Search

Background: Tree ontogeny is the genetic trajectories of regenerative processes in trees, repeating in time and space, including both development and reproduction. Understanding the principles of tree ontogeny is a key priority in emulating natural ecological patterns and processes that fall within the calls for closer-to-nature forest management. By recognizing and respecting the growth and development of individual trees and forest stands, forest managers can implement strategies that align with the inherent dynamics of forest ecosystem. Therefore, this study aims to determine the ontogenetic characteristics of tree regeneration and growth in northern European hemiboreal forests. Methodology: We applied a three-step process to review i) the ontogenetic characteristics of forest trees, ii) ontogenetic strategies of trees for stand-forming species, and iii) summarise the review findings of points i and ii to propose a conceptual framework for transitioning towards closer-to-nature management of hemiboreal forest trees. To achieve this, we applied the super-organism approach to forest development as a holistic progression towards the establishment of natural stand forming ecosystems. Results: The review showed multiple aspects; first, there are unique growth and development characteristics of individual trees at the pre-generative and generative stages of ontogenesis under full and minimal light conditions. Second, there are four main modes of tree establishment, growth and development related to the light requirements of trees; they were described as ontogenetic strategies of stand-forming tree species: gap colonisers, gap successors, gap fillers and gap competitors. Third, the summary of our analysis of the ontogenetic characteristics of tree regeneration and growth in northern European hemiboreal forests shows that stand-forming species occupy multiple niche positions relative to forest dynamics modes. Conclusions: This study demonstrates the importance of understanding tree ontogeny under the pretext of closer-to-nature forest management, and its potential towards formulating sustainable forest management that emulates the natural dynamics of forest structure. We suggest that scientists and foresters can adapt closer-to-nature management strategies, such as assisted natural regeneration of trees, to improve the vitality of tree communities and overall forest health. The presented approach prioritizes ecological integrity and forest resilience, promoting assisted natural regeneration, and fostering adaptability and connectivity among plant populations in hemiboreal tree communities. [ABSTRACT FROM AUTHOR]

Abstract Background Plant meristems are structured organs consisting of distinct layers of stem cells, which differentiate into new plant tissue. Mutations in meristematic layers can propagate into large sectors of the plant. However, the characteristics of meristematic mutations remain unclear, limiting our understanding of the genetic basis of somaclonal phenotypic variation. Results Here, we analyse the frequency and distribution of somatic mutations in an apricot tree. We separately sequence the epidermis (developing from meristem layer 1) and the flesh (developing from meristem layer 2) of several fruits sampled across the entire tree. We find that most somatic mutations (> 90%) are specific to individual layers. Interestingly, layer 1 shows a higher mutation load than layer 2, implying different mutational dynamics between the layers. The distribution of somatic mutations follows the branching of the tree. This suggests that somatic mutations are propagated to developing branches through axillary meristems. In turn, this leads us to the unexpected observation that the genomes of layer 1 of distant branches are more similar to each other than to the genomes of layer 2 of the same branches. Finally, using single-cell RNA sequencing, we demonstrate that layer-specific mutations were only transcribed in the cells of the respective layers and can form the genetic basis of somaclonal phenotypic variation. Conclusions Here, we analyse the frequency and distribution of somatic mutations with meristematic origin. Our observations on the layer specificity of somatic mutations outline how they are distributed, how they propagate, and how they can impact clonally propagated crops.

Background Tree ontogeny is the genetic trajectories of regenerative processes in trees, repeating in time and space, including both development and reproduction. Understanding the principles of tree ontogeny is a key priority in emulating natural ecological patterns and processes that fall within the calls for closer-to-nature forest management. By recognizing and respecting the growth and development of individual trees and forest stands, forest managers can implement strategies that align with the inherent dynamics of forest ecosystem. Therefore, this study aims to determine the ontogenetic characteristics of tree regeneration and growth in northern European hemiboreal forests. Methodology We applied a three-step process to review i) the ontogenetic characteristics of forest trees, ii) ontogenetic strategies of trees for stand-forming species, and iii) summarise the review findings of points i and ii to propose a conceptual framework for transitioning towards closer-to-nature management of hemiboreal forest trees. To achieve this, we applied the super-organism approach to forest development as a holistic progression towards the establishment of natural stand forming ecosystems. Results The review showed multiple aspects; first, there are unique growth and development characteristics of individual trees at the pre-generative and generative stages of ontogenesis under full and minimal light conditions. Second, there are four main modes of tree establishment, growth and development related to the light requirements of trees; they were described as ontogenetic strategies of stand-forming tree species: gap colonisers, gap successors, gap fillers and gap competitors. Third, the summary of our analysis of the ontogenetic characteristics of tree regeneration and growth in northern European hemiboreal forests shows that stand-forming species occupy multiple niche positions relative to forest dynamics modes. Conclusions This study demonstrates the importance of understanding tree ontogeny under the pretext of closer-to-nature forest management, and its potential towards formulating sustainable forest management that emulates the natural dynamics of forest structure. We suggest that scientists and foresters can adapt closer-to-nature management strategies, such as assisted natural regeneration of trees, to improve the vitality of tree communities and overall forest health. The presented approach prioritizes ecological integrity and forest resilience, promoting assisted natural regeneration, and fostering adaptability and connectivity among plant populations in hemiboreal tree communities.

Hazelnut (Corylus avellana) cultivation is increasing worldwide. A 3D model of its structure could improve managerial techniques such as pruning. This study aims to analyse, over two successive years, hazelnut architectural development to implement a functional structural plant model. One hundred and four one-year-old shoots of own-rooted hazelnut trees were selected and analysed in winter 2020 and 2021. Exploratory analyses, generalized linear models and multinomial regression models were used to describe the architectural processes. The existence of sylleptic shoots on hazelnut one-year-old shoots, characterized by the presence of the male inflorescence on apical position, was detected. Along proleptic shoots, the branching pattern was described by (i) blind nodes located in the proximal part (ii) sylleptic shoots and mixed buds in the median part (iii) vegetative buds in the distal part. Apical bud died during the growing season, suggesting that Tonda di Giffoni has a sympodial branching. The models revealed dependencies among buds located at the same node, in the case of proleptic shoots. Especially, the probability of a bud bursting depended on both its type (i.e. mixed or vegetative) and the presence of other buds, either mixed or vegetative. Based on these local models and on a flow diagram, which defines the steps that led to the construction of hazelnut tree architecture, the first functional–structural plant model of hazelnut tree architecture was built. Further experiments will be needed and should be repeated over the following years to extend this study towards the juvenile phase and tree architecture over time. [ABSTRACT FROM AUTHOR]

In order to achieve sustainable food production, non-chemical weed management practices need to be developed for fruit growing. Tailor-made floor management systems enable efficient weed regulation, but they also affect the soil quality in an orchard. In this article, the effects of various floor management systems in a 'Red Jonaprince' apple (Malus × domestica Borkh.) orchard on the soil properties and the trees' nutritional status and initial development during the first two years after the orchard's establishment were assessed. The experiment was set up in the spring of 2017 in the Experimental Orchard of WULS. 'Red Jonaprince' cv. trees grafted on M.9 rootstock were planted with 3.5 × 1 m spacing between them. Different floor management systems were applied to the rows, including the selected organic mulches: Miscanthus × giganteus straw (MG1 and MG2), spent mushroom substrates (SMS1 and SMS2), herbicide strip (HS), clear mechanical soil cultivation (MC), and synthetic black mulch (BC). The organic mulches affected the soil properties significantly. Spent mushroom substrates (SMS1, SMS2) increased the P and K contents in the soil, increased the salinity 10-fold, and retarded the growth in terms of the trunk cross-section area (TCSA) and its increment compared with other systems. Miscanthus × giganteus straw mulch (MG1, MG2) was associated with a more vigorous shoot growth compared with other combinations in the first year of the study as it provided a better tree nitrogen nutritional status. The floor management system affected the generative development of the trees. Mulching with a spent mushroom substrate boosted the flower bud formation intensity, but it did not affect the yielding quantity. Moreover, due to the poor fruit set, the trees mulched with a spent mushroom substrate (SMS2) gave a low initial bearing. High crop loads were noted for the trees treated with black synthetic mulch (BC) and the trees mulched with Miscanthus × giganteus straw (MG1). This was an effect of the tree size rather than the blooming intensity, while there were no differences in the cropping efficiency index (CEI) parameter. [ABSTRACT FROM AUTHOR]

In order to achieve sustainable food production, non-chemical weed management practices need to be developed for fruit growing. Tailor-made floor management systems enable efficient weed regulation, but they also affect the soil quality in an orchard. In this article, the effects of various floor management systems in a ‘Red Jonaprince’ apple (Malus × domestica Borkh.) orchard on the soil properties and the trees’ nutritional status and initial development during the first two years after the orchard’s establishment were assessed. The experiment was set up in the spring of 2017 in the Experimental Orchard of WULS. ‘Red Jonaprince’ cv. trees grafted on M.9 rootstock were planted with 3.5 × 1 m spacing between them. Different floor management systems were applied to the rows, including the selected organic mulches: Miscanthus × giganteus straw (MG1 and MG2), spent mushroom substrates (SMS1 and SMS2), herbicide strip (HS), clear mechanical soil cultivation (MC), and synthetic black mulch (BC). The organic mulches affected the soil properties significantly. Spent mushroom substrates (SMS1, SMS2) increased the P and K contents in the soil, increased the salinity 10-fold, and retarded the growth in terms of the trunk cross-section area (TCSA) and its increment compared with other systems. Miscanthus × giganteus straw mulch (MG1, MG2) was associated with a more vigorous shoot growth compared with other combinations in the first year of the study as it provided a better tree nitrogen nutritional status. The floor management system affected the generative development of the trees. Mulching with a spent mushroom substrate boosted the flower bud formation intensity, but it did not affect the yielding quantity. Moreover, due to the poor fruit set, the trees mulched with a spent mushroom substrate (SMS2) gave a low initial bearing. High crop loads were noted for the trees treated with black synthetic mulch (BC) and the trees mulched with Miscanthus × giganteus straw (MG1). This was an effect of the tree size rather than the blooming intensity, while there were no differences in the cropping efficiency index (CEI) parameter.

Pterogyne nitens is commonly known in northeastern Brazil as a lesser-known fast-growing species in the Caatinga biome, which is a difficult place for tree development due to the low natural fertility soils and low availability of water. Due to the importance of expanding information about the anatomical wood properties of Caatinga native species, the aim of this work was to characterize the anatomical elements, to macroscopically describe the wood and make inferences about its possible end-uses. Maceration was performed which enabled measuring fiber dimensions, pore frequency and the following technological indexes: cell wall fraction, slenderness ratio, Runkel index and flexibility coefficient. Histological sections enabled describing the arrangements of the cellular elements in different observation sections and to determine the pore diameter. P. nitens wood has anatomical arrangements characterized by confluent axial parenchyma, being diffuse-porous with the presence of tylosis and heterogeneous/stratified rays (biseriate). The fibers were classified as very short (length 0.81 mm), not flexible and Runkel index 0.82. The pores were few in number with a frequency of 32.9 pores/mm2, distributed in a diffuse format and many were obstructed by tylosis. Based on the anatomical results and considering other technological studies, P. nitens wood is most suitable for charcoal production. [ABSTRACT FROM AUTHOR]

Motivation Therapeutic peptides failing at clinical trials could be attributed to their toxicity profiles like hemolytic activity, which hamper further progress of peptides as drug candidates. The accurate prediction of hemolytic peptides (HLPs) and its activity from the given peptides is one of the challenging tasks in immunoinformatics, which is essential for drug development and basic research. Although there are a few computational methods that have been proposed for this aspect, none of them are able to identify HLPs and their activities simultaneously. Results In this study, we proposed a two-layer prediction framework, called HLPpred-Fuse, that can accurately and automatically predict both hemolytic peptides (HLPs or non-HLPs) as well as HLPs activity (high and low). More specifically, feature representation learning scheme was utilized to generate 54 probabilistic features by integrating six different machine learning classifiers and nine different sequence-based encodings. Consequently, the 54 probabilistic features were fused to provide sufficiently converged sequence information which was used as an input to extremely randomized tree for the development of two final prediction models which independently identify HLP and its activity. Performance comparisons over empirical cross-validation analysis, independent test and case study against state-of-the-art methods demonstrate that HLPpred-Fuse consistently outperformed these methods in the identification of hemolytic activity. Availability and implementation For the convenience of experimental scientists, a web-based tool has been established at http://thegleelab.org/HLPpred-Fuse. Contact glee@ajou.ac.kr or watshara.sho@mahidol.ac.th or bala@ajou.ac.kr Supplementary information Supplementary data are available at Bioinformatics online. [ABSTRACT FROM AUTHOR]

The woodwasp, Sirex noctilio Fabricius, is an exotic pest of Pinus L. in the southern hemisphere and North America, and it is an emerging threat in northeastern China. Adult woodwasps have numerous insect competitors for oviposition substrates, and developing larvae must compete for resources with other subcortical invaders. Its mutualistic fungus Amylostereum areolatum (Fr.) Boidon, is less competitive than many other fungal colonists present in pine ecosystems. This study investigated the effects of incidental, host-colonizing fungi on the growth and development of woodwasp larvae and A. areolatum. Fungi were isolated from dead S. noctilio larvae within galleries (primarily Trichoderma Pers, Ophiostoma Sydow, and Sphaeropsis Sacc.), and effects of these fungi on woodwasp brood survival were investigated via inoculations of S. noctilio -infested logs. Larval mortality was significantly increased in sample logs inoculated with Ophiostoma minus (Hedgc.) Sydow Phlebiopsis gigantea (Fr.) Jülich, Trichoderma atroviride Bissett, Trichoderma viride Pers, and Trichoderma harzianum Rifai. Inoculation of logs with O. minus resulted in the highest mortality and greatest reductions in wood moisture content. When grown on artificial media, these fungi grew faster than and inhibited growth of A. areolatum mycelium. We propose that the adverse effects of incidental fungi on the survival of S. noctilio larvae may be caused at least in part by an indirect mechanism involving inhibition of the fungal symbiont. The findings provide potentially valuable information for suppressing S. noctilio populations using microbial control agents. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of different crop arrangements and weed management in integrated crop–forage–forestry systems on weed incidence, yield of maize and forage grass, quality of total harvested and tree development. The experiment was analyzed as split-plot and as randomized complete block design. Whole plots were crop arrangements containing maize, Marandu palisadegrass, Basilisk signalgrass, Piatã palisadegrass, eucalyptus and acacia, and subplots were the weed management (1.5 kg ha−1 of atrazine and 1.5 kg ha−1 of atrazine + 0.006 kg ha−1 of nicosulfuron). Planting was done under no-tillage system and herbicides were applied 22 days after maize emergence. The weeds incidence was not affected by treatments. Applying the mixture of atrazine and nicosulfuron reduced the grasses yield. However, the total dry mass harvested was not affected. The average yield of whole-plant corn in the intercropping systems was 12.9 t ha−1 of dry mass. The simultaneous establishment of the integrated crop–forage–forestry systems does not reduce the productivity and quality of whole-plant corn nor the production of the tree component at the first cultivation year. Despite the reduced grasses yield, the application of nicosulfuron and atrazine does not improve the production and quality of whole-plant corn in relation to the application of atrazine alone. [ABSTRACT FROM AUTHOR]

To elucidate the development of heartwood, bark, sapwood, pith and specific gravity of wood in fast-growing teak (Tectona grandis) plantations in Costa Rica, we sampled three trees in each of 55 plantations and modelled each variable with age, site and different tree heights. Age and stand density of plantations were significant correlated with stem diameter at breast height and total height of the tree. Formation of heartwood was initiated at the age of 4-year-old and increased in direct proportion with age. The age of plantation had a significant relationship with stem diameter at breast height, heartwood percentage, sapwood thickness, sapwood percentage, percentage of bark, pith diameter and percentage, and specify gravity. The model for these tree parameters was model with these parameters as dependent variable and in relation to age as independent variable. [ABSTRACT FROM AUTHOR]

The emerald ash borer (EAB) Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive woodboring beetle native to northeastern Asia that continues to expand its range within North America and European Russia. The insect reproduces within and kills most North American species of ash Fraxinus spp.Because both the adult and larval life stages of EAB are difficult to detect prior to development of tree symptoms, much work has focused on quantifying spread and clarifying the potential movement pathways to improve early detection and monitoring strategies.In the present study, we retrospectively analyzed county‐level infestations of emerald ash borer in the state of Iowa, U.S.A., subsequent to the initial detection of EAB in 2010. Visual data analysis had suggested that new infestations were not in accordance with the expected patterns of establishment along roads, near campgrounds or by large population centres.We found a positive correlation between the establishment and detection of EAB in Iowa counties and the length of railroads in each county. To our knowledge, this is the first statistically significant association between rail pathways and the spread of EAB on the North American continent. [ABSTRACT FROM AUTHOR]

Key message: In adult walnut trees, poor light environments increase the number of catkins on a shoot, reducing the probability of bearing fruits. Growth units become shorter with the aging of the tree, tending to reach a stable length. Tree architecture results from the functioning of populations of meristems across consecutive periods of extension or growing cycles. The study of growth units (GUs) and the type of their axillary meristem lead to a better understanding of tree growth and allow the prediction of tree development under different environmental conditions. To study the effect of position inside the canopy on branch development and the relationship between parent wood and new shoots, 348 GUs from 14 five-to-six-year-old limbs (7 from upper/exposed and 7 from lower/shaded zones within the canopy) were analyzed. Each node was classified according to its axillary meristem type as: 0 (bud, dormant bud, bud scar and dead bud), 1 (fruit and fruit peduncle scar), 2 (male inflorescence or "catkin", catkin scar and dead catkin) and 3 (branch and branch scar). Data were analyzed through a multinomial logistic model to summarize the distribution of axillary meristem type as a function of explanatory variables. Length of GUs and the number of catkins were modeled through a generalized linear mixed model, whereas the probability of finding fruit on apical nodes was analyzed through generalized additive models. Results show that axillary meristem type is affected by zone, node rank and wood age. On GUs of wood age two or younger, apical buds from upper/exposed zones showed higher probabilities of producing fruits compared with apical buds from lower/shaded zones. The latter was not observed for older wood. In upper/exposed zones, the slope of the relationship between the length of GUs and the length of parent wood increased with wood age. The number of catkins was higher in the lower/shaded than in the upper/exposed zone. The results of this study improve our understanding about walnut tree growth as affected by factors like ontogenetic changes and different light conditions within the tree canopy and might be useful to address tree managements such as training and pruning systems. [ABSTRACT FROM AUTHOR]

The infrequent and unpredictable nature of earthquakes means that their landslide‐generated impacts on forests are rarely investigated. In montane forests, landslides are the main cause of tree death and injury during earthquakes. Landslides range from soil movements that uproot and bury trees over extensive areas to rock falls that strike individual trees. We examined unexplored relationships between tree survival and distance from an epicentre, soil‐available phosphorus (P) as an indicator of soil development and tree diameter. We expected decreased tree growth in damaged forests because of tree injury.We used a plot network, established in 1974 and resurveyed regularly ever since, to quantify survival and growth responses 6–30 km from the epicentre of a 1994 earthquake in New Zealand's Southern Alps. Our Bayesian analysis used 8,518 trees from 250 plots that representatively sampled a naturally monospecific Nothofagus forest. As the time‐scales over which responses could emerge were unknown, we compared relationships for a pre‐earthquake period with 0–5 years post‐earthquake, and with 5+ years post‐earthquake.Not all plots were affected by the earthquake. We found that 0–5 years post‐earthquake survival increased logarithmically with distance from the epicentre with lowered survival up to 20 km from the epicentre. Survival was low on plots with high soil‐available P. An inverted U‐shaped relationship between survival and diameter pre‐earthquake was not found 0–5 years post‐earthquake. This was because of surprisingly high survival by large trees. The earthquake most often suppressed 0–5 years post‐earthquake growth up to 15 km from the epicentre, but this was only apparent after accounting for more general growth differences among periods. The positive relationship between growth and soil‐available P pre‐earthquake and 5+ years post‐earthquake reflected enhanced growth on young soils. This contrasted with a negative effect of soil‐available P on growth 0–5 years post‐earthquake.Synthesis. Soil‐available P, tree diameter and distance from the epicentre independently determined how tree survival and growth responded to an earthquake. The impacts on survival and growth largely occurred 0–5 years post‐earthquake and suggests a level of resilience in mountain beech forests. [ABSTRACT FROM AUTHOR]

Planning the sidewalk afforestation composition is critical to understanding tree development over time, as well as enabling trees to deliver their many quality benefits. The objective of this work was to evaluate the number of small, medium and large-sized tree species during eight growth projection moments on the streets of Irati city- PR. Different streets with and without power grids and streets with sidewalks larger and smaller than three meters were evaluated by counting the number of suitable trees in the appropriate spaces and the average increase in crown area of Lagerstroemia indica, Handroanthus albus and Paraptadenia rigida, over 5, 10, 15, 20, 25, 30, 35 and 40 years of growth projection. Data was transformed to attend the normality criteria and compared by the Tukey test at 5% probability, using an experimental design in subdivided plots. There was a significant difference and interaction between species size and projection time. The large-sized species presented higher increase in crown area throughout the years, despite the smaller number of trees that could be planted. This kind of species is advised for planting as long as proper maintenance is considered for trees to provide maximum benefits. [ABSTRACT FROM AUTHOR]

The purpose of this research is evaluating the results of the effect of M. bracteata, Desmodium sp y P. phaseoloides cover crops in growth, and their influence in the phytosanitary conditions of a two years old natural rubber crop in the "Altillanura Colombiana". We established treatments by cover crop with three repeats and a control crop. The development of the trees was evaluated through the measurement of perimeter and total height. Additionally, inoculations of C. gloesporioides were carried out in the three cover crops under semi-controlled conditions. It was found that the three cover crops generated a slight increase in the organic matter of the soil and have a favorable effect on the development of the trees. Also, that the most frequently isolated fungi corresponded to Cladosporium sp., E. sorgui and Fusarium sp., and that the inoculations showed that the three coverages are susceptible to C. gloesporioides. [ABSTRACT FROM AUTHOR]

In order to improve the efficiency of tree planting ⑽d the automation 肋d intellectualization level of ^ planter with little damage to the surrounding primary vegetation is designed in this paper. On the basis of kinematics analysis of planting mechanism of tree planter, a control system scheme based on programmable logic controller (PLC) is provided. The work program of hydraulic control system of tree planter, automatic operation cycle scheme of tree planter and plant spacing control scheme are emphatically studied. The results show that the control system of intermittent hole digging and planting mechanism can realize the control of moving intermittent hole digging and planting, intelligently adjusting planting depth and precise plant spacing. The operation of each mechanism is reasonable and non - interference, and the planting efficiency is 400 ~ 500 plants per hour. This provides a way for the development of tree planter to automation and intellectualization. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engenharia na Agricultura is the property of Engenharia na Agricultura and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Overaged full-sun cacao plantations and the need for sustainable production systems call for combining rehabilitation of plantations with the establishment of agroforestry. We tested the effect of drastic rehabilitation pruning of old cacao tree stock and the introduction of both high- and low-diversity agroforestry on survival, growth and yield of T. cacao in a commercial plantation in peninsular Malaysia over a period of 5 years. We further determined the incidence of pests and diseases of cacao pods and assessed the performance of the whole system for smallholder farmers, including yields of by-crops. Rehabilitation pruning negatively affected cacao tree development and short-term yield. No more effects of pruning on cacao yield were observed starting in the third year on in the monoculture and starting in the fourth year on in low-diversity agroforestry. We found similar cacao tree development and yield in the low-diversity agroforestry and a common practice monoculture, suggesting that the implementation of agroforestry is a commercially feasible strategy, due to additional income generated through timber production. Reduced cacao tree development and yield in the high-diversity agroforestry were compensated by additional harvests of cassava and banana compared to monoculture. Incidence of cocoa pod borer (Conopomorpha cramerella) was lower in the agroforestry systems, especially the high-diversity system, while the incidence of black pod disease (Phytophthora spp.) did not differ between agroforestry and monoculture. The findings highlight the potential of agroforestry to reconcile ecologically sustainable land use with natural, cost-effective pest management. While pruning needs to be done with timing and disease pressure in mind to minimize short-term yield losses, this measure proved to be a feasible strategy for establishing agroforestry on extant plantations. [ABSTRACT FROM AUTHOR]

Questions: Peatland ecosystems are a globally important carbon storage that is predicted to turn into a carbon source due to water level drawdown (WLD) associated with climate change. The predictions assume stable plant communities but how realistic is this assumption? If the vegetation is not stable, what are the nature and rate of changes? Location: Peatland complex in Southern Finland. Methods: We conducted a water level drawdown (WLD of ~10 cm) experiment over 17 years in three peatland types differing in their fertility. On each peatland type, we included an adjacent forestry drained (FD, with water table ca. 40 cm lower than in control) area for comparison. Results: Peatland type had a clear impact on the response to WLD: at the ecosystem level, the two minerotrophic fens underwent rapid species turnover, while the vegetation in nutrient‐poor bog was more resilient to change. In nutrient‐rich sites, WLD initiated tree canopy development and created understorey conditions that strengthened impact of WLD. In nutrient‐poor site, tree establishment was seen only in the FD area. In addition to high nutrient level, high wetness accelerated change at the plant community level, where we found three types of responses: accelerating change, decelerating change, and stability. Succession resulted in an overall loss of community heterogeneity. Conclusions: Interaction between hydrology, nutrient availability, and biological factors in boreal peatlands is important: the drop in water table required to achieve the shift from open peatland to forested system is inversely proportional to the nutrient level of the system. The results suggest that predictive models of peatland functions under climate change should consider compositional change for fens and their diverse plant communities but are more realistic for bogs. The response of bog vegetation to climate change may, however, be more dependent on changes in rainfall regime and therefore needs to be further addressed. [ABSTRACT FROM AUTHOR]

Dendrochronological data provides insight in the tree development, and used in conjunction with forest inventory, can supply inputs for growth and yield modeling. However, accurate and precise measurements of a large number of incremental cores require significant resources. One possible source of valuable tree ring data are national forest inventories (NFI), which process a large amount of data annually. A NFI that places a significant effort on dendrochronological data is the Romanian NFI, which, to date, collected, measured, and cross-dated more than 50,000 incremental cores. This amount of incremental cores makes Romania the holder of the largest dendrochronological NFI library. The present article presents the method of processing the incremental cores and makes available to the interested entities the tree ring data for the three main species from Romania, namely Norway spruce, European beech, and Sessile oak. To ensure utility, the dataset is limited to pure (i.e., one species) strict even-aged stands (i.e., age difference ≤ 5 years), that were un-thinned (i.e., no active forest management). The data is stored as an ASCII file, and contains six fields: ecoregion, species, year, age, average ring width, and variance. To ensure privacy of information, the average ring width was estimated over a 5 years interval, for which the variance is also computed. [ABSTRACT FROM AUTHOR]

Several genomic prediction models combining genotype × environment (G×E) interactions have recently been developed and used for genomic selection (GS) in plant breeding programs. G×E interactions reduce selection accuracy and limit genetic gains in plant breeding. Two data sets were used to compare the prediction abilities of multienvironment G×E genomic models and two kernel methods. Specifically, a linear kernel, or GB (genomic best linear unbiased predictor [GBLUP]), and a nonlinear kernel, or Gaussian kernel (GK), were used to compare the prediction accuracies (PAs) of four genomic prediction models: 1) a single-environment, main genotypic effect model (SM); 2) a multienvironment, main genotypic effect model (MM); 3) a multienvironment, single-variance G×E deviation model (MDs); and 4) a multienvironment, environment-specific variance G×E deviation model (MDe). We evaluated the utility of genomic selection (GS) for 435 individual rubber trees at two sites and genotyped the individuals via genotyping-by-sequencing (GBS) of single-nucleotide polymorphisms (SNPs). Prediction models were used to estimate stem circumference (SC) during the first 4 years of tree development in conjunction with a broad-sense heritability (H 2) of 0.60. Applying the model (SM, MM, MDs, and MDe) and kernel method (GB and GK) combinations to the rubber tree data revealed that the multienvironment models were superior to the single-environment genomic models, regardless of the kernel (GB or GK) used, suggesting that introducing interactions between markers and environmental conditions increases the proportion of variance explained by the model and, more importantly, the PA. Compared with the classic breeding method (CBM), methods in which GS is incorporated resulted in a 5-fold increase in response to selection for SC with multienvironment GS (MM, MDe, or MDs). Furthermore, GS resulted in a more balanced selection response for SC and contributed to a reduction in selection time when used in conjunction with traditional genetic breeding programs. Given the rapid advances in genotyping methods and their declining costs and given the overall costs of large-scale progeny testing and shortened breeding cycles, we expect GS to be implemented in rubber tree breeding programs. [ABSTRACT FROM AUTHOR]

Premise: The resumption of stem growth varies across the ontogenetic development of trees. Compared with younger trees, older ones have thicker outer bark with a temperature‐insulating effect that could potentially prevent the stem from warming in the spring. However, the question of whether xylogenesis in old trees is influenced by the thick bark still remains unresolved. Methods: We investigated the onset of xylogenesis across the ontogenetic development of Smith fir (Abies georgei var. smithii) trees in the Sygera Mountains, southeastern Tibetan Plateau. The outer bark of older trees was also removed. Xylogenesis was monitored in microcores we collected every 3 days during May and June in 2017. Results: Xylogenesis began in late May in young (<50 yr) and mature (50–100 yr) trees, 1 week earlier than in adult (>100–150 yr) and old (>150–200 yr) trees. Older (>200 yr) trees had the latest onset of xylogenesis, 2 weeks after young trees. The resumption of xylogenesis was similar between the control and bark‐removed trees. Conclusions: Growth resumption was delayed in older and bigger trees. Outer bark did not affect the onset of xylogenesis, which indicated that the delayed resumption of growth during the lifespan of trees could be more related to endogenous factors than to an insulating effect of the thick bark of older individuals. [ABSTRACT FROM AUTHOR]

Date palm gardening economy has faced with many challenges in function, production, maintenance infrastructure, and marketing in the less developed countries, including Iran- which is the major producer of this product. Therefore, understanding the nature and relational dynamics that exist between actors is of great importance. Accordingly, this study aims to trace and construct a spatial relationships between human and nonhuman actors in the field of commercial ability of date palms to develop the functions of date palm economy in the Makkoran area. This research is conducted based on a mixed-methods (sequential strategy- variable) approach. The statistical population of the research consists of 17493 farmers and 32 agricultural experts. A purposive-probabilistic sampling method is used for sampling. For determining the sample size in the qualitative stage, the "adequacy of information" method, and the "representativeness" method based on the Cochran formula is employed in the quantitative stage. The type of analytical method used in the study is "Sequential Combinatorial Analysis" based on a sequential qualitative-quantitative strategy. Qualitative data is analyzed using "NVIVO" software, and quantitative one is analyzed using statistical methods in the SPSS software environment. Final analysis and inference of data are based on Latour's argument (1987) in the "translation" method. The findings of the study show that various spatial relationships between actors (human and inhuman) are established or developing. Based on these relationships, factors such as geographical location, climate, date palm, farmer, capital, target market, refrigerator, government, spatial distance, transportation technology are considered as the key and active actors in commercialization of date palm as they shape a broader and stronger network of actors with durable relationships. [ABSTRACT FROM AUTHOR]

Cette étude avait pour but d'évaluer le comportement de l'Arganier en plantation sur site in situ dans son aire de répartition naturelle et aux endroits ex situ, dans la région sud-ouest Algérienne. Les résultats obtenus ont montré que les meilleurs taux de reprise ont été enregistrés à Adrar et Timimoun avec respectivement 85 et 80%. En ce qui concerne la croissance, les plants poussant dans la pépinière d'Adrar ont donné la longueur moyenne des tiges la plus élevée (51,3 ± 4,1 cm). Après 16 ans de transplantation, nous signalons le bon comportement de l'Arganier dans les différents sites ex situ. Les mesures dendrométriques des sujets ont donné un accroissement moyen annuel en diamètre de 0,55 centimètre pour une hauteur de 0,23 mètre. The purpose of this study was to assess the development of the argan tree in situ planting in its natural area of distribution and ex situ regions in the southwest region of Algeria. The results obtained showed that the best recovery rates were recorded in Adrar and Timimoun with 85% and 80% respectively. In terms of growth, the plants growing in the Adrar nursery gave the highest average stem length (51.3 ± 4.1 cm). After 16 years of transplantation, we report the good development of the argan tree in the various ex situ sites. The dendrometric measurements of the subjects yielded an average annual increase in diameter of 0.55 santimtir to a height of 0.23 mitr. [ABSTRACT FROM AUTHOR]

The primary goal in a remote system is to have a beyond any doubt information conveyance from the begin to end. One reason for information conveyance disappointments as often as possible happening in remote applications is hub developments. One answer for this issue is to recreate the course so that the impacts of topology change are decreasing. Then again, a few assets are required to finish this errand. In this paper, we make the consistency in hub versatility designs and guarantee that correspondence of information between the hubs is adequate. The positions of the switches are planned, and tree topology grew so that all hubs activities coordinate with the foundation of the tree. Initially send the hubs in a system then ascertain the most extreme in degree every hub. The facilitator hub is unified with most extreme in-degree lastly develop the tree to send the information to the destination. On the off chance that in-degree hub numbers are the same in any two hubs the best hub is picked in light of a background marked by the two hubs. On the off chance that the limit of both the hubs is same and hub reliability is ascertained utilizing the proposal framework and a most dependable hub is picked as the facilitator hub. This procedure diminishes the clog in the system furthermore the loss of information parcels in the system. [ABSTRACT FROM AUTHOR]

The ability to predict new chemical entity performance using in vivo animal models has been under investigation for more than two decades. Pharmaceutical companies use their own strategies to make decisions on the most appropriate formulation starting early in development. In this paper the biopharmaceutical decision trees available in four EFPIA partners (Bayer, Boehringer Ingelheim, Bristol Meyers Squibb and Janssen) were discussed by 7 companies of which 4 had no decision tree currently defined. The strengths, weaknesses and opportunities for improvement are discussed for each decision tree. Both pharmacokineticists and preformulation scientists at the drug discovery & development interface responsible for lead optimization and candidate selection contributed to an overall picture of how formulation decisions are progressed. A small data set containing compound information from the database designed for the IMI funded OrBiTo project is examined for interrelationships between measured physicochemical, dissolution and relative bioavailability parameters. In vivo behavior of the drug substance and its formulation in First in human (FIH) studies cannot always be well predicted from in vitro and/or in silico tools alone at the time of selection of a new chemical entity (NCE). Early identification of the risks, challenges and strategies to prepare for formulations that provide sufficient preclinical exposure in animal toxicology studies and in FIH clinical trials is needed and represents an essential part of the IMI funded OrBiTo project. This article offers a perspective on the use of in vivo models and biopharmaceutical decision trees in the development of new oral drug products. [ABSTRACT FROM AUTHOR]

An ultrasound scan with volume reconstruction and study of chorion blood flow in pregnant women with a luteal insufficiency was carried out. The volume of chorion and the parameters of volume flow rate, the vascularization index and the blood flow index were determined. It was established that in women with luteal phase insufficiency, a slowdown in the development of a chorion tree from the early stages of pregnancy is observed. At weeks 5-8 a significant decrease of the vascularization index to 7.81±1.03 was observed. At weeks 12-13, more significant changes of this indicator were detected (9.55±0.88), pointing for a risk factor in the development of primary placental dysfunction. [ABSTRACT FROM AUTHOR]

• Traditional agricultural landscapes with trees maintain multiple ecosystem services. • Maintenance of veteran-type oaks in agro-silvo-pastoral systems is a key challenge. • We compared four categories of oak tree development in three socio-economic contexts. • Two distinct oak recruitment patterns – prolonged and short – were distinguished. • Reconnecting rural economies and ecologies as a way forward for oakscape restoration. Semi-open oak woods and solitary oaks commonly dominate the wooded fabric (i.e. the 'oakscape') of European traditional rural agricultural landscapes based on animal husbandry. However, modern land use systems fail to perpetuate oakscapes, posing a serious threat to biodiversity conservation and the associated diversity of ecosystem services. Reconstructing the dynamics of oakscape remnants can provide valuable insights concerning the maintenance of oakscapes. We used the socio-economic transitions at the European Union's eastern border as a natural experiment to explore the drivers for successful oak recruitment in 27 selected units representing 4 oakscape categories. Analyses of tree-ring data, historical maps, and orthophotos were used to reconstruct the oakscapes' establishment trajectories in relation to land use changes in the period 1790–2010. The oaks in cultural semi-open woods and wood-pastures differed substantially from those in closed canopy forests by more stocky shape and faster early age DBH annual increase. We found two distinct recruitment patterns: (1) FAST – recruitment usually completed within 2–3 decades, attributed to an unconstrained succession of abandoned agricultural land, and (2) SLOW – recruitment extending over several or more decades. In Ukraine, frequent illegal grass burning in marginal woods was the most successful mechanism perpetuating oak recruitment. Top-down policy encouraging specialized intensive farming, sustained yield forestry, and conservation efforts concentrated on the preservation of closed canopy forests compromise the future of traditional agro-silvo-pastoral systems. Maintenance of traditional integrated agro-silvo-pastoral management sustaining oakscapes needs to combine local traditional knowledge and landscape stewardship. [ABSTRACT FROM AUTHOR]

Gölhisar Basin which is located in the southern part of Lakes Region, in SW of Turkey contains four main geologic parent materials composed of serpentine-peridotite, Mesozoic limestone, Neogene marl deposit and Quaternary colluvial deposit on which Calabrian pine (Pinus brutia) and Anatolian black pine (Pinus nigra subsp. pallasiana) grow. Tree productivity and/or growth rate is considerably different on these parent materials. This is mainly related to the weathering degree of serpentine-peridotite, stratification and compactness of marl deposit and the crack structure of limestone. For example, the productive Calabrian pine (Pinus brutia) trees grow on the deeply weathered serpentineperidotite parent material in the Gölhisar basin. Draft appearances of Calabrian pines are found on exposed peridotite-serpentine in sloping areas. Besides, tree biomass is low on compact marl deposit due to the fact that taproot development of trees is mostly prevented by the compact marl deposit and horizontal marl layers. The productivity of Calabrian pine and black pine (Pinus brutia) trees on the limestone is higher than on the marl deposit and low weathered serpentine in the study area, in general. The aim of this study is to illustrate the importance of parent materials containing serpentine-peridotite, limestone, marl and colluvial deposits on the growth of Pinus brutia and Pinus nigra trees in the Gölhisar Basin. [ABSTRACT FROM AUTHOR]

A total of 10 sub-regions were identified and tree total volume equations were developed for economically important Dahurian larch species in northeast China (Daxing’an Mountain region/Heilongjiang province). These equations were based on a simple power function and adjusted to the forest inventory data volumes of three mountainous regions, including the northwest of northern slope of Yilehuli Mountains (NWYLHLM), the southeast of northern slope of Yilehuli Mountains (SAYLHLM) and the eastern slope of northern part of Daxin’an Mountains (NDXAM). The volume equations were tested to determine if differences by ecoregion were statistically significant. Results varied by species, volume and ecoregion suggesting that the relationship between tree volume and tree diameter of Dahurian larch (Larix gmelinii Rupr) tree species is significantly different between the three geographic regions, depending on local climatic, soil and ecological conditions. This implies that the provincial and regional models of volume-diameter relationships are not appropriate for predicting tree volume at ecoregional level. In addition, the use of an ecoregional specific model will lead to significant bias in predicting the total volume of trees. The ecoregion-based volume models developed in this study could provide more accurate information on tree growth and development to forest resource managers and planners. [ABSTRACT FROM AUTHOR]

In this study, individual tree-biomass equations are developed for the different biomass components (foliage, branch, bark, stem, and total aboveground biomass) of Quercus frainetto Ten., Quercus cerris L., and Quercus petraea (Matt.) Liebl. species, which are the main oak species in coppice-originated oak forests. This research was conducted in northern Turkish Thrace, an important coppice-oak area. A total of 474 oak trees at different development stages over different sites were destructively sampled to obtain biomass models of the major oak species in the region. Two main biomass models are established to estimate the biomass components: according to the diameter at breast height (DBH) alone and according to the d2h variable, which is the combined DBH and tree height. The goodness-of-fit statistics of the models are calculated to compare these models. The models that use the DBH alone as an independent variable explain 68–95% of the variation in the biomass of the tree components. After adding the tree height to the model, the accuracy for the bark-, stem-, and total aboveground-biomass estimates increased, while the accuracy of the foliage- and branch-biomass estimates decreased. Different oak species have different biomass components depending on their development stages. The amount of biomass components in the total aboveground biomass and foliage decreased from 20% (SDF) to 4% (LDF), the amount of bark decreased from 17% (SDF) to 12% (LDF), and the amount of stems increased from 42% (SDF) to 66% (LDF) when increasing the mean DBH of the sample plots. [ABSTRACT FROM AUTHOR]

• Minimum annual heights for eventual canopy (co)dominance varied with site quality. • Minimum annual heights were similar among competing species on a given site class. • Species similarity suggest common developmental pressures during canopy recruitment. • Validated efficacy of results to assist managers with early silvicultural decisions. Tree height development has been studied extensively. Nonetheless, there is limited quantitative guidance for height expectations during the regeneration period, particularly for common species with low commercial value. Site index models, for example, often omit the initial 15–20 years of development. We examined height development of juvenile trees during the first twenty years after overstory removal in naturally regenerated, mixed stands in the Missouri Ozarks to identify milestones indicative of eventual recruitment into the upper canopy by the end of the regeneration period. Such milestones quantify minimum height requirements for recruitment success from trees that occupied codominant and dominant crown classes at the end of the regeneration period. Results show these milestones differed statistically by site class and those differences increased over time. Species-specific milestones were similar and while some statistical differences were observed, the practical, if not ecological, consequences of those differences appeared limited. The similarity in milestones among species suggests that there is a minimum height threshold for eventual canopy recruitment success after overstory removal in the Missouri Ozarks. This was validated using independent data from a nearby long-term study with tagged individuals. Less than 1% of trees that failed the milestones by year 3 met them after 16 years, and less than 1% of trees failing the milestones at year 8 met them by year 16. Thus, the presented milestones are a tool that can be used to assess individual tree height development during the recruitment process. A tree that attains these milestones early in development is not guaranteed to remain successful throughout the regeneration period, but success without first reaching these milestones is highly improbable. [ABSTRACT FROM AUTHOR]

Today, big data processing has become a challenging task due to the amount of data collected using various sensors increasingly significantly. To build knowledge and predict the data, traditional data mining methods calculate all numerical attributes into the memory simultaneously. The data stream method is a solution for processing and calculating data. The method streams incrementally in batch form; therefore, infrastructure memory is sufficient to develop knowledge. The existing method for data stream prediction is FIMT-DD (Fast Incremental Model Tree-Drift Detection). Using this method, knowledge is developed in tree form for every instance. In this paper, enhanced FIMT-DD is proposed using ARDEV (Average Restrain Divider of Evaluation Value). ARDEV utilizes the Chernoff bound approach with error evaluation, improvement in learning rate, modification of perceptron rule calculation, and utilization of activation function. Standard FIMT-DD separates the tree formation process and perceptron prediction. The proposed method evaluates and connects the development of the tree for knowledge formation and the perceptron rule for prediction. The prediction accuracy of the proposed method is measured using MAE, RMSE and MAPE. From the experiment performed, the utilization of ARDEV enhancement shows significant improvement in terms of accuracy prediction. Statistically, the overall accuracy prediction improvement is approximately 6.99 % compared to standard FIMT-DD with a traffic dataset. [ABSTRACT FROM AUTHOR]

• Crown and branch sizes decrease ~20% per 25% increase in neighborhood density. • >15-cm-diameter appendages develop in ~160 ± 60 yr due to neighborhood density. • Appendages associated with reiterated trunks strongly correlate with crown injury. • An empirical neighborhood-density and injury-based developmental model is presented. • Aggregate Picea crown structure develops ~100% faster than in Psuedotsuga menziesii. Large trees are critically important for structuring ecosystems and providing habitat, and trees with complex crowns provide more of these services than comparably sized trees with simple crowns. Forest managers are increasingly emulating old-growth structure by retaining various densities of aggregated and dispersed trees. This study explores how individual within-crown complexity develops in a wide range of tree densities and interprets them in terms of management goals. Stratified LiDAR data were used to select 36 Picea sitchensis trees 55 to 91 m tall and from the complete range of tree densities in Olympic rainforests. These were climbed, three-dimensionally mapped—including the trunk and every appendage—to quantify tree allometry and habitat-related structures within their crowns. Sampled trees were then aged with crossdated increment cores to construct a chronosequence of crown development. The sample ranged from 70 to 250 cm diameter and 100 to 400 years old. Circular 30 m radius plots were installed around each tree to quantify neighborhood density. An additional 19 trees ranging from 10 to 94 m tall were added to the sample (N = 55) to describe baseline crown development and then compared to the 36-tree sample in which we modeled how this baseline is altered by neighborhood competition. After ∼200 yr, crown mass increases faster than trunk mass due to accumulation and growth of large appendages. The largest neighbors within 25 m compete with Picea , reducing trunk and appendage diameters as well as crown volume by roughly 20% for each 25% increase in density for a given tree age. Reduced growth and higher mortality of lower-crown appendages in dense forests delays development of large (>15 cm diameter) appendages for over 100 yr. Abundance of structures associated with reiterated trunks is unrelated to neighborhood density but increases with crown damage. These findings contribute to an empirically-based conceptual framework for crown development in Picea and interpretation of management guidelines. Picea is then compared to Pseudotsuga menziesii —another well-studied tall conifer of Olympic rainforests. Picea accumulates ecologically important crown structures much faster than Pseudotsuga yet has roughly half the longevity, indicating that these co-occurring species have complementary functions. Because of its shade tolerance and extremely rapid growth in rainforests, Picea can be used to accelerate development of complex crown structures in forests typically planted with Pseudotsuga after logging. [ABSTRACT FROM AUTHOR]

The research aims to identify the effectiveness of the problem tree strategy in the development of multiple intelligences among preparatory school students. The sample consisted of two groups: one was the experimental group (30) students, the other was the control group (30) students, (Imam Ali Preparatory School) has been chosen from the research community represented by secondary and preparatory schools belonging to the Directorate of Education of Babil Governorate/the center. The empirical research method was adopted as a methodology for conducting the research which includes an independent variable (problem tree strategy) and one dependent variable (multiple intelligences). The partial experimental design was chosen to control the research variables. Before starting the experiment, the research groups were equalized for accurate results with the following variables: (time age calculated by months, the first semester grads of students, Raven’s test for intelligence). After the parity between the two sets of research, the application requirements of plans, objectives, and tests were prepared for the two research groups. The data results were statistically analyzed by t-test for two independent variables. The results showed that the experimental group was superior to the control group according to the problem tree strategy in multiple intelligences. [ABSTRACT FROM AUTHOR]

Based on the slice materials of 35 kV and 110 kV XLPE cables, an experimental platform is built to study the relationship between electrical tree and PDs in XLPE with different voltage levels. There are three significant statistical characteristics of the PDs during the growth of electrical trees. The analysis of the results shows that each growth stage has certain characteristics. Different features existed between the growth of the electrical trees and the PD in the insulation of the 35 and 110 kV cables. Evident characteristics such as large spans of time and frequency were present as the electrical trees grew violently in the equivalent time-frequency diagram at every stage. These results could provide criteria for the identification of the deterioration using PD to monitor cables in service at rated voltages. The results are important for the identification of defects in cable insulation in order to provide an early warning of insulation breakdown in the cables. [ABSTRACT FROM AUTHOR]

Tree biomechanics and biomechanical tree stability are research problems that have been discussed in world literature for many years. The biomechanical profile formation in trees is an extremely complicated problem and has not been fully clarified to date. It is influenced by many factors, which determine tree growth, tree development, multifunctionality of organs, and anatomical elements in xylem. The phenomenon is further affected by the overlapping of functions and development of numerous interactions between all the systems found in living trees. This paper presents a synthetic description of selected research results, providing insight into the mechanical functioning of trees, from initial theories of mechanical tree formation to the influence of dynamic load on tree stability. Trees are a biological structure that shows high adaptability to external conditions. Thus, the response to a specific environmental stressor, including abiotic and biotic factors, should be considered. Analyses of the biomechanical system in plants need to be considered in a broader context than a selected single load. Due to the complexity of these phenomena and numerous interactions, we need more multidisciplinary research to explain biomechanical mechanism of tree development. [ABSTRACT FROM AUTHOR]

Walnut is a species of high vigour, with relatively slow growth, and the size of trees grows with each year of growth. Accumulation of wood biomass, and respectively, productivity, is a resultant synthesis of physiological processes and interaction of trees with environmental factors. The authors have assessed growth characteristics of genotypes standing on their own roots in the sands area of Oltenia (Romania). In terms of tree height, it ranged from 8.53 m to 18.00 m, while trunk circumference varied between 40 cm and 229 cm, in genotypes with ages between the 16 and 44 years. Environmental factors, by influencing cambium tissue activity, cell differentiation processes, cell walls growth processes, are inducing particular characteristics of annual rings, in terms of size. The average value of growth ring was 7.09 mm, with a minimum of 3.53 mm, a maximum of 13.94 mm and variation coefficient of 40.20%. The obtained results show that climatic and edaphic factors of the culture area are influencing the trees growth and development and indicate a good adaptability of genotypes to these conditions. [ABSTRACT FROM AUTHOR]