Bark gnawing of forest trees by voles during the growing season

This study investigated the impact of small rodents on young trees during three growing seasons (2018–2020) in the Czech Republic. Tree damage by small rodents, the quantity and quality of herbaceous plant biomass and the species composition of small mammals were monitored at two sites in European beech forest plantations. The number of trees damaged during three growing seasons correlated positively with fibre content and negatively with nitrogen content in herbaceous plant biomass. The importance of winter precipitation is reflected in the positive correlation with nitrogen content in herbaceous plant biomass. The observed tree-gnawing damage correlated positively with the abundance of one rodent species only—the bank vole. The highest damage occurred after the concurrence of a dry winter and a higher number of voles. Given current climate variability, this situation could become more common in the future. Gnawing may be a limiting factor for the successful restoration of trees with thin bark—in our case, European beech. In addition, the proportion of this woody species should be increased to achieve a more stable and closer composition in the Czech Republic.

     

Sedimentary archive of contamination in the confined channel of the Ohře River,Czech Republic

Purpose

The Oh?e River has received contamination from metal mining and metallurgy (mainly Cu, Pb, Sn, U, Zn) over the previous five centuries. This contamination history has been poorly documented. Contamination has entered the river system in its middle reach, where the channel is incised and bedrock confined, which impedes overbank deposition. Our objective was to locate and describe a sedimentary record in this unfavourable depositional setting.

Materials and methods

Three former channel bars that have coalesced with the riverbank were revealed by examination of historical and current maps and a digital terrain model. Manual coring in the bar and in situ (handheld) X-ray fluorescence (XRF) spectroscopy provided data for developing a contamination chemostratigraphy, which was correlated with the mining history in the region. Detailed topographic examination of the bar and valley edge was important to understanding the evolution of one of the bars. Optically stimulated luminescence (OSL) dating was used to verify the timing of deposition.

Results and discussion

Handheld XRF for in situ analysis of element composition is efficient for studying contaminated sediment bodies with complex stratigraphy, which require extensive coring and stratigraphic correlation. Despite the unfavourable settings, the channel bars trapped sufficient sediment to produce a record that correlates with the history of contamination in the drainage basin. In the bar studied in greatest detail, we observed a surprising amount of contamination passing through the Oh?e River channel (up to 300 mg kg^?1 of Cu, 340 mg kg^?1 of Pb and 630 mg kg^?1 of Sn in fine sand and silt deposits) associated with a pollution climax in the sixteenth and seventeenth centuries. Modern contamination (Hg and U deposited in the nineteenth and twentieth centuries) was entrapped with low efficiency based on comparable concentrations of Hg and U located 90 km downstream.

Conclusions

The efficacy of the use of historical maps and detailed fieldwork was demonstrated by identification of unique depositional meso-environments, which are rare in bedrock-confined fluvial systems. The contamination chemostratigraphy of the bar deposits was correlated with the local mining and pollution history and contributed to an understanding of the bar evolution. The approach used in our study may be applicable to other montane rivers with historic ore mining and processing in their basins.

     

Conversion of Norway spruce forests in the face of climate change: a case study in Central Europe

Steadily increasing damage to Norway spruce forests in Europe has caused researchers and managers to consider whether these forests can be converted to more stable ecosystems. In a central European mountain region, we investigated whether management systems (MSs) specified by regional stakeholders provide sound alternatives to the currently applied management. We used the forest model Sibyla to explore whether the tested MSs differ in their sensitivity to climate change in terms of altered biomass production, stand structure, forest damage, and financial outcome. The tested MSs were no-management (NM), currently applied management (BAU), and management based on the preferences of forest managers (FM) or on the preferences of other stakeholders (OSH). With NM, spruce remained dominant during the simulation period 2010–2100, and the rate of damage significantly increased. Spruce also remained dominant with FM, while the abundance of non-spruce species significantly increased with BAU and OSH. The rate of salvage logging converged at 50% of the total harvest for all MSs up to 2050. Climate change reduced biomass production (?15%) with all MSs but had a negligible effect on biodiversity indicators. The average initial value of the simulated stands was 20,000 € ha^?1 and the nominal value in 2100 was between 1900 and 10,900 € ha^?1. The Net Present Value calculated with the 2% interest rate was negative during the whole simulation period (?5600 to ?18,500 € ha^?1 in 2100). Effect of climate change on all financial indicators was negative. Our findings indicate that secondary spruce forests are highly vulnerable and that the systems proposed by both forest managers and other regional stakeholders failed to significantly reduce forest damage and stabilize forest production.     

Spatial and microgeographical genetic differentiation of black alder (Alnus glutinosa Gaertn.) populations

Three Alnus glutinosa populations from central Slovakia were investigated by means of isozyme analysis. The average expected heterozygosity ranged from 0.151 to 0.173. Despite significant differences in allele frequencies among populations, genetic differentiation was low (F_ST=0.022). Intrapopulation fixation indices indicate no or very slight deviation from panmictic expectations towards the heterozygote deficiency. No indications were found that the investigated populations have experienced recent bottlenecks in population size. A spatial autocorrelation analysis based on Moran’s I indicates the existence of a spatial genetic structuring in the population Král’ová. Patch size was estimated to be 70–100 m, which is more than observed in other broadleaved tree species. This difference is explained by the linear shape of alder populations and a higher mobility of seeds.     

Effect on the immune system of germ-free piglets of probiotics potentiated with polyunsaturated fatty acids

The present study investigated the influence of polyunsaturated fatty acids (PUFA) on the immune system of germ-free piglets. Oil with increased content of omega-3 PUFA was administered to piglets from the experimental group (EG) for four weeks. Piglets from the control group (CG) received identical volumes of saline solution. At the age of 21 days both groups of germ-free piglets were inoculated perorally with Lactobacillus casei subsp. casei at a dose of 2 ml (1x10(8) mli). At the age of 28 days, i.e. after one-week colonisation of germ-free piglets with Lactobacillus casei subsp. casei, significant differences were recorded in phagocytic activity of neutrophils (PANe) and phagocytic activity of potentially phagocytizing cells (PA) (P < 0.05). Between EG and CG there have been observed no significant differences in absolute numbers of CD4+ and CD8+ T lymphocytes and numbers of IgM cells and in additional investigated parameters - number of CD2+ T lymphocytes, index of phagocytic activity of neutrophils (IPANe) and index of phagocytic activity (IPA).The total number of leukocytes (Le) in EG was also higher. Of the parameters determined in blood serum we observed a significant increase in concentration of alpha linolenic, eicosapentaenoic and docosahexaenoic acids and a parallel decrease in the level of arachidonic acid.     

A Comparison of Tree Rings and Peat Deposit Geochemical Archives in the Vicinity of a Lead Smelter

The content of Pb, Cd, Mn, K, Ca, Mg and ²⁰⁶Pb/²⁰⁷Pb isotope ratios in spruce tree rings (Picea abies) and peat cores from the Brdy Hills area (10 km W of the Pb smelter) were compared with those in spruce tree rings in the vicinity of the Pb smelter. Maximum Pb content in tree rings (up to 60 mg kg^?1 Pb) corresponds to a peak of metallurgical production in the mid 1970s and highest smelter emissions in the early 1970s. The Pb concentration curves obtained from peat deposit profiles closely correlate with the Pb concentrations in tree rings at both sampling sites. The small differences between the individual tree cores, with the identical general trend, may be attributed to the difference in distance from the smelter and the altitude of each sampling site. Similar behaviour to Pb can be observed for Cd and Ca. Lead isotope composition in tree rings (²⁰⁶Pb/²⁰⁷Pb ~1.143–1.174) is controlled mainly by the smelter emissions (²⁰⁶Pb/²⁰⁷Pb ~1.16–1.17), with the exception of the youngest segments from the more distant locality from the smelter, which yield isotopic signatures corresponding to car-emission Pb (²⁰⁶Pb/²⁰⁷Pb ~1.143–1.150). Higher content of Mn, Mg and Ca in tree rings corresponding to the 1970s and 1980s may be related to soil chemistry changes caused by acid deposition. In addition, an increase in K, Mg (and in some cases also Mn) in the youngest part of wood cores corresponds to the physiological processes in sapwood, and may be influenced by a decrease in Pb in organic soil horizons, which limited the cycling of basic inorganic nutrients.     

Haematological and biochemical profiles of carp blood following nitrite exposure at different concentrations of chloride

Haematological parameters of 2‐year‐old carp (Cyprinus carpio L.) were assessed to study the protective effect of chloride on the health of fish exposed to elevated nitrite concentrations. Four groups of carp were exposed to different concentrations of nitrite and chloride for 96 h (group E1: 67 mg L^?1 NO₂^?, 11 mg L^?1 Cl^?; group E2: 67 mg L^?1 NO₂^?, 100 mg L^?1 Cl^?; group E3: 0 mg L^?1 O₂^?, 100 mg L^?1 Cl^? and group C: 0 mg L^?1 NO₂^?, 11 mg L^?1 Cl^?). The main haematological response of carp to an acute exposure to nitrite (group E1) was a significant decrease (P<0.05) in haemoglobin concentrations (53.40±6.61 g L^?1), haematocrit (0.21±0.02 LL^?1), erythrocyte count (1.13±0.12 TL^?1), leucocyte count (7.1±4.19 GL^?1) and lymphocyte count (5.28±2.51 GL^?1), and a significant increase in methaemoglobin concentration (90.50±4.38%, P<0.01) and mean corpuscular haemoglobin concentration (0.27±0.2 LL^?1, P<0.05). At higher chloride concentrations (group E2), a lower nitrite toxicity was observed. In group E2 carp, methaemoglobin made up 38.32±13.30%. Erythrocytes in carp exposed to nitrite showed qualitative changes. Compared with the control group C, group E1 carp showed a significantly higher number (P<0.05) of elongated erythrocytes, with the nucleus located at one cell pole (0.519±0.388 TL^?1). All erythrocytes of group E1 carp had remarkably clear cytoplasms compared with the cytoplasm in the control group C. The biochemical values found were comparable with those found in controls. The main histological lesions were found in the gills of carp exposed to nitrite and consisted of hyperplasia and an elevated number of chloride cells.     

Impact of Aluminum on Phosphate Uptake and Acid Phosphatase Activity in Root Tips of Lotus Japonicus

The effect of aluminum (Al) on phosphate homeostasis and induction of acid phosphatase activity and isoenzymes was analyzed in root tips of Lotus japonicus. The rapid uptake of phosphate as well as the decrease of soluble inorganic phosphate in tissues suggested, that the presence of Al in root apoplast causes precipitation of the most of absorbed phosphate. Acid phosphatase (ACP) isoenzymes are affected differentially during low pH and Al stress and both Al induced increases and decreases of ACP isoenzyme activities were observed.     

The Yields and Carbon and Nitrogen Balances in the Polyfactorial Field Experiments

The polyfactorial long-term field experiments have been founded in 1979 in several experimental stations located in different soil and climatic conditions, representing a climate and pedosequence of arable soils in the Czech Republic. Four of these experiments exist till the present time. Essentially, the same experimental design that includes different fertilisation with farmyard manure and/or with mineral fertilisers (N, P, K), liming and stand density, each in five levels with four replications, have been applied for all these experiments. Practically, the same eight year crop rotations were applied during the first and second rotations. A conventional tillage has been applied. Organic carbon and nitrogen contents in soil, dry matter of the main and second products, nitrogen uptake by the main and second products and carbon and nitrogen balances have been evaluated in six selected variants of organic and mineral fertilisation over the time period 1996 to 2000.     

Ecologically based height growth model and derived raster maps of Norway spruce site index in the Western Carpathians

The purpose of this study was to find the ecological factors that most affect height growth of Norway spruce (Picea abies Karst.) over the Western Carpathians. The specific aim was to find climate and soil parameters which are influenced by climate change and can thus be used to make a forest growth model more sensitive to climate. From the results, a regression model was built which can predict top height growth of Norway spruce from ecological parameters. Data collected on 201 plots established within National Forest Inventory of Slovakia were used. The plots selected for the study were distributed almost over the whole Western Carpathians. Mean height of the 20 % largest spruce trees was used as dependent variable. From all investigated ecological factors, the growing season length explained as the number of days with temperature over 5 °C, the carbon-to-nitrogen ratio and soil acidity were shown to have the major impact on top height growth of Norway spruce. Finally, 76 % of total variability in top height was explained by the mentioned site variables. To obtain a user-friendly output, a probability matrix was developed showing the likelihood of a discrete site index to occur on different combinations of site factors. Moreover, raster maps showing the site index of spruce and its probability distribution were developed.