Natural Stands Research Articles

Nutritional Assessment and Comparison of the Composition of Oil Extracted from Argan Nuts Collected from a Plantation and Two Natural Forest Stands of ARGAN Trees

Argan oil (AO), extracted from the argan tree’s fruits, is principally composed of mono-unsaturated fatty acids, polyphenols, tocopherols, and sterols. This unique chemical composition is likely to be responsible for its beneficial effects. The argan tree (Argania spinosa) grows endemically in the southwest of Morocco. This study aimed to evaluate the chemical composition of three types of argan oil from three geographical locations: argan oil extracted from argan nuts collected from a plantation (Casablanca, AOC) and two forest stands of argan trees growing naturally in their native environment of the south-west of Morocco ((regions of Essaouira (AOE) and Taroudant (AOT)). The composition of the three oils corresponds to the known composition of argan oil in terms of fatty acids and unsaponifiable fraction. The chemical analyses revealed that the argan oil extracted from the plantations (AOC) is significantly richer in linoleic acid, linolenic acid, and tocopherols compared to the oil from the two natural stands (AOE and AOT) of argan trees. These results suggest that it is possible to facilitate an assisted migration of the argan tree outside its natural area into sites exposed to sea spray without affecting the quality of its argan oil.

Genetic variability ofChamaerops humilis(Arecaceae) throughout its native range highlights two species movement pathways from its area of origin

AbstractThe European fan palm (Chamaerops humilis, Arecaceae) is the only native palm in continental Europe, providing ecosystem services that are hard to obtain from other species. However, its populations are declining in some areas due to anthropogenic effects including climate change. Knowledge of genetic variability among natural populations is needed to establish conservation plans, to prevent genetic contamination of native stands by cultivated germplasm and to exploit it as an ornamental species. However, information on the genetic similarities among C. humilis populations is scarce. The aims of this work were to study genetic structure in C. humilis using a set of specifically designed genetic markers and to highlight genetic similarities and their relationships with geographical proximity. We sampled 301 specimens from 42 natural populations throughout the distribution area and analysed these with ten di-, tri- and tetra-nucleotide simple sequence repeats. Relationships between genetic similarities and geographical distances were analysed and populations grouped according to a genetic, geographical or national clustering. We found lower variability in populations from the eastern half of the distribution, and this lower variability was accompanied by a stronger relationship between genetic differences and spatial proximity. In addition, we found that C. humilis probably showed two patterns of spread and further differentiation: one from Morocco to southern continental Spain and then to Portugal and the Balearic Islands, and one from Morocco to Algeria, Tunisia, Sicily and continental Italy. Populations from Sardinia and France showed similarities to those from Spain and Tunisia, respectively, and may have arisen from multiple colonization events. Our results support the hypothesis that isolation on large islands may have increased diversification of the species even if all populations shared the same founder. These results have important implications for both the ecological management and the conservation of the species.

Polna struktura pajasena (Ailanthus altissima (Mill.) Swingle) u zaštićenom prirodnom dobru "Bajfordova šuma" na području Beograda - osnova za biološku kontrolu širenja i plansku redukciju

Tree-of-Heaven (Ailanthus altissima (Mill.) Swingle) is an invasive tree species in Serbia that threatens the floristic biodiversity in natural stands and urban areas. It is a heliophyte with rapid growth in the initial phase of development and a well-expressed adaptability to different environmental conditions in open habitats. With early maturity and abundant fruiting almost every year, and the ability of seeds to be transported far from the maternal tree, the tree-of-heaven can rapidly colonize the stands (with disturbed stand structure) of other tree species. It is also a dioecious woody plant. If gender dimorphism of tree-of-heaven is used as a criterion for tree selection in thinning, it can be applied to affect the generative expansion of the species. Within the stand canopy closure, it can be used to influence the growth and survival of generative and vegetative offspring. Differentiation of fruit bearing-female and non-fruit-bearing-male trees is carried out during the flowering phase on the basis of its inflorescences. Selection of fruitbearing-female flowers is carried out during the whole year by checking for the presence of fruit and inflorescence petioles that are retained in the crown after the fruit shedding. Gender dimorphism of the species served as the basis for the gender structure determination in the protected natural area ,,Bajfordova šuma" in Belgrade. Out of 40.08 ha of the protected natural area, tree-of-heaven was recorded individually or in groups, in an area of 27.09 ha, with 131 sexually differentiated trees with diameters within the range of 5-74 cm and heights within the range of 5-21 m. Within the aforementioned number of trees, the share of female and male trees is almost equal, but varies spatially. The recorded female and male trees are the basis for monitoring, planned reduction and tree-of-heaven growing in a non-invasive form in the protected natural area ,,Bajfordova šuma"

新疆艾比湖胡杨凋落物与裸斑土壤代谢物差异比较

PDF HTML阅读 XML下载 导出引用 引用提醒 新疆艾比湖胡杨凋落物与裸斑土壤代谢物差异比较 DOI: 10.5846/stxb202102030358 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 绿洲生态重点实验室开放课题-胡杨冠下草本植物稀疏的机制研究(2020D04003) Comparison of soil metabolite differences between litter of Populus euphratica and bare spots in Ebinur Lake area, Xinjiang Author: Affiliation: Fund Project: Open Project of Key Laboratory of Xinjiang Uygur Autonomous Region-《Study on the Mechanisms of Herbs Sparsity under Populus euphratica Canopy》 (Grant number: 2020D04003). 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在干旱区荒漠胡杨疏林中,胡杨冠下存在草本植物极其稀疏的裸露斑块(简称裸斑)。为研究胡杨冠下裸斑形成化感机理,以裸斑内、外土壤以及冠下凋落物为研究对象,利用液相色谱-质谱联用技术对不同样本进行代谢组分析,使用PLS-DA鉴定并筛选各组代谢物差异,筛选出裸斑内、外土壤样本中差异显著的代谢物质及其代谢相关通路。研究结果显示,土壤样品中共鉴定出总代谢物质908种(615正,293负);凋落物样品中共鉴定出总代谢物质1291种(760正,531负)。通过筛选、注释并分类各组间差异显著的代谢物发现曲酸、微囊藻毒素、茶碱、辛二酸、花生四烯酸以及反式肉桂酸等化感物质相对定量值均为裸斑内显著大于裸斑外土壤;儿茶素、咖啡酸、吲哚、棕榈油酸、孜然醛、阿魏酸、反式肉桂酸、花生四烯酸、水杨醇以及香豆素等化感物质相对定量值均为凋落物样中显著大于土壤样品。以上胡杨潜在化感物质的积累可能增强植物的化感效应,导致胡杨冠下草本植物种子萌发及生长受到限制。 Abstract:The herbaceous plants are rare under the crown of the natural Populus euphratica stands (referred to as bare spots) in the arid Populus euphratica sparse forest area. To study the allelopathic formation mechanism of the bare spots under the Populus euphratica canopy, the soil inside and outside the bare spots and the litter under the canopy were used as the research objects in Ebinur Lake. We analyzed metabolomes of different samples using LC-MS technology, used PLS-DA to identify and screen metabolite differences in each group, and screened out significant differences in metabolites and their metabolic pathways in soil samples inside and outside of the bare spots. The results of the study showed that 908 total metabolites (615 positive and 293 negative) were identified in soil samples; a total of 1,291 total metabolites (760 positive and 531 negative) were identified in litter samples. By annotation and classification, it is found that the relatively quantitative values of allelochemicals such as Kojic acid, Microcystin, Theophylline, Suberic acid, Arachidonic acid and Trans-cinnamic acid were significantly higher in the bare spot than that in the soil under the tree canopy; In litter samples the relative quantitative values of allelochemicals such as Catechin, Caffeic acid, Indole, Palmitoleic acid, Cumin aldehyde, Ferulic acid, Trans-cinnamic acid, Arachidonic acid, Salicylic alcohol and Coumarin were significantly higher than that in soil samples. The accumulation of the above potential allelopathic substances in soil under Populus euphratica canopy and its litter may enhance the allelopathic effect of plants, leading to restrictions on the germination and growth of herb seeds under the Populus euphratica canopy. 参考文献 相似文献 引证文献

Typha latifolia resilience to high metal stress: Antioxidant response in plants from mine and flotation tailing ponds

Typha latifolia (cattail) forms natural stands in the transition zone of artificial flotation and mine tailings ponds and is contaminated with extremely high concentrations of metals. We assessed the absorption capacity of the plant, metal transfer to leaves, and the effects of elevated metal concentrations on antioxidant enzyme activities. Soil acidity, the pseudototal and available metal content of the substrate, and metal concentrations in plants were examined. The effects of elevated metal concentrations in plants on antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, glutathione reductase) were assessed. Cattails exhibited high metal accumulation levels in roots and a low transfer rate to the leaves. The effects of metal concentrations on antioxidant enzyme activities were found to depend on the type of enzyme, metal concentrations in the plant and their molar ratios, as well as on the pH of the substrate. High activities of antioxidant enzymes indicate increased generation of reactive oxygen species (ROS) and show that metal detoxification mechanisms are insufficient to restrain their toxicity. Pronounced resistance to elevated metal concentrations and high efficiency in metal phytostabilization show that cattail could be a valuable component of biological treatment systems for removing metals from multi-metal and heavily contaminated substrates in the pH range from ultra-acidic to neutral.

Irrigated urban trees exhibit greater functional trait plasticity compared to natural stands.

Urbanization creates novel ecosystems comprised of species assemblages and environments with no natural analogue. Moreover, irrigation can alter plant function compared to non-irrigated systems. However, the capacity of irrigation to alter functional trait patterns across multiple species is unknown but may be important for the dynamics of urban ecosystems. We evaluated the hypothesis that urban irrigation influences plasticity in functional traits by measuring carbon-gain and water-use traits of 30 tree species planted in Southern California, USA spanning a coastal-to-desert gradient. Tree species respond to irrigation through increasing the carbon-gain trait relationship of leaf nitrogen per specific leaf area compared to their native habitat. Moreover, most species shift to a water-use strategy of greater water loss through stomata when planted in irrigated desert-like environments compared to coastal environments, implying that irrigated species capitalize on increased water availability to cool their leaves in extreme heat and high evaporative demand conditions. Therefore, irrigated urban environments increase the plasticity of trait responses compared to native ecosystems, allowing for novel response to climatic variation. Our results indicate that trees grown in water-resource-rich urban ecosystems can alter their functional traits plasticity beyond those measured in native ecosystems, which can lead to plant trait dynamics with no natural analogue.

Floristički sastav bukovih staništa pet godina nakon čiste seče i sindinamika biljnih zajednica na sečinama u Timočkom šumskom području

In the winter of 2014/2015, an impactful natural disaster hit the eastern region of Serbia, leading to substantial forest tree damage due to ice breaks and falls. This catastrophe resulted in the near-complete destruction of artificial conifer stands established on beech sites, and varying degrees of damage to natural stands. In response, approximately 2000 hectares of land had to be clear-cut, inducing significant ecosystem transformations that may have altered the floristic composition. This study involved the inventarisation of vascular flora within the clear-cut areas, which was then compared to the floristic composition at similar site condition on location "Vinatovača" beech primeval forest. The key objectives of this research were to assess the extent of degradation experienced by natural beech sites and explore the prospects and courses for establishing natural, indigenous forest ecosystems through natural succession. Following clear-cutting, beech sites exhibited notably greater floristic diversity in contrast to the natural beech primeval forests. Considerable area of beech sites turned into meadows or were weed covered. The study identified 176 taxa of vascular flora on the clearcut sites (107 taxa in the premival forest). In addition to plants from mesophilic beech communities, plants from the aliance of thermophilic communities are also present. The identified plants were categorised into two groups: Pteridophyta, with only 2 species, and Spermatophyta, encompassing 174 species (in contrast, the premival forest had 10 species of Pteridophyta and 97 species of Spermatophyta). The Spermatophyta plants were further classified into two classes: Dicotyledons, represented by 149 species, and Monocotyledons, represented by 25 species (in the premival forest, Dicotyledons accounted for 76 species, and Monocotyledons 21 species).

Flowering variation of a young Scots pine (Pinus sylvestris L.) clonal seed orchard based on years

In this research, it was tried to determine the male and female flower yield in young clonal seed orchard (YCSO) with the expectation that the flowering variation would be decreased among years, clones and ramets thanks to aging. The measurements were made on five ramets for each of 30 clones in four years in a Scots pine (Pinus sylvestris L.) seed orchard. The orchard, originated from the Araç-Dereyayla seed stand in Kastamonu, was established in 1995 by using two years-old grafts in Kastamonu, located northwestern Black Sea region of Türkiye. The examined characters were number of male (NMF), and female flowers (NFF). When the four-year of data from the YCSO was evaluated, mean values from NMF and NFF among the clones were significant and variation of the ramets was high. The coefficient of variation (Cv) from the NMF of the clones gradually decreased with the subsequent years (Cv2006=147.54%, Cv2010=59.04%), whereas the Cv in the NFF did not show any decrease with the same years. In addition, there were significant differences among the years as to the NMF, and NFF. Over the four years, the NMF was significantly lower than that of the NFF, and even in some years the NFF was doubled compared with the NMF (NMF2006=65.9; NMF2007=314.29; NMF2008=427.85; NMF2010=115.73 & NFF2006=123.80; NFF2007=604.68; NFF2008=394.62; NFF2010=196.72). Abundant flowering periods seen in natural stands were also observed in the male and female flowers of the clonal seed orchards. For the studied seed orchard high variation both among the clones and the ramets indicates the high selection capacity in the breeding programs. The bigger variation among the ramets confirm that the genotypes have responded against the heterogeneity of growing area in seed orchard or the ramets have not reached the optimum flowering period. These results have shown the importance of the practices which increase the flowering yield and effectiveness of fertilization in YCSO.

Varijabilnost i diskriminacijska moć anatomskih parametara kod linija polusrodnika juglans regia podrijetlom iz prirodnih sastojina u Đerdapskoj klisuri, Srbija u rasadničkim uvjetima

This paper presents analysis of anatomical parameters of leaves in Juglans regia half-sib lines from natural stands in Đerdap Gorge in Serbia. Thirty-five half-sib lines were examined, designated according to the number of their mother trees from R1-R35. Twenty measured and derived anatomical parameters were examined, describing stomatal and leaf blade cross-section traits. According to Hierarchical analysis of variance, variation of the majority of characters describing stomatal properties were significantly affected by effect of half-sib lines. The effect of variation between plants within half-sib lines was significant for all examined stomatal traits. However, in cross-section characters, the effect of differences between half-sib lines was significant only for thickness of spongy mesophyll (SL). The discrimination model with seven selected traits achieved 60.5% of correct allocation, while the correct allocation of the model with all 20 examined traits was 81.6%. According to the results of stepwise discriminant analysis, the most powerful trait in discrimination of these half-sib lines were stomatal aperture width/stomatal aperture length ratio (Wb/La) and stomatal aperture length/ stomata guard cell length ratio (La/LA). Presented results strongly support implementation of stomatal and cross-section leaf traits in further studies that would deal with description of variability of Juglans regia.

Safeguarding sandalwood: A review of current and emerging tools to support sustainable and legal forestry

Societal Impact StatementSandalwood and other high value tree species are under significant threat from illegal harvest. Illegal logging is an increasing problem contributing to deforestation, biodiversity loss, human rights abuses and funding transnational crime. Successful prosecution of illegal logging is hindered by a lack of methods to provide evidence of the origin of timber. New analytical techniques have been developed to trace timber back to its source. These methods, together with the establishment of sustainable sources of forest resources, can help protect vulnerable species by providing evidence to prosecute illegal harvest and ensure that commercially available forest products come from sustainable sources.SummarySandalwood is highly valued for its fragrant oil and has a long history of cultural and economic importance in many regions of the world. Historical overharvest and poor management have depleted natural populations of sandalwood, which are slow to regenerate. The increasing establishment of plantation sandalwood creates an alternative resource for the sandalwood industry while potentially relieving harvesting pressure on natural stands. Due to the high demand for sandalwood, remaining wild populations are still under threat from illegal logging and methods to identify the source of harvested sandalwood are needed. Laws and regulations aimed at preventing illegal harvest and possession of sandalwood have been put in place but cannot be enforced without the forensic tools to independently verify claimed origin or product quality. The high value of sandalwood combined with the difficulties in enforcing illegal logging laws makes these species particularly vulnerable to poaching. There is an immediate need to develop tools that can identify illegally sourced and adulterated sandalwood products. This paper reviews the current and developing scientific tools that can help identify and control illegal activity in sandalwood supply chains and provides recommendations for future research. Topics include isotope and DNA analysis for tracing illegally harvested sandalwood, chemical profiling for quality control of sandalwood oils, network and policy development to establish a framework for future regulation of the sandalwood trade.

Table Mountain Pine (Pinus pungens): Genetic Diversity and Conservation of an Imperiled Conifer

Abstract Table Mountain pine (Pinus pungens Lamb.) is an imperiled tree species endemic to the southern and central Appalachian Mountains. Generally reliant on fire for regeneration, its fragmented but widespread distribution has declined in recent decades. We quantified the genetic diversity of 26 populations across the range of the species using data from seven highly polymorphic simple sequence repeat (SSR) loci. The species was relatively inbred whereas differentiation among populations was relatively low. Differentiation was significantly but weakly associated with geographic distance among populations. We detected minor genetic differences between northern and southern seed collection zones established based on climate similarity. We conducted a series of simulations using SSR data from 498 seedlings, grown from seed collected from five natural stands of Table Mountain pine, to assess the genetic consequences of different strategies for deploying collected seed in ex situ conservation plantings. Results indicated that reducing the number of families in a planting would not substantially affect the conservation of common alleles but would affect the representation of rare alleles and overall allelic richness. These findings add to our limited knowledge of genetic variation across the distribution of this rare conifer and offer some guidance for its effective genetic conservation.

Influence of Soil Nutrients, Tree Age, and Sandalwood Provenances on Sandalwood Oil Yield and Quality

East African Sandalwood (Osyris laceolata) is an important tree species used in perfumery and pharmaceutical industries. In Kenya, the tree is illegally poached and smuggled mostly to India as a substitute for Asian sandalwood. Therefore, there is a need to domesticate E. A. sandalwood to ease pressure on natural stands. The aim of this study is to determine ecological factors influencing Osyris oil yield and quality to guide the selection of provenances for on-farm domestication. Soil and woody samples were obtained from 12 provenances and used for soil and oil analysis, respectively. The results showed that only tree age significantly influenced the oil yield (r = 0.31, p = 0.04 ). The GC-MS quality results recorded nine common and most abundant compounds across the study sites. These were Z-alpha-trans-bergamotol, alpha bisabolol, lanceol cis, beta bisabolene, alpha santalol, beta santalol, cis-alpha-copaene-8-ol, isopropyl myristate, and isopropyl palmitate. Baringo and Mbooni provenances had the highest number of compounds (8), followed by Homabay (7) while the majority (Chyulu, Kitui, Loita, Maralal, Marsabit, Muranga, and Narosura) had six and Ol Donyo Sabuk and Namanga had the least (5). The species diversity is therefore important for breeding, domestication, and conservation purposes.

Ecological Aspects of the Analysis of the Age Structure of the Stand of the National Park “Buzuluksky Bor”

The forests of the steppe Trans-Urals cover a small area and are represented to a greater degree by island forests, birch outlier and inundable poplar forests. However, it is difficult to overestimate their bioecological, habitat forming, soil-fixing, protective and recreational functions. Currently, due to various forest growth conditions and forestry operations, in natural and artificial forest stands, there are processes of shrinking of the stand, epiphytoxics of the stand with harmful insects and fungal diseases, an increase in the proportion of overmature stands, which worsen the general condition of the forest, lead to the development of outbreaks of diseases and create an inflammability. The tree plantations Buzuluksky Bor National Park are exposed to periodic droughts, high temperatures in spring and summer, fires in large areas, diseases, as well as continuous logging carried out in the past, which leads to a change in the structure of the stand. The article provides a history of the bor formation, which in the process of its formation was undergone serai change, the influence of various both positive and negative factors, which can be attributed to an anthropogenous factor. An analytical analysis of the changes in the forest fund of the national park Buzuluksky Bor National Park because of the use of logging of the main use and the impact of the pyrogenic factor is given. Changes in the area of plantings of individual species by years of forest management are also presented. The optimal age structure is determined, the value of the normative distribution of the areas of plantings for each kind of wood is calculated. Conservation and restoration of forest territories of the steppe zone, in particular Buzuluksky Bor National Park, the productive capacity of tree plantations, continuing of protective functions, as well as biodiversity and their contribution to global ecological processes are currently the task of prime importance and criterion for sustainable management of forest resources.

Modelling the stand dynamics after a thinning induced partial mortality: A compensatory growth perspective.

With increasing forest areas under management, dynamics of managed stands have gained more attention by forest managers and practitioners. Improved understanding on how trees and forest stands would respond to different disturbances is required to predict the dynamics of managed stand.s. Partial mortality commonly occurs in stand development, and different response patterns of trees and stands to partial mortality would govern stand dynamics. To investigate the possible response patterns using existing knowledge of growth and yield relationships, we developed TreeCG model, standing for Tree's Compensatory Growth, a state-dependent individual tree-based forest growth model that simulates the compensatory growth of trees after experiencing a partial mortality. The mechanism behind the simulation is the redistribution of resources, including nutrients and space, freed from died trees to surviving trees. The developed new algorithm simplified the simulations of annual growth increments of individual trees over a long period of stand development. The model was able to reproduce the forest growth patterns displayed in long-term precommercial thinning experiments. The simulated forest growth displayed the process of compensatory growth from under compensation, to compensation-induced-equality, and to overcompensation over time. Our model can simulate stand growth trajectories after different partial harvest regimes at different times and intensities, thus support decisions in best partial harvest strategies. This generic model can be refined with given tree species and specific site conditions to predict stand dynamics after given partial mortality for any jurisdictions under management. The simulation reassembles growth trajectories of natural stands when no thinning is conducted.

THE CYPRESS JEWEL BEETLE <i>LAMPRODILA FESTIVA</i> (LINNAEUS, 1767) (COLEOPTERA: BUPRESTIDAE) - A REAL THREAT TO THE RELICT JUNIPER FORESTS OF THE BLACK SEA COAST OF THE CAUCASUS

Here are presented new materials on the distribution of the Cypress Jewel Beetle Lamprodila ( Palmar ) festiva , first discovered in natural stands оf relict juniper forests in the vicinity of the villages Sukko and Bolshoi Utrish in the Abrau Peninsula of the Black Sea coast of the Caucasus.

Variability of soil properties with fire severity in pine forests and reforested areas under Mediterranean conditions

Abstract It is well known how fires affect the properties of forest soils depending on its severity. A better understanding of the magnitude of these impacts is essential to setup effective management actions after fire against the losses of soil and biodiversity. However, physical, chemical and biological processes in burnt soils are complex, resulting in a diversity of fire-induced changes, as acknowledged in many literature studies. Moreover, these changes may be even variable between natural forests and reforested areas. This study explores the changes in the most important soil properties with fire severity, from low to high. The main chemical parameters of soils were measured after field sampling in different pine forests (burnt natural stands, reforested areas as well as unburnt sites) of Castilla La Mancha (Central Eastern Spain). In comparison to the unburnt soils, the investigation has shown in the burnt areas: (i) no evident changes in soil pH at all fire severities, except in natural stands burnt at a very high severity (showing an increase of about 10%); (ii) increases in the organic carbon content (by about 70%) of soils burnt at a moderate fire severity under both forest ecosystems, and in reforested areas at very high fire severities (+95%); (iii) small differences in the nitrogen content of soil, except for a significant increase measured in soils burnt at an moderate fire severity under both the natural pine stand and reforested area (about +300%); (iv) a limited variability of the phosphorous content in the soil, with only an increase in soils under natural pine stands burnt at moderate fire severity (by 250%); (v) increases in magnesium and potassium contents in soils burnt at the highest fire severities for both land conditions, and decreases in calcium content in reforested areas burnt at the highest severity. Due to some negative impacts (increase in pH and decrease in organic carbon), the implementation of post-fire management actions at natural pine stands burnt at the highest fire severity should be a priority over reforested areas. Overall, this study did not show a straightforward pattern between soil properties, fire severity and land condition. This means that other parameters (for instance, the hydrological properties of soils) that were not explored in this investigation could have played an important role, and therefore must be taken into consideration when defining post-fire management actions.

Norway spruce phenotype variability determined by needle anatomy in Bohemian Forest compared to other regions of the Czech Republic

Young trees (saplings) of the Norway spruce (Picea abies [L.] Karst.) regenerating populations were analysed on 7 plots in the Šumava Mts. (Bohemian Forest), on 5 plots in the Jeseníky Mts. (Eastern Sudetes), and 1 plot in the Krkonoše (Giant Mts.). All 13 plots were located at the forest altitudinal (vegetation) zones of natural Picea abies stands. Each selected tree was characterized by microscopic features of the first-year needles. The free-hand needle cross-sections were prepared from three needles of each tree and measured by digital microphotos. The following needle characteristics were measured: width, thickness, and vascular bundle diameter. Each population was described by variability of these parameters. Populations were classified based on the data set. Two artificially planted populations were most different. Populations resulting in natural stands have different phenotype variability, possibly as a result of the parent stand history: two extreme examples are Eustaška locality (Jeseníky Mts.) with no known disturbance, and Trojmezí locality (Šumava Mts.), where wind and bark beetle disturbances were repeatedly recorded.

Specificity of Individual Response Radial Increment of Scots Pine in the Voronezh Biosphere Reserve on the Differentiated Forest Conditions.

The purpose of our study was to assess the individual variability of the response to climatic conditions of the radial increment of Pinus sylvestris L. trees aged 100-140 years. The studied pine stand grows in the conditions of a site with a heterogeneous microrelief in the Voronezh Reserve. The calculated coefficients of synchronicity and correlation of radial increment of a sample of individual Scots pine trees (wood cores). It has been established that in the radial increment of pine trees in the Voronezh Reserve, there is a significant diversity in the reflection of the climatic signal, which, as a rule, manifests itself in certain years that are not extreme in terms of climatic conditions. The reasons for the differentiated reaction of trees to climate are the differentiated conditions of the microrelief, and also, probably, the genetic diversity of forest stands. In natural stands there are individual trees showing very low values of synchronicity coefficients (GLK, %) or correlation coefficients (CC, %) with stand average values. Intrapopulation differences in the response of pine forest stands to fluctuations in climatic factors are one of the forms of protective mechanisms for the survival of a species that have developed as a result of evolutionary development. As our study showed, intrapopulation differences are large in stands of natural origin and not subject to anthropogenic impacts.

Mortality and basal area growth following precommercial thinning in stands affected by Armillaria, Laminated and Tomentosus root diseases in southern British Columbia

AbstractPrecommercial thinning aims to reduce the density of immature stands to stimulate growth of well‐spaced crop trees of preferred species and free from defects and disease. The chronic persistence of Armillaria, Laminated and Tomentosus root diseases in coniferous forests of British Columbia, Canada may offset potential gains in timber yield of commercially important tree species by creating stumps that the fungi utilize as an energy source to infect neighbouring trees. In juvenile plantations and naturally regenerated stands in six biogeoclimatic (BEC) zones with evidence of root disease caused by Armillaria ostoyae (8 sites), Coniferiporia sulphurascens (2 sites) or Onnia tomentosa (1 site), five of ten 20 m square plots per site were randomly selected for thinning to British Columbia Ministry of Forests specifications. Crop tree diameter at breast height and mortality from all causes were recorded at establishment and periodically thereafter up to 19 years post‐thinning. Logistic regression analysis of mortality rates showed significant differences among root disease pathogens, between planted and natural stands, and among ecological zones. Yet over all sites, differences between thinned and control plots were not significant. At the final assessment, crop tree basal area was higher in thinned than in control plots at 10 of 11 sites. Root disease, including infected and dead trees and other lethal biotic and abiotic agents, reduced potential yield in both treatments (thinned and control). At several Armillaria sites, mortality was slightly to substantially higher in thinned than in control plots, suggesting that thinning can increase the amount and potential of inoculum which may continue to adversely impact productivity of those stands. Recommendations for silvicultural management of the three root diseases are discussed.

Simultaneous component analysis as an interesting preliminary data analysis method in GC-MS – An example of headspace screening of Polish grasses

Abstract70 species of grasses family (Poaceae), coming from genera: Agrostis, Alopecurus, Anthoxanthum, Apera, Arrhenatherum, Avena, Brachypodium, Briza, Bromus, Calamagrostis, Corynephorus, Cynosurus, Dactylis, Danthonia, Deschampsia, Digitaria, Echinochloa, Elymus, Eragrostis, Festuca, Glyceria, Helictotrichon, Hierochloe, Holcus, Hordeum, Koeleria, Leymus, Lolium, Milium, Molinia, Nardus, Panicum, Phalaris, Phleum, Phragmites, Poa, Saccharum and Setaria, collected mostly from natural stands in Poland during 2020 season, were subjected to GC-MS fingerprinting of headspace volatile fraction above dried material. Obtained mass spectrometry data were analyzed by means of principal component analysis (PCA) and hierarchical cluster analysis (HCA). Five species: Glyceria maxima (Hartm.) Holmb., Lolium multiflorum Lam., Hordeum jubatum L., Bromus tectorum L. and Bromus secalinus L. were identified as outliers, which is consistent with our earlier analysis by thin layer chromatography. These species deserve further look and their outliance is orthogonal to coumarin content, which was independently observed for odorant species of grasses.