Macronutrients in tree stems and foliage: a comparative study of six temperate forest species planted at the same sites

Common European tree species ( oak, ash, beech, birch, lime and spruce) planted in adjacent stands on six sites were compared in terms of macronutrient concentrations in foliar and stem wood ( including bark) biomass. The nutrient concentrations in both biomass compartments were much more dependent on species than on site although soil conditions differed between the sites. Differences between species regarding stem wood nutrient concentrations only partly corresponded to the differences in species foliage. The concentrations in spruce were considerably lower than in deciduous species, except P in foliage, and Ca in both stem wood and foliar biomass. Differences were also observed between the deciduous species both regarding foliar and stem wood nutrient concentrations. The differences should be considered when modelling nutrient circulation in forest stands and when evaluating the long-term sustainability of forest management

Nutritional ecology of selected Scandinavian tree species with special emphasis on hardwoods.

This thesis considers several important aspects of nutrient dynamics and allocation in adult stands of Swedish forest tree species (Quercus robur L., Tilia cordata Mill., Fraxinus excelsior L., Betula pendula Roth., Fagus sylvatica L. and Picea abies (L.) Karst) planted on the same soils. Differences between species in macro- (N, P, K, Ca, Mg, S), and micro- (B, Cu, Fe, Mn, Zn) nutrient levels in aboveground biomass, in re-translocation and in fluxes of the elements prior to leaf senescence (via litterfall and throughfall) and in their interactions with soil chemistry were examined. With the exception of Fe in spruce stemwood, nutrient levels in the foliage were considerably higher than in stemwood. Differences between the species in terms of stemwood concentrations only partly corresponded to foliar differences between the species, indicating that nutrient mobility and allocation differed between the species. An investigation of nutrient fluxes in a deciduous forest during the period of leaf senescence showed that, with the exception of K in an ash stand, the nutrient input to the soil surface via leaf litterfall was considerably higher than the throughfall fluxes. The amounts of elements in the throughfall per unit stand leaf area showed a clear dependency on the original amounts in the leaves and on the species’ susceptibility to foliar leaching, which was highest in ash leaves. Nutrient resorption prior to leaf senescence was high for N, P, K and S (accounting for 30-70% of the green leaf contents). Cu and Fe were the most efficiently resorbed micronutrients. Inter-specific differences in nutrient resorption efficiency were also observed. The study clearly demonstrated that stands with different species planted on former agricultural land had differing impacts, after just 40 years of growth, on the chemical characteristics of the uppermost layer of the mineral soil. The most prominent differences were between lime stands (which had considerably higher pH, base saturation, base cations and boron pools) and spruce stands (which had the most acidifying effect on the mineral topsoils). Among the deciduous species, beech had the most similar effect to spruce on topsoil chemistry. Differences in nutrient dynamics in studied species should be taken into account when using trees of different species in environmental monitoring and when assessing their nutrient status. The differences are also of particular importance for evaluating the effects of different forest management strategies on long-term nutrient sustainability

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

Autumn nutrient resorption and losses in four deciduous forest tree species

Nutrient resorption prior to leaf senescence is an important mechanism of nutrient conservation in forest tree species. However, despite the abundance of literature on the subject, inter-specific comparison of common temperate tree species is complicated by both the variability of resorption efficiency, which is affected by many environmental factors, and methodological differences between the studies, especially in relation to measurements of nutrient losses. This study compares the autumn nutrient resorption and nutrient losses via throughfall and litterfall of N, P, K, S, Mg, Ca, Cu, Fe and Mn in adjacent 40-year-old stands of Quercus robur L., Tilia cordata Mill., Fraxinus excelsior L. and Betula pendula Roth. In addition, the relative susceptibility of leaves to leaching was studied in the laboratory. For all species and elements, except K in ash stands, nutrient losses via throughfall were considerably lower than the losses via litterfall during the sampling period (from the end of August to the middle of October). Nutrient amounts in the throughfall were mostly governed by the susceptibility of the respective species to foliar leaching, which was highest in ash trees, but also depended on nutrient amounts in the pre-senescent leaves. K showed the highest losses via throughfall among the studied elements, 30% of the green leaf content being lost in the ash stand and 8-11% in the other stands. Ash also showed considerable throughfall losses (9-19% of green leaf content) of S, Mn, Mg, Ca and P, while the corresponding losses of these elements in other species were lower in relation to the nutrient content of their foliage. Species with higher amounts of nutrients in the green leaves tended to have higher amounts of nutrients in their litter, but this tendency was not observed for all species and elements. Nutrient resorption efficiency, calculated on leaf area basis, differed among species and was highest for N (ranging from 36% in ash to 69% in birch), P (from 37 in ash to 59% in lime), K (from 38% in ash to 51% in lime) and S (from 31% in ash to 48% in birch). Fe and Cu were the most efficiently withdrawn micronutrients (the amounts resorbed ranging from 7-10% in lime to 20-37% in the other species). (c) 2006 Elsevier B.V. All rights reserved

The impact of six European tree species on the chemistry of mineral topsoil in forest plantations on former agricultural land

Influences on mineral topsoils of common European tree species (oak-Quercus robur L., lime-Tilia cordata Mill., ash-Fraxinus excelsior L., birch-Betula pendula Roth., beech-Fagus sylvatica L. and spruce-Picea abies (L.) Karst.) were studied in 30 to 40-year-old stands planted in adjacent plots on former arable land. Mineral soil samples from two depth layers (0-10 and 20-30 cm) under the different species were compared in terms of pH, base saturation, pools and concentrations of exchangeable macro- and micronutrients, total nitrogen and carbon. With the exception of pH (H2O) and extractable Al and Fe, no significant differences between species were detected in the lower layer. The upper (0-10 cm) layer was, however, affected differently depending on tree species: significant differences in pH, base saturation, exchangeable base cations and other nutrients were observed. The most prominent differences were between lime and spruce. Lime had considerably higher pH, base saturation, base cation and boron pools compared to spruce, which had the most acidifying effect on the mineral topsoils. Among the deciduous species, beech had the most similar effect to spruce on the upper layer of mineral topsoils. Soil C, N and C/N ratios did not differ significantly among species

Multiwavelength Monitoring of the Gamma-Bright Blazar Mkn 421

We present the results of photo-polarimetric monitoring observations of the blazar Markarian 421 carried out with different telescopes (the 0.4 m telescopes of St. Petersburg State University and the Pulkovo Observatory, the 0.7 m telescope of the Crimean Astrophysical Observatory) during 2008–2015. We analyse the optical data as well as gamma-ray ligh t curves obtained with the Fermi Large Area Telescope. The multiwavelength flux variations are discussed