies obtained from drought sensitive living trees and historical timber from one of the driest and warmest regions of Austria, the Weinviertel. For this, samples of four different tree species − fir (Abies alba Mill.), spruce (Picea abies (L.) Karst.), oak (Quercus petraea Liebl., Q. robur L., Q. cerris L.), and pine (Pinus sylvestris L., P. nigra Arnold) were collected from 88 sites (23 forest stands and 65 historical constructions). 1589 samples (oak: 592 samples, pine: 577, spruce: 212, fir: 208) were dated. Dendro-provenancing was required to ensure that only regional material has entered the chronologies. According to the analyses, historical pine and oak wood were nearly 100% regional, while spruce and fir wood were imported to a great extent with only 44% spruce and 35% fir confirmed to be regional. Because site conditions of historical wood samples are unknown but can have a significant influence on tree growth, changes to site replication over time were important in the assessment of chronology reliability. We also controlled for potential artificial increases in sample depth when more than one construction element is made from a single trunk.We assessed the pine (1584-2011 AD) and oak (1244-2011 AD) chronologies’ potential for reconstructing past hydroclimatic variability by means of response functions in a 17-months window from previous June to current October with climate data from three weather stations (Vienna, Retz, Brno) from 1897 to 2010 AD. The highest seasonal response coefficients are for oak and pine ring width (∼0.43) with respect to aggregated March to July precipitation totals and Thornthwaite climatic water balance. These chronologies reveal a high potential for estimating past changes in regional-scale moisture availability during the earlier growing season.     

Soil water status influences plant nitrogen use: a case study

We studied differences in nitrogen use efficiency (NUE) among six species [Calamagrostis epigejos (L.) Roth., Carex duriuscula C.A. Mey., Phragmites communis (L.) Trin., Salix gordejevii Y.L. Chang, Salix cheilophila Schneid., and Typha minima Funk.] growing in two contrasting habitat types, i.e., a riverine wetland with high water supply and a riparian zone with low water supply. The two sites were different in soil water supply, but not in nitrogen supply. Here, NUE was defined as the total net primary production per unit nitrogen absorbed. There was no significant difference in NUE between the species growing in the riverine wetland (Carex duriuscula, P. communis, S. cheilophila, T. minima) and the species growing in the river bank (Carex duriuscula, Calamagrostis epigejos, P. communis, S. gordejevii). We further analyzed NUE as the product of the nitrogen productivity (A, the rate of dry matter production per unit of nitrogen in the plant) and the mean residence time of nitrogen (MRT, the period of time a unit of nitrogen is present in the plant). The species growing in the riverine wetland had larger A but lower MRT than the species growing in the river bank. There was an inverse relationship between A and MRT. Consequently, NUE was similar among species and habitats. These results suggested that environmental factors, such as soil water supply, can influence N use by plants.     

Responses of crown architecture in Betula pendula to competition are dependent on the species of neighbouring trees

We measured the growth responses of individual shoots and branches of Betula pendula when growing next to trees of the same species or Pinus sylvestris, Larix sibirica or Alnus glutinosa. We used the three-dimensionally digitized response variables and the size and distance of trees growing within a 5-m radius of the study trees to establish a relationship between tree performance and the effect of competing neighbouring tree species on crown architecture. B. pendula was able to modify its crown architecture and thus alter its strategy to compete with different neighbours. Trees of B. pendula growing beside species counterparts had the highest growth of new long shoots in relation to the already existing branch length [growth vigour (GV)], while GV was the lowest next to L. sibirica. With B. pendula or P. sylvestris as its main neighbour, B. pendula invested in short shoots by growing them rather densely in short branches with limited numbers, whereas with L. sibirica the number, length and angle of the branches were high. The competitive response was also strongly dependent on tree ontogeny and the shoot and branch characteristics were significantly affected by their location inside the crown. B. pendula was able to respond to the challenges posed by its neighbours, which was also reflected in the GV. The ability to maintain steady growth with alternative crown designs in different neighbourhoods reflects plasticity in the crown responses.     

Being evergreen in an aquatic habitat with attenuated seasonal contrasts – a major competitive advantage?

This study experimentally compares growth of four aquatic macrophytes species (Sparganium emersum Rehm., Hippuris vulgaris L., Groenlandia densa (L.) Fourr., Luronium natans (L.) Raf.) with different modes of winter persistence in a thermally buffered habitat. The question is whether the above-ground persistence of photosynthetic structures during winter can compensate for low growth rates of evergreens when they compete with fast growing, non-evergreen species. The experiment was carried out in experimental boxes installed in a former river channel fed by stenothermic ground-water. Species were planted pairwise in experimental boxes in autumn, monitoring was carried out in the following year: degree of evergreenness was evaluated through number of ramets present prior to the main growing season, competitive ability of species was assessed during the growing season through cover measurements at three dates. Degree of evergreenness varied considerably between species, ranging from increase of ramet numbers during winter in Luronium over preservation of ramet numbers in Groenlandia and Hippuris to nearly complete winter die-back in Sparganium. Luronium presented the highest cover during the entire growing season. Only by the end of summer did Sparganium attain a similar cover through a high growth rate. Despite large differences in cover, growth appeared largely unaffected by the kind of treatment partner a species was confronted with. Nevertheless, this study demonstrates that being evergreen can compensate for a low growth rate during the main growing season when it is associated to extensive growth outside this main growing season.     

Arsenate phytoextraction abilities of one-year-old tree species and its effects on the nutritional element content in plant organs

Abstract

The aim of the study was to evaluate the As phytoextraction potential of four tree species: Acer pseudoplatanus L., Betula pendula Roth., Quercus robur L., and Ulmus laevis Pall. in light of their prospective use in the phytoremediation of arsenate [As(V)] contaminated soils. The content of nutritional elements: B, Ca, K, Mg, Na, Si, P, and S was also analyzed. The trees were grown for 1?month in hydroponic cultures (Knop medium) supplemented with As(V), (1?mM). The results showed that the highest As accumulation efficiency was characterized by B. pendula (BCF = 0.87) and Q. robur (BCF = 0.5). Betula pendula accumulated about 80% of As in its roots (TF = 0.22) whereas Q. robur accumulated more than 60% of As in its shoots (TF = 1.60). The other tree species accumulated significantly lower amounts of As, more than 60% of which collected in their shoots. As(V) phytoextraction led to a significantly lower level of P and S in the roots of all tested tree species. Betula pendula seems promising for phytostabilisation and Q. robur for phytoextraction of As(V) from contaminated soils. The obtained results confirm the accumulation and translocation of As(V), as well as the acquisition of nutritional elements by the selected tree species.     

The importance of forest type,tree species and wood posture to saproxylic wasp (Hymenoptera) communities in the southeastern United States

Although the forests of the southeastern United States are among the most productive and diverse in North America, information needed to develop conservation guidelines for the saproxylic (i.e., dependent on dead wood) fauna endemic to the region is lacking. Particularly little is known about the habitat associations and requirements of saproxylic parasitoids even though these organisms may be even more vulnerable than their hosts. We sampled parasitoids emerging from dead wood taken from two forest types (an upland pine-dominated forest and a lowland hardwood-dominated forest), three tree species (Liquidambar styraciflua L., Pinus taeda L., and Quercus nigra L.) and two wood postures (standing dead trees (i.e., snags) and fallen logs) in South Carolina. Parasitoid abundance did not differ between forest types or among tree species, but did differ between wood postures, being higher in snags than logs. This difference may have been due to the logs being in contact with the ground or surrounding vegetation and therefore less accessible to parasitoids. Parasitoid abundance and density decreased with height on both snags and logs. Species richness did not differ between forest types, among tree species or between wood postures. According to analysis of similarities, parasitoid communities did not differ between forest types, but did differ among tree species. The wasp communities associated with the different tree species and posture combinations were distinct. In addition, communities associated with the upper boles and crowns of snags were distinct from those occurring lower on snags. These results emphasize the importance of maintaining tree diversity in managed forests as well as retaining or creating entire snags at the time of harvest.     

Micronutrient levels in some temperate European tree species: a comparative field study

Micronutrient concentrations in foliage and stemwood (including bark) of six European tree species (Betula pendula Roth., Quercus robur L., Fraxinus excelsior L., Fagus sylvatica L., Tilia cordata Mill. and Picea abies (L.) Karst.) planted on the same type of soil at six sites in three different countries were studied. Micronutrient concentrations in foliage were considerably higher than in stemwood for all elements and species studied, except for Fe in spruce. Interspecies comparisons revealed significant differences in concentrations both in foliar and stemwood biomass, as well as in stemwood:foliage nutrient ratios. Lime foliage showed a considerably higher concentration of B than all other species, while the stemwood concentration of this element was highest in ash. Mn concentration in both foliar and stemwood biomass of ash was extremely low compared with concentrations in other species. Birch stemwood showed nearly double the level of Zn in other species at all sites. Zn concentrations in the birch foliage were also higher than in other species, with the exception of the Lithuanian sites, which showed lower EDTA-extractable Zn concentrations in the soils. The concentration of Cu was lowest in spruce foliage, while Cu concentrations in stemwood were similar in all species. It was concluded that species-related differences in microelement nutrition must be taken into account when evaluating the nutrient status of common European forest tree species, and when using them as bio-indicators of the effects of environmental pollution.