Tree pasture interactions at a range of tree densities in an agroforestry experiment. I. Rooting patterns

1990 ◽  
Vol 41 (4) ◽  
pp. 683 ◽  
Author(s):  
J Eastham ◽  
CW Rose
Keyword(s):  
Root Growth ◽  
Root Systems ◽  
Tree Density ◽  
Root Production ◽  
Total Length ◽  
Rooting Patterns ◽  
Root:Shoot Ratios

The effects of tree density on the distribution of tree and pasture roots under an agroforestry experiment were investigated. Trees were planted in a Nelder fan design, and three planting densities of 2150,304 and 82 stems per hectare were chosen for this study. Proximity to trees and increase in tree density reduced pasture root growth, with lowest concentrations of pasture roots occurring under the highest tree density. Tree root systems were deeper and denser at high tree densities, although total length and mass of roots produced per tree decreased with increasing tree density. Tree root:shoot ratios increased as tree density decreased owing to greater root production at low tree densities.

Root growth in a polar semidesert environment

1978 ◽  
Vol 56 (20) ◽  
pp. 2470-2490 ◽  
Author(s):  
Katherine L. Bell ◽  
L. C. Bliss
Keyword(s):  
Root Growth ◽  
Vascular Plants ◽  
Vascular Plant ◽  
Plant Cover ◽  
Root Systems ◽  
High Arctic ◽  
Moisture Gradient ◽  
Small Roots ◽  
Total Plant ◽  
Root:Shoot Ratios

Within the northwestern islands of the High Arctic, the vegetation and flora of King Christian Island are very representative. Five plant communities were recognized in a moisture gradient from a moss–rush moist meadow with 22 species of vascular plants and 13% cover (total plant cover 93%) to lichen barrens on low ridges with 8 species of vascular plants and 3% cover (total plant cover 24%). Root systems of 30 of the 34 known vascular plant species were examined. Root:shoot ratios (alive) are generally 0.2 to 0.7. Roots are estimated to live 1.5 years in Phippsia algida, 3.4–3.7 years in Alopecurus alpinus and Puccinellia vaginata, and 7–13 years in Luzula nivalis, L. confuse), and Cerastium arcticum. Optimal root growth occurs at 12 to 20 °C but cold field soils (1 to 3 °C) reduce these rates by 90%. Root growth was also reduced by low soil water potentials (< − 14 bars (1 bar = 100 kPa)), conditions seldom encountered in these sites. Limited root growth due to cold soils is combined with the adaptive advantages of small roots to produce small plants and sparse cover in these polar semidesert lands.

Effects of Temperature on Root Morphology and Ectendomycorrhizal Development in Pinusresinosa Ait.

1975 ◽  
Vol 5 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Hugh E. Wilcox ◽  
Ruth Ganmore-Neumann
Keyword(s):  
Root Growth ◽  
Root System ◽  
Root Morphology ◽  
Root Systems ◽  
Second Order ◽  
Root Temperature ◽  
First Order ◽  
Effects Of Temperature

Seedlings of Pinusresinosa were grown at root temperatures of 16, 21 and 27 °C, both aseptically and after inoculation with the ectendomycorrhizal fungus BDG-58. Growth after 3 months was significantly influenced by the presence of the fungus at all 3 temperatures. The influence of the fungus on root growth was obscured by the effects of root temperature on morphology. The root system at 16 and at 21 °C possessed many first-order laterals with numerous, well developed second-order branches, but those at 27 °C had only a few, relatively long, unbranched first-order laterals. Although the root systems of infected seedlings were larger, the fungus increased root growth in the same pattern as determined by the temperature.

scholarly journals Contemporary Concepts of Root System Architecture of Urban Trees

2010 ◽  
Vol 36 (4) ◽  
pp. 149-159
Author(s):  
Susan Day ◽  
P. Eric Wiseman ◽  
Sarah Dickinson ◽  
J. Roger Harris
Keyword(s):  
Built Environment ◽  
Root Growth ◽  
Root System ◽  
Root Architecture ◽  
Root Systems ◽  
Growth Patterns ◽  
Urban Trees ◽  
Rooting Depth ◽  
Similar Species ◽  
Urban Settings

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.

scholarly journals Biomass Allocation to Resource Acquisition Compartments Is Affected by Tree Density Manipulation in European Beech after Three Decades

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 940
Author(s):  
Bohdan Konôpka ◽  
Milan Barna ◽  
Michal Bosela ◽  
Martin Lukac
Keyword(s):  
Fine Root ◽  
Standing Stock ◽  
European Beech ◽  
Forest Harvesting ◽  
Tree Density ◽  
Resource Acquisition ◽  
Root Turnover ◽  
Root Production ◽  
Fine Root Production ◽  
Mature Forest

This study reports on an investigation of fine root and foliage productivity in forest stands dominated by European beech (Fagus sylvatica L.) and exposed to contrasting intensities of mature forest harvesting. The main aim of this study was to consider the long-term effects of canopy manipulation on resource acquisition biomass compartments in beech. We made use of an experiment established in 1989, when five different light availability treatments were started in plots within a uniform forest stand, ranging from no reduction in tree density to full mature forest removal. We measured fine root standing stock in the 0–30 cm soil layer by coring in 2013 and then followed annual fine root production (in-growth cores) and foliage production (litter baskets) in 2013–2015. We found that the plot where the tree density was reduced by 30% had the lowest foliage and the highest fine root production. In 2013, this plot had the highest fine root turnover rate (0.8 year−1), while this indicator of fine root dynamics was much lower in the other four treatments (around 0.3 year−1). We also found that the annual fine root production represented around two thirds of annual foliage growth on the mass basis in all treatments. While our findings support the maintenance of source and sink balance in woody plants, we also found a long-lasting effect of tree density manipulation on investment into resource acquisition compartments in beech forests.

scholarly journals Biodynamic preparations, greater root growth and health, stress resistance, and soil organic matter increases are linked

2019 ◽  
Vol 4 (1) ◽  
pp. 187-202
Author(s):  
Walter A. Goldstein ◽  
Herbert H. Koepf ◽  
Chris J. Koopmans
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Winter Wheat ◽  
Root Growth ◽  
Soil Quality ◽  
Stress Condition ◽  
Root Production ◽  
Biodynamic Preparations ◽  
Root Health ◽  
Enhanced Yield

AbstractThe effects of biodynamic preparations were tested in the context of comparisons of conventional, organic, and biodynamic systems and diverse crop rotations in Washington and Wisconsin, USA. Wisconsin research also entailed testing a new nettle-and-manure-based field spray preparation (NCP). Focus was on winter wheat and maize and on soil quality. In Washington, preparations increased root growth of winter wheat, microbial biomass, and soil organic matter. In Wisconsin, applying a combination of preparations that included NCP increased root growth of maize, root health, and particulate organic matter in the soil. Relative to the organic treatments, root dry matter increases associated with the use of preparations varied from 12% to 39% and root length differences varied from 10% to 37% depending on the experiment, crop, year, and preparation application. The biodynamic + NCP treatment also induced substantial, positive yield compensatory effects for maize and wheat under stress condition years. The response slopes were practically identical for wheat and maize, indicating that the effect is of the same magnitude for both crops. Results were higher average grain yields and gross financial returns than for organic grain. The greater root production and root health stimulated by preparations is probably linked to greater vegetative growth, enhanced yield under stress conditions, and increased soil quality and carbon in soils.

Relationships among litterfall, fine-root growth, and soil respiration for five tropical tree species

2007 ◽  
Vol 37 (10) ◽  
pp. 1954-1965 ◽  
Author(s):  
Oscar J. Valverde-Barrantes
Keyword(s):  
Soil Respiration ◽  
Root Growth ◽  
Tree Species ◽  
Fine Root ◽  
Tropical Tree ◽  
Root Production ◽  
Fine Root Production ◽  
Soil C ◽  
Tropical Tree Species ◽  
Fine Root Growth

Although significant advances have been made in understanding terrestrial carbon cycling, there is still a large uncertainty about the variability of carbon (C) fluxes at local scales. Using a carbon mass-balance approach, I investigated the relationships between fine detritus production and soil respiration for five tropical tree species established on 16-year-old plantations. Total fine detritus production ranged from 0.69 to 1.21 kg C·m–2·year–1 with significant differences among species but with no correlation between litterfall and fine-root growth. Soil CO2 emissions ranged from 1.61 to 2.36 kg C·m–2·year–1 with no significant differences among species. Soil respiration increased with fine-root production but not with litterfall, suggesting that soil C emissions may depend more on belowground inputs or that both fine root production and soil respiration are similarly influenced by an external factor. Estimates of root + rhizosphere respiration comprised 52% of total soil respiration on average, and there was no evidence that rhizosphere respiration was associated with fine-root growth rates among species. These results suggest that inherent differences in fine-root production among species, rather than differences in aboveground litterfall, might play a main role explaining local-scale, among-forest variations in soil C emissions.

Root responses of triticale and soybean to soil compaction in the field are reproducible under controlled conditions

2016 ◽  
Vol 43 (2) ◽  
pp. 114 ◽  
Author(s):  
Tino Colombi ◽  
Achim Walter
Keyword(s):  
Root Growth ◽  
Soil Compaction ◽  
Root Systems ◽  
Oxygen Availability ◽  
Compacted Soils ◽  
Root Branching ◽  
Controlled Conditions ◽  
Glycine Max L ◽  
Limited Oxygen

Soil compaction includes a set of underlying stresses that limit root growth such as increased impedance and limited oxygen availability. The aims of the present study were to (i) find acclimations of triticale (× Triticosecale) and soybean (Glycine max L.) roots to compacted soils in the field; (ii) reproduce these under controlled conditions; and (iii) associate these responses with soil physical properties. To this end, plants were grown at two different soil bulk densities in the field and under controlled conditions representing mature root systems and the seedling stage respectively. Diameters, lateral branching densities, the cortical proportion within the total root cross-section and the occurrence of cortical aerenchyma of main roots were quantified. Soil compaction caused decreasing root branching and increasing cortical proportions in both crops and environments. In triticale, root diameters and the occurrence of aerenchyma increased in response to compaction in the field and under controlled conditions. In soybean, these acclimations occurred at an initial developmental stage but due to radial root growth not in mature roots. These results showed that responses of root systems to compacted soils in the field are, to a large extent, reproducible under controlled conditions, enabling increased throughput, phenotyping-based breeding programs in the future. Furthermore, the occurrence of aerenchyma clearly indicated the important role of limited oxygen availability in compacted soils on root growth.

Fine root growth and mortality in different-aged ponderosa pine stands

2008 ◽  
Vol 38 (7) ◽  
pp. 1797-1806 ◽  
Author(s):  
Chris P. Andersen ◽  
Donald L. Phillips ◽  
Paul T. Rygiewicz ◽  
Marjorie J. Storm
Keyword(s):  
Root Growth ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Standing Crop ◽  
Fine Root ◽  
Tree Age ◽  
Root Production ◽  
Age Classes ◽  
Old Growth ◽  
Pine Stands

Root minirhizotron tubes were installed at two sites around three different age classes of ponderosa pine ( Pinus ponderosa Dougl. ex Laws.) to follow patterns of fine root (≤2 mm diameter) dynamics during a 4 year study. Both sites were old-growth forests until 1978, when one site was clear-cut and allowed to regenerate naturally. The other site had both intermediate-aged trees (50–60 years) and old-growth trees (>250 years old). Estimates of fine root standing crop were greatest around young trees and least around intermediate-aged trees. Root production was highly synchronized in all age classes, showing a single peak in late May – early June each year. Root production and mortality were proportional to standing root crop (biomass), suggesting that allocation to new root growth was proportional to root density regardless of tree age. The turnover index (mortality/maximum standing crop) varied from 0.62 to 0.89·year–1, indicating root life spans in excess of 1 year. It appears that young ponderosa pine stands have greater rates of fine root production than older stands but lose more fine roots each year through mortality. The results indicate that soil carbon may accumulate faster in younger than in older stands.

scholarly journals Toward Marker-assisted Breeding for Root Architecture Traits in Southern Highbush Blueberry

2016 ◽  
Vol 141 (5) ◽  
pp. 414-424 ◽  
Author(s):  
Gerardo H. Nunez ◽  
Hilda Patricia Rodríguez-Armenta ◽  
Rebecca L. Darnell ◽  
James W. Olmstead
Keyword(s):  
Root Growth ◽  
Root Architecture ◽  
Root Systems ◽  
Vaccinium Corymbosum ◽  
Lower Percentage ◽  
Soil Conditions ◽  
Growth Substrate ◽  
Family Pedigree ◽  
Southern Highbush ◽  
Trait Associations

Root growth and root system architecture (RSA) are affected by edaphic and genetic factors and they can impact plant growth and farm profitability. Southern highbush blueberries [SHBs (Vaccinium corymbosum hybrids)] develop shallow, fibrous root systems, and exhibit a preference for acidic soils where water and ammonium are readily available. The amendments used to create these soil conditions negatively affect the profitability of SHB plantations. Hence, breeding for RSA traits has been suggested as an alternative to soil amendments. Vaccinium arboreum is a wild species that is used in SHB breeding. V. arboreum exhibits greater drought tolerance and broader soil pH adaptation than SHB, and—according to anecdotal evidence—it develops deep, taproot-like root systems. The present study constitutes the first in-depth study of the RSA of Vaccinium species with the intention of facilitating breeding for RSA traits. Root systems were studied in rhizotron-grown seedling families. In separate experiments, we tested the effect that growth substrate and family pedigree can have on root growth and RSA. Subsequently, a genotyping by sequence approach was used to develop single nucleotide polymorphism (SNP) markers that could be used along with the phenotyping method to investigate the heritability of RSA traits and look for marker-trait associations. We found that RSA is affected by growth substrate and family pedigree. In addition, we found that V. arboreum exhibited greater maximum root depth and a lower percentage of roots in the top 8 cm of soil than SHB, and interspecific hybrids generally exhibited intermediate phenotypes. Also, we found that RSA traits exhibit moderate to low heritability and genetic correlations among them. Finally, we found 59 marker-trait associations. Among these markers, 37 were found to be located in exons, and 16 of them were annotated based on protein homology with entries in National Center for Biotechnology Information (NCBI) GenBank. Altogether, the present study provides tools that can be used to breed for root architecture traits in SHB.

scholarly journals Modeling and Analysis of Disease-Induced Host Growth in the Epidemiology of Take-All

2004 ◽  
Vol 94 (5) ◽  
pp. 535-540 ◽  
Author(s):  
D. J. Bailey ◽  
C. A. Gilligan
Keyword(s):  
Root Growth ◽  
Mechanistic Model ◽  
Secondary Infection ◽  
Active Role ◽  
Root Production ◽  
Modeling And Analysis ◽  
Epidemiological Modeling ◽  
Host Growth ◽  
Over Time ◽  
Take All

Epidemiological modeling, together with parameter estimation to experimental data, was used to examine the contribution of disease-induced root growth to the spread of take-all in wheat. Production of roots from plants grown in the absence of disease was compared with production of those grown in the presence of disease and the precise form of diseaseinduced growth was examined by fitting a mechanistic model to data describing change in the number of infected and susceptible roots over time from a low and a high density of inoculum. During the early phase of the epidemic, diseased plants produced more roots than their noninfected counterparts. However, as the epidemic progressed, the rate of root production for infected plants slowed so that by the end of the epidemic, and depending on inoculum density, infected plants had fewer roots than uninfected plants. The dynamical change in the numbers of infected and susceptible roots over time could only be explained by the mechanistic model when allowance was made for disease-induced root growth. Analysis of the effect of disease-induced root production on the spread of disease using the model suggests that additional roots produced early in the epidemic serve only to reduce the proportion of diseased roots. However, as the epidemic switches from primary to secondary infection, these roots perform an active role in the transmission of disease. Some consequence of disease-induced root growth for field epidemics is discussed.

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