Engineering › Mechanical Engineering

Tree Root and Stability Studies

Works Count: 28224

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Description

This cluster of papers focuses on the mechanical effects of plant roots, particularly their role in reinforcing soil and enhancing slope stability. It explores topics such as root reinforcement, slope stability, wind damage, biomechanics of roots, and their implications for forest management and landslide prevention.

Keywords

Root Reinforcement; Slope Stability; Mechanical Effects; Plant Roots; Wind Damage; Soil Reinforcement; Forest Management; Biomechanics; Landslides; Vegetation

Techniques and approaches in forest tree ecophysiology

1991-01-01

James P. Lassoie , Thomas M. Hinckley

Papers from a workshop held at Cornell Univeristy's Arnot Teaching and Research Forest near Ithaca, N.Y., Aug. 16-19, 1986 and cosponsored by the Dept. of Natural Resources, Cornell University ... … Papers from a workshop held at Cornell Univeristy's Arnot Teaching and Research Forest near Ithaca, N.Y., Aug. 16-19, 1986 and cosponsored by the Dept. of Natural Resources, Cornell University ... [et al.].

Biotechnical and soil bioengineering slope stabilization: a practical guide for erosion control

1997-02-01

Donald H. Gray , Robbin B. Sotir

This book reviews the horticultural and engineering basis for biotechnical and soil engineering treatments. It explains the role of woody plants in stabilizing slopes against both surficial erosion and mass … This book reviews the horticultural and engineering basis for biotechnical and soil engineering treatments. It explains the role of woody plants in stabilizing slopes against both surficial erosion and mass movement and provides details on a broad range of soil bioengineering methods, including live staking, live fascines, brushlaying, live crib walls, branch packing and live slope gratings. The book describes various biotechnical methods and materials, including the incorporation of vegetation in erosion control blankets, flexible mats, cellular revetments (geocells), rock armour (rip rap) and gabion and open-front crib walls. Four illustrated case studies are included.

Estimating the mechanical effects of riparian vegetation on stream bank stability using a fiber bundle model

2005-07-01

Natasha Pollen , Andrew Simon

Recent research has suggested that the roots of riparian vegetation dramatically increase the geomechanical stability (i.e., factor of safety) of stream banks. Past research has used a perpendicular root reinforcement … Recent research has suggested that the roots of riparian vegetation dramatically increase the geomechanical stability (i.e., factor of safety) of stream banks. Past research has used a perpendicular root reinforcement model that assumes that all of the tensile strength of the roots is mobilized instantaneously at the moment of bank failure. In reality, as a soil‐root matrix shears, the roots contained within the soil have different tensile strengths and thus break progressively, with an associated redistribution of stress as each root breaks. This mode of progressive failure is well described by fiber bundle models in material science. In this paper, we apply a fiber bundle approach to tensile strength data collected from 12 riparian species and compare the root reinforcement estimates against direct shear tests with root‐permeated and non‐root‐permeated samples. The results were then input to a stream bank stability model to assess the impact of the differences between the root models on stream bank factor of safety values. The new fiber bundle model, RipRoot, provided more accurate estimates of root reinforcement through its inclusion of progressive root breaking during mass failure of a stream bank. In cases where bank driving forces were great enough to break all of the roots, the perpendicular root model overestimated root reinforcement by up to 50%, with overestimation increasing an order of magnitude in model runs where stream bank driving forces did not exceed root strength. For the highest bank modeled (3 m) the difference in factor of safety values between runs with the two models varied from 0.13 to 2.39 depending on the riparian species considered. Thus recent work has almost certainly overestimated the effect of vegetation roots on mass stability of stream banks.

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The Shear Resistance of Root-Permeated Homogeneous and Stratified Soil

1977-09-01

L. J. Waldron

Abstract Mechanical reinforcement which stabilizes soil on slopes has been attributed to plant roots. To measure such reinforcement, direct shear tests were made on 25‐cm diameter root‐permeated soil columns. Roots … Abstract Mechanical reinforcement which stabilizes soil on slopes has been attributed to plant roots. To measure such reinforcement, direct shear tests were made on 25‐cm diameter root‐permeated soil columns. Roots of alfalfa ( Medicago sativa ), barley ( Hordeum vulgare ), and yellow pine ( Pinus ponderosa ), each increased the shear resistance of homogeneous and compacted layers of silty clay loam at 30‐cm depth. One‐year‐old alfalfa had a much greater reinforcing effect than pine trees 16 months after transplanting or barley at its maximum growth. Barley had a greater effect in the clay loam than pine, but its effectiveness decreased as depth increased from 15 to 30 to 45 cm. Alfalfa roots were more effective than either pine or barley roots in increasing the resistance to shearing between a dense gravel‐sand layer (simulating weathered rock) and the overlying soil, increasing shearing resistance to as much as 5 times that of fallow soil. A model is presented of soil reinforced by nonrigid roots. Calculations are given of slope safety factor increases from root reinforcement.

Tree structures: Deducing the principle of mechanical design

1976-07-01

Thomas A. McMahon , Richard E. Kronauer

The Role of Wheat Awns in the Seed Dispersal Unit

2007-05-10

Rivka Elbaum , Liron Zaltzman , Ingo Burgert +1 more

The dispersal unit of wild wheat bears two pronounced awns that balance the unit as it falls. We discovered that the awns are also able to propel the seeds on … The dispersal unit of wild wheat bears two pronounced awns that balance the unit as it falls. We discovered that the awns are also able to propel the seeds on and into the ground. The arrangement of cellulose fibrils causes bending of the awns with changes in humidity. Silicified hairs that cover the awns allow propulsion of the unit only in the direction of the seeds. This suggests that the dead tissue is analogous to a motor. Fueled by the daily humidity cycle, the awns induce the motility required for seed dispersal.

Plant biomechanics: An engineering approach to plant form and function

1993-03-01

N. Michele Holbrook

Uprooting and snapping of trees: structural determinants and ecological consequences

1983-10-01

Francis E. Putz , Phyllis D. Coley , Karen L. Lu +2 more

The influence of mechanical and architectural properties of trees on growth rates, mortality rates, and relative probabilities of snapping and uprooting were examined on Barro Colorado Island, Republic of Panama. … The influence of mechanical and architectural properties of trees on growth rates, mortality rates, and relative probabilities of snapping and uprooting were examined on Barro Colorado Island, Republic of Panama. Of 310 fallen trees, 70% snapped, 25% uprooted, and 5% broke off at ground level. Stepwise discriminant analysis between snapped and uprooted trees indicated that of the variables measured, wood properties were the most important factors determining the type of death in trees. Uprooted trees tended to be larger, shorter for a given stem diameter, and to have denser, stiffer, and stronger wood than snapped trees. There were no significant differences between trees that snapped and trees that uprooted in the extent of buttress development or in the slope of the ground upon which they grew. Trees with low density wood grew faster in stem diameter than those with high density wood but also suffered higher mortality rates. After damage, many of the snapped trees sprouted; small trees sprouted more frequently than large trees. Sprouting is proposed as a means by which weak-wooded fast-growing trees partially compensate for being prone to snapping.

The role of fine and coarse roots in shallow slope stability and soil erosion control with a focus on root system architecture: a review

2007-03-29

Bert Reubens , Jean Poesen , Frédéric Danjon +2 more

Mechanics of Fiber Reinforcement in Sand

1983-03-01

Donald H. Gray , Harukazu Ohashi

Direct shear tests were run on a dry sand reinforced with different types of fibers. Both natural and synthetic fibers plus metal wires were tested. Experimental behavior was compared with … Direct shear tests were run on a dry sand reinforced with different types of fibers. Both natural and synthetic fibers plus metal wires were tested. Experimental behavior was compared with theoretical predictions based on a force equilibrium model of a fiber reinforced sand. Test results showed that fiber reinforcement increased the peak shear strength and limited post peak reductions in shear resistance. The fiber reinforcement model correctly predicted the influence of various sand‐fiber parameters through shear strength increases that were: (1) Directly proportional to concentration or area ratio of fibers; (2) greatest for initial fiber orientations of 60° with respect to the shear surface; and (3) approximately the same for a reinforced sand tested in a loose and dense state, respectively. The findings of this study are relevant to such diverse problems as the contribution of roof reinforcement to the stability of sandy, coarse textured soils in granitic slopes, dune and beach stabilization by pioneer plants, tillage in root permeated soils, and soil stabilization with low modulus, woven fabrics.

Growing‐Season Microclimatic Gradients from Clearcut Edges into Old‐Growth Douglas‐Fir Forests

1995-02-01

Jiquan Chen , Jerry F. Franklin , Thomas A. Spies

Edge is an important landscape feature of fragmented forest landscapes in the Pacific Northwest, USA. Our primary objective of this study is to characterize the changes in microclimatic variables from … Edge is an important landscape feature of fragmented forest landscapes in the Pacific Northwest, USA. Our primary objective of this study is to characterize the changes in microclimatic variables from recent clearcut edges into the old‐growth Douglas‐fir forests as influenced by edge exposures and local weather conditions. Microclimatic gradients are described along transects extending from recently clearcut edges 240 m into stands of old‐growth Douglas‐fir (Pseudotsuga menziesii (Mirb.) Franco) forest west of the Cascade Range in the U.S. Pacific Northwest. Data for air temperature, soil temperature, relative humidity, short‐wave radiation, and wind speed were collected over the course of the day from 16 different edges representing a range of edge orientations and local weather conditions over two growing seasons (1989‐1990). Data for soil moisture were collected over three consecutive days in September 1990. Two indices, significance of edge influence (SEI) and depth of edge influence (DEI), were used to evaluate the effects of edges on microclimatic variables. Edge effects typically extended 30 to >240 m into the forest. From the edge into the forest, air temperatures decreased during the day and increased at night; the reversal produced mid‐morning and late‐afternoon periods when a gradient was absent. Changes in soil temperature from the edge into the forest were comparable to those for air temperature, except that edge effects did not extend as deeply into the forest. The gradient for relative humidity increased from the edge and was steepest in mid‐afternoon. Humidity effects sometimes extended >240 m into the forest. Short‐wave radiation decreased rapidly with distance from the edge, reaching interior forest levels by 30‐60 m. Wind speed decreased exponentially from the edge into the forest, depending on the relationship of edge orientation to wind direction; stronger winds influenced conditions deeper inside the forest, sometimes >240 m from the edge. Edge orientation played a critical role for all variables; for air and soil temperature and humidity, it affected the times of day at which maximum and minimum values peaked. Influence of local weather conditions on gradients was highly variable. Overall, however, gradients generally were longest and steepest on partially clear, warm, dry days, at southwest‐facing edges, and for air temperature, soil temperature, and relative humidity. SEI and DEI were found to be necessary measurements for evaluating edge effects on microclimatic variables, which responded differently depending on time of day, edge orientation, and local weather. No single value could be calculated for DEI. Because many ecological features near edges, such as tree stocking and regeneration, dispersal of flying insects, and decomposition of woody debris, seem related to microclimatic gradients, forest management to protect interior conditions should shift from the traditional charge ("create as much edge as possible") to a new charge in which the amount of edge is reduced at both the stand and landscape levels.

Plant biomechanics: an engineering approach to plant form and function

1993-03-01

Karl J. Niklas

Subject classification:- Earth Sciences: Paleontology Biological Sciences: Ecology Biological Sciences: Botany Biological Sciences: Physiology, Biomechanics, and Morpholog. Subject classification:- Earth Sciences: Paleontology Biological Sciences: Ecology Biological Sciences: Botany Biological Sciences: Physiology, Biomechanics, and Morpholog.

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Desirable plant root traits for protecting natural and engineered slopes against landslides

2009-09-22

Alexia Stokes , Claire Atger , A. Glyn Bengough +2 more

Root tensile strength and root distribution of typical Mediterranean plant species and their contribution to soil shear strength

2008-02-20

Sarah De Baets , Jean Poesen , Bert Reubens +3 more

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Phenotypic plasticity for plant development, function and life history

2000-12-01

Sonia E. Sultan

Angiosperm wood structure: Global patterns in vessel anatomy and their relation to wood density and potential conductivity

2010-02-01

Amy E. Zanne , Mark Westoby , Daniel S. Falster +4 more

Woody stems comprise a large biological carbon fraction and determine water transport between roots and leaves; their structure and function can influence both carbon and hydrological cycles. While angiosperm wood … Woody stems comprise a large biological carbon fraction and determine water transport between roots and leaves; their structure and function can influence both carbon and hydrological cycles. While angiosperm wood anatomy and density determine hydraulic conductivity and mechanical strength, little is known about interrelations across many species. We compiled a global data set comprising two anatomical traits for 3005 woody angiosperms: mean vessel lumen area (Ā) and number per unit area (N). From these, we calculated vessel lumen fraction (F = ĀN) and size to number ratio (S = Ā/N), a new vessel composition index. We examined the extent to which F and S influenced potential sapwood specific stem conductivity (K(S)) and wood density (D; dry mass/fresh volume). F and S varied essentially independently across angiosperms. Variation in K(S) was driven primarily by S, and variation in D was virtually unrelated to F and S. Tissue density outside vessel lumens (D(N)) must predominantly influence D. High S should confer faster K(S) but incur greater freeze-thaw embolism risk. F should also affect K(S), and both F and D(N) should influence mechanical strength, capacitance, and construction costs. Improved theory and quantification are needed to better understand ecological costs and benefits of these three distinct dimensions.

The relationship between xylem conduit diameter and cavitation caused by freezing

1999-10-01

Stephen D. Davis , John S. Sperry , Uwe G. Hacke

The centrifuge method for measuring the resistance of xylem to cavitation by water stress was modified to also account for any additional cavitation that might occur from a freeze‐thaw cycle. … The centrifuge method for measuring the resistance of xylem to cavitation by water stress was modified to also account for any additional cavitation that might occur from a freeze‐thaw cycle. A strong correlation was found between cavitation by freezing and mean conduit diameter. On the one extreme, a tracheid‐bearing conifer and diffuse‐porous angiosperms with small‐diameter vessels (mean diameter <30 μm) showed no freezing‐induced cavitation under modest water stress (xylem pressure = −0.5 MPa), whereas species with larger diameter vessels (mean >40 μm) were nearly completely cavitated under the same conditions. Species with intermediate mean diameters (30–40 μm) showed partial cavitation by freezing. These results are consistent with a critical diameter of 44 μm at or above which cavitation would occur by a freeze–thaw cycle at −0.5 MPa. As expected, vulnerability to cavitation by freezing was correlated with the hydraulic conductivity per stem transverse area. The results confirm and extend previous reports that small‐diameter conduits are relatively resistant to cavitation by freezing. It appears that the centrifuge method, modified to include freeze–thaw cycles, may be useful in separating the interactive effects of xylem pressure and freezing on cavitation.

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Root elongation, water stress, and mechanical impedance: a review of limiting stresses and beneficial root tip traits

2010-11-30

A. Glyn Bengough , Blair M. McKenzie , Paul D. Hallett +1 more

Root elongation in drying soil is generally limited by a combination of mechanical impedance and water stress. Relationships between root elongation rate, water stress (matric potential), and mechanical impedance (penetration … Root elongation in drying soil is generally limited by a combination of mechanical impedance and water stress. Relationships between root elongation rate, water stress (matric potential), and mechanical impedance (penetration resistance) are reviewed, detailing the interactions between these closely related stresses. Root elongation is typically halved in repacked soils with penetrometer resistances >0.8–2 MPa, in the absence of water stress. Root elongation is halved by matric potentials drier than about –0.5 MPa in the absence of mechanical impedance. The likelihood of each stress limiting root elongation is discussed in relation to the soil strength characteristics of arable soils. A survey of 19 soils, with textures ranging from loamy sand to silty clay loam, found that ∼10% of penetration resistances were >2 MPa at a matric potential of –10 kPa, rising to nearly 50% >2 MPa at – 200 kPa. This suggests that mechanical impedance is often a major limitation to root elongation in these soils even under moderately wet conditions, and is important to consider in breeding programmes for drought-resistant crops. Root tip traits that may improve root penetration are considered with respect to overcoming the external (soil) and internal (cell wall) pressures resisting elongation. The potential role of root hairs in mechanically anchoring root tips is considered theoretically, and is judged particularly relevant to roots growing in biopores or from a loose seed bed into a compacted layer of soil.

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Wind as a natural disturbance agent in forests: a synthesis

2012-09-04

Stephen J. Mitchell

Windthrow is all too often looked at as an exceptional, catastrophic phenomenon rather than a recurrent natural disturbance that falls within the spectrum of chronic and acute effects of wind … Windthrow is all too often looked at as an exceptional, catastrophic phenomenon rather than a recurrent natural disturbance that falls within the spectrum of chronic and acute effects of wind on forests, and that drives ecosystem patterns and processes. This paper provides an integrative overview of the nature, contributing factors and impacts of wind-caused disturbance in forests, including its effects on trees, stands, landscapes and soils. Windthrow is examined through the integrating concepts of: the capacity of trees for acclimative growth, the limitation of acclimative growth under inter-tree competition, the recurrent nature of severe weather, how terrain and soil conditions affect local stand vulnerability and the effect of recurrent windthrow on stand dynamics and soils. Windthrow management should take place within a framework of general risk management, with evaluation of the likelihood, severity and potential impacts of wind damage considered – with reference to the broad and specific aims of management. There is much to be gained from interdisciplinary communication about the nature and consequences of recurrent wind damage. There are opportunities for climatologists, engineers, ecologists, geomorphologists and others to develop integrative process models at the tree, stand and landscape scales that will improve our collective understanding, and inform management decision-making.

Testing hypotheses that link wood anatomy to cavitation resistance and hydraulic conductivity in the genus Acer

2010-11-04

Frederic Lens , John S. Sperry , Mairgareth A. Christman +3 more

Tansley medal winner p 509 Tansley medal winner p 509

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The variability of root cohesion as an influence on shallow landslide susceptibility in the Oregon Coast Range

2001-10-01

Kevin M. Schmidt , Joshua J. Roering , J. D. Stock +3 more

Decades of quantitative measurement indicate that roots can mechanically reinforce shallow soils in forested landscapes. Forests, however, have variations in vegetation species and age which can dominate the local stability … Decades of quantitative measurement indicate that roots can mechanically reinforce shallow soils in forested landscapes. Forests, however, have variations in vegetation species and age which can dominate the local stability of landslide-initiation sites. To assess the influence of this variability on root cohesion we examined scarps of landslides triggered during large storms in February and November of 1996 in the Oregon Coast Range and hand-dug soil pits on stable ground. At 41 sites we estimated the cohesive reinforcement to soil due to roots by determining the tensile strength, species, depth, orientation, relative health, and the density of roots [Formula: see text]1 mm in diameter within a measured soil area. We found that median lateral root cohesion ranges from 6.823.2 kPa in industrial forests with significant understory and deciduous vegetation to 25.694.3 kPa in natural forests dominated by coniferous vegetation. Lateral root cohesion in clearcuts is uniformly [Formula: see text]10 kPa. Some 100-year-old industrial forests have species compositions, lateral root cohesion, and root diameters that more closely resemble 10-year-old clearcuts than natural forests. As such, the influence of root cohesion variability on landslide susceptibility cannot be determined solely from broad age classifications or extrapolated from the presence of one species of vegetation. Furthermore, the anthropogenic disturbance legacy modifies root cohesion for at least a century and should be considered when comparing contemporary landslide rates from industrial forests with geologic background rates.Key words: root strength, cohesion, landslide, debris flow, land use, anthropogenic disturbance.

The Mechanical Diversity of Stomata and Its Significance in Gas-Exchange Control

2006-11-17

Paul W. Franks , Graham D. Farquhar

Abstract Given that stomatal movement is ultimately a mechanical process and that stomata are morphologically and mechanically diverse, we explored the influence of stomatal mechanical diversity on leaf gas exchange … Abstract Given that stomatal movement is ultimately a mechanical process and that stomata are morphologically and mechanically diverse, we explored the influence of stomatal mechanical diversity on leaf gas exchange and considered some of the constraints. Mechanical measurements were conducted on the guard cells of four different species exhibiting different stomatal morphologies, including three variants on the classical “kidney” form and one “dumb-bell” type; this information, together with gas-exchange measurements, was used to model and compare their respective operational characteristics. Based on evidence from scanning electron microscope images of cryo-sectioned leaves that were sampled under full sun and high humidity and from pressure probe measurements of the stomatal aperture versus guard cell turgor relationship at maximum and zero epidermal turgor, it was concluded that maximum stomatal apertures (and maximum leaf diffusive conductance) could not be obtained in at least one of the species (the grass Triticum aestivum) without a substantial reduction in subsidiary cell osmotic (and hence turgor) pressure during stomatal opening to overcome the large mechanical advantage of subsidiary cells. A mechanism for this is proposed, with a corollary being greatly accelerated stomatal opening and closure. Gas-exchange measurements on T. aestivum revealed the capability of very rapid stomatal movements, which may be explained by the unique morphology and mechanics of its dumb-bell-shaped stomata coupled with “see-sawing” of osmotic and turgor pressure between guard and subsidiary cells during stomatal opening or closure. Such properties might underlie the success of grasses.

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Inter‐vessel pitting and cavitation in woody Rosaceae and other vesselled plants: a basis for a safety versus efficiency trade‐off in xylem transport

2005-03-16

James K. Wheeler , John S. Sperry , Uwe G. Hacke +1 more

ABSTRACT The hypothesis that greater safety from cavitation by air‐seeding through inter‐vessel pits comes at the cost of less porous pit membranes with greater flow resistance was tested . Sixteen … ABSTRACT The hypothesis that greater safety from cavitation by air‐seeding through inter‐vessel pits comes at the cost of less porous pit membranes with greater flow resistance was tested . Sixteen vessel‐bearing species were compared: 11 from the Rosaceae, four from other angiosperm families, and one fern. Unexpectedly, there was no relationship between pit resistance (and hence the prevailing membrane porosity) and cavitation pressure. There was, however, an inverse relationship between pit area per vessel and vulnerability to cavitation ( r 2 = 0.75). This suggests that cavitation is caused by the rare largest membrane pore per vessel, the average size of which increases with total pit area per vessel. If safety from cavitation constrains pit membrane surface area, it also limits vessel surface area and the minimum vessel resistivity. This trade‐off was consistent with an approximately three‐fold increase in vessel resistivity with cavitation pressure dropping from −0.8 to −6.6 MPa. The trade‐off was compensated for by a reduction in the percentage of vessel wall pitted: from 10–16% in vulnerable species to 2–4% in resistant species. Across species, end‐wall pitting accounted for 53 ± 3% of the total xylem resistivity. This corresponded to vessels achieving on average 94 ± 2% of their maximum possible conductivity if vessel surface area is constrained.

Strength of tree roots and landslides on Prince of Wales Island, Alaska

1979-02-01

Tien H. Wu , William P. McKinnell , Douglas N. Swanston

The stability of slopes before and after removal of forest cover was investigated. Porewater pressures and shear strengths were measured and the soil properties were determined by laboratory and in … The stability of slopes before and after removal of forest cover was investigated. Porewater pressures and shear strengths were measured and the soil properties were determined by laboratory and in situ tests. A model of the soil–root system was developed to evaluate the contribution of tree roots to shear strength. The computed safety factors are in general agreement with observed behaviors of the slopes. Decay of tree roots subsequent to logging was found to cause a reduction in the shear strength of the soil–root system.

Ecological limits to plant phenotypic plasticity

2007-11-08

Fernando Valladares , Ernesto Gianoli , José M. Gómez

Phenotypic plasticity is considered the major means by which plants cope with environmental heterogeneity. Although ubiquitous in nature, actual phenotypic plasticity is far from being maximal. This has been explained … Phenotypic plasticity is considered the major means by which plants cope with environmental heterogeneity. Although ubiquitous in nature, actual phenotypic plasticity is far from being maximal. This has been explained by the existence of internal limits to its expression. However, phenotypic plasticity takes place within an ecological context and plants are generally exposed to multifactor environments and to simultaneous interactions with many species. These external, ecological factors may limit phenotypic plasticity or curtail its adaptive value, but seldom have they been considered because limits to plasticity have typically addressed factors internal to the plant. We show that plastic responses to abiotic factors are reduced under situations of conservative resource use in stressful and unpredictable habitats, and that extreme levels in a given abiotic factor can negatively influence plastic responses to another factor. We illustrate how herbivory may limit plant phenotypic plasticity because damaged plants can only rarely attain the optimal phenotype in the challenging environment. Finally, it is examined how phenotypic changes involved in trait-mediated interactions can entail costs for the plant in further interactions with other species in the community. Ecological limits to plasticity must be included in any realistic approach to understand the evolution of plasticity in complex environments and to predict plant responses to global change.

Effects of Wind on Plants

2008-01-01

Emmanuel de Langre

This review surveys the large variety of mechanical interactions between wind and plants, from plant organs to plant systems. These interactions range from leaf flutter to uprooting and seed dispersal, … This review surveys the large variety of mechanical interactions between wind and plants, from plant organs to plant systems. These interactions range from leaf flutter to uprooting and seed dispersal, as well as indirect effects on photosynthesis or insect communication. I first estimate the relevant nondimensional parameters and then discuss turbulence, plant dynamics, and the mechanisms of interaction in this context. Some common features are identified and analyzed in relation to the wind engineering of manmade structures. Strong coupling between plants and wind exists, in which the plant motion modifies the wind dynamics. I also present some related biological issues in which the relation between plant life and wind environment is emphasized. [V]oici la lourde nappe/Et la profonde houle et l’océan des blés [Like a sheet/The deep swell on a sea of wheat] Charles Péguy (1873–1914)

Chilling Injury in Plants

1973-06-01

James M. Lyons

Crop loss due to soil salinization is an increasing threat to agriculture worldwide. This review provides an overview of cellular and physiological mechanisms in plant responses to salt. We place … Crop loss due to soil salinization is an increasing threat to agriculture worldwide. This review provides an overview of cellular and physiological mechanisms in plant responses to salt. We place cellular responses in a time- and tissue-dependent context ...Read More

The hierarchical structure and mechanics of plant materials

2012-08-08

Lorna J. Gibson

The cell walls in plants are made up of just four basic building blocks: cellulose (the main structural fibre of the plant kingdom) hemicellulose, lignin and pectin. Although the microstructure … The cell walls in plants are made up of just four basic building blocks: cellulose (the main structural fibre of the plant kingdom) hemicellulose, lignin and pectin. Although the microstructure of plant cell walls varies in different types of plants, broadly speaking, cellulose fibres reinforce a matrix of hemicellulose and either pectin or lignin. The cellular structure of plants varies too, from the largely honeycomb-like cells of wood to the closed-cell, liquid-filled foam-like parenchyma cells of apples and potatoes and to composites of these two cellular structures, as in arborescent palm stems. The arrangement of the four basic building blocks in plant cell walls and the variations in cellular structure give rise to a remarkably wide range of mechanical properties: Young's modulus varies from 0.3 MPa in parenchyma to 30 GPa in the densest palm, while the compressive strength varies from 0.3 MPa in parenchyma to over 300 MPa in dense palm. The moduli and compressive strength of plant materials span this entire range. This study reviews the composition and microstructure of the cell wall as well as the cellular structure in three plant materials (wood, parenchyma and arborescent palm stems) to explain the wide range in mechanical properties in plants as well as their remarkable mechanical efficiency.

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On the maximum extent of tree roots

1991-12-01

E. L. Stone , P. J. Kalisz

The Influence of Plant Root Systems on Subsurface Flow: Implications for Slope Stability

2011-11-01

Murielle Ghestem , Roy C. Sidle , Alexia Stokes

Although research has explained how plant roots mechanically stabilize soils, in this article we explore how root systems create networks of preferential flow and thus influence water pressures in soils … Although research has explained how plant roots mechanically stabilize soils, in this article we explore how root systems create networks of preferential flow and thus influence water pressures in soils to trigger landslides. Root systems may alter subsurface flow: Hydrological mechanisms that promote lower pore-water pressures in soils are beneficial to slope stability, whereas those increasing pore pressure are adverse. Preferential flow of water occurs in the following types of root channels: (a) channels formed by dead or decaying roots, (b) channels formed by decayed roots that are newly occupied by living roots, and (c) channels formed around live roots. The architectural analysis of root systems improves our understanding of how roots grow initially, develop, die, and interconnect. Conceptual examples and case studies are presented to illustrate how root architecture and diverse traits (e.g., diameter, length, orientation, topology, sinuosity, decay rate) affect the creation of root channels and thus affect preferential flow.

Trends in wood density and structure are linked to prevention of xylem implosion by negative pressure

2001-02-01

Uwe G. Hacke , John S. Sperry , William T. Pockman +2 more

Global patterns of leaf mechanical properties

2011-01-25

Yusuke Onoda , Mark Westoby , Peter B. Adler +7 more

Leaf mechanical properties strongly influence leaf lifespan, plant-herbivore interactions, litter decomposition and nutrient cycling, but global patterns in their interspecific variation and underlying mechanisms remain poorly understood.We synthesize data across … Leaf mechanical properties strongly influence leaf lifespan, plant-herbivore interactions, litter decomposition and nutrient cycling, but global patterns in their interspecific variation and underlying mechanisms remain poorly understood.We synthesize data across the three major measurement methods, permitting the first global analyses of leaf mechanics and associated traits, for 2819 species from 90 sites worldwide.Key measures of leaf mechanical resistance varied c. 500-800-fold among species.Contrary to a long-standing hypothesis, tropical leaves were not mechanically more resistant than temperate leaves.Leaf mechanical resistance was modestly related to rainfall and local light environment.By partitioning leaf mechanical resistance into three different components we discovered that toughness per density contributed a surprisingly large fraction to variation in mechanical resistance, larger than the fractions contributed by lamina thickness and tissue density.Higher toughness per density was associated with long leaf lifespan especially in forest understory.Seldom appreciated in the past, toughness per density is a key factor in leaf mechanical resistance, which itself influences plantanimal interactions and ecosystem functions across the globe.

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Redefining fine roots improves understanding of below‐ground contributions to terrestrial biosphere processes

2015-03-10

Michael McCormack , Ian A. Dickie , David M. Eissenstat +7 more

Summary Fine roots acquire essential soil resources and mediate biogeochemical cycling in terrestrial ecosystems. Estimates of carbon and nutrient allocation to build and maintain these structures remain uncertain because of … Summary Fine roots acquire essential soil resources and mediate biogeochemical cycling in terrestrial ecosystems. Estimates of carbon and nutrient allocation to build and maintain these structures remain uncertain because of the challenges of consistently measuring and interpreting fine‐root systems. Traditionally, fine roots have been defined as all roots ≤ 2 mm in diameter, yet it is now recognized that this approach fails to capture the diversity of form and function observed among fine‐root orders. Here, we demonstrate how order‐based and functional classification frameworks improve our understanding of dynamic root processes in ecosystems dominated by perennial plants. In these frameworks, fine roots are either separated into individual root orders or functionally defined into a shorter‐lived absorptive pool and a longer‐lived transport fine‐root pool. Using these frameworks, we estimate that fine‐root production and turnover represent 22% of terrestrial net primary production globally – a c . 30% reduction from previous estimates assuming a single fine‐root pool. Future work developing tools to rapidly differentiate functional fine‐root classes, explicit incorporation of mycorrhizal fungi into fine‐root studies, and wider adoption of a two‐pool approach to model fine roots provide opportunities to better understand below‐ground processes in the terrestrial biosphere. Contents Summary 505 I. Introduction 506 II. Ordered variation in fine‐root traits – different functions of different roots 506 III. Pitfalls and platforms – understanding bias and improving estimates of root processes 508 IV. Moving forward using root orders and functional classifications 512 V. Can we integrate mycorrhizal fungi with root classifications? 513 VI. Conclusions and recommendations 514 Acknowledgements 515 References 515

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Rain-, wind-, and touch-induced expression of calmodulin and calmodulin-related genes in Arabidopsis

1990-02-01

Janet Braam , Ronald W. Davis

In response to water spray, subirrigation, wind, touch, wounding, or darkness, Arabidopsis regulates the expression of at least four touch-induced (TCH) genes. Ten to thirty minutes after stimulation, mRNA levels … In response to water spray, subirrigation, wind, touch, wounding, or darkness, Arabidopsis regulates the expression of at least four touch-induced (TCH) genes. Ten to thirty minutes after stimulation, mRNA levels increase up to 100-fold. Arabidopsis plants stimulated by touch develop shorter petioles and bolts. This developmental response is known as thigmomorphogenesis. TCH 1 cDNA encodes the putative Arabidopsis calmodulin differing in one amino acid from wheat calmodulin. Sequenced regions of TCH 2 and TCH 3 contain 44% and 70% amino acid identities to calmodulin, respectively. The regulation of this calmodulin-related gene family in Arabidopsis suggests that calcium ions and calmodulin are involved in transduction of signals from the environment, enabling plants to sense and respond to environmental changes.

Mechanical Defences to Herbivory

2000-11-01

Peter W. Lucas

The two major mechanical defences of plants are toughness and hardness. These have different material causes and ecological functions. In any non-metal, high toughness is achieved by composite construction (i.e. … The two major mechanical defences of plants are toughness and hardness. These have different material causes and ecological functions. In any non-metal, high toughness is achieved by composite construction (i.e. by an organized mixture of components). The primary source of toughening in plants is the composite cell wall (cellulosic microfibrils set in a hemicellulose and, sometimes, lignin matrix), with a toughness of 3.45 kJ m −2 , which is ten-times the probable toughness of its individual components if they could be isolated. The toughness of most plant tissues is roughly proportional to the volume fraction of tissue occupied by cell wall ( Vc ) and, compared to animal tissues and non-biological composites, is very low. High toughness in plant cells is not produced by the walls themselves, but by their plastic intracellular collapse. This is a truly cellular toughening mechanism, one of the most potent ever discovered by materials scientists, depending on an elongate cell shape with microfibrils directed uniformly at a small angle to the cellular axis. Only 'woody' cells, tracheids and fibres, have this framework and only in the S2 layer of their secondary wall. Despite this non-optimum configuration, toughness is elevated by this mechanism ten-times above that due to cell wall resistance alone. The effectiveness of toughness in preventing herbivory is indisputable, but largely indirect due to confusion over a false equivalence between nutritional 'fibre content' and toughness. In contrast, generalized hardness requires high density. If hardness is due to high Vc , this conflicts with 'woody' toughness because there is then no lumen for cell walls to collapse into. Thus, dense seed shells may be brittle (i.e. low toughness) even if built from fibres. However, solid cell wall is not very hard. Instead, high hardness in plants is associated with amorphous silica and is always localized. The efficacy of hardness is more difficult to evaluate than toughness because some animals specialize in coping with it. Copyright 2000 Annals of Botany Company

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Intra‐ and inter‐plant variation in xylem cavitation in Betula occidentalis

1994-11-01

John S. Sperry , Nicanor Z. Saliendra

ABSTRACT A modified version of a method that uses positive air pressures to determine the complete cavitation response of a single axis is presented. Application of the method to Betula … ABSTRACT A modified version of a method that uses positive air pressures to determine the complete cavitation response of a single axis is presented. Application of the method to Betula occidentalis Hook, gave a cavitation response indistinguishable from that obtained by dehydration, thus verifying the technique and providing additional evidence that cavitation under tension occurs by air entry through interconduit pits. Incidentally, this also verified pressure‐bomb estimates of xylem tension and confirmed the existence of large (i.e. >0·4 MPa) tensions in xylem, which have been questioned in recent pressure‐probe studies. The air injection method was used to investigate variation within and amongst individuals of B. occidentalis. Within an individual, the average cavitation tension increased from 0·66±0·27 MPa in roots (3·9 to 10·7 mm diameter), to 1·17±0·10 MPa in trunks (12 to 16 mm diameter), to 1·36±0·04 MPa in twigs (3·9 to 5 mm diameter). Cavitation tension was negatively correlated with the hydraulically weighted mean of the vessel diameter, and was negatively correlated with the conductance of the xylem per xylem area. Native cavitation was within the range predicted from the measured cavitation response and in situ maximum xylem tensions: roots were significantly cavitated compared with minimal cavitation in trunks and twigs. Leaf turgor pressure declined to zero at the xylem tensions predicted to initiate cavitation in petiole xylem (1·5 MPa). Amongst individuals within B. occidentalis , average cavitation tension in the main axis varied from 0·90 to 1·90 MPa and showed no correlation with vessel diameter. The main axes of juveniles (2–3 years old) had significantly narrower vessel diameters than those of adults, but there was no difference in the average cavitation tension. However, juvenile xylem retained hydraulic conductance to a much higher xylem tension (3·25 MPa) than did adult xylem (2·25 MPa), which could facilitate drought survival during establishment.

Species and Stand Response to Catastrophic Wind in Central New England, U.S.A.

1988-03-01

David R. Foster

(1) The effect of catastrophic hurricane wind on forest vegetation in central New England was examined at the species and stand level. (2) Species susceptibility to wind is largely explained … (1) The effect of catastrophic hurricane wind on forest vegetation in central New England was examined at the species and stand level. (2) Species susceptibility to wind is largely explained by canopy position: fast-growing, pioneer species that form overstorey dominants (Pinus strobus, P. resinosa, Populus spp. and Betula papyrifera) suffered much greater damage than slower growing, or tolerant species occurring primarily in codominant, intermediate and suppressed canopy positions (Carya spp., Acer rubrum, Quercus alba, Q. velutina and Tsuga canadensis). Uprooting was much more important than breakage as the primary form of damage. This result, which contrasts with the findings of most studies of wind damage, may perhaps be explained by the very high levels of precipitation that accompanied the storm, saturating the soil and loosening the roots. (3) Damage to forest stands exhibits a positive, linear relationship with stand age and height and negative relationship with density. Conifer forests are significantly more susceptible than hardwood forests. Pinus strobus and P. resinosa stands are susceptible to wind at 15 years of age and are completely destroyed at 30 years; hardwood stands exhibit increasing damage from age 20 years, but are not completely blown down until age 80-100 years. (4) Within stands, damage shifts progressively from the dominant trees in young stands to include trees in the codominant, intermediate and suppressed layers in older forests. Parallel changes with age in the type of damage include a decline in the number of leaning trees and increase in uprooting. (5) Damage to species and stands from a catastrophic windstorm occurs quite predictably and specifically within the forests studied. This discriminating impact of wind has profound consequences on the vegetation at a range of spatial scales and is largely mediated by historical factors and structural and compositional aspects of the vegetation mosaic.

Freezing and Injury in Plants

1976-06-01

M. J. Burke , Lawrence V. Gusta , H. A. Quamme +2 more

Review: Wind impacts on plant growth, mechanics and damage

2016-01-27

Barry Gardiner , Peter Berry , Bruno Moulia

Compression Wood in Gymnosperms

1986-01-01

T. E. Timell

Characteristics and Functions of Root Systems

2002-03-29

Alastair Fitter

The root systems of terrestrial plants perform two primary functions: the acquisition of soil-based resources (principally water and ions), and anchorage. Other root system functions, such as storage, synthesis of … The root systems of terrestrial plants perform two primary functions: the acquisition of soil-based resources (principally water and ions), and anchorage. Other root system functions, such as storage, synthesis of growth regulators, propagation, and dispersal, can be seen as secondary. Little is known of the early evolution of the nonaerial parts of plants, although root traces have been found in fossil soils from Silurian deposits (Retallack, 1997), but it is certain that most of the first land plants, such as Cooksonia, Aglaophyton, and Rhynia, dating from the late Silurian and early Devonian periods, had poorly developed root systems (Collinson and Scott, 1987; see also Chapter 1 by Kenrick in this volume). Such fragments as preserved are of large diameter, and sparingly and often dichotomously branched. Early land plants were small and lived in very wet environments; evidence for plants with developed root systems growing in welldrained soils does not appear until the late Devonian (Driese et al., 1997). Neither anchorage nor acquisition of water is therefore likely to have been a serious problem: the tree habit, necessitating deep rooting for anchorage, did not develop until the mid-Devonian, when the evolution of the seed further freed plants from dependence on wet environments (Algeo and Scheckler, 1998; Bateman et al., 1998). It is likely that the most difficult function for early root systems to perform was the acquisition of poorly mobile resources, especially phosphate (Pirozynski and Malloch, 1975; Lewis, 1987). Modern plants with similar underground parts, such as those with "magnolioid" roots, i.e., thick, littlebranched root systems typified by the primitive family Magnoliaceae (Baylis, 1975), or achlorophyllous orchids (e.g., Neottia, Epipogium), are habitually or even obligately mycorrhizal. It is almost certain that Aglaophyton also was mycorrhizal, since arbuscules, the diagnostic structures of the most abundant group of mycorrhizal fungi, have been identified in its fossils (Remy et al., 1994). Mycorrhizal fungal spores have been found in Silurian deposits that certainly predate the evolution of root systems (Redecker et al., 2000).

The wood from the trees: The use of timber in construction

2016-10-14

Michael H. Ramage , Henry C. Burridge , Marta Busse‐Wicher +7 more

Trees, and their derivative products, have been used by societies around the world for thousands of years. Contemporary construction of tall buildings from timber, in whole or in part, suggests … Trees, and their derivative products, have been used by societies around the world for thousands of years. Contemporary construction of tall buildings from timber, in whole or in part, suggests a growing interest in the potential for building with wood at a scale not previously attainable. As wood is the only significant building material that is grown, we have a natural inclination that building in wood is good for the environment. But under what conditions is this really the case? The environmental benefits of using timber are not straightforward; although it is a natural product, a large amount of energy is used to dry and process it. Much of this can come from the biomass of the tree itself, but that requires investment in plant, which is not always possible in an industry that is widely distributed among many small producers. And what should we build with wood? Are skyscrapers in timber a good use of this natural resource, or are there other aspects of civil and structural engineering, or large-scale infrastructure, that would be a better use of wood? Here, we consider a holistic picture ranging in scale from the science of the cell wall to the engineering and global policies that could maximise forestry and timber construction as a boon to both people and the planet.

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Hydrologic regulation of plant rooting depth

2017-09-18

Ying Fan , Gonzalo Miguez‐Macho , Estéban G. Jobbágy +2 more

Significance Knowledge of plant rooting depth is critical to understanding plant-mediated global change. Earth system models are highly sensitive to this particular parameter with large consequences for modeled plant productivity, … Significance Knowledge of plant rooting depth is critical to understanding plant-mediated global change. Earth system models are highly sensitive to this particular parameter with large consequences for modeled plant productivity, water–energy–carbon exchange between the land and the atmosphere, and silicate weathering regulating multimillion-year-timescale carbon cycle. However, we know little about how deep roots go and why. Accidental discoveries of >70-m-deep roots in wells and >20-m-deep roots in caves offer glimpses of the enormous plasticity of root response to its environment, but the drivers and the global significance of such deep roots are not clear. Through observations and modeling, we demonstrate that soil hydrology is a globally prevalent force driving landscape to global patterns of plant rooting depth.

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Sand and Sandstone

1987-01-01

F. J. Pettijohn , Paul Edwin Potter , Raymond Siever

Plant Cell Expansion: Regulation of Cell Wall Mechanical Properties

1984-01-01

L Taiz

Optimal curling of thin-walled cross-sections under flexural performance considerations

2025-06-25

Léon Chiriatti , Vincent Magnenet , Vincent Le Houérou | Structures

The influence of branch inclination angles on the dynamic response of the olive tree to trunk shaking

2025-06-24

Pedro Sánchez-Cachinero , Fernando Aragón-Rodríguez , Sergio Tombesi +1 more | Journal of Agricultural Engineering

Traditional and intensive olive groves account for a large part of today’s olive orchards and their harvesting is based on trunk shakers. The vibration parameters set in these machines and … Traditional and intensive olive groves account for a large part of today’s olive orchards and their harvesting is based on trunk shakers. The vibration parameters set in these machines and the biomechanical properties of the olive tree influence the detachment process. Tree geometry and morphology are fundamental factors influencing the propagation of vibration. Understanding the effect of tree geometry on vibration propagation can provide useful indications for tree training and pruning. The aim of this work is to study the effect of branch inclination on the vibration response when a trunk shaker is applied, as there is no experimental information on this variable in the literature. We randomly selected 80 olive trees from an intensive olive orchard, and the acceleration of the trunk and one of the main branches was recorded for each tree when forced vibration was applied using a trunk shaker. Two triaxial MEMS accelerometers were used to measure the vibration and, in addition, the location of each sensor, the trunk and branch diameters and the branch angle were measured. It was observed that in all cases there was an amplification of acceleration from the trunk to the branch: the mean acceleration transmissibility value was 139.5%. The highest acceleration values occurred in branches with an inclination between 30 and 60 degrees, which also had the highest acceleration transmissibility, with an increase of 13.8-16.8% and 6.3-10.5%, respectively. In addition, the highest relative kinetic energy ratio was higher in branches with an inclination between 30 and 60 degrees.

Pattern of secondary growth in monocot roots: unveiling longitudinal and cross-sectional variability

2025-06-24

Jan Marcinkiewicz , Joanna Jura‐Morawiec | Planta

Abstract Main conclusion Monocot cambium activity varies along the root axis and circumference, resulting in eccentric secondary growth. Variation in secondary growth structure along the root diameter indicates functional specialization … Abstract Main conclusion Monocot cambium activity varies along the root axis and circumference, resulting in eccentric secondary growth. Variation in secondary growth structure along the root diameter indicates functional specialization but without reaction wood characteristics. Abstract Secondary growth in roots is one of the most important adaptive features, providing mechanical support to stabilize the aboveground part of an arborescent plant. Our knowledge of this phenomenon in arborescent monocots is limited: it occurs exclusively in Dracaena species, it has a bundled structure and it is formed by the monocot cambium. To add to our understanding, we investigated the pattern of secondary thickening along the axis and along the diameter of the stem-borne roots of a dragon tree Dracaena draco L. by analyzing the direction of eccentricity vector and examining root anatomy. We hypothesized that the distribution of secondary growth changes along the root and that there are anatomic differences between concentric secondary growth (uniform around the root) and eccentric secondary growth (asymmetric), that may shed light on its adaptive significance. We found that roots show irregular eccentricity, with the direction of the eccentricity vector changing from up to sideways, counterclockwise or clockwise. Vascular bundle density was lower in eccentric secondary growth and these bundles differed in size, shape, and components (tracheid lumen fraction, tracheid wall fraction) compared to concentric secondary growth. Distinct arcs in eccentric secondary growth were the result of varying thickness of the ground parenchyma cell walls, variation in bundle size, or a combination of both. Our study was a pioneering effort to investigate the variability of secondary growth along roots in monocots, and suggests a spatial separation of the mechanical and transport functions in the root, but without the contribution of features characteristic of reaction wood.

Spatial Differentiation of Soil by Physical Properties in Intensive Apple Orchards by the Time of Their Uprooting

2025-06-24

V.L. Zakharov , Г.Н. Пугачев , Sergey Shubkin +2 more | Indian Journal of Agricultural Research

Background: The study was conducted between 2019 and 2025 in intensive non-irrigated apple orchards in the Lipetsk and Tambov regions. The research focused on soil conditions in orchard aisles and … Background: The study was conducted between 2019 and 2025 in intensive non-irrigated apple orchards in the Lipetsk and Tambov regions. The research focused on soil conditions in orchard aisles and trunk strips, analyzing soil structure and water retention before uprooting 16-year-old trees. Methods: Soil properties were examined at various depths (up to 90 cm) in both the row-to-row zones and trunk strips. Key parameters analyzed included aggregate water resistance, soil structure coefficient, solid phase density, bulk density, total porosity, hygroscopicity, maximum hygroscopic moisture and soil moisture retention. The correlation between total humus content and water-physical parameters was also assessed. Result: The water resistance of aggregates greater than 0.25 mm was significantly lower in the row-to-row zones compared to trunk strips, particularly in the 0-20 cm layer. The soil structure coefficient in row spacings was 1.7-4.4 times lower than in trunk strips, with differences observed up to 60 cm deep. Solid phase density in row spacings was 0.1-0.15 g/cm³ higher than in trunk strips, with bulk density differences of 0.1-0.2 g/cm³ up to 90 cm deep. The total porosity in the 20-50 cm layer of row spacings was 5.8% lower than in trunk strips. Soil hygroscopicity in the 0-90 cm layer was 0.55-0.7% lower in row-to-row zones compared to trunk strips, with the 0-30 cm layer in row zones having 2 times lower hygroscopicity than in its virgin form. Maximum hygroscopic moisture in the 0-30 cm row-to-row layer was 4 times lower than in the virgin type and in the 30-60 cm layer, 5.6 times lower. The lowest moisture capacity in the 0-60 cm row-to-row layer was 9.0-15.0% lower than in the trunk strip, where it remained at virgin soil levels. Soil moisture at the rupture of capillary bonds in the 0-60 cm range was 2.2-2.3 times lower in the intensive orchard than in row-to-row zones. The correlation coefficient (r) between total humus content and water-physical parameters ranged from 0.55 to 0.7.

Developing Nature-based Solutions in the Alps: an Ex-situ Experiment to Select Willows for Subalpine Soil and Water Bioengineering Structures

2025-06-23

Juliette Rousset , Sarah Menoli , Adeline François +2 more | Environmental Management

Mass and Volume Modeling of Strawberry Fruits (Arbutus unedo L) Based on Engineering Properties and Image Processing Approach

2025-06-23

Adinath Kate , Praween Nishad | Journal of Agricultural Engineering (India)

Strawberry fruits are often graded based on size, shape, and colour, but it could be more efficient to grade them using mass or volume. Therefore, the relationships between the physical … Strawberry fruits are often graded based on size, shape, and colour, but it could be more efficient to grade them using mass or volume. Therefore, the relationships between the physical characteristics of fruit and its mass or volume are needed. Present study aims to predict the mass and volume of strawberry fruit based on measured values of selected physical parameters, and develop single and multivariate regression models like linear, quadratic, power, and exponential for prediction. Further, the mass and volume models were presented under different categories such as based on dimensions (including length, width, perimeter, and projected area), volumes, and density values. Among these models, quadratic was found appropriate. The experimental data analysis showed that the R2 of the quadratic model for the mass and the length, width, perimeter, and projected area were 0.893, 0.864, 0.908, and 0.909, respectively. In contrast, for the volume, R2 values were 0.887, 0.872, 0.905, and 0.910 for length, width, perimeter, and projected area, respectively. The results revealed that mass and volume modeling based on the projected area were the best-fit models with better prediction accuracy. The highest coefficient of determination (R2) was obtained for mass modeling of strawberries based on measured volume as R2 = 0.975. Mass modeling was recommended as the most accurate, reliable, and appropriate modeling compared to volume modeling. The findings of these study can be used as hyperparameters in automated grading system based on volume or weight of the individual fruit.

Mitigating tropical cyclone susceptibility in pecan (Carya illinoinensis) orchards

2025-06-21

Jeffery B. Cannon , Andrew W. Whelan , A. Johnson +1 more | Scientia Horticulturae

Drought Stress Grading Model for Apple Rootstock Softwood Cuttings Based on the CU-ICA-Net

2025-06-21

Xu Wang , Pengfei Wang , Jianping Li +2 more | Agronomy

In order to maintain adequate hydration of apple rootstock softwood cuttings during the initial stage of cutting, a drought stress grading model based on machine vision was designed. This model … In order to maintain adequate hydration of apple rootstock softwood cuttings during the initial stage of cutting, a drought stress grading model based on machine vision was designed. This model was optimized based on the U-Net (U-shaped Neural Network), and the petiole morphology of the cuttings was used as the basis for classifying the drought stress levels. For the CU-ICA-Net model, which is obtained by improving U-Net with the ICA (Improved Coordinate Attention) module designed using a cascaded structure and dynamic convolution, the average accuracy rate of the predictions for the three parts of the cuttings, namely the leaf, stem, and petiole, is 93.37%. The R2 values of the prediction results for the petiole curvature k and the angle α between the petiole and the stem are 0.8109 and 0.8123, respectively. The dataset used for model training consists of 1200 RGB images of cuttings under different grades of drought stress. The ratio of the training set to the test set is 1:0.7. A humidification test was carried out using an automatic humidification system equipped with this model. The MIoU (Mean Intersection over Union) value is 0.913, and the FPS (Frames Per Second) value is 31.90. The test results prove that the improved U-Net model has excellent performance, providing a method for the design of an automatic humidification control system for industrialized cutting propagation of apple rootstocks.

Tree fruit harvesting: Recent developments and future challenges for robotic harvesting

2025-06-21

G Thamarai selvi , B. Suthakar , A. Surendrakumar +2 more | Plant Science Today

Tree fruit harvesting is a vital process in agriculture, involving the collection of ripe fruits from trees. This review examines manual, mechanical and automated harvesting methods, focusing on their benefits, … Tree fruit harvesting is a vital process in agriculture, involving the collection of ripe fruits from trees. This review examines manual, mechanical and automated harvesting methods, focusing on their benefits, challenges and potential advancements. Manual methods, such as hand-picking and using ladders, are highly labour-intensive and time-consuming. To address these challenges, mechanical systems like trunk shakers, canopy shakers, limb shakers and catch-and-frame methods have been introduced. These systems use vibrations and capturing mechanisms to improve efficiency and reduce labour costs. However, mechanical methods are not commonly used for fresh fruit harvesting due to the risk of damaging soft fruits and trees. To solve this issue, precise shake-and-catch systems with controlled vibration frequency and amplitude are being developed, achieving fruit removal rates of up to 93.3 %. Harvesting speeds vary, with manual pickers managing 0.5 th-1, trunk shakers 10 th-1 and canopy shakers 25 th-1. Automated harvesting offers even greater efficiency by using robots equipped with advanced technologies, such as deep learning, image processing and specialized grippers, to detect and pick fruits. These systems can complete harvesting in just 4 seconds per fruit. This review highlights the strengths and weaknesses of current methods and explores strategies to enhance fruit harvesting technologies.

Modelling peak vertical ground reaction force from smart watch metrics reveals link between higher forces and softer cushioning perception

2025-06-20

Cristopher D. Garduno Luna , Brian Ruhe , Christopher Ertel +1 more | Footwear Science

Three-Dimensional Scanning and Computational Simulation of Coffee Tree Branches

2025-06-20

Dayanne Ellen da Silva e Silva , Ricardo Rodrigues Magalhães , Fábio Lúcio Santos +2 more | Agriculture

Coffee has significant economic importance in Brazil, which is the world’s largest exporter of this product. The main focus of this work is to obtain a computational model of coffee … Coffee has significant economic importance in Brazil, which is the world’s largest exporter of this product. The main focus of this work is to obtain a computational model of coffee branches, using scanning techniques and experimental validation through modal analysis, to understand their mechanical behaviors due to dynamic and static properties. The main mechanical properties of the branches, including specific gravity and elastic modulus, were obtained in the laboratory and used as input parameters for the simulations. Geometric models were obtained by means of three-dimensional scanning and analyzed using the finite element method to predict the static and dynamic behaviors of the branches. The methodology was validated in experimental tests. The results of vibration frequencies obtained in the branches showed variations between simulations and experimental tests ranging from 2% to 20%, and the statistical analysis did not find significant differences. The results demonstrate important indicators for predicting the static and dynamic behaviors of plagiotropic branches of a coffee tree. These results can be considered in vibration analysis for coffee harvesting, which represents a technological advance in the area, since simplified models are usually obtained by geometric coordinates to obtain geometric models of a coffee tree.

Progressive synergistic evolution characteristics of soil arching in supported arch-locked colluvial landslides

2025-06-20

Miao Ren | Ain Shams Engineering Journal

Influence of carbon-fiber insole stiffness on dynamic stability during running: insights from nonlinear objective analysis combined with subjective assessment

2025-06-20

Zixiang Gao , Robin Trama , Abdul Asim +5 more | Footwear Science

Some Slopes Are Bigger Than Others

2025-06-19

Thomas J. Linneman | Routledge eBooks

DEVELOPMENT OF TIMBER JOINTS USING TENSILE BOLTS WITH DISTANTLY SPACED SETS OF NUTS AND WASHERS

2025-06-19

K. Mizuno , Takaaki KURIHARA , Sota KURUMA +4 more | AIJ Journal of Technology and Design

Comparative Assessment of Woody Species for Runoff and Soil Erosion Control on Forest Road Slopes in Harvested Sites of the Hyrcanian Forests, Northern Iran

2025-06-17

Pejman Dalir , Ramin Naghdi , S. Jafari +1 more | Forests

Soil erosion and surface runoff on forest road slopes are major environmental concerns, especially in harvested areas, making effective mitigation strategies essential for sustainable forest management. The study compared the … Soil erosion and surface runoff on forest road slopes are major environmental concerns, especially in harvested areas, making effective mitigation strategies essential for sustainable forest management. The study compared the effectiveness of three selected woody species on forest road slopes as a possible mitigating action for runoff and soil erosion in harvested sites. Plots measuring 2 m × 3 m were set up with three species—alder (Alnus glutinosa (L.) Gaertn.), medlar (Mespilus germanica L.) and hawthorn (Crataegus monogyna Jacq.)—on the slopes of forest roads. Within each plot, root abundance, root density, canopy percentage, canopy height, herbaceous cover percentage, and selected soil characteristics were measured and analyzed. Root frequency and Root Area Ratio (the ratio between the area occupied by roots in a unit area of soil) measurements were conducted by excavating 50 × 50 cm soil profiles at a 10-cm distance from the base of each plant in the four cardinal directions. The highest root abundance and RAR values were found in hawthorn, followed by alder and medlar in both cases. The same order of magnitude was evidenced in runoff (255.42 mL m−2 in hawthorn followed by 176.81 mL m−2 in alder and 67.36 mL m−2 in medlar) and the reverse order in terms of soil erosion (8.23 g m−2 in hawthorn compared to 22.5 g m−2 in alder and 50.24 g m−2 in medlar). The results of the study confirm that using plant species with dense and deep roots, especially hawthorn, significantly reduces runoff and erosion, offering a nature-based solution for sustainable forest road management. These results highlight the need for further research under diverse ecological and soil conditions to optimize species selection and improve erosion mitigation strategies.

The Proportion of Frost‐Damaged Leaves: A Simple and Robust Approach for Evaluating Frost Damage in Wheat (<scp>Triticum aestivum</scp> L.)

2025-06-16

Lei Li , Bichun Li , Yong Yang +4 more | Journal of Agronomy and Crop Science

ABSTRACT Frost resistance is a crucial trait in wheat breeding, and accurately assessing the phenotype of frost damage is vital for the genetic improvement of wheat resistance to frost damage. … ABSTRACT Frost resistance is a crucial trait in wheat breeding, and accurately assessing the phenotype of frost damage is vital for the genetic improvement of wheat resistance to frost damage. However, the unpredictability of cold wave events and regional variations in frost damage levels complicate the precise evaluation of frost damage. Survival rate and frost damage grade (on a scale of 1 to 5) are commonly used indicators for evaluating frost damage. However, these methods are mainly effective in extreme low‐temperature conditions that cause significant wheat mortality or result in severe frost damage ratings above 3. They are not well‐suited for the more subtle phenotypic variations associated with common low temperatures, such as those ranging from −10°C to −5°C. In this study, we employed four different phenotyping methods to evaluate the severity of frost damage in a panel of 50 wheat recombinant inbred lines in two distinct environments, and proposed a novel approach to quantify frost damage based on the proportion of frost‐damaged leaves (PFD), which proves to be simple and robust for assessing the severity of frost damage in wheat across multiple biological replicates and a spectrum of environmental conditions.

Viscoelastic Response of Sugar Beet Root Tissue in Quasi-Static and Impact Loading Conditions

2025-06-14

Paweł Kołodziej , Krzysztof Gołacki , Zbigniew Stropek | Sensors

This paper presents the results of quasi-static tests carried out using a texturometer and of impact tests combined with stress relaxation on a stand equipped with a heavy pendulum of … This paper presents the results of quasi-static tests carried out using a texturometer and of impact tests combined with stress relaxation on a stand equipped with a heavy pendulum of the hammer type. The tests were carried out using fresh roots and those stored at 20 °C for 120 h. The impact velocities Vd were 0.001, 0.002, 0.01, 0.02, 0.75, and 1.25 m·s-1. Compiling the relaxation times T1 for Vd indicated their large drops for both fresh and stored roots. The largest average values T1 were obtained in the range from 0.197 s to 0.111 s at the small velocities of deformation 0.001-0.02 m·s-1 and the smallest ones in the range from 0.0252 to 0.0228 s at the Vd equal to 0.75 and 1.25 m·s-1. A decrease in T2 values was observed in the average range of 8.02-4.27 s at Vd = 0.001-0.02 m·s-1 for fresh beets. For the velocities 0.75 m·s-1 and 1.25 m·s-1 and stored roots, the range of average values was smaller and ranged from 6.13 s to 4.54 s. The reaction forces of the Fp sample reached the highest average levels from 168.2 N to 190.8 N for fresh roots and 46.5 to 56.2 N for 5-day-old roots. However, the lowest Fp was recorded at speeds (0.001-0.02 ms-1) 57.5-62.3 N for the fresh roots and 46.5-56.2 N for the 5-day-old roots. For the velocities greater than 0.75 m·s-1 and 1.25 m·s-1, the values of reaction forces increased at the average values 168.2-190.8 N for the fresh roots and 158.2-175.4 N for 5-day-old ones.

Microclimate—The Physical Environment Experienced by Plants

2025-06-12

James R. Ehleringer , Russell K. Monson | CRC Press eBooks

Wind acclimation in a subtropical forest: trees on wind‐exposed slopes are shorter with smaller crowns

2025-06-12

Roi Ankori‐Karlinsky , Toby Jackson , Yuan Gan +4 more | New Phytologist

Summary Tree architecture is an important component of forest community dynamics – taller trees with larger crowns often outcompete their neighbors, but they are generally at higher risk of wind‐induced … Summary Tree architecture is an important component of forest community dynamics – taller trees with larger crowns often outcompete their neighbors, but they are generally at higher risk of wind‐induced damage. Yet, we know little about wind impacts on tree architecture in natural forest settings, especially in complex tropical forests. Here, we use airborne light detection and ranging (LiDAR) and 30 yr of forest inventory data in Puerto Rico to ask whether and how chronic winds alter tree architecture. We randomly sampled 124 canopy individuals of four dominant tree species ( n = 22–39). For each individual, we measured slenderness (height/stem diameter) and crown area (m 2 ) and evaluated whether exposure to chronic winds impacted architecture after accounting for topography (curvature, elevation, slope, and soil wetness) and neighborhood variables (crowding and previous hurricane damage). We then estimated the mechanical wind vulnerability of trees. Three of four species grew significantly shorter (2–4 m) and had smaller crown areas in sites exposed to chronic winds. A short‐lived pioneer species, by contrast, showed no evidence of wind‐induced changes. We found that three species' architectural acclimation to chronic winds resulted in reduced vulnerability. Our findings demonstrate that exposure to chronic, nonstorm winds can lead to architectural changes in tropical trees, reducing height and crown areas.

Research on the Quality Evaluation System of Rammed Earth Sites in Arid Areas

2025-06-12

Kai Cui , Li Yu , Xiang Zhang +3 more | International Journal of Architectural Heritage

Characteristics of soil physical properties based on soil profile depth in forest stands and upland farms in Andisols

2025-06-10

Jaka Suyana , S. O. Idris , Endang Setia Muliawati +1 more | Journal of Aridland Agriculture

Information on the effect of forest stands and upland farms on soil physical properties is important for soil management. This study evaluated the effect of forest stands and upland farms … Information on the effect of forest stands and upland farms on soil physical properties is important for soil management. This study evaluated the effect of forest stands and upland farms on the physical properties of Andisols soils in the Mount-Merbabu National Park, Indonesia. A total of 108 soil samples were collected from each Pine, Acacia, Puspa (Schima noronhae Theaceae), Bintamin (Cupressus sp.), mixed, and upland farms at soil depths of 0-10, 10-20, 20-30, 30-50, 50-70 and 70-100 cm with three replications at each depth. The results showed that the sand fraction was in the range of 40.7%-73.8%, the silt fraction was in the range of 21.2%-42.6%, and the clay fraction was in the range of 3.2%-9.9%. Soil permeability shows that the value decreases with soil depth and shows different rates between forest stands and upland farms. The highest permeability in forest stands is found in Puspa stands 0-10 cm depth (7.50 cm h-1) and 20-30 cm depth (14.36 cm h-1) in the upland farms, the lowest rate is found in Pine stands 70-100 cm depth (3.07 cm h-1) and 70-100 cm (1.23 cm h-1) in the upland farms. Porosity shows a decreasing value with soil depth where the highest porosity is found in mixed stands at a depth of 10-20 cm (66.17%) and the lowest porosity in Puspa stands at a depth of 70-100 cm (44.41%). Upland farms shows a higher sand fraction content (0-100 cm depth) than forest stands, and forest stands show a higher silt fraction content (0-100 cm depth). Puspa stands have higher permeability than other forest stands (0-10 cm depth).

Effect of Diameter and Number of Bolts on the Rotation Stiffness of Beam-to-Column Timber Joints

2025-06-06

Yosafat Aji Pranata , Olga Catherina Pattipawaej , Amos Setiadi | Journal of Building Material Science

Beam-to-column joints affect the behavior of the building. This research aims to obtain an empirical equation of the rotational stiffness of the beam-to-column timber joints with variations in the number … Beam-to-column joints affect the behavior of the building. This research aims to obtain an empirical equation of the rotational stiffness of the beam-to-column timber joints with variations in the number and diameter of bolts. The method used is the destructive method to obtain elastic and post-elastic history of load and deformation of timber joints. The scope of the research is the timber using red meranti (Shorea spp.) species, with a cross-sectional size of 50mm x 100mm, bolts using various diameters of 8, 10, and 12mm. Beam-to-column timber joints use a variety of one, two, and three bolts. Testing uses a monotonic loading type. The behaviors reviewed are load-carrying capacity and rotational stiffness. The results obtained from this research, which are the proposed bilinear moment-rotational stiffness relationship curve model for beam-to-column timber joints, can provide benefits in modeling and analyzing the structure of multi-storey wooden buildings, especially in modeling parameters of spring elements for beam-to-column joints of red meranti (Shorea spp.) timber. The proposed equation for moment capacity and rotational stiffness in terms of elastic range, namely My and θy, has an R2 of 0.86 and 0.87, respectively. These results indicate a strong relationship between moment capacity, bolt diameter size, and number of bolt variables in a statistical model. In the design context, the parameters used are at elastic limit range conditions. The results of the research show that the number of bolts has a significant effect on the beam-to-column joint, namely the non-linear moment and rotational capacity increases.

Recovery of the forest’s protective effect after stand-replacing wind disturbances

2025-06-05

Christine Moos , Kaya Dietrich , Alexandra Erbach +4 more | Scientific Reports

Study on the interaction mechanism between stubble-breaking blades and unidirectional maize root-soil composites

2025-06-02

Xuanting Liu , Peng Gao , Xiaohu Jiang +3 more | Biosystems Engineering

Root pull-out resistance and surface microstructural characteristics of adapted plants in the water-level fluctuation zone of the three parallel rivers area

2025-06-02

Zhong-Yu Wang , Pan Luo , Yuanjun Yang +2 more | PLoS ONE

Root pull-out resistance is an important index to measure the soil-fixing ability of roots. The study aims to investigate the root pull-out resistance and root surface microstructural characteristics of plants … Root pull-out resistance is an important index to measure the soil-fixing ability of roots. The study aims to investigate the root pull-out resistance and root surface microstructural characteristics of plants adapted to the Water-Level Fluctuation Zone (WLFZ) and provide a reference for the study of vegetation soil reinforcement capacity in the WLFZ of the Three Parallel Rivers area. The study subjects are the four-year-old Arundo donax ‘Versicolor’ , Cyperus involucratus , and Acorus calamus . The study employs the single root pull-out resistance experiments to determine their resistance. Additionally, SEM and paraffin sectioning methods were utilized to measure the microstructure of the root surface and to explore the differences in microstructure and their impact on the friction between the root and soil. The findings revealed (1) The failure modes of the single root pull-out experiments included both pull-out and breakage, with 70.83%, 81.48%, and 57.69% of the roots being broken for A. donax ‘Versicolor’ , C. involucratus , and A. calamus , respectively. (2)There were significant differences in the average maximum pull-out resistance and average frictional strength among the three plants (P < 0.05), with the average maximum pull-out resistance being A. donax ‘Versicolor’ (27.88 N) > C. involucratus (20.53 N) > A. calamus (13.75 N), and the average frictional strength was A. donax ‘Versicolor’ (43.48 Pa) > C. involucratus (31.77 Pa) > A. calamus (19.05 Pa). The root surface roughness also showed significant differences among the three plants (P < 0.05), with the surface roughness of A. donax ‘Versicolor’ (20.13%) > C. involucratus (16.12%) > A. calamus (9.23%). (3) The root system of A. donax ‘Versicolor’ was relatively rough, with dense depressions and protrusions. In contrast, the root system of A. calamus was relatively smooth with no significant depressions or protrusions, and C. involucratus was intermediate between the two. The results suggested that the maximum pull-out force of single roots for the three plants followed the order of A. donax ‘Versicolor’ > C. involucratus > A. calamus . Moreover, the microstructure of the root surface had a significant impact on the maximum pull-out force of the roots, The rougher the root surface. The greater the single root drawing force.

Bearing capacity, shear band evolution, and deformation characteristics of slopes reinforced by root-inspired anchors using transparent soil model testing

2025-06-01

R. Stephanie Huang , Wengang Zhang , Jiaying Xiang +6 more | Journal of Rock Mechanics and Geotechnical Engineering

The comparative effects of arboricultural cabling, bracing and species-specific morphology on tree biomechanics

2025-06-01

Stella R. Dee , Simos Gerasimidis , Sanjay R. Arwade +3 more | Urban forestry & urban greening

Finite Element Modeling of Apple Tissue Mechanics: A Comparative Study of Elastic and Elastoplastic Behavior Across Ripening Stages

2025-06-01

Monika Słupska , Szymon Kuprianiuk , Roman Stopa +1 more | Journal of Food Engineering

Large-scale modelling wind damage vulnerability through combination of high-resolution forest resources maps and ForestGALES

2025-06-01

Morgane Merlin , Tommaso Locatelli , Barry Gardiner +1 more | Forest Ecosystems

Vibration transmission analysis in monumental olive trees for precision pruning: the PULP system approach

2025-06-01

F. Vicino , Francesco Maldera , Giuseppe Lopriore +5 more | Acta Horticulturae

Near real-time warning for urban tree destruction under coupled wind and rain loads: Prediction framework and case study

2025-06-01

Yin Gu , Yi Liu , Yongqiang Chen +1 more | International Journal of Disaster Risk Reduction

Dəniz boru kəmərlərində sızmaların yaranma səbəbləri və mexanizmlərinin təhlili

2025-05-31

Nurlan Abdullazadə | SCIENTIFIC WORK

STUDY ON FATIGUE BEHAVIOR OF TIMBER STRUCTURES SUBJECTED TO REPEATED EARTHQUAKE MOTIONS (PART 3) : PERFORMANCE EVALUATION OF TIMBER SHEAR WALL STRUCTURES CONSIDERING CUMULATIVE DAMAGE BY MULTIPLE EARTHQUAKES

2025-05-31

Yoshihiro Yamazaki , Ryosuke TSUCHIKURA , Kazuhiro Matsuda +1 more | Journal of Structural and Construction Engineering (Transactions of AIJ)

Performance characteristics of self-regulating low energy clay-based irrigation system in different soil types

2025-05-31

Gilbert Osei , Livingstone K. Sam-Amoah , Joshua D. Owusu-Sekyere +3 more | Journal of the Ghana Institution of Engineering (JGhIE)

The purpose of this study was to assess the performance characteristics of a self-regulating low-energy clay-based irrigation (SLECI) system in different soil types. A laboratory experiment was laid out in … The purpose of this study was to assess the performance characteristics of a self-regulating low-energy clay-based irrigation (SLECI) system in different soil types. A laboratory experiment was laid out in a completely randomized design with nine replicates. The treatment consisted of three types of soil (clay, sand and loam). Data was collected on performance parameters of the SLECI system such as seepage rate, hydraulic conductivity and drainage porosity. The results showed that the highest hydraulic conductivity of 0.000186 cm/s was recorded in sandy soils, followed by 0.0001752 cm/s in loamy soils, and the minimum hydraulic conductivity of 0.0001163 cm/s was recorded in clay soils. There were no significant differences (p>0.05) between the seepage rates recorded in sandy soil (4.853 cm2/day) and loamy soil (4.227 cm2/day), but both were significantly higher than that of the clay soil (3.363 cm2/day). The highest wetting perimeter of 75.9 cm was recorded in loamy soils, followed by 56.73 cm and 55.89 cm for clay and sandy soils respectively, translating into 25% and 26.3% greater wetting perimeter. This study shows that the SLECI system performs differently in different soil types with different hydraulic characteristics which might influence water availability for plants’ uptake.

Growth characteristics of a Podocarpus macrophyllus (Thunb.) Sweet forest on a sand spit in the western Izu peninsula.

2025-05-31

Satoshi Osawa , Ayame NOZAKI | Journal of the Japanese Society of Revegetation Technology