Seasonal changes in the pigment composition of needles of representatives of the genus spruce in the Nizhny Novgorod region

Изучали таксационные показатели лесных культур лиственницы Сукачева, заложенных в 1986 г. на юго-западной границе естественного распространения вида в Сергачском межрайонном лесничестве Нижегородской области. Координаты первого участка N 55.541378, E 45.471119; второго – N 55.541388, E 45.471125. Получена оценка эффективности их создания в указанном регионе. Методологической основой рабочих методик служил принцип единственного логического различия. Работа выполнялась полевым стационарным методом. Характеристика культур лиственницы давалась по результатам натурного обследования. Пробные площади закладывали в соответствии с действующим отраслевым стандартом. Подтверждена благоприятность лесорастительных условиях для естественного произрастания лиственницы Сукачева и широкие возможности интродукции близкородственных видов. Обнаружена неодинаковая изменчивость таксационных показателей. В частности, по диаметру ствола и его высоте она незначительна и отнесена преимущественно к низкому уровню: на первом участке 14,21% и 11,34%; на втором – 17,11 и 9,16% соответственно. По другим признакам изменчивость выше (чаще средний и повышенный уровень) и в ряде случаев достигает высокого (объем ствола) и очень высокого (коэффициент асимметрии кроны) уровня. Зафиксированы существенные различия между участками лесных культур по большинству таксационных показателей, подтвержденные дисперсионным анализом. Эффект их влияния на общий фон фенотипической дисперсии неодинаков. По диаметру ствола он минимален и составил 6,68±1,37%. Наибольшие оценки получены по расстоянию до первого живого сучка – 30,42±1,05%. Определено, что лесные культуры лиственницы Сукачева, созданные в Нижегородской области, достигая к возрасту 34 высоты 14 – 15 м, формируют насаждения первого класса бонитета. We studied the taxation indicators of forest crops of Sukhdev larch, laid in 1986 on the south-western border of the natural distribution of the species in the Sergachsky interdistrict forestry of the Nizhny Novgorod region. The coordinates of the first section are N 55.541378, E 45.471119; the second section is N 55.541388, E 45.471125. An assessment of the effectiveness of their creation in the specified region was obtained. The methodological basis of the working methods was the principle of the only logical difference. The work was carried out by the field stationary method. The characteristics of larch crops were given based on the results of a field survey. The test areas were laid in accordance with the current industry standard. The favorable forest conditions for the natural growth of Sukachev larch and the wide opportunities for the introduction of closely related species were confirmed. Unequal variability of taxation indicators was found. In particular, in terms of trunk diameter and height, it is insignificant and is mainly attributed to the low level: in the first section, 14.21% and 11.34%; in the second-17.11 and 9.16%, respectively. According to other signs, the variability is higher (more often the average and increased level) and in some cases reaches a high (trunk volume) and very high (crown asymmetry coefficient) level. Significant differences between forest crop plots were recorded in most of the taxation indicators, which were confirmed by the analysis of variance. The effect of their influence on the general background of the phenotypic variance is not the same. By the diameter of the trunk, it is minimal and amounted to 6.68±1.37%. The highest estimates were obtained for the distance to the first live knot – 30.42±1.05%. It is determined that the forest cultures of Sukachev larch, created in the Nizhny Novgorod region, reaching a height of 14-15 m by the age of 34, form plantings of the first class of bonitet.

Comparative Metagenomic and Metabolomic Profiling of Rhizospheres of Panax notoginseng Grown under Forest and Field Conditions

The present study investigated the potential changes in the structure of bacterial communities and their functional profiles in the rhizospheres of Panax notoginseng cultivated under field (CK) and pine forest conditions (T). The rhizospheres of two-year-old P. notoginseng plants were used to extract DNA for metagenomic sequencing and metabolites for metabolomic profiling. The results revealed a higher root weight (p < 0.05) in plants grown under the forest than CK. The rhizospheric bacterial community comprised mainly three dominant phyla including Acidobacteria, Proteobacteria, and Candidatus rokubacteria which accounted for 75% of the total microbial population. Among them, Acidobacteria was the most abundant bacterial taxa, accounting for 42.4% and 40.4% of the total populations in CK and T, respectively. Relative abundances of bacterial genera revealed that Bradyrhizobium, Candidatus koribacter and Edaphobacter, were the dominant genera in both groups. Comparatively, a higher Proteobacteria to Acidobacteria ratio was observed in forest rhizospheres than in field conditions. Candidatus Rokubacteria and Candidatus nitrostelea were identified as biomarker taxa in forest rhizospheres, while the same could be said for taxa belonging to betaproteobacteria and gammaproteobacteria, Burkholderiales and Verrucomicrobia for field rhizospheres. No differential metabolite contents were observed between the two rhizosphere groups, indicating no adverse effects of P. notoginseng cultivation on the soil quality under forest plantation.

Fumigation of Insect-Infested Wooden Logs by EDN Using Two Scenarios of Plastic Tent-Tarpaulin Sealing: Wooden Logs Stacks Placed on Bottom Plastic Sheets or Directly on Underlying Soil

Recently, the largest bark beetle calamity (Ips typographus) of the last 100 years has erupted in Central Europe, including the Czech Republic. This calamity may threaten the sustainability of growing large areas of monoculture Norway spruce (Picea abies) in this area. Limited economically feasible physical and chemical pest control options are available to prevent the bark beetle spread. However, from these options, only mechanical bark removal or gas-insecticide fumigation result in instant deactivation of all pest stages throughout the entire stack of stored logs. Due to the ban on the use of methyl bromide (MeBr) for the fumigation of log piles under tarpaulin, the adaptation of the phyto-quarantine method EDN to the destruction of I. typographus bark beetles in harvested wood directly in forests was newly proposed in the Czech Republic. The methodical experience with fumigation of the harvested logs, however, was only available for wood fumigation in chambers or in tent-tarps fumigation placed on paved (concrete/asphalt) surfaces mainly in ship harbors. Prior to the introduction of the new EDN fumigation method of bark beetle infested wood stored directly in the forests, it was initially unclear whether it was necessary to use or neglect bottom sheets to optimize exposure and maximize Ct products for the permitted fixed initial dose (50 g·m−3). Therefore, the initial validation pilot trials were aimed at the estimation and comparison of EDN temporal dynamics and Ct products under real forest conditions and two fumigation scenarios: Wooden log pile placed on bottom plastic sheets or directly on soil without the bottom sheets. Field trials were performed under both identical as well as different environmental conditions. In addition, they revealed that the concentration decrease was significantly faster and Ct products were significantly lower in the case of trials without the bottom sheets. The experiments indicated high EDN sorption by the uncovered soil under the tent. Quantitatively, the average Ct product was 4.8 (identical conditions) and 3.7 (different conditions) times lower in EDN trials without the bottom sheets when compared to the use of bottom sheets. The initial field-forest fumigation validation trials indicated a necessity to carry out EDN fumigation under tent-tarps also using bottom sheets, although this fumigation procedure increases the labor-demands to some extent. Based on the presented results and additional data, the Czech authority issued for the EDN plant protection product an authorization for the limited and controlled use of wooden logs. Therefore, this work became the basis of the historically and first officially authorized use of any fumigant for pest control under commercial forest conditions.

Can standardisation of the unit costs of wood extraction be applied in the financial system of the State Forests?

The paper presents a method for grouping forest districts that are characterised by similar natural and forest conditions and the results of standardisation of wood extraction costs for forest districts and regional directorates of the State Forests. The adopted standard costs referred to the costs which determine the reasonable level of costs necessary to perform a specific management task in the given natural, forest and economic conditions of forest districts. Forest districts were grouped based on the forest habitat types and the land diversity index (Wtri), which were determined with statistical methods to be the factors that shape wood extraction costs. In order to determine the standard unit costs of wood extraction, source materials for the year 2017 have been used, which had been obtained from the State Forests Information System for all forest districts in the country. The method of standardising wood extraction unit costs on the basis of forest district groups with similar natural and forest conditions was reduced in 2017 to the designation of eight uniform forest district groups in terms of forest habitat type structure and Wtri index. Standard unit costs of wood extraction, determined on the basis of the methodology presented in the paper, should be used in the State Forests’ financial system.

Comparison of Low-Cost Commercial Unpiloted Digital Aerial Photogrammetry to Airborne Laser Scanning across Multiple Forest Types in California, USA

Science-based forest management requires quantitative estimation of forest attributes traditionally collected via sampled field plots in a forest inventory program. Three-dimensional (3D) remotely sensed data such as Light Detection and Ranging (lidar), are increasingly utilized to supplement and even replace field-based forest inventories. However, lidar remains cost prohibitive for smaller areas and repeat measurements, often limiting its use to single acquisitions of large contiguous areas. Recent advancements in unpiloted aerial systems (UAS), digital aerial photogrammetry (DAP) and high precision global positioning systems (HPGPS) have the potential to provide low-cost time and place flexible 3D data to support forest inventory and monitoring. The primary objective of this study was to assess the ability of low-cost commercial off the shelf UAS DAP and HPGPS to create accurate 3D data and predictions of key forest attributes, as compared to both lidar and field observations, in a wide range of forest conditions in California, USA. A secondary objective was to assess the accuracy of nadir vs. off-nadir UAS DAP, to determine if oblique imagery provides more accurate 3D data and forest attribute predictions. UAS DAP digital terrain models (DTMs) were comparable to lidar DTMS across most sites and nadir vs. off-nadir imagery collection (R2 = 0.74–0.99), although model accuracy using off-nadir imagery was very low in mature Douglas-fir forest (R2 = 0.17) due to high canopy density occluding the ground from the image sensor. Surface and canopy height models were shown to have less agreement to lidar (R2 = 0.17–0.69), with off-nadir imagery surface models at high canopy density sites having the lowest agreement with lidar. UAS DAP models predicted key forest metrics with varying accuracy compared to field data (R2 = 0.53–0.85), and were comparable to predictions made using lidar. Although lidar provided more accurate estimates of forest attributes across a range of forest conditions, this study shows that UAS DAP models, when combined with low-cost HPGPS, can accurately predict key forest attributes across a range of forest types, canopies densities, and structural conditions.

APPLICATION OF HERBICIDES IN THE CONTROL OF THE INVASIVE SPECIES HERACLEUM SOSNOWSKYI MANDEN. (SOSNOWSKY’S HOGWEED) IN FORESTRY

A representative of the family Apiacea, Sosnowsky's hogweed ( Heracleum sosnowskyi Manden.) previously cultivated as a fodder plant and now occupying vast territories along roads and railways, in and near settlements, uncultivated agricultural lands, on farms and in many other areas, poses a serious threat to human health. On these lands, an active eradication campaign has been going on for over 15 years. This invasive species also spreads actively on the lands of the forest fund including plantations, felling sites, young stands of natural origin, clearings and hayfields, forest stands of different ages with a small basal area, and in the most productive forest conditions. As a result, in forest plantations growth of woody plants (primarily of coniferous species) is inhibited, their death is observed, and environmental, aesthetic and industrial damage increases due to the growth and dominance of Sosnowsky's hogweed. As a result of field experiments in the Leningrad Region, a high effectiveness of a number of modern herbicides (Roundup, Anchor-85, and Magnum) for control of Sosnowsky's hogweed and other unwanted herbaceous vegetation, as well as their selectivity in relation to pine and spruce, has been demonstrated.