Root-system morphology of common boreal forest trees in Alberta, Canada

1983 ◽  
Vol 13 (6) ◽  
pp. 1164-1173 ◽  
Author(s):  
W. L. Strong ◽  
G. H. La Roi

Twenty-four specimens of six boreal tree species were excavated: eight Pinusbanksiana Lamb., five Populustremuloides Michx., four Piceaglauca (Moench) Voss, three Piceamariana (Mill.) B.S.P., two Abiesbalsamea (L.) Mills., and two Lara laricina (Du Roi) K. Koch. Root systems were described, and percent biomass determined for above- and below-ground components for half these specimens. Tree ages ranged from 3 to 120 years. Horizontally spreading lateral roots dominated the root systems of all species and occurred within 3– 15 cm of the ground surface. Nutrient and moisture absorption appear to be the principal functions of lateral roots. Maximum vertical root growth occurred near the tree stump as: tap-, heart, sinker, and oblique lateral roots. Vertical root morphology is influenced by site conditions. In addition to providing mechanical support, sinker and taproots may be important adaptations for deep-water utilization on xeric sites. Our data suggest that roots may be important in boreal succession processes through two related mechanisms: (i) nutrient and water deprivation occurring through preemptive growth of tree roots from climax species over roots of serai species, and through interception by mosses; and (ii) niche partitioning occurring below ground between serai and climax, and among climax tree species, by vertical separation of the root systems.

2019 ◽  
Vol 48 (No. 12) ◽  
pp. 549-564 ◽  
Author(s):  
J. Kodrík ◽  
M. Kodrík

Beech is, thanks to its root system, in general considered to be a wind-resistant woody plant species. Nevertheless, the research on beech root systems has revealed that it is not possible to mechanically divide the woody plants into deep rooted and shallow rooted, because their root systems are modified according to various stand conditions. The root system shape, growth and development are mostly influenced by soil conditions and groundwater level. In the case of a high groundwater level beech root systems do not form tap roots and the lateral roots are rather thin and weak. Important factor for the tree static stability is number of roots with diameter 3–10 cm. The most important for the tree stability are roots with diameter over 10 cm. Wood-destroying fungi have strong negative impact on tree static stability. There are differences between beech below-ground biomass growing in soils rich in nutrients and poor in nutrients. The total below-ground biomass of the beech stands poor in nutrients is higher.


1990 ◽  
Vol 68 (3) ◽  
pp. 551-578 ◽  
Author(s):  
Mark Brundrett ◽  
Gracia Murase ◽  
Bryce Kendrick

The structure of roots and mycorrhizae of trees belonging to 20 important Ontario tree genera were examined. During this study efficient methods for examining root anatomy were developed, and tree root information was compiled. The ultimate lateral roots of most species examined were consistently mycorrhizal, and many species had heterorhizic root systems with separate long and short lateral roots. Tree roots displayed enough structural diversity in features such as thickened, lignified, or suberized walls, and secondary metabolite-containing cells to allow identification of genera. The roots of trees belonged to four major anatomical groups as a result of the major differences between angiosperm and gymnosperm roots, and between those with ectomycorrhizal (ECM) or vesicular–arbuscular mycorrhizal (VAM) associations, (i) Members of the Pinaceae had structurally similar heterorhizic roots that had ECM with a cortical Hartig net. (ii) Thuja (Cupressaceae) had distinctive nonheterorhizic roots with phi thickenings and VAM. (iii) Angiosperms with ECM belonged to diverse families, but all had similar heterorhizic root systems with ECM short roots that had an epidermal Hartig net and a narrow cortex of thick-walled cells, (iv) Most angiosperms with VAM had nonheterorhizic roots, and this group had the greatest diversity of root structural features. Possible structural and defensive roles of root features and potential influences of these features on mycorrhizal formation are considered.


2021 ◽  
Vol 13 (6) ◽  
pp. 3563
Author(s):  
Marianthi Tsakaldimi ◽  
Panagiota Giannaki ◽  
Vladan Ivetić ◽  
Nikoleta Kapsali ◽  
Petros Ganatsas

Pinus nigra is one of the most widely used tree species for reforestation within its geographical distribution, as well as being a potential substitute for other tree species in Central Europe under future climate scenarios. P. nigra is transplanted into the field as two-year or three-year old seedlings because of its relatively low growth rate in the nursery. This study investigated the effects of fertilization programs and shading on P. nigra seedlings, aiming to accelerate early growth, and thus to reduce the nursery rearing time. The experiment (a completely randomized block design) was conducted in an open-air nursery by sowing seeds from Grevena, Northern Greece, in Quick pots filled with peat and perlite in a 2:1 ratio. The seedlings were subjected to two levels of fertilization—5 and 10 g L−1 NPK (30-10-10)—and two shading levels: 50% and 70%. At the ends of the first and second nursery growing season, we recorded the seedlings’ above- and below-ground morphology and biomass data. The results show that the application of all of the treatments produced seedlings which met the targeted quality standards for outplanting. However, the combination of a high fertilization rate and low shading level resulted in seedlings of a higher morphological quality, which is often considered to be an indicator for a successful seedling establishment in the field.


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.


2022 ◽  
Vol 41 (1) ◽  
pp. 54-61
Author(s):  
Moyagabo K. Rapetsoa ◽  
Musa S. D. Manzi ◽  
Mpofana Sihoyiya ◽  
Michael Westgate ◽  
Phumlani Kubeka ◽  
...  

We demonstrate the application of seismic methods using in-mine infrastructure such as exploration tunnels to image platinum deposits and geologic structures using different acquisition configurations. In 2020, seismic experiments were conducted underground at the Maseve platinum mine in the Bushveld Complex of South Africa. These seismic experiments were part of the Advanced Orebody Knowledge project titled “Developing technologies that will be used to obtain information ahead of the mine face.” In these experiments, we recorded active and passive seismic data using surface nodal arrays and an in-mine seismic land streamer. We focus on analyzing only the in-mine active seismic portion of the survey. The tunnel seismic survey consisted of seven 2D profiles in exploration tunnels, located approximately 550 m below ground surface and a few meters above known platinum deposits. A careful data-processing approach was adopted to enhance high-quality reflections and suppress infrastructure-generated noise. Despite challenges presented by the in-mine noisy environment, we successfully imaged the platinum deposits with the aid of borehole data and geologic models. The results open opportunities to adapt surface-based geophysical instruments to address challenging in-mine environments for mineral exploration.


2018 ◽  
Vol 285 (1885) ◽  
pp. 20181240 ◽  
Author(s):  
Xiaojuan Liu ◽  
Stefan Trogisch ◽  
Jin-Sheng He ◽  
Pascal A. Niklaus ◽  
Helge Bruelheide ◽  
...  

Forest ecosystems are an integral component of the global carbon cycle as they take up and release large amounts of C over short time periods (C flux) or accumulate it over longer time periods (C stock). However, there remains uncertainty about whether and in which direction C fluxes and in particular C stocks may differ between forests of high versus low species richness. Based on a comprehensive dataset derived from field-based measurements, we tested the effect of species richness (3–20 tree species) and stand age (22–116 years) on six compartments of above- and below-ground C stocks and four components of C fluxes in subtropical forests in southeast China. Across forest stands, total C stock was 149 ± 12 Mg ha −1 with richness explaining 28.5% and age explaining 29.4% of variation in this measure. Species-rich stands had higher C stocks and fluxes than stands with low richness; and, in addition, old stands had higher C stocks than young ones. Overall, for each additional tree species, the total C stock increased by 6.4%. Our results provide comprehensive evidence for diversity-mediated above- and below-ground C sequestration in species-rich subtropical forests in southeast China. Therefore, afforestation policies in this region and elsewhere should consider a change from the current focus on monocultures to multi-species plantations to increase C fixation and thus slow increasing atmospheric CO 2 concentrations and global warming.


2020 ◽  
Author(s):  
Charlene N. Kelly ◽  
Geoffrey W. Schwaner ◽  
Jonathan R. Cumming ◽  
Timothy P. Driscoll

AbstractThe soil microbiome plays an essential role in processing and storage of nitrogen (N) and carbon (C), and is influenced by vegetation above-ground through imparted differences in chemistry, structure, mass of plant litter, root physiology, and dominant mycorrhizal associations. We used shotgun metagenomic sequencing and bioinformatic analysis to quantify the abundance and distribution of gene families involved in soil microbial N and C cycling beneath three deciduous hardwood tree species: ectomycorrhizal (ECM)-associated Quercus rubra (red oak), ECM-associated Castanea dentata (American chestnut), and arbuscular mycorrhizal (AM)-associated Prunus serotina (black cherry). Chestnut exhibited the most distinct soil microbiome of the three species, both functionally and taxonomically, with a general suppression of functional genes in the nitrification, denitrification, and nitrate reduction pathways. These changes were related to low inorganic N availability in chestnut stands as soil was modified by poor, low-N litter quality relative to red oak and black cherry soils.IMPORTANCEPrevious studies have used field biogeochemical process rates, isotopic tracing, and targeted gene abundance measurements to study the influence of tree species on ecosystem N and C dynamics. However, these approaches do not enable a comprehensive systems-level understanding of the relationship between microbial diversity and metabolism of N and C below-ground. We analyzed microbial metagenomes from soils beneath red oak, American chestnut, and black cherry stands and showed that tree species can mediate the abundance of key microbial genes involved in N and (to a lesser extent) C metabolism pathways in soil. Our results highlight the genetic framework underlying tree species’ control over soil microbial communities, and below-ground C and N metabolism, and may enable land managers to select tree species to maximize C and N storage in soils.


1991 ◽  
Vol 21 (2) ◽  
pp. 207-216 ◽  
Author(s):  
P. M. Miller ◽  
L. E. Eddleman ◽  
J. M. Miller

Plants are balanced systems that integrate processes of carbon fixation and uptake of water and nutrients to optimize resource acquisition. Response of Juniperusoccidentalis Hook. to reductions in above- and below-ground tissue was measured to determine effects on carbon dioxide assimilation, leaf conductance, intercellular carbon dioxide, xylem water potential, foliage nutrient concentration, aboveground growth, water-use efficiency, and potential photosynthetic nitrogen-use efficiencies. Approximately 50% of the old foliage was removed and lateral roots were severed at the canopy edge in early April 1988; physiological processes were measured during three periods in the summer of 1988. Foliage removal increased rates of carbon dioxide assimilation and photosynthetic nitrogen-use efficiency, but neither increased growth nor improved water status or nitrogen concentration of remaining foliage. Cutting lateral roots reduced assimilation, leaf conductance, foliage nitrogen concentration, branchlet elongation, water-use efficiency, and photosynthetic nitrogen-use efficiency. By late August, juvenile and small-adult J. occidentalis in the cut-top treatment had compensated for foliage removal by reestablishing patterns of water-use efficiencies similar to those of control plants, which may indicate that an overall metabolic control was functioning to regulate the balance between carbon dioxide assimilation and water loss. Cutting lateral roots had a more lasting effect on efficiencies; by late August, juveniles and small adults still had significantly lower water-use efficiencies than controls.


Author(s):  
Earl B. Alexander ◽  
Roger G. Coleman ◽  
Todd Keeler-Wolfe ◽  
Susan P. Harrison

We walk on soils frequently, but we seldom observe them. Soils are massive, even though they are porous. Soil 1m (40 inches) deep over an area of 1 hectare (2.5 acres) might weigh 10,000–15,000 metric tons. It is teeming with life. There are trillions, or quadrillions, of living organisms (mostly microorganisms), representing thousands of species, in each square meter of soil (Metting 1993). In fact, species diversity, or number of species, may be greater below ground than above ground. We seldom see these organisms because we seldom look below ground or dig into it. The many worms and insects one finds digging in a garden are a small fraction of the species in soils because the greatest diversity of soil-dwelling species exists among microscopic insects, mites, roundworms (or nematodes), and fungi. Even though individual organisms in soils are mostly very small or microscopic, the total mass of living organisms in a hectare of soil, excluding plant roots, may be 1–5 or 10 metric tons. More than one-half of that biomass is bacteria and fungi. Living microorganism biomass generally accounts for about 1%–5% of the organic carbon and about 2%–6% of the nitrogen in soils (Lavelle and Spain 2001). The upper limit of soil is the ground surface of the earth. The lower limit is bedrock for engineers, or the depth of root penetration for edaphologists. Unconsolidated material that engineers call soil can be called “regolith” (Merrill 1897, Jackson 1997) to distinguish it from the soil of pedologists and edaphologists. Regolith may consist of disintegrated bedrock, gravel, sand, clay, or other materials that have not been consolidated to form rock. Pedologists investigate the upper part of regolith, where changes are effected by exchanges of gases between soil and aboveground atmosphere and by biological activity. This soil of pedologists may coincide with that of edaphologists or include more regolith. In fact, the lower limit of soil that pedologists investigate is arbitrary, unless this limit is a contact with bedrock that is practically impenetrable with pick and shovel.


2019 ◽  
Vol 11 (18) ◽  
pp. 5117 ◽  
Author(s):  
Stratópoulos ◽  
Zhang ◽  
Häberle ◽  
Pauleit ◽  
Duthweiler ◽  
...  

: Under changing climatic conditions, drought may become a critical constraint for trees in urban areas, particularly at roadsides and highly paved squares. As healthy urban trees have proven to be an important mitigation and adaptation tool for climate change as well as a significant provider of ecosystem services, there is a need for planting species and cultivars capable of coping with the limited water supply. However, data on species’ and cultivars’ response to drought, particularly their water supplying root systems remains rare. To consider the whole plant responses to drought situations, we studied the growth and phenology of three frequently planted tree species and cultivars with a diameter of 5–6 cm during a one-year rainfall exclusion experiment conducted in a nursery field as well as the dry biomass of the compartments branch, stem, and root after excavation. Our results revealed that species’ and cultivars’ performance were linked to their within-plant carbon partitioning. A high tolerance to drought was noted for Acer campestre, with a particularly high ratio of root:shoot ratio, which made it presumably less susceptible to droughts. Tilia cordata ‘Greenspire’ was highly affected by the reduced water availability visible through prematurely leaf senescence, while Carpinus betulus ‘Fastigiata’ suffered from losing a considerable part of its root biomass, which resulted in the lowest root:shoot ratio of all species and cultivars. This study demonstrated the need for investigating the reaction patterns of species and cultivars by considering both the above-and the below-ground plant parts. We recommend that, for future tree plantings at harsh and challenging urban sites, an important selection criterion should be species’ and cultivars’ capability to develop and retain strong and dense root systems even under limited water supply, as that is believed to be an important trait for drought tolerance.


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