The frequency method in studying habitat preferences of common forest birds

This paper presents the results of a study on the habitat preferences of selected species of the bird community in the Morgi Forest, the Kolbuszowa Forest Division (SE Poland), with the use of the point-stand bird census method. The aim of the study was to test the effectiveness of the method in determining the frequency of colonisation of stands with different habitat parameters by the most abundant bird species. In 270 tree stands of a forest complex with diverse habitats, a bird census was carried out with four counts per each stand. Next, a list of the tree stands and the bird species recorded in the stands was compiled. The stands were divided into categories according to the forest habitat type, dominant species and age class. In the next step, the occurrence frequency of the most abundant bird species was calculated for each stand category. Among the analysed species, the majority showed a positive correlation between the frequency of occurrence and habitat fertility. The influence of the dominant stand species on the occurrence frequency of bird species was largely driven by habitat fertility. The lowest average frequency of the identified avian species was found in stands dominated by pine Pinus sylvestris, birch Betula sp. and black alder Alnus glutinosa. There was generally a positive relationship between age class and the bird community parameters. It is concluded that the point-stand method of bird census provides informative results for research on the habitat selectivity of bird populations.

Antioxidant Activity of Different Extracts from Black Alder (Alnus glutinosa) Bark with Greener Extraction Alternative

Phenolic compounds isolated from plant biomass consist of bioactive components showing a wide range of benefits for humans, including antioxidant, antimicrobial or anti-inflammatory effects. This paper presents the potential value of black alder (Alnus glutinosa (L.) Gaertn. (Betulaceae)) bark for the production of biologically active substances, despite its current use as a low value fuel source. Most of the extraction methods employ neat organic solvents to obtain extracts with a high antioxidant potential from biomass. The aim of this work is to show the advantages and disadvantages of the extraction process by taking into account the principles of ‘green chemistry’ and replacing the organic solvents with ‘green’ solvent water. Using the advantages of accelerated solvent extraction (ASE), it has been shown that the use of deionized water has the prospect of replacing organic solvents. In the case of the one-step water extraction, the total polyphenol content (TPC) varies from 0.55 to 0.62 Gallic acid equivalent (GAE) g/g in the extracts, depending on the temperature, whereas with the result of the sequential extraction with the organic solvents, the TPC content of the 40% (v:v) ethanol extracts ranges from 0.39 to 0.61 GAE g/g, depending on the temperature. The influence of the total polyphenol content and the total proanthocyanidin content on the antioxidant activity is shown. The antioxidant activity (IC50, mg/L) of the extracts obtained with the organic solvents in the (2,2-diphenyl-1-picrylhydrazyl) DPPH• test varies from 4.05 to 9.58, depending on the temperature in the range of 70–150 °C, respectively, while the results obtained with the deionized water showed promising results in the range of 6.33–7.36 in the temperature range of 70–150 °C, respectively. The extraction with the deionized water showed that approximately 90% of the substances in the extracts obtained with the organic solvents by sequential extraction are possible to obtain as deionized water extracts.

Morphological variability of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) cones in the context of seed extraction

In the paper generating curves given by fourth-degree polynomials were used to model the shape of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) cones from the Polish Forest Districts of Kołaczyce (one batch) and Opole (two batches), and to calculate the surface area and volume of individual cones. However, it was not possible to construct generalized equations for the surface area and volume of Douglas fir cones due to the high variability of empirical coefficients. The surface area and volume of the cones were also calculated from their length and diameter based on formulas for a cylinder and a barrel corrected by constants k1 and k2. The mean surface area of closed Douglas fir cones determined for the first, second, and third batch using the generating function was 4,348.4 mm2, 3,857.0 mm2, and 2,844.7 mm2, and the volume was 27,212.4 mm3, 21,012.9 mm3, and 12,844.4 mm3, respectively. The corresponding values calculated from the geometric formulas for solids were 4,332.0 mm2, 3,838.0 mm2, and 2,862.9 mm2 for the surface area and 27,366.0 mm3, 20,648.9 mm3, and 13,375.3 mm3 for the volume. The evaporation area of open cones was found to be five times greater than that of closed cones, with the difference being statistically significant. The outer and inner surfaces of scales taken from the middle segment of Douglas fir cones were photographed using a Quanta 200 scanning microscope (FEIC). The characteristic elements of scale morphology were evaluated by means of MultiScan Base software package. The outer and inner surfaces of Douglas fir scales were found to differ in some important ways, similarly as it has been reported in the literature for the Scots pine, silver fir, European larch, and black alder. The outer surface of scales is formed by thick-walled cells with marked protrusions, while the inner surface reveals cells with thin, frayed walls in the region adjacent to the seeds and wings. Knowledge of the geometry of Douglas fir cones and the morphology of their scales may be helpful in optimizing seed extraction parameters for those cones. Key words: seed extraction, model, shape curve, surface area, volume, scanning electron microscope

Influence of Extracts from Bark of Deciduous Trees on the Activity of the Amylolytic Enzyme - Alpha Amylase

The effect of water extracts obtained from bark of growing in Latvia and widely spread in Europe grey alder (Alnusincana), black alder (Alnusglutinosa) and aspen tree (Populustremula), on the amylase activity in human saliva was evaluated. The extracts were obtained using advanced ACE equipment and distilled hot water as a solvent. The total yields of extractives from bark were rather similar and varied from 16 % to 21 % based on dry bark. However, the content of proantocianidine and salicine derivatives used as diagnostic characteristic for evaluation of effect of extracts on activity of amylase – a glucose-polymers cleavage enzyme - differed significantly. The results of in-vitro tests realized using the model of human gastrointestinal pass have shown that the abovementioned extracts in micro dosages are able to increase significantly activity of amylase. However, this effect is dose dependent and when the dose is exceeded the opposite effect – inhibition of amylase activity - is observed. This effect is explained by increasing of proantocianidins component in the volume of the tested extract dose, because pure proantocianidins, isolated from grey alder bark significantly inhibited activity of amylase. The further investigation is necessary in order to estimate effective and safe dosages for application of extracts providing a guaranteed unambiguous effect of activation or inhibition of amylase activity.

Chemical Engineering for Improvement of the Efficiency of Microwave Energy Use in Processing of Plant Biomass

Combined coaxial-circular waveguide equipped with protective module allowing the transmission of microwave energy of three magnetrons with the output of 0.9 kW per each into the pressurized reaction chamber and capable of operating at temperatures of up to 250 °C and a pressure of up to 10 bars was designed and tested. Choke flange junction of the waveguide sections was used instead of contact flange connection. The developed waveguide construction allows to place the radio transparent partition inside the free space volume of a choke flange junction performing protection of emitters and summing of microwave energy of three magnetrons with an efficiency close to 100% that was proven by tests with fresh water as a microwave energy absorber. The extraction set-up equipped with the above-mentioned waveguide has demonstrated the stable and safety operation of the transmitting block and the accurate automatic control of the temperature and pressure inside the reaction chamber in the presence of a strong electromagnetic field. The construction of the microwave extraction set-up allows to use the impact of the combination of temperature and pressure on the cell wall, promoting the high rate isolation of secondary metabolites from biomass that was demonstrated by water extraction of black alder bark.

Tree Form of Juniper (Juniperus communis L.) in the Forests of the Vologda Region

Common juniper (Juniperus communis L.) is one of the most widespread undergrowth species in the forests of Russia. It has not only important silvicultural significance but is also widely used in economic activities. Numerous works of Russian and foreign authors are devoted to its study. The article shows the results of geobotanical and forest inventory studies of a unique area of pine plantation in the Kirillovskiy district of the Vologda region. In the second understorey of which tree-form common juniper grows. The stand was classified as high-density (relative fullness – 0.85) and low quality (quality class – V–IV). The total stock of trunk wood on the site is 280 m3/ha, including the stock of juniper wood – 28 m3/ha. The average diameter of juniper trunks is 14 cm, the average height is 11 m and the age is 180 yrs. This is several times higher than its usual parameters in other forests. A significant number of specimens of juniper (50 pcs/ha) are in the stage of drying out or have already died and represent dead wood of different years. The number of small and medium-sized juniper undergrowth is 1.5 ths pcs/ha or 62.5 % of the growing. Undergrowth of European spruce, downy birch and black alder is also found. The existing undergrowth is assessed as promising, but Scots pine undergrowth is missing. The ground cover is dominated by green and sphagnum mosses as well as shrubs of the Ericaceae and Vacciniaceae families. The study of such objects, extremely rare not only in the north of the European part of Russia, but also everywhere, is of great practical importance. It is also important for understanding the biology of the only representative of the Cupressaceae family that naturally grows here. The tree-form juniper in the pine plantation has survived and reached a size not typical for this species due to the inaccessibility of the site, the lack of fires and forest felling. Such forest areas should be identified, protected, and subjected to stationary research. For citation: Evdokimov I.V., Dobrynin A.P., Armeeva N.A. Tree Form of Juniper (Juniperus communis L.) in the Forests of the Vologda Region. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 201–209. DOI: 10.37482/0536-1036-2021-5-201-209

Investigation of antiparasitic activity of ten European tree bark extracts on Toxoplasma gondii and bioguided identification of triterpenes in Alnus glutinosa barks

Toxoplasmosis is a worldwide parasitosis that affects one-third of the population. People at risk, such as immunocompromised patients (AIDS, chemotherapy treatment) or fetuses (maternal-fetal transmission) can develop severe forms of the disease. The antiparasitic activity of extracts of different polarities ( n -heptane, MeOH, MeOH/H 2 O) of ten tree species endemics to temperate regions was investigated against Toxoplasma gondii infection in vitro . Our results showed that the n -heptane extract of the black alder ( Alnus glutinosa ) exhibited a significant antiparasitic activity without any cytotoxicity at the tested concentrations, with an IC 50 of up to 25.08 μg/mL and a selectivity index higher than 3.99. The chemical profiling of this extract revealed triterpenes as major constituents. The ability of commercially available triterpene (betulin, betulinic acid, and betulone) to inhibit the growth of T. gondii was evaluated and showed growth inhibition rates of 44%, 49%, and 99% at 10 μM, respectively.

Assessing a novel modelling approach with high resolution UAV imagery for monitoring health status in priority riparian forests

Background Black alder (Alnus glutinosa) forests are in severe decline across their area of distribution due to a disease caused by the soil-borne pathogenic Phytophthora alni species complex (class Oomycetes), “alder Phytopththora”. Mapping of the different types of damages caused by the disease is challenging in high density ecosystems in which spectral variability is high due to canopy heterogeneity. Data obtained by unmanned aerial vehicles (UAVs) may be particularly useful for such tasks due to the high resolution, flexibility of acquisition and cost efficiency of this type of data. In this study, A. glutinosa decline was assessed by considering four categories of tree health status in the field: asymptomatic, dead and defoliation above and below a 50% threshold. A combination of multispectral Parrot Sequoia and UAV unmanned aerial vehicles -red green blue (RGB) data were analysed using classical random forest (RF) and a simple and robust three-step logistic modelling approaches to identify the most important forest health indicators while adhering to the principle of parsimony. A total of 34 remote sensing variables were considered, including a set of vegetation indices, texture features from the normalized difference vegetation index (NDVI) and a digital surface model (DSM), topographic and digital aerial photogrammetry-derived structural data from the DSM at crown level. Results The four categories identified by the RF yielded an overall accuracy of 67%, while aggregation of the legend to three classes (asymptomatic, defoliated, dead) and to two classes (alive, dead) improved the overall accuracy to 72% and 91% respectively. On the other hand, the confusion matrix, computed from the three logistic models by using the leave-out cross-validation method yielded overall accuracies of 75%, 80% and 94% for four-, three- and two-level classifications, respectively. Discussion The study findings provide forest managers with an alternative robust classification method for the rapid, effective assessment of areas affected and non-affected by the disease, thus enabling them to identify hotspots for conservation and plan control and restoration measures aimed at preserving black alder forests.