The future performance of native tree species under climate change conditions is frequently discussed, since increasingly severe and more frequent drought events are expected to become a major risk ...for forest ecosystems. To improve our understanding of the drought tolerance of the three common European temperate forest tree species Norway spruce, silver fir and common beech, we tested the influence of climate and tree‐specific traits on the inter and intrasite variability in drought responses of these species. Basal area increment data from a large tree‐ring network in Southern Germany and Alpine Austria along a climatic cline from warm‐dry to cool‐wet conditions were used to calculate indices of tolerance to drought events and their variability at the level of individual trees and populations. General patterns of tolerance indicated a high vulnerability of Norway spruce in comparison to fir and beech and a strong influence of bioclimatic conditions on drought response for all species. On the level of individual trees, low‐growth rates prior to drought events, high competitive status and low age favored resilience in growth response to drought. Consequently, drought events led to heterogeneous and variable response patterns in forests stands. These findings may support the idea of deliberately using spontaneous selection and adaption effects as a passive strategy of forest management under climate change conditions, especially a strong directional selection for more tolerant individuals when frequency and intensity of summer droughts will increase in the course of global climate change.
•We applied machine learning to EVI profiles to iden6fy SFD pixels.•We analyzed the influence of topographic factors on SFD pixels distribu6on.•We analyzed the produc6vity loss of SFD pixels compared ...to the previous 15 years.•Eleva6on proved to be the main topographic driver for SFD pixels distribu6on.•A produc6vity loss of 14% occurred compared to the previous 15 years.
In common beech forests the most damaging frosts are those that occur at the end of spring. At that time the fresh new leaves are at a vulnerable stage and risk to be readily killed by the freezing temperatures. The ability to identify late spring frost spatial dynamics is a key issue for understanding forest patterns and processes linked to such extreme event. The aim of this study is to detect, map and quantify the vegetation anomalies that occurred in the mono-specific beech forest of the Lazio, Abruzzo and Molise National Park (Italy) after an exceptional spring frost recorded on the 25th of April 2016. Results showed that, beech forests at lower elevations that had an early greening process were subject to spring frost damage (SFD pixels) and their productivity performance strongly decreased with respect to the previous 15 years; to the contrary the beech forests located at higher elevations did not suffer the spring frost effects (NSFD pixels) thanks to their delayed leaf unfolding phase. The duration of the effects of freezing stress for the SFD pixels was about two months, until the end of June, confirmed by Net Ecosystem Exchange measurements. This greening hiatus led to an average 14% loss of productivity compared to the previous 15 years. Elevation had a significant role on the probability of occurrence of SFD pixels. Productivity loss in SFD pixels was more severe at elevations in the range 1500–1700 m, on steeply terrains and North aspects. This study represents a step forward the systematic use of automated techniques to study areas subject to stress or anomalies from multitemporal satellite imagery and to identify break points and recovery of the greening process.
Results are presented for the chemical composition of the forest litterfall and lysimetric waters of Cambisols from the intensive monitoring stationary sample plot of the forest ecosystems. ...Litterfall (litter biomass fraction) had fallen on the soil surface with acid reaction, which in the period 2011 - 2018 varied from 5.1 to 5.4. The established contents of calcium (6.9 mg.g-1 ), magnesium (0.52 mg.g-1 ), potassium (3.58 mg.g-1 ), nitrogen (7.28 mg.g1 ) and phosphorus (0.55 mg.g-1 ) were low and those of manganese (1754 µg.g-1 ), iron (185 µg.g-1 ), copper (11 µg.g-1 ) and zinc (36 µg.g-1 ) were high. The lysimetric waters in the surface horizon were very strongly acidic – pHH2O= 4.6. The amounts of all the tested parameters in them were very low – dissolved organic matter (8.0 mg.dm3 ), potassium (2.6 mg.dm3 ), calcium (5.7 mg.dm3 ) and others. Only the content of manganese was increased, which in some years exceeded the maximum value pointed in the literature for the European forests. It is assumed that degradation processes take place in the mineral part of the soil which lead to its impoverishment of macro and microelements.
We studied the insecticidal effects of ashes from three different tree species (common beech, Norway spruce, and black locust) on the mortality of Sitophilus zeamais adults under laboratory ...conditions. A diatomaceous earth formulation, SilicoSec® was used as a positive control. We studied the contact effects of ashes on adults and the insecticidal effect of ash mixed with wheat grain. The experiment was carried out at three different temperatures (15, 20 and 25 °C) and at two different relative humidity r.h. values (55% and 75%). The study on contact effects (immediate mortality and delayed mortality) was carried out in Petri dishes, where we applied ash in two concentrations, 10 and 20 g/m2. After 7 d there was more than 97% mortality for the beetles in all three wood ashes at 25 °C and 55% R.h., while after 14 d wood ash of Norway spruce showed the highest effectiveness (87%) at 20 °C and 55% R.h. 96% mortality was recorded at 20 °C and 55%, when SilicoSec® was applied. The experiment with the mixture of ashes and grains was performed by mixing 2.5 or 5 w% of ash with wheat. In both approaches, we established that lower R.h. in combination with higher temperatures led to higher adult mortality rates. Regardless of the approach, the preparation concentrations did not influence adult mortality. The most efficient ash was that of Norway spruce, yet we attribute its effectiveness not only to its highest content of SiO2 (11.68%) but also to the other ingredients in ash, which can enhance its hygroscopic properties. Our research demonstrated that wood ash can efficiently protect stored crops from maize weevils. However, before introducing wood ash into the systems of protecting stored wheat grains against harmful insects, the influence of concentrations of ashes and their hygroscopic properties should be studied.
•All tested wood ashes were slightly less effective than SilicoSec®, in controlling maize weevil (Sitophilus zeamais), however the most promising results were confirmed with wood ash of Norway spruce.•Significantly higher mortality of was achieved with higher temperature in combination to lower relative humidity.•High percentage of Slovenian forest is covered with Norway spruce, which offers good possibilities for implementation of its wood ash for effective grain protectant.
Most European wood species do not have durable wood. In order to be used in outdoor conditions, non-durable material must be protected. Non-biocidal solutions for wood protection have been attracting ...a lot of attention, particularly in class 2 and 3 applications. One non-biocidal technique is treatment of wood with water repellents, such as wax emulsions and oils. Linseed oil and tung oil are frequently used water repellents. This research reports on the performance of linseed- and tung-oil-treated Norway spruce and beech wood against wood-decay fungi. Additionally, short-term hydrophobic properties were determined (with a tensiometer), as well as long-term hydrophobic properties (by soaking in water) in laboratory and outdoor conditions (electrical resistance measurements). Wood treated with tung oil and linseed oil is protected against brown- and white-rot fungi; however, tung oil was found more effective. Not only did the oils tested prove efficacious against wood-decay fungi, but also they worked against short-, medium-, and long-term water uptake as well. Oil treated wood takes up less water during laboratory tests, as well as during outdoor testing.
•Impregnation of wood with linseed and tung oil improves performance of impregnated wood against wood decay fungi.•Short term and long term water uptake of liquid water in tung and linseed oil treated wood is reduced as well.•Reduced water uptake was proven with laboratory and long term field tests.•Tung and linseed oil is and effective replacement for biocidal treatment in les hazardous applications.
Common beech is one of the most widespread and important European tree species, widely used in timber industry and for energy production. Under specific set of complex factors, it facutatetivly ...develops false heartwood, which considerably decreases market demand and value of processed logs. Due to its properties, false heartwood is more susceptible to attack of wood decay fungi, which leads to further loss of wood quality and value. One of the most common fungi able to cause heart rot in beech is Meripilus giganteus, known for its spread in the basal parts of the tree, where it can affect most valuable sections of round wood. The aims of this study were to monitor the distribution of fungus and appearance of its fruiting bodies in research area, and to analyze the extent of fungus impact on shape and size of false heartwood and occurrence and length of rot in infected trees, while taking into account the observed stem damage as a possible influential factor. Fruiting bodies occurrence, life span and position on a tree were monitored during a six-year period. For trees with confirmed infection, stem damage was evaluated and appointed to one of four size classes. False heartwood shape and share in associated stem cross-section were observed and measured on 1–4 cross-sections per tree at different heights, and compared between infected and uninfected trees. If present, length of wood decay extent on butt-log was measured. The obtained results confirmed increased susceptibility of mature trees to infection, which seemed to occur mostly via roots from where mycelium spread into stem base. It was found that Meripilus giganteus has a significant impact on enlargement and change of FH shape from cloud- to star-like, up to approximately 5 m of the stem height, thus causing devaluation of the first assortments. The presence of rot was confirmed on the majority of infected trees, extending averagely 0.5 m into the first processed log, causing the loss of utilizable volume and thus the value of round wood. Stem damage category showed no significant effect on false heartwood or rot, supporting the prevailing impact of the fungus.
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•Physiological traits of beech seedlings tested under natural and artificial shade.•Increasing shade resulted in lower photosynthetic rates.•Good correspondence between natural and ...artificial shade results.
Commitment to sustainable forest management (alternatives to clearfelling) has led to a renewed interest in continuous cover forestry systems, which promote the control of light to produce stand benefits. Physiological performance of shade-tolerant European beech (Fagus sylvatica L.) in response to light availability was investigated in natural regeneration below the canopy in contrast to planted seedlings under artificial-shade conditions. Although beech seedlings had higher photosynthetic capacity with increasing light availability, they were able to maintain positive CO2 assimilation rates under low light levels in both field and controlled conditions. Leaves of seedlings under low light had the ability to use light more efficiently (higher PSII efficiency) than those in high light, which offer some physiological explanation for the ability of beech seedlings to grow under very low light conditions. Whilst caution is advised to interpret results from controlled to field studies, the overall general correspondence in the trend of the physiological response to light levels within beech grown below the canopy and under artificial-shade conditions suggests that it might be possible to extrapolate results from studies performed under artificial shade (nets) to field conditions. Hence, the use of nets may be an alternative way of assessing the potential physiological responses of seedlings to light availability.
Common beech is one of the most widespread and important European tree species, widely used in timber industry and for energy production. Under specific set of complex factors, it facutatetivly ...develops false heartwood, which considerably decreases market demand and value of processed logs. Due to its properties, false heartwood is more susceptible to attack of wood decay fungi, which leads to further loss of wood quality and value. One of the most common fungi able to cause heart rot in beech is Meripilus giganteus, known for its spread in the basal parts of the tree, where it can affect most valuable sections of round wood. The aims of this study were to monitor the distribution of fungus and appearance of its fruiting bodies in research area, and to analyze the extent of fungus impact on shape and size of false heartwood and occurrence and length of rot in infected trees, while taking into account the observed stem damage as a possible influential factor. Fruiting bodies occurrence, life span and position on a tree were monitored during a six-year period. For trees with confirmed infection, stem damage was evaluated and appointed to one of four size classes. False heartwood shape and share in associated stem cross-section were observed and measured on 1–4 cross-sections per tree at different heights, and compared between infected and uninfected trees. If present, length of wood decay extent on butt-log was measured. The obtained results confirmed increased susceptibility of mature trees to infection, which seemed to occur mostly via roots from where mycelium spread into stem base. It was found that Meripilus giganteus has a significant impact on enlargement and change of FH shape from cloud- to star-like, up to approximately 5 m of the stem height, thus causing devaluation of the first assortments. The presence of rot was confirmed on the majority of infected trees, extending averagely 0.5 m into the first processed log, causing the loss of utilizable volume and thus the value of round wood. Stem damage category showed no significant effect on false heartwood or rot, supporting the prevailing impact of the fungus.
Gall-inducing organisms change the chemical properties of galled organs and host plants due to the development of gall tissues that are supposed to shelter the galler and provide it with nutrients. ...Hartigiola annulipes and Mikiola fagi represent the gall midge family (Diptera; Cecidomyiidae). They share a host plant species, the common beech (Fagus sylvatica), whose leaves they use for galling. Their galls are single-chambered and occur on the upper side of the leaf blade. The morphologies of their galls are different, but there is a lack of studies comparing the impact of both species on the common host. Therefore, we analysed the total contents of carbon, nitrogen, soluble carbohydrates, starch, soluble phenolics and tannins in galls, galled leaves with removed galls and leaves without galls. Samples were collected in two different forest stands in western Poland (Scots pine forest with artificially planted beech trees and a natural beech forest). The influence of the studied gallers on the leaves is species- and forest-dependent. Perhaps seasonal changes and the level of infestation are also responsible for the chemical changes. The content of soluble carbohydrates in the galls of H. annulipes reaches an optimized level and is independent on the forest type. A high infestation level by H. annulipes is manifested itself in an elevated content of total soluble phenolics and tannins in leaves, while gall tissues do not accumulate soluble phenolics. The low levels of nitrogen in the gall tissues of both gallers leads to the rejection of the nutrition hypothesis; however, M. fagi galls act as sinks for soluble carbohydrates.
Keywords: plant galls, chemistry, gall midge, common beech, biochemistry
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