Abiotic Agents Research Articles

Udder Health Maintenance to Augment Milk Production in Dairy Cattle: A Review

The burning problems of udder health /subclinical mastitis (SCM) in dairy cattle is considered as a worldwide silent threat which is major reasons for low yield and poor quality milk and causes substantial economic loss. The present work was conducted at ICAR-NDRI, ERS, Kalyani (WB) through a project (2017-2020). The article’s aim is to review important advances in udder health maintenance to ameliorate SCM for higher quantity and quality milk production. Many researchers worked to identify effective practices to control SCM caused by Streptococcus agalactiae and Staphylococcus aureus. Worldwide different researchers aimed to achieve better udder health and focused to detect SCM, mechanisms associated with infection, differentiating between clinical and subclinical stages, invent suitable diagnostic tests, understand exposure time, recognize specific characteristics of pathogen and establishing scientific milking procedures, etc. Establishment of standard operative programs, as discussed in this paper, resulted in better udder health maintenance. In changing climatic scenario and varying farm management practices globally researchers worked to redefine procedures to control SCM caused by different biotic and abiotic agents. Although, researchers achieved significant advances in SCM management, however changing herd structure and increased milk demand indicates that SCM /udder health will be one of the major issues to be dealt by scientists, entrepreneurs, dairy workers.

Cumulative Impact of Biotic and Abiotic Damage Agents on Lodgepole Pine Tree Form and Stand Structure in Southern British Columbia

Not all pests kill trees or compromise final tree form; however, the cumulative effect of one or more damage agents over time can significantly limit final expectations at harvest, severely reducing or compromising wood quality and timber supply expectations going forward. This study highlights the effects of damage agents on young lodgepole pine insouthern British Columbia during the formative years of stand development. Over 4,300ntrees were monitored for up to three decades with over 40 damage agents recorded, causing significant repercussions on stocking, health, and form of potential crop trees. By the final assessment, density of potential crop trees had declined dramatically, with 84% affectedby one or more pests, and 63% of natural ingress dead. Most natural ingress was severely suppressed; thus, it is unlikely to fill in stand gaps caused by mortality and damage agents affecting larger potential crop trees. Lodgepole pine terminal weevil and western gall rust were the predominant damage agents influencing form and quality of potential crop trees. Lodgepole pine terminal weevil attacked up to 73% of pine and over 24% suffered multiple attacks. Results from this study emphasize the need for more short- and long-term monitoring of young stands to inform the development of forest policy and promote healthy, resilient new forests. KEYWORDS: lodgepole pine, damage agents, lodgepole pine terminal weevil, western gall rust, Southern British Columbia

Applications of chitosan to the roots and shoots change the accumulation pattern of cadmium in Talinum patens (Talinaceae) cuttings.

Chitosan induces tolerance to abiotic stress agents in plants. However, studies on the different application forms of this biopolymer are limited. This study evaluated the effect of two forms of chitosan application on the morphophysiology of and metal accumulation by Talinum patens cuttings subjected to Cd to develop new cadmium (Cd) decontamination technologies. Cuttings from 75-day-old plants were transferred to a hydroponic system. For 30 days, three Cd concentrations (0, 7, and 14 mg L-1) and three forms of chitosan application (without application, root, and foliar) were applied. The cuttings were tolerant to Cd because the metal did not influence biomass production or photosynthetic efficiency. Neither chitosan application nor Cd increased the modified chlorophyll content and fluorescence parameters. However, foliar chitosan reduced the transpiration rate. At the highest concentration of Cd, the application of chitosan in the root reduced the Mg content of the root system and shoots. The root application of chitosan increased the surface area and volume of thicker roots at the expense of finer ones. The foliar application resulted in greater total root length and surface area, mainly those finer. Furthermore, chitosan applied to the leaves activated catalase in the roots and leaves. In contrast to the root application, foliar application increased the accumulation of Cd in the roots. The action of catalase and the increase of fine roots may have favored a greater absorption of the nutrient solution and Cd in the chitosan foliar application treatment. It is concluded that chitosan foliar spraying can improve Cd rhizofiltration with T. patens.

Metaheuristic Techniques for Classification Used in Identification of Plant Diseases

Agriculture plays an important role in the economic development of a country. If proper care is given to the growth of crops, it returns to the efforts put in by farmers throughout the year. However, since past few years it is observed that the quality and production of crops are degrading due to the diseases caused by some biotic and abiotic agents. It is deemed necessary to detect crop diseases in time. Conventional methods of identifying a crop disease require a dedicated individual or an expert who can manually detect such diseases. But it is very time consuming process and increases the cost too. Here arises the need to develop automated systems that cannot only detect the plant diseases but saves time and cost. This manuscript will reflect the comparative analysis of classification techniques in terms of accuracies and will help the researchers to identify best practices for their research so as to enhance the efficiency and accuracy of diseases detection systems being developed.

Heterochrony and repurposing in the evolution of gymnosperm seed dispersal units

BackgroundPlant dispersal units, or diaspores, allow the colonization of new environments expanding geographic range and promoting gene flow. Two broad categories of diaspores found in seed plants are dry and fleshy, associated with abiotic and biotic dispersal agents, respectively. Anatomy and developmental genetics of fleshy angiosperm fruits is advanced in contrast to the knowledge gap for analogous fleshy structures in gymnosperm diaspores. Improved understanding of the structural basis of modified accessory organs that aid in seed dispersal will enable future work on the underlying genetics, contributing to hypotheses on the origin of angiosperm fruits. To generate a structural framework for the development and evolution of gymnosperm fleshy diaspores, we studied the anatomy and histochemistry of Ephedra (Gnetales) seed cone bracts, the modified leaves surrounding the reproductive organs. We took an ontogenetic approach, comparing and contrasting the anatomy and histology of fleshy and papery-winged seed cone bracts, and their respective pollen cone bracts and leaves in four species from the South American clade.ResultsSeed bract fleshiness in Ephedra derives from mucilage accumulated in chlorenchyma cells, also found in the reduced young leaves before they reach their mature, dry stage. Cellulosic fibers, an infrequent cell type in gymnosperms, were found in Ephedra, where they presumably function as a source of supplementary apoplastic water in fleshy seed cone bracts. Papery-winged bract development more closely resembles that of leaves, with chlorenchyma mucilage cells turning into tanniniferous cells early on, and hyaline margins further extending into “wings”.ConclusionsWe propose an evolutionary developmental model whereby fleshy and papery-winged bracts develop from an early-stage anatomy shared with leaves that differs at the pollination stage. The ancestral fleshy bract state may represent a novel differentiation program built upon young leaf anatomy, while the derived dry, papery-winged state is likely built upon an existing differentiation pattern found in mature vegetative leaves. This model for the evolution of cone bract morphology in South American Ephedra hence involves a novel differentiation program repurposed from leaves combined with changes in the timing of leaf differentiation, or heterochrony, that can further be tested in other gymnosperms with fleshy diaspores.

Alginate-Induced Disease Resistance in Plants.

Plants are continuously exposed to a wide range of pathogens, including fungi, bacteria, nematodes, and viruses; therefore, survival under these conditions requires a sophisticated defense system. The activation of defense responses and related signals in plants is regulated mainly by the hormones salicylic acid, jasmonic acid, and ethylene. Resistance to pathogen infection can be induced in plants by various biotic and abiotic agents. For many years, the use of abiotic plant resistance inducers has been considered in integrated disease management programs. Recently, natural inducer compounds, such as alginates, have become a focus of interest due to their environmentally friendly nature and their ability to stimulate plant defense mechanisms and enhance growth. Polysaccharides and the oligosaccharides derived from them are examples of eco-compatible compounds that can enhance plant growth while also inducing plant resistance against pathogens and triggering the expression of the salicylic acid-dependent defense pathway.

Evolution in small steps and giant leaps.

The first Editor of Evolution was Ernst Mayr. His foreword to the first issue of Evolution published in 1947 framed evolution as a "problem of interaction" that was just beginning to be studied in this broad context. First, I explore progress and prospects on understanding the subsidiary interactions identified by Mayr, including interactions between parts of organisms, between individuals and populations, between species, and between the organism and its abiotic environment. Mayr's overall "problem of interaction" framework is examined in the context of coevolution within and among levels of biological organization. This leads to a comparison in the relative roles of biotic versus abiotic agents of selection and fluctuating versus directional selection, followed by stabilizing selection in shaping the genomic architecture of adaptation. Oligogenic architectures may be typical for traits shaped more by fluctuating selection and biotic selection. Conversely, polygenic architectures may be typical for traits shaped more by directional followed by stabilizing selection and abiotic selection. The distribution of effect sizes and turnover dynamics of adaptive alleles in these scenarios deserves further study. Second, I review two case studies on the evolution of acquired toxicity in animals, one involving cardiac glycosides obtained from plants and one involving bacterial virulence factors horizontally transferred to animals. The approaches used in these studies and the results gained directly flow from Mayr's vision of an evolutionary biology that revolves around the "problem of interaction."

Apparent and resistant section parametric modelling of timber structures in HBIM

Historic timber structures are frequently composed by elements with irregular sections. Moreover, due to abiotic and biotic agent action, wood is especially vulnerable to decay, which can lead to destruction of external layers of the element. Due to this, a beam's resistant cross-section, which is the healthy section part that supports the structure, and the beam external apparent cross-section may not coincide. This can lead to an improper structural assessment regarding the load-capacity of that element. HBIM technology is currently being used for the representation and analysis of historic timber constructions' structural health. In this work, a methodology is proposed and applied that, based on the combination of LIDAR data with non-destructive tests, allows to obtain a single 3D HBIM model of decayed irregular wooden structures. This HBIM model contains both the apparent parametric model, that represents the structure external geometry and collects all necessary data for construction's conservation analysis, and also a parametric resistant model, that represents the beam's undamaged section, allowing to carry out a more accurate structural analysis. In this work, the methodology was first applied to an irregular and decayed beam at laboratory conditions for framework calibration, and then applied to a case study for validation. With respect to the storage space, the volume difference between the rendered models and the proposed parametric models was on average 3.2%, whereas the occupied memory space was 10 times lower in the parametric models. The case study was the Guimarães chamber roof (Portugal) which structure is made up of several truss systems composed by irregular beams, several of which with signs of past decay activity.

NUMERICAL ANALYSIS OF HARDWOOD TIMBER BEAMS REINFORCED WITH STEEL PLATE SCREWED

There are several technologies to recover and strengthen timber structures. Two usual alternatives are: the use of steel plates screwed and carbon fiber mats glued with epoxy adhesive. A gap was observed in the literature regarding the study of reinforcement in hardwood timber beams with cross-section loss, commonly found in attacks by biotic or abiotic agents. This study aimed to analyze the flexural stiffness recovery capacity of steel plate screwed to a timber beam with different cross-sectional losses, with a special interest in the effect caused by different bolt arrangements. The results were compared with simulations made using a carbon fiber mat (CF). It was possible to observe that, despite presenting lower efficiency than the CD, the use of steel plate screwed could return the initial stiffness in some models, and the specification of the bolts is relevant in obtaining the results.

Development, structure, and secretion of leaf colleters in Clusia criuva Cambess. subsp. criuva (Clusiaceae)

Colleters produce a secretion composed of hydrophilic and/or lipophilic substances which lubricates and protects the shoot apical meristem against biotic and abiotic agents. Little attention has been given to these structures in Clusiaceae. In the present study, the structure and development of the leaf colleters of Clusia criuva subsp. criuva were described and variations in the exudate composition of the colleters at different stages of leaf development were identified. The samples were collected and processed according to techniques for light and scanning electron microscopy. Colleters are of the standard type and not vascularized, and during leaf development, changes in color, structure, and secretion abundance were observed. Asynchrony in the development was noticeable in the leaf primordia and young leaves, from colleters in early formation to those in early senescence. In early phases there was an abundance of polysaccharide, lipid, and protein secretions, whereas adult and senescent leaves revealed an accumulation of phenolic compounds and cell degradation. The secretion was released by the rupture of the cuticle. The structural changes and secretion composition during leaf development emphasize the role of colleters in protecting meristems and developing organs.

Oxidative Stress in Roots: Detection of Lipid Peroxidation and Total Antioxidative Capacity.

Various abiotic and biotic agents disturb the fine balance between cellular oxidants and antioxidants. The resulting oxidative stress occurs either due to the increasing levels of reactive oxygen species (ROS) or weak antioxidative system that cannot scavenge ROS burst. In addition to their harmful role, ROS can also act as signaling molecules, and oxidative stress is often the initial step in the programmed cell death. Here we describe two parameters of oxidative stress that can be measured spectrophotometrically: lipid peroxidation via the content of the by-product malondialdehyde, and the amount of all non-enzymatic antioxidants named as total antioxidative capacity. Both methods are presented using young radish (Raphanus sativus) seedlings after treatment with extract from the invasive plant species Japanese knotweed (Fallopia japonica).

Exploring a library of water-soluble polymers as abiotic phytoremediation agents for treating (Pseudo)metal ion-contaminated soil

Herein, we investigate the effect of eleven water-soluble polymers on the growth of Sedum alfredii and its uptake of As, Cd, or Pb in polluted soil in a pot experiment. The polymers selected are generally non-toxic, metal-chelating, and hygroscopic. They also range from acidic (carboxylate-containing polymers) to neutral (e.g. polyacrylamide, polyvinyl alcohol) and to basic (polyethylene imine). It has been found that sodium alginate exhibits a significant growth-promoting effect (as much as ∼8-fold) as determined by plant total dry weight, while all other tested polymers exert either minor growth promotion or a negative effect. To examine the absorption of heavy (pseudo)metals, the pollutant content in above- and below-ground portions of the plant were separately studied by inductively coupled plasma mass spectrometry. Among the tested polymers, sodium alginate emerges as the strongest absorption accelerator for all three metal pollutants in the above-ground part of the plant (∼3-4-fold increase over blank), mainly due to promotion of plant growth. On the other hand, polyethylene imine is the most potent inhibitor of metal absorption (10%–51% of blank) due to a combination of plant growth inhibition and absorption deactivation. Polymers with such effects may be used to reduce the contamination of (pseudo)metals in crops.

Development of a catalogue of damage in Portuguese forest associated with extreme extratropical cyclones

In European forests, extreme wind events associated with severe extratropical cyclones are considered the main abiotic agent of forest vulnerability, leading to high economic losses in forests due to damage caused by the uprooting of trees and trunk breaks. Despite the importance recognized to severe cyclones and associated extreme phenomena, the impact on forest stocks is not always properly reported, leading to underestimation in the perception of losses, with direct consequences on forest governance decisions. This is particularly true in countries where other agents traditionally have a high impact, such as the countries under the influence of the Mediterranean, where wildfire is a recurrent menace with devastating effects. This work characterizes the situation observed in Portugal and presents the methodology followed to obtain information about forest damages and the procedure to identify the extreme extratropical cyclones responsible for those damages. As an example, available information and the recording of damage occurring in the Portuguese forest in winter 2017–2018 are presented and discussed. The study shows how difficult and demanding it is to obtain past information about the damage. In addition, there is high uncertainty about the precise identification of the event that caused the damage, as field records often occur several days or even weeks after the storm. To reduce the constraints, it is proposed to use a model whose skeleton of information has been designed to obtain useful information from traditional registries. The proposed model is useful for the characterization of losses and to support national policies to reduce the impact of damage associated with extreme wind events. The design of the catalogue can be used for recording information at the stand scale level by stakeholders and ensure compatibility with international databases for updating information purposes.

A Nondestructive Longitudinal Laboratory Test Method for Detection of Incipient Ultrastructural Changes in Wood

Abstract The established methods for determining the effects of ultrastructural changes in structural wood members rely upon traditional, possibly outmoded, testing paradigms. These methods usually involve destructive testing of wood specimens that are exposed to environmental conditions infrequently experienced in buildings. Understanding how the ultrastructure changes with time within the same specimen is crucial for building practitioners in assessing risks to life-safety, assessing remaining service life of structural components, and aiding in the identification of mitigation or remediation measures. The primary agents causing ultrastructural modifications to wood are wood rotting basidiomycetes but may also include other biotic and abiotic agents; the methods contained herein should be applicable to all such longitudinal experiments. This article reviews existing literature on decay testing and validates a new method to assess longitudinal changes in mechanical properties with time using nondestructive test measures at relevant moisture contents. The validation testing shows this method has a good degree of repeatability and should permit the initial detection and monitoring of ultrastructure changes (e.g., decay). The method uses a repeatable, nondestructive four-point testing procedure for specimens controlled to specific moisture contents using energy dissipation as the salient performance metric. Recommendations are provided to refine this novel test method.

A Diagnostic TaqMan Real-Time PCR Assay for In Planta Detection and Quantification of Colletotrichum theobromicola, Causal Agent of Boxwood Dieback.

Boxwood dieback, caused by Colletotrichum theobromicola, is spreading at an alarming rate in the boxwood industry in the United States. Although C. theobromicola has been accepted as a distinct species within the C. gloeosporioides species complex, it is difficult to distinguish it from other closely related species based on morphology. Moreover, molecular identification of C. theobromicola requires amplification and sequencing of multiple loci, which can be expensive and time consuming. Therefore, a diagnostic TaqMan real-time PCR assay was developed for early and accurate detection and quantification of C. theobromicola in boxwood. The study involved the design of species-specific primers and a TaqMan probe to differentiate C. theobromicola from other closely related Colletotrichum species. The primers and probe discriminate between C. theobromicola and other species in the C. gloeosporioides species complex and can detect C. theobromicola at very low concentrations, illustrating the high specificity and sensitivity of the assay. This TaqMan real-time PCR assay accurately and rapidly distinguishes boxwood dieback from other diseases with similar symptomatology, including Macrophoma blight, Phytophthora root rot, and Volutella blight, as well as some disorders produced by abiotic agents.

Colleters, Extrafloral Nectaries, and Resin Glands Protect Buds and Young Leaves of Ouratea castaneifolia (DC.) Engl. (Ochnaceae).

Buds usually possess mechanical or chemical protection and may also have secretory structures. We discovered an intricate secretory system in Ouratea castaneifolia (Ochnaceae) related to the protection of buds and young leaves. We studied this system, focusing on the distribution, morphology, histochemistry, and ultrastructure of glands during sprouting. Samples of buds and leaves were processed following the usual procedures for light and electron microscopy. Overlapping bud scales protect dormant buds, and each young leaf is covered with a pair of stipules. Stipules and scales possess a resin gland, while the former also possess an extrafloral nectary. Despite their distinct secretions, these glands are similar and comprise secreting palisade epidermis. Young leaves also possess marginal colleters. All the studied glands shared some structural traits, including palisade secretory epidermis and the absence of stomata. Secretory activity is carried out by epidermal cells. Functionally, the activity of these glands is synchronous with the young and vulnerable stage of vegetative organs. This is the first report of colleters and resin glands for O. castaneifolia. We found evidence that these glands are correlated with protection against herbivores and/or abiotic agents during a developmental stage that precedes the establishment of mechanical defenses.

Detection of Genetic Polymorphisms using Random Amplified Polymorphic DNA (RAPD)-PCR in Fenugreek (Trigonella foenum-graecum) Plants after Seed Treatment with Biotic and Abiotic Agents

Trigonella foenum-graecum L. is a widely used herb in traditional medicine. The aim of this study was to evaluate the genetic polymorphisms in fenugreek plants following the treatment of fenugreek seeds with different combinations of biotic and abiotic agents using the random amplified polymorphic DNA (RAPD)-PCR technique. We assessed the effects of two strains of the fungus Trichoderma harzianum (Th-1 and Th-2), methyl jasmonate (MeJA), and Aloe vera gel (AVG) on growth parameters of fenugreek plants. Combinations of Th-1, MeJA, AVG significantly increased fenugreek root length, shoot length, shoot fresh weight, number of true leaves, and chlorophyll content. The Th-2 isolate, on the other hand, markedly slowed plant development (except for root length which was not affected significantly). In contrast, the combination with MeJA had no considerable effect on all growth measures, whereas the combination with VAG resulted in a substantial drop in shoot height and chlorophyll content when compared to other growth parameters that were unaffected. The present study has shown that the PCR amplification of DNA, using five primers for RAPD analysis, produced 62 DNA fragments that could be scored in all genotypes. The total number of polymorphic bands was 26, and the average percentage of polymorphism was 54.21%. The RAPD-PCR results showed that the treatment of fenugreek seeds with Th-1 alone or in combination with MeJA and AVG induced polymorphisms in fenugreek leaves.

Effectiveness of some biotic and abiotic agents to control tomato early blight disease caused by Alternaria solani

Bacillus megaterium, Bacillus subtilis, Pseudomonas fluorescens, Trichoderma harzianum, Trichoderma album and Trichoderma viride isolates, as well as different concentrations of chemical inducers, such as chitosan and salicylic acid were evaluated against Tomato early blight, under laboratory and greenhouse conditions. Under laboratory conditions, all tested bio agents, as well as the different concentrations of the tested chemical inducers, decreased the linear growth of A. solani, as the inhibition of fungal growth was increased by increasing the concentration of both chemical inducers in the growing medium. The chemical inducer chitosan at a concentration of 4.0 mg/mL PDA medium, caused the highest inhibition of linear growth of the fungus, followed by anti-fungus T. harzianum. When, different concentrations of chitosan and salicylic acid were tested on spore germination of A. solani, a concentration of 4.0 (mg/mL), for chitosan and a concentration of 25.0 (mM), for salicylic acid were the best concentrations used to reduce the spore germination of A. solani. Under greenhouse conditions, spraying tomato plants (cv. Super Strain B hybrid), with any of the tested biological agents as well as different concentrations of both the chemical inducers before infection of tomato plants by A. solani reduced the severity of early blight, in addition, to increase the fresh and dry weight of tomato plants. The chemical inducer chitosan at a concentration of 4.0 (mg/mL), caused the highest decrease of the disease severity, and the highest increase in fresh and dry weight of tomato plants, followed by the bio agent T. harzianum. The activities of defense-related enzymes i.e., polyphenoloxidase, peroxidase and chitinase were significantly increased in all treated plants with the tested biotic and abiotic agents. Chitosan at a concentration of 4.0 (mg/mL) resulted in the highest activity of oxidative enzymes, followed by T. harzianum. Meanwhile, the total content of phenols was higher in treated plants than in the untreated ones. The tested bio agents and chemical inducers might be playing an important role in management of tomato early blight through induction of induced systemic resistance.

Acute exposure to microcystin-LR induces hepatopancreas toxicity in the Chinese mitten crab (Eriocheir sinensis).

The Chinese mitten crab is an important economic species in the Chinese aquaculture industry due to its rich nutritional value and distinct flavor. The hepatopancreas is a popular edible part of the Chinese mitten crab, and therefore, hepatopancreatic health directly determines its quality. However, a large-scale outbreak of hepatopancreatic necrosis syndrome ("Shuibiezi" disease in Chinese), which is caused by abiotic agents correlated with cyanobacteria bloom outbreaks, adversely affects the Chinese mitten crab breeding industry. Cyanobacterial blooms that occur in high-density farming ponds can produce microcystin-LR (MC-LR), which is hepatotoxic in fish and mammals. Hepatopancreas toxicity of MC-LR (0, 25, 50 and 75 μg/kg) was investigated after 48 h of exposure. The MC-LR can cause hepatopancreatic injury by inducing hepatopancreatic structural damage, subcellular structural changes, and cell apoptosis, followed by enhanced lipid peroxidase, reactive oxygen species, and apoptosis-related enzyme (Caspase 3, 8, and 9) activities. These in turn promote gene and protein expression of apoptosis-associated proteases (Caspase 3, 7, and 8, Bcl-2, and Bax), and alter antioxidant system responses (superoxide dismutase, glutathione S-transferase, glutathione peroxidase, glutathione reductase activities, and glutathione content). The present study is the first report on MC-LR hepatotoxicity in the Chinese mitten crab and confirms hepatopancreas toxicity, providing a theoretical basis for enhancing MCs resistance and developing preventive and curative measures against hepatopancreatic disease in the Chinese mitten crab breeding industry.

Estimating the Service Life of Timber Structures Concerning Risk and Influence of Fungal Decay—A Review of Existing Theory and Modelling Approaches

Wood is a renewable resource and a promising construction material for the growing bio-based economy. Efficiently utilising wood in the built environment requires a comprehensive understanding of the dynamics regarding its usability. Durability is an essential property to consider, as various types of exposure create conditions for the deterioration of wood through biotic and abiotic agents. Biodegradable materials introduce increased complexity to construction and design processes, as material decomposition during a structure’s lifetime presents a physical risk to human health and safety and costs related to repairs and maintenance. Construction professionals are thus tasked with utilising wooden elements to accentuate the material’s beneficial properties while reducing the risk of in-service decomposition. In this paper, only the cause and effect of fungal induced decay on the service life of wooden buildings and other wood-based construction assets are reviewed. The service life of wood components can thus be extended if suitable growing conditions are controlled. Multiple existing modelling approaches are described throughout the text, with special attention given to the two most comprehensive ones; TimberLife and the WoodExter. In choosing an appropriate model for a specific application, the authors recommend evaluating the model’s regional specificity, complexity, practicality, longevity and adaptability.