scholarly journals The role of root system in silver birch (Betula pendula Roth) dieback in the air-polluted area of Krušné hory Mts

2012 ◽  
Vol 49 (No. 5) ◽  
pp. 191-199 ◽  
Author(s):  
O. Mauer ◽  
E. Palátová

120 root systems and trunks of 20 years old birch trees and 60 root systems and trunks of 15 years old birch trees affected by defoliation and with no visual symptoms of damage were analyzed in the air-polluted area of Krušné hory Mts. In the given area, birch develops a superficial or anchoring root system of circular shape. A greater effect of defoliation was recorded in trees with the superficial root system. The defoliation was in correlation with the extent of bole rot, root system rot and rooting depth. The proportion of root system branches infested by rot increased with increasing defoliation. Dominating fungi on roots were Armillaria gallica and Armillaria ostoyae. The degree of defoliation was directly proportional to the extent of bole rot induced by Trametes confragosa and Armillaria gallica, infecting frost ribs in the trunks. Extensive defoliation was recorded if more than 25% of peripheral tissues of the trunk and over 15% of root system branches were infected by rot. The defoliated trees showed a marked loss of fine roots, impaired longevity of fine roots and a change of ectomycorrhiza into ectendomycorrhiza.

1975 ◽  
Vol 5 (1) ◽  
pp. 109-121 ◽  
Author(s):  
D. C. F. Fayle

Extension of the root system and stem during the first 30 years of growth of plantation-grown red pine (Pinusresinosa Ait.) on four sites was deduced by root and stem analyses. Maximum rooting depth was reached in the first decade and maximum horizontal extension of roots was virtually complete between years 15 and 20. The main horizontal roots of red pine seldom exceed 11 m in length. Elongation of vertical and horizontal roots was examined in relation to moisture availability and some physical soil conditions. The changing relations within the tree in lineal dimensions and annual elongation of the roots and stem are illustrated. The development of intertree competition above and below ground is considered.


2010 ◽  
Vol 36 (4) ◽  
pp. 149-159
Author(s):  
Susan Day ◽  
P. Eric Wiseman ◽  
Sarah Dickinson ◽  
J. Roger Harris

Knowledge of the extent and distribution of tree root systems is essential for managing trees in the built environment. Despite recent advances in root detection tools, published research on tree root architecture in urban settings has been limited and only partially synthesized. Root growth patterns of urban trees may differ considerably from similar species in forested or agricultural environments. This paper reviews literature documenting tree root growth in urban settings as well as literature addressing root architecture in nonurban settings that may contribute to present understanding of tree roots in built environments. Although tree species may have the genetic potential for generating deep root systems (>2 m), rooting depth in urban situations is frequently restricted by impenetrable or inhospitable soil layers or by underground infrastructure. Lateral root extent is likewise subject to restriction by dense soils under hardscape or by absence of irrigation in dry areas. By combining results of numerous studies, the authors of this paper estimated the radius of an unrestricted root system initially increases at a rate of approximately 38 to 1, compared to trunk diameter; however, this ratio likely considerably declines as trees mature. Roots are often irregularly distributed around the tree and may be influenced by cardinal direction, terrain, tree lean, or obstacles in the built environment. Buttress roots, tap roots, and other root types are also discussed.


Author(s):  
Roger W. Ruess ◽  
Ronald L. Hendrick

The patterns of production described in Chapter 11 tell only half of the story about boreal forest production because a large proportion of the carbon (C) acquired by plants is allocated belowground in ways that have traditionally been extremely difficult to quantify. Work in the Bonanza Creek LTER provides considerable insight into the patterns, causes, and consequences of this belowground C allocation. Belowground allocation has a number of important ecosystem consequences beyond the simple fact that C allocated belowground comes at the expense of aboveground growth. Belowground and aboveground tissues differ substantially in the rates of C and nitrogen (N) incorporation into new tissue, the ratio of growth to respiration, and the rate of tissue decay. For example, despite the small biomass of fine roots relative to aboveground tissues in forest ecosystems, disproportionate amounts of C and N cycle annually through fine roots, which grow, die, and decompose very rapidly and have high N concentrations (Hendrick and Pregitzer 1992, Ruess et al. 1996, 2003). The objectives of this chapter are to (1) summarize our understanding of the structure and function of fine-root systems in forest types within the Bonanza Creek Experimental Forest, (2) compare our findings with the results of studies of other boreal and temperate ecosystems in order to develop a broader understanding of fine-root function, and (3) identify critical research gaps in our understanding of the role of fine-root systems in boreal ecosystem function. Fine roots grow more rapidly than the rest of the root system in a forest and are responsible for the bulk of nutrient and water acquisition. Until recently, fine roots were defined rather arbitrarily as roots less than 1–2 mm in diameter, while roots larger than this were considered coarse roots. Only one data set for fine and coarse root biomass has been published for interior Alaskan forests (Ruess et al. 1996), which shows (1) live fine-root biomass ranging from 221 g m-2 in floodplain white spruce stands to 832 g m-2 in upland birch-aspen stands, (2) a positive correlation between fine-root and coarse-root biomass, with coarse-root biomass averaging 50% greater than fine roots, and (3) no relationship between aboveground biomass and fine or coarse root biomass.


2020 ◽  
Author(s):  
◽  
Sulaiman Ahmed Ali

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI-COLUMBIA AT REQUEST OF AUTHOR.] Soybean (Glycine max (L.) is currently grown throughout the world because it has been adapted to many environments and because of the high protein and oil content of the seeds. Water scarcity is responsible for the biggest crop losses worldwide and this is expected to worsen; thus, much attention is directed towards the development of drought tolerant crops. The root system is fundamentally important for plant growth and survival because of its role in water and nutrient uptake. Crops with deep roots can capture more soil resources, particularly water, to support shoot growth and yield formation. However, the investigation of root systems is difficult and remains challenging, especially under field conditions. Nonetheless, a better understanding of root system form and function is critical to develop strategies to breed for more stress-resilient crops for local production environments. Studies of soybean root systems in general, and rooting depth in particular have been limited. Thus, the aims of the research described in this dissertation were to (i) identify genotypic diversity in rooting depth and distribution of roots in the soil profile and relate these traits to above ground characteristics including yield under rainfed field conditions in a wide range of soybean genotypes, (ii) characterize, compare and contrast root systems of selected soybean genotypes grown under field- and greenhouse-conditions, and (iii) explore the influence of scion and rootstock genotype on root growth of contrasting soybean genotypes under well-watered and water deficit stress conditions. In the first series of experiments, a set of five soybean genotypes that represented contrasting root rooting depths and root elongation rates were selected based on greenhouse experiment and grown under rainfed field conditions. The core break method was used to assess root distributions of these genotypes in two years. The main goals of this experiment were to confirm genotypic variation for key root traits, including rooting depth and distribution, and to determine whether rooting depth is related to seed yield and selected shoot traits. This study confirmed significant variation among genotypes regarding their rooting depth and root distribution in the soil profile. Genotypes with greater maximum rooting depth also exhibited greater numbers of roots in the lower soil strata than shallower rooting genotypes, and rooting depth was positively correlated with seed yield. Confirmation of differences in rooting depth among these genotypes and the relationship with seed yield under field conditions establishes the suitability of the selected genotypes for physiological studies, studies of genetic mechanisms underpinning maximum rooting depth in soybean, and to confirm the potential for yield increase as a result of selection for deep rooting. A second study consisted of two greenhouse experiments to evaluate the effect of water availability on the rooting depth plasticity of deep- and shallow-rooted genotypes. Six contrasting genotypes were grown in PVC pipes under well-watered and dry-down conditions. The soil media was a mixture of soil and sand with a ratio of 4:1, respectively. Significant genotype, water treatment, and genotype by water treatment interaction effects were observed for maximum rooting depth. Maximum rooting depth increased in the dry-down compared to the well-watered treatment and induced a reallocation of root length from shallow strata to deeper regions in the profile for all genotypes. The extent of the difference in rooting depth between well-watered and dry-down treatments, measured as plasticity, was significantly different among genotypes. Thus, plasticity in maximum rooting depth appears to be under genetic control in soybean and may be a suitable target for breeding efforts aimed at increasing yields under drought. In a final study, the influence of scion and rootstock genotype on shoot growth and root system characteristics was examined in deep tubes in an automated rainout shelter. Plants were sown into 1.5- m deep tubes filled with a soil-sand mix (4:1) and grown under well-watered and dry-down conditions. Nine days after sowing, self and reciprocal grafts were made using the wedge grafting method. The dry-down treatment resulted in significantly increased rooting depth for all grafted as well as the non-grafted treatments compared to well-watered treatment. As expected, root length densities in the top 30 cm of the soil were greater for well-watered plants than plants in the dry-down treatment whereas the opposite was true for root length density at depth. Overall, whether self-grafted or serving as rootstock only, the deep-rooted genotype had a stimulatory effect on root growth in most soil strata, particularly under dry-down conditions. In general, limited differences observed among the grafting treatments suggest a small influence of the scion or rootstock genotype on the rooting depth and root distribution in the soil profile. However, grafting studies with additional genotypes should be conducted to explore whether this observation is specific to the genotype combination used in this study or whether it applies more generally for soybean. The experiments described in this dissertation lay the foundation for additional physiological and genetic studies. Further research is needed to ascertain the physiological mechanism behind the responses of contrasting genotypes, and to identify molecular markers and/or genes to facilitate incorporation of desirable root traits into a breeding program to increase yields and/or yield stability under drought conditions.


Author(s):  
Viktor Gjamovski ◽  
Marjan Kiprijanovski ◽  
Tosho Arsov

This paper analyses the distribution of root systems of nine dwarf apple rootstocks (M.9 T 984, M.9 T 337, Jork 9, Mark 9, Budagowski 9, M.9 EMLA, Pajam 1, Pajam 2 and Supporter 4). All rootstocks were grafted with apple cultivar Granny Smith. The study was performed in the experimental orchard established in the Prespa region (Resen, R. Macedonia). The experimental orchard was established in 2004, with a planting distance 3.5 m x 1.5 m. At the end of the 7th growing season following characteristics were evaluated: length and weight of the fine (fibrous) and coarse roots, and depth distribution of the root system. Among the evaluated rootstocks statistically significant differ-ences in total length of the fine roots were not found. Between different rootstocks the results for total length of coarse roots showed more variability. In general, even 89% of the total length of root system belonged to fine roots, and the highest percentage (35%) was located at depths of 20 to 40 cm. Trees grafted on Mark 9 rootstock had the highest value for total root length, while the smallest values were registered on those grafted on Pajam 1 rootstock. Trees grafted on Supporter 4 rootstock had the greatest weight of the root system, while the smallest one was found on rootstock Budagowski 9.


Author(s):  
Ирина Викторовна Евстафьева

В статье исследуются вопросы попечительства в отношении несовершеннолетних, отбывающих наказание в виде лишения свободы. Проблема, поднимаемая автором настоящей статьи, многогранна, касается различных аспектов отбывания наказания несовершеннолетними в воспитательных колониях и требует комплексного исследования, способного ответить на определенно значимый вопрос: является ли колония законным представителем находящихся в ней несовершеннолетних со всеми вытекающими из статуса законных представителей последствиями. При этом необходимо обращать внимание на специфику правового статуса лиц, отбывающих наказание в воспитательных колониях, которые, во-первых, являются несовершеннолетними, то есть не обладают дееспособностью в полном объеме и нуждаются в особой заботе, защите и представительстве, а во-вторых, осуждены за совершение тяжкого или особо тяжкого преступления, влекущего изоляцию от общества и определенные ограничения и лишения. Отечественное законодательство достаточно детально регламентирует особенности режима отбывания наказания в виде лишения свободы несовершеннолетними, не определяя при этом статуса воспитательных колоний, кем они являются: воспитателями, попечителями или исключительно учреждениями исполнения наказаний. Между тем правильное понимание значения и роли воспитательной колонии в жизни находящихся в ней несовершеннолетних преступников, по мнению автора, поможет избежать ряда проблем, объективно складывающихся в учреждениях подобного рода. С этой точки зрения предлагаемая тема представляет интерес не только для ученых-теоретиков, но и для практиков - сотрудников соответствующих учреждений. Особо следует подчеркнуть, что исследований по данной тематике в специальной литературе нет. Отдельные исследования, встречающиеся в современной литературе, касаются исключительно общего гражданско-правового статуса несовершеннолетних осужденных. Однако это обстоятельство может свидетельствовать только о новизне данной темы, но никак не об отсутствии самой проблемы. The article analyzes the issues of the status of educational colonies as guardians of minors serving a sentence of imprisonment. In fact, the problem raised by the author of this article is multifaceted, concerns various aspects of the serving of punishment by minors in educational colonies and requires a comprehensive study that can answer, it seems, a definitely significant question: whether the colony is the legal representative of the minors in it with all the consequences arising from the status of legal representatives in the form of duties and responsibilities. At the same time, it seems, it is necessary to pay attention to the specifics of the legal status of citizens serving sentences in educational colonies, who, firstly, are minors, i.e. do not have full legal capacity and need special care, protection and representation, and, secondly, are convicted of committing a serious or particularly serious crime, entailing isolation from society and certain restrictions and deprivation. Domestic legislation regulates in sufficient detail the peculiarities of the regime of serving sentences in the form of deprivation of liberty by minors, without determining the status of educational colonies. Who are they: educators, Trustees or only institutions of execution of punishments. Meanwhile, the correct understanding of the importance and role of the educational colony in the life of juvenile offenders in it, according to the author, will help to avoid a number of problems that objectively develop in institutions of this kind. From this point of view, the proposed topic is of interest not only for theoretical scientists, but for practitioners-employees of relevant institutions. It should be emphasized that there are no studies on this subject in the special literature. However, this circumstance can testify only about novelty of the given subject, but in any way about absence of the problem. It seems that the relevance and importance of a problem is not always measured by the number of studies devoted to it. Sometimes these its traits are manifest only under particularly careful consideration.


Author(s):  
Thomas Köllen ◽  
Susanne Kopf

AbstractSo far, management research on mechanisms of exclusion of employee groups has mainly applied constructs of racism to understanding issues of origin-based ostracism. This research has primarily focused on issues faced by employees whose heritage is markedly different from the heritage shared by the norm group in the given socio-cultural, linguistic, and geographical setting. Against this backdrop, the present study investigates how ostracism plays out when the heritages involved are similar, as exemplified by German employees in Austria. Study 1 examines the discursive production of Austrian stereotyping of Germans in the usage of different terms of reference for ‘Germans’ in Austrian discourse. A corpus analysis of online comments on newspaper sites highlights the implicit Austrian need for delineation against Germany. Study 2 analyzes Germans’ perception of Austrians’ exclusionary linguistic practices and how this impacts on their employment experience and turnover intention. A quantitative analysis of survey data from 600 German nationals employed in Austria reveals that the degree of exposure to these demarcating practices is associated with lower job satisfaction, a higher burnout level and an increase in turnover intention. This study is amongst the first to shed light on the central role of nationalism and national identities in organizational mechanisms of exclusion.


2021 ◽  
Vol 31 (3) ◽  
Author(s):  
Pierre-Philippe Dechant

AbstractRecent work has shown that every 3D root system allows the construction of a corresponding 4D root system via an ‘induction theorem’. In this paper, we look at the icosahedral case of $$H_3\rightarrow H_4$$ H 3 → H 4 in detail and perform the calculations explicitly. Clifford algebra is used to perform group theoretic calculations based on the versor theorem and the Cartan–Dieudonné theorem, giving a simple construction of the $${\mathrm {Pin}}$$ Pin and $${\mathrm {Spin}}$$ Spin covers. Using this connection with $$H_3$$ H 3 via the induction theorem sheds light on geometric aspects of the $$H_4$$ H 4 root system (the 600-cell) as well as other related polytopes and their symmetries, such as the famous Grand Antiprism and the snub 24-cell. The uniform construction of root systems from 3D and the uniform procedure of splitting root systems with respect to subrootsystems into separate invariant sets allows further systematic insight into the underlying geometry. All calculations are performed in the even subalgebra of $${\mathrm {Cl}}(3)$$ Cl ( 3 ) , including the construction of the Coxeter plane, which is used for visualising the complementary pairs of invariant polytopes, and are shared as supplementary computational work sheets. This approach therefore constitutes a more systematic and general way of performing calculations concerning groups, in particular reflection groups and root systems, in a Clifford algebraic framework.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lei Feng ◽  
Wanli Xu ◽  
Guangmu Tang ◽  
Meiying Gu ◽  
Zengchao Geng

Abstract Background Raising nitrogen use efficiency of crops by improving root system architecture is highly essential not only to reduce costs of agricultural production but also to mitigate climate change. The physiological mechanisms of how biochar affects nitrogen assimilation by crop seedlings have not been well elucidated. Results Here, we report changes in root system architecture, activities of the key enzymes involved in nitrogen assimilation, and cytokinin (CTK) at the seedling stage of cotton with reduced urea usage and biochar application at different soil layers (0–10 cm and 10–20 cm). Active root absorption area, fresh weight, and nitrogen agronomic efficiency increased significantly when urea usage was reduced by 25% and biochar was applied in the surface soil layer. Glutamine oxoglutarate amino transferase (GOGAT) activity was closely related to the application depth of urea/biochar, and it increased when urea/biochar was applied in the 0–10 cm layer. Glutamic-pyruvic transaminase activity (GPT) increased significantly as well. Nitrate reductase (NR) activity was stimulated by CTK in the very fine roots but inhibited in the fine roots. In addition, AMT1;1, gdh3, and gdh2 were significantly up-regulated in the very fine roots when urea usage was reduced by 25% and biochar was applied. Conclusion Nitrogen assimilation efficiency was significantly affected when urea usage was reduced by 25% and biochar was applied in the surface soil layer at the seedling stage of cotton. The co-expression of gdh3 and gdh2 in the fine roots increased nitrogen agronomic efficiency. The synergistic expression of the ammonium transporter gene and gdh3 suggests that biochar may be beneficial to amino acid metabolism.


1994 ◽  
Vol 37 (3) ◽  
pp. 338-345 ◽  
Author(s):  
D. Ž. Doković ◽  
P. Check ◽  
J.-Y. Hée

AbstractLet R be a root system (in the sense of Bourbaki) in a finite dimensional real inner product space V. A subset P ⊂ R is closed if α, β ∊ P and α + β ∊ R imply that α + β ∊ P. In this paper we shall classify, up to conjugacy by the Weyl group W of R, all closed sets P ⊂ R such that R\P is also closed. We also show that if θ:R —> R′ is a bijection between two root systems such that both θ and θ-1 preserve closed sets, and if R has at most one irreducible component of type A1, then θ is an isomorphism of root systems.


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