The paper presents the results of a study on the impact of forest stand structure and development in 1998 to 2018 on the occurrence of dog’s tooth violets (Erythronium dens-canis L.) in the Medník ...National Nature Monument, Czech Republic. The research was carried out in mixed European hornbeam and sessile oak stands, herb-rich European beech stands and the Sázava-river Norway spruce ecotype stands. The site and stand characteristics of the following three forest stand types were compared: 1) oak-hornbeam forests, 2) herb-rich beech forests and 3) secondary spruce forests. The results showed that the ratio of sterile and fertile plants was 2.9 to 1. The occurrence of E. dens-canis was higher in older stands with differentiated structure. On the contrary, stands characterized by a higher number of trees and basal area negatively affected the population size of E. dens‑canis. Significantly, the density of E. dens-canis decreased with increasing stand density index (SDI) and increased with increasing diameter differentiation index in relation to tree neighbours (TMd). During the period of 20 years, the E. dens-canis population increased by 40.4% on permanent research plots, while the highest changes were observed on spruce plots (+92.1%) and the lowest increase was in oak-hornbeam forests (+18.0%). The highest numbers of E. dens-canis plants were found in herb-rich beech forests (1 774 plants·ha–1), lower numbers occurred in oak-hornbeam forests (784 plants·ha–1) and minimal in secondary spruce forests (51 plants·ha–1).
The experimental plots used in the study were located in the middle forest zone (elevation: 900-950 m a.s.l.) on two nappes of the flysch Carpathians in southern Poland. The aim of this study was to ...assess the effects of serpentinite in combination with nitrogen, phosphorus, and potassium fertilizers on selected chemical properties of the soil and activity of dehydrogenase and urease in the studied soils. All fertilizer treatments significantly enriched the tested soils in magnesium. The use of serpentinite as a fertilizer reduced the molar ratio of exchangeable calcium to magnesium, which facilitated the uptake of magnesium by tree roots due to competition between calcium and magnesium. After one year of fertilization on the Wisła experimental plot, the pH of the Ofh horizon increased, while the pH of the mineral horizons significantly decreased. Enrichment of serpentinite with nitrogen, phosphorus, and potassium fertilizers stimulated the dehydrogenase activity in the studied organic horizon. The lack of a negative effect of the serpentinite fertilizer on enzyme activity in the spruce stand soil showed that the concentrations of the heavy metals added to the soil were not high enough to be toxic and indicated the feasibility of using this fertilizer in forestry.
Data of the vascular plant species composition in the ecotone “forest – forest edge – cutover” ten years after logging of a bilberry spruce stand in the north-taiga subzone of the Arkhangelsk Region ...are reported. Differences among zones of the ecotone complex regarding species percent covers and frequency of occurrence were revealed. Changes in the ground cover species abundance compared to earlier reforestation stages (2–5 years after logging) are discussed. Plant species were grouped according to their response to logging and subsequent tree layer restoration. The first group consists of typically forest-dwelling species whose phytosociological optimum corresponds to bilberry spruce forest conditions (Goodyera repens, Listera cordata, Vaccinium vitis-idaea, V. myrtillus, Hylocomium splendens). The second group includes the forest species that have demonstrated a negative response to logging and have been actively recovering their abundance since the time of tree layer formation in the cutover site (Carex globularis, Chamaepericlymenum suecicum, Equisetum sylvaticum, Gymnocarpium dryopteris, Luzula pilosa, Maianthemum bifolium, Melampyrum pratense, Oxalis acetosella, Pleurozium schreberi, Rubus arcticus, Trientalis europaea). The third group is made up of forest edge species (Empetrum nigrum and Orthilia secunda). The forth group comprised typically forest-dwelling apophytes, which responded positively to logging, but declined in abundance as the tree layer was forming (Avenella flexuosa, Chamaenerion angustifolium, Polytrichum commune). A separate group consists of the species whose response to logging and subsequent tree layer formation could not be detected by geobotanical, and has no statistic proof. It is shown that 10 years after logging, although the tree layer has formed, each zone of the ecotone complex has preserved their specific traits of the ground cover structure.
Abstract European spruce bark beetle Ips typographus is an important driver of ecological processes in spruce stands, with severe effects on forestry economies. To prevent bark beetle outbreaks, ...early detection of infestations is a crucial step in forest management. It is expected that bark beetle infestation modifies biochemical composition of wood and needles, alters physiological responses in the early stage of infestation, which results in the reduction of tree growth and ultimately a tree death. Therefore, we studied the differences in biochemical composition of wood, content of photosynthesis-related pigments, shoot morphology, and growth between the healthy Siberian spruce trees ( Picea obovata ) and trees which were infested by I. typographus . The study was performed in five experimental plots established in the south of the Udmurt Republic in the European part of the Russian Federation. Three infested and three non-infested trees were chosen on each plot. Our results showed no significant effect of bark beetle infestation on the content of main structural components of wood – holocellulose (cellulose and hemicellulose) and lignin. On the other hand, we found differences in the content of extractive substances in the wood. Specifically, we found a higher tannin content in the non-infested trees. The content of photosynthesis-related pigments differed between the non-infested and infested trees as well. Unexpectedly, bark beetle infestation caused the overproduction of both pigment types rather than their degradation. Moreover, we observed that a higher amount of total extractive substances positively affected the incremental growth, whereas tannins supported the growth of shoots and needles.
Abstract Nowadays, a large area of Norway spruce forest stands in Europe is disturbed by windstorm and, subsequently, bark beetle outbreaks. We investigated the state of three disturbed spruce stands ...along an altitudinal gradient in Tatra National Park (Slovakia) through various physiological processes. Tree-growth characteristics, the mineral nutrition in the needles, and photosynthetic efficiency were assessed. Two techniques of chlorophyll a fluorescence and analyses of assimilatory pigments were used to detect the changes in photosynthesis functioning. Also, the heat sensitivity of photosystem II was tested. Our results showed that these stands are located in nutrient-poor environments. We recorded similar contents of nitrogen, phosphorus, potassium, sodium, zinc, and iron in all stands. Down the vertical transect, the contents of calcium, magnesium, and manganese significantly decreased and the non-essential aluminium increased. Based on stem circumference measurements, water deficit occurred during the vegetation season in all stands, but with the smallest magnitude highest U–stand. We found some photosynthetic constraints: slightly lower chlorophyll contents in all stands were recorded; however, seasonal dynamics with increasing chlorophyll concentration in the highest U–stand were observed. Moreover, the photochemistry of the lowest D–stand was the most negatively influenced by simulated heat, as the photosynthetic performance index, and the density of the active reactions centres significantly decreased and the values of the K–step and basal fluorescence increased. Therefore, we can conclude the different levels of physiological vitality in these naturally damaged spruce stands, with the best physiological performance of the trees in the highest stand.
• Effects of warming on root morphology, root mass distribution and microbial activity were studied in organic and mineral soil layers in two alpine ecosystems over > 10 yr, using open-top chambers, ...in Swedish Lapland. • Root mass was estimated using soil cores. Washed roots were scanned and sorted into four diameter classes, for which variables including root mass (g dry matter (g DM) m⁻²), root length density (RLD; cm cm⁻³ soil), specific root length (SRL; m g DM⁻±), specific root area (SRA; m² kg DM⁻±), and number of root tips m⁻² were determined. Nitrification (NEA) and denitrification enzyme activity (DEA) in the top 10 cm of soil were measured. • Soil warming shifted the rooting zone towards the upper soil organic layer in both plant communities. In the dry heath, warming increased SRL and SRA of the finest roots in both soil layers, whereas the dry meadow was unaffected. Neither NEA nor DEA exhibited differences attributable to warming. • Tundra plants may respond to climate change by altering their root morphology and mass while microbial activity may be unaffected. This suggests that carbon may be incorporated in tundra soils partly as a result of increases in the mass of the finer roots if temperatures rise.
Solar radiation reaching densely forested slopes is one of the main factors influencing the water balance between the atmosphere, tree stands and the soil. It also has a major impact on site ...productivity, spatial arrangement of vegetation structure as well as forest succession. This paper presents a methodology to estimate variations in solar radiation reaching tree stands in a small mountain valley. Measurements taken in three inter-forest meadows unambiguously showed the relationship between the amount of solar insolation and the shading effect caused mainly by the contour of surrounding tree stands. Therefore, appropriate knowledge of elevation, aspect and tilt angles of the analysed planes had to be taken into consideration during modelling. At critical times, especially in winter, the diffuse and reflected components of solar radiation only reached some of the sites studied as the beam component of solar radiation was totally blocked by the densely forested mountain slopes in the neighbourhood. The cross-section contours and elevation angles of all obstructions are estimated from a digital surface model including both digital elevation model and the height of tree stands. All the parameters in a simplified, empirical model of the solar insolation reaching a given horizontal surface within the research valley are dependent on the sky view factor (
SVF
). The presented simplified, empirical model and its parameterisation scheme should be easily adaptable to different complex terrains or mountain valleys characterised by diverse geometry or spatial orientation. The model was developed and validated (
R
2
= 0.92 ,
σ
= 0.54) based on measurements taken at research sites located in the Silesian Beskid Mountain Range. A thorough understanding of the factors determining the amount of solar radiation reaching woodlands ought to considerably expand the knowledge of the water exchange balance within forest complexes as well as the estimation of site productivity.
The results of research into the changes occurring in the ground cover of bilberry spruce forests in the north-taiga subzone of the Arkhangelsk Region in the first five years after clear-cutting are ...reported. In the clear-cuts situated away from roads and settlements the diversity of species (number and composition) remained practically unchanged compared to the forest before the cutting, but their abundances differed fundamentally between the three conventional ecotone zones: “forest”, “forest margin”, “clear-cut”. Changes in the percent cover and frequency of occurrence of 29 vascular plant species were investigated. Most of the species were classified into two groups: 1) where the percent cover and occurrence decreased after forest was changed to clear-cut (Carex globularis L., Empetrum nigrum L. s. l., Goodyera repens (L.) R. Br., Linnaea borealis L., Listera cordata (L.) R. Br., Melampyrum sylvaticum L., Orthilia secunda (L.) House, Oxalis acetosella L., Vaccinium myrtillus L.) and 2) positively responding to clear-cutting with a rise in abundance (Avenella flexuosa (L.) Drej, Calamagrostis phragmitoides C. Hartm., Chamaenerion angustifolium (L.) Scop., Luzula pilosa (L.) Willd., Melampyrum pratense L., Solidago virgaurea L., Maianthemum bifolium (L.) F. W. Schmidt, Rosa acicularis Lindl., and Vaccinium vitis-idaea L.). For the rest of the species the response to stand logging could not be determined by geobotanical methods, since their abundance was low in all the zones of the ecotone complex.
► We empirically model the S-shaped wind profile under the canopy of spruce stand. ► All parameters of the model depend on biometric features of a given tree stand. ► Total basal area mainly ...determines the shape of the vertical wind profile. ► Topography of a mountain valley was taken into consideration. ► Parameterization scheme is easily adaptable to stands composed of other tree species.
The wind speed in a forest is one of the main factors deciding upon the amount of water balance between the atmosphere and the soil. Inside a forest complex, the distribution of vertical wind speed has a characteristic S-shape. This paper presents a simplified, empirical model of such an S-shaped wind profile within a stem layer of an Istebna spruce stand. Measurements of the wind speed were taken at four levels in 9 homogeneous, even-aged stands of different age-class: from a 10-year-old natural seeding to a 121-year-old mature stand. Recorded data unambiguously confirmed the existence of the secondary maximum inside the stem layer. The main aim of this paper was to make all model parameters conditional on biometrics features of tree stand as well as the geographical location of research sites on the slopes in a mountain valley. All parameters describing the simplified, empirical model of S-shaped wind profile within the stem layer strictly depend on the well-known total basal area TBA m2h−1. TBA is determined by only an average number of trees per hectare and a mean diameter at a breast height, i.e. 130cm above ground, which are easy to be measured with high accuracy ‘from ground’. Presented data analysis shows that the estimated wind speed at the secondary maximum and a mean wind speed within a stem layer are contingent upon a biomass density in the crown layer and its elevation above ground. A biomass density can be equated with the leaf area index (LAI).
The presented simplified, empirical model of the vertical wind speed profile for a spruce stand and its parameterization scheme, which is to be measured in an effortless way, should be easily adaptable to stands composed of other tree species, taking into consideration specific differences between spaces. The necessary improvements of the presented empirical model would be possible after some series of measurements taken within various types of tree stands. A thorough understanding of the biological factors creating the observed S-shaped wind profile ought to considerably expand the knowledge of the forest ‘ventilation’ process, which determines vaporization from the soil as well as the CO2 advection.
We investigated the diversity of ectomycorrhiza associated with the endemic Picea crassifolia in Mount Helan National Nature Reserve in Inner Mongolia, China. Toward this objective, we conducted ...morphological and molecular identification of ectomycorrhizae in soil cubes taken from pure P. crassifolia stands. Eleven types of ectomycorrhizal (ECM) organisms were separated, briefly described, and identified. Nine morphotypes belonged to the phylum Basidiomycotina Amphinema byssoides, Cortinarius sp (cf. limonius), Cortinarius vernus, Inocybe cf. nitidiscula, Inocybe sp 1, Sebacina incrustans, Sebacina sp, Suillus luteus, and Piceirhiza tuberculata x Picea crassifolia (comb. Nov.), and two morphotypes to the phylum Ascomycotina (Cenococcum geophilum and Helvella sp). The diversity of ECM organisms in P. crassifolia was lower than that reported by other studies on spruce or pine forests, or on sporocarp diversity in the high-mountain forests of China. Most of the fungi in the rhizosphere did not correspond to species previously recorded as sporocarps above ground. Here, several new ectomycorrhiza morphotypes are proposed and described. We also confirmed the ectomycorrhizal status of the genus Sebacina (order Sebacinales).
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