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Data capturing multiple axes of tree size and shape, such as a tree's stem diameter, height and crown size, underpin a wide range of ecological research-from developing and testing theory on forest structure and dynamics, to estimating forest carbon stocks and their uncertainties, and integrating remote sensing imagery into forest monitoring programmes. However, these data can be surprisingly hard to come by, particularly for certain regions of the world and for specific taxonomic groups, posing a real barrier to progress in these fields. To overcome this challenge, we developed the Tallo database, a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured. These data were collected at 61,856 globally distributed sites, spanning all major forested and non-forested biomes. The majority of trees in the database are identified to species (88%), and collectively Tallo includes data for 5163 species distributed across 1453 genera and 187 plant families. The database is publicly archived under a CC-BY 4.0 licence and can be access from: https://doi.org/10.5281/zenodo.6637599. To demonstrate its value, here we present three case studies that highlight how the Tallo database can be used to address a range of theoretical and applied questions in ecology-from testing the predictions of metabolic scaling theory, to exploring the limits of tree allometric plasticity along environmental gradients and modelling global variation in maximum attainable tree height. In doing so, we provide a key resource for field ecologists, remote sensing researchers and the modelling community working together to better understand the role that trees play in regulating the terrestrial carbon cycle.

The shea tree, Vitellaria paradoxa, shields people, crops and livestock in West African parkland agroforestry systems from climate variability. Accurate estimates of accumulated biomass of such key species may support ways to secure financial incentives within global climate policies. In this quest, variation in allometric relations used for biomass (carbon stock) estimates on the basis of stem diameter matters, but parameters a and b of the standard format (AGB = a Db; AGB = aboveground biomass, D = stem diameter) are correlated and are directly related to tree shapes. Functional branch analysis (FBA) allows non-destructive derivation of allometrics. For Koutiala and Yanfolila shea populations empirical branching parameters were scale-independent, matching FBA assumptions. Allometry (AGB = 169 (D/20)2.64 and AGB = 146 (D/20)2.65, kg tree−1) implied 22%, 16% and 11% larger vegetative aboveground biomass in Koutiala than in Yanfolila at stem diameters (D) of 10, 20 and 32 cm, respectively. Below-ground biomass predictions (BGBi = 8.73 (Di/10)2.35 and BGBi = 8.16 (Di/10)2.38, kg per proximal root) differed − 6% and − 15% for root diameters Di of 10 and 32 cm, respectively. On a dry weight basis, the shoot:root ratio was 2.7 and 2.9, respectively for the two sites. Stand-level above-and below-ground carbon stocks in Koutiala (2.16 ± 0.44 and 0.8 ± 0.15 Mg C ha−1) were not significantly different from those in Yanfolila (3.21 ± 0.60 and 1.26 ± 0.21 Mg C ha−1), respectively. Further research is required to include (potential) fruit production to the plant architectural model.

Funder: Agua Salud Project, Funder: U.S. Department of Energy; Id: http://dx.doi.org/10.13039/100000015, Funder: CAPES; Id: http://dx.doi.org/10.13039/501100002322, Data capturing multiple axes of tree size and shape, such as a tree's stem diameter, height and crown size, underpin a wide range of ecological research-from developing and testing theory on forest structure and dynamics, to estimating forest carbon stocks and their uncertainties, and integrating remote sensing imagery into forest monitoring programmes. However, these data can be surprisingly hard to come by, particularly for certain regions of the world and for specific taxonomic groups, posing a real barrier to progress in these fields. To overcome this challenge, we developed the Tallo database, a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured. These data were collected at 61,856 globally distributed sites, spanning all major forested and non-forested biomes. The majority of trees in the database are identified to species (88%), and collectively Tallo includes data for 5163 species distributed across 1453 genera and 187 plant families. The database is publicly archived under a CC-BY 4.0 licence and can be access from: https://doi.org/10.5281/zenodo.6637599. To demonstrate its value, here we present three case studies that highlight how the Tallo database can be used to address a range of theoretical and applied questions in ecology-from testing the predictions of metabolic scaling theory, to exploring the limits of tree allometric plasticity along environmental gradients and modelling global variation in maximum attainable tree height. In doing so, we provide a key resource for field ecologists, remote sensing researchers and the modelling community working together to better understand the role that trees play in regulating the terrestrial carbon cycle.

The Tallo database (v1.0.0) is a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured. Data were compiled from 61,856 globally distributed sites and include measurements for 5,163 tree species.

Seed propagation of pequizeiro (Caryocar brasiliense) has many disadvantages, including low germination rates and high genetic variability of the resulting plants. Therefore, vegetative propagation techniques, such as the air layering process, are potentially important for this species. This study evaluated the effects of stem diameter and parental plant on the air layering efficacy of pequizeiro. The air layering process was carried out in mid-December 2019, in the following stem diameters: less than 15 mm; 15-19 mm; 20-24 mm; 25-29 mm and above 29 mm. The treatments comprised four replicates of 10 air layers. After 3 months, the percentages of survival, callus formation and rooting were evaluated, in addition to the rooting vigor. The percentages of survival and callus formation observed in the air layering, regardless the parental plant, were higher than 85%, showing the high potential of this technique in the propagation of pequizeiro. The callus differentiation rate in roots varied between the parental plants. Considering the evaluated parameters, stem diameters ranging from 20 to 24 mm are the most suitable ones for the air layering process in pequizeiro. These results indicated the high potential of the air layering technique for the commercial propagation of pequizeiro. RESUMO: A propagação seminal de pequizeiro acarreta grande variabilidade na taxa de germinação e no genótipo das mudas produzidas, mostrando a necessidade do desenvolvimento de técnicas para a propagação vegetativa dessa espécie, como a alporquia. Os objetivos deste estudo foram avaliar a eficácia da alporquia, bem como o efeito do diâmetro do caule e da planta-mãe na sobrevivência, no calejamento e no enraizamento de alporques de pequizeiro. O processo de alporquia foi realizado em meados de dezembro de 2019, nos seguintes diâmetros de caule: inferior a 15 mm; 15-19 mm; 20-24 mm; 25-29 mm e superior a 29 mm. Os tratamentos foram testados em quatro repetições de 10 alporques. Após três meses, avaliaram-se as porcentagens de sobrevivência, de calejamento e de enraizamento, além do vigor de enraizamento. As porcentagens de sobrevivência e de calejamento nos alporques, independentemente da planta matriz, foram superiores a 85%, mostrando o grande potencial dessa técnica na reprodução de pequizeiro. A taxa de diferenciação de calos em raízes variou entre as matrizes. Considerando os parâmetros avaliados, diâmetros de caule de 20 a 24 mm são os mais adequados para a alporquia em pequizeiro. Esses resultados indicam o potencial da técnica de alporquia para a produção comercial de mudas de pequizeiro.

Solving the problem of the stem contour extraction of maize is difficult under open field conditions, and the stem diameter cannot be measured quickly and nondestructively. In this paper, maize at the small and large bell stages was the object of study. An adaptive threshold segmentation algorithm based on the color space model was proposed to obtain the stem contour and stem diameter of maize in the field. Firstly, 2D images of the maize stem in the field were captured with an RGB-D camera. Then, the images were processed by hue saturation value (HSV) color space. Next, the stem contour of the maize was extracted by maximum between-class variance (Otsu). Finally, the reference method was used to obtain the stem diameter of the maize. Scatter plots and Dice coefficients were used to compare the contour extraction effects of the HSV + fixed threshold algorithm, the HSV + Otsu algorithm, and the HSV + K-means algorithm. The results showed that the HSV + Otsu algorithm is the optimal choice for extracting the maize stem contour. The mean absolute error, mean absolute percentage error (MAPE), and root mean square error (RMSE) of the maize stem diameter at the small bell stage were 4.30 mm, 10.76%, and 5.29 mm, respectively. The mean absolute error, MAPE, and RMSE of the stem diameter of the maize at the large bell stage were 4.78 mm, 12.82%, and 5.48 mm, respectively. The MAPE was within 10–20%. The results showed that the HSV + Otsu algorithm could meet the requirements for stem diameter measurement and provide a reference for the acquisition of maize phenotypic parameters in the field. In the meantime, the acquisition of maize phenotypic parameters under open field conditions provides technical and data support for precision farming and plant breeding.

International audience; AbstractKey messageWe used lightweight terrestrial laser scanning (TLS) to detect over 3000 stems per hectare across a 12-ha permanent forest plot in French Guiana, 81% of them

In this study, five different compatible taper equations were used for Brutian pine (Pinus brutia Ten.) trees within the border of Asar Forest Sub-district in Antalya Forest Management Directorate of Antalya Forest District Regional. These five equations were produced from the equations of Max & Burkhart (1976), Jiang et al. (2005) and 3 different models of Kozak (1988). The fitting results of these equations were compared. As a result of the comparison that made according to success criteria’s, the equation of Jiang et al. (2005) with 95.95% model explanation was found to be more successful in predicting stem diameter of Brutian pine. The suitability of Jiang et al. (2005) of the equation was tested by using an independent data group with paired sample t test and it was concluded that the equation can be applied to the study area at p

A field experiment was conducted during autumn season 2018 in Al-Qurna Agriculture research station which is located in about 70 km away north of AL-Basrah Center at 47°.45’ east longitude and 31°00’ north latitude. The aim is to Study the effect of three tillage systems (No tillage; T1, chisel plow a depth of 30 cm plowing + 10 cm disc harrows a depth of 10 cm; T2, Moldboard plow a depth of plowing 30 cm + disc harrows a depth of 10 cm; T3) on some growth characters of some maize genotypes (Zea mays L.). The genotypes were Fajer-1 (V1), Baghdad-3 (V2), Al-Maha (V3), Sara (V4). The design of the experiment was randomized complete block design (RCBD) in a split plot arrangement with three replications. The results showed that the tillage system T3 was superior as compared to other tillage systems in stem diameter, while as the treatment T2 was superior in number of days up to 50% tasseling and leaf area. The cultivar Maha (V3) was superior as compared to other cultivars in number of days up to 50% tasseling and leaf area. The interaction between corn genotypes and tillage system was significant on leaf area, that is the genotype V3 under the tillage system T2 gave the highest leaf area reached to 4847.893 cm2.

Background: Manchurian fir (Abies nephrolepis Maxim) and Korean spruce (Picea koraiensis Nakai) are primary conifer species of economic and ecological importance in northeast China. Several taper studies have analyzed for fir and spruce species in the countries harboring the boreal forests. However, taper models do not exist for Manchurian fir and Korean spruce in China or abroad. This study aimed to develop stem taper models for these species. A dataset of 188 destructively sampled trees (Manchurian fir 123 and Korean spruce 65) was used to evaluate eight well-known taper models. These models were fitted with generalized non-linear least squares by using 3,570 diameter and height measurements. We incorporated a first-order continuous-time error structure to adjust the inherent autocorrelation. Results: The form-class segmented model of Clark et al. (1991) best predicted the diameter, merchantable volume, and stem volume of the species when the upper stem diameter at 5.3 m was available or predicted. Conclusion: When diameter measurements at 5.3 m were not available, the Kozak (2004) and Max and Burkhart (1976) models were superior to other models in estimating the diameter of both species and volume of Korean spruce. For Manchurian fir, the Fang et al. (2000) model was more accurate in volume estimates.

Stem and canopy architecture traits are superior predictors of floral biomass yield and offer a good indication of hybrid uniformity in field plantings of genetically diverse cannabinoid hemp populations., The breeding of hybrid cultivars of hemp (Cannabis sativa L.) is not well described, especially the segregation and inheritance of traits that are important for yield. A total of 23 families were produced from genetically diverse parents to investigate the inheritance of morphological traits and their association with biomass accumulation and cannabinoid yield. In addition, a novel classification method for canopy architecture was developed. The strong linear relationship between wet and dry biomass provided an accurate estimate of final dry stripped floral biomass. Of all field and aerial measurements, basal stem diameter was determined to be the single best selection criterion for final dry stripped floral biomass yield. Along with stem diameter, canopy architecture and stem growth predictors described the majority of the explainable variation of biomass yield. Within-family variance for morphological and cannabinoid measurements reflected the heterozygosity of the parents. While selfed populations suffered from inbreeding depression, hybrid development in hemp will require at least one inbred parent to achieve uniform growth and biomass yield. Nevertheless, floral phenology remains a confounding factor in selection because of its underlying influence on biomass production, highlighting the need to understand the genetic basis for flowering time in the breeding of uniform cultivars.

Using a suitable planting density and proper weed control are important factors in achieving high yield in red beans. In order to investigate the effects of plant density and weed control on the growth and yield of red beans, a factorial experiment was conducted in three replications in completely randomized blocks at the Agricultural Research Center of Khoy, North-West of Iran in 2017-2018. Three planting densities (20, 25 and 30 plants/m2) and four weed control method strategies including uncontrolled, selective herbicide (Bentazone), manually controlled and non-selective herbicide application (Paraquat) were selected. The results showed that the interaction effect of planting density and weed control methods significantly affected the number of lateral branches, the distance of the first lateral branch from the ground, the main stem’s diameter, the dry weight of the plant and seed yield. The highest seed yield (3391 kg/ha) was obtained in the planting density of 30 plants/m2 and manually controlled weeding and the highest seed protein percentage (24.8%) was obtained in the planting density of 20 plants/m2 and manual-weeding method. The results of this study showed that the manual weed control method has a relative advantage over the other methods of weed control and the use of non-selective herbicide alone is not effective in controlling red bean weeds. The production of greatest seed yield with a population density of 30 plants/m2 indicates a positive response of red beans to high plant densities.

The stem diameter, an important agronomic trait, affects cucumber growth and yield. However, no genes responsible for cucumber stem diameter have been identified yet. In this study, the stem diameter of 88 cucumber core germplasms were measured in spring 2020, autumn 2020 and autumn 2021, and a genome-wide association study (GWAS) was carried out based on the gene sequence and stem diameter of core germplasms. A total of eight loci (gSD1.1, gSD2.1, gSD3.1, gSD3.2, gSD4.1, gSD5.1, gSD5.2, and gSD6.1) significantly associated with cucumber stem diameter were detected. Of these, five loci (gSD1.1, gSD2.1, gSD3.1, gSD5.2, and gSD6.1) were repeatedly detected in two or more seasons and were considered as robust and reliable loci. Based on the linkage disequilibrium sequences of the associated SNP loci, 37 genes were selected. By further investigating the five loci via analyzing Arabidopsis homologous genes and gene haplotypes, five genes (CsaV3_1G028310, CsaV3_2G006960, CsaV3_3G009560, CsaV3_5G031320, and CsaV3_6G031260) showed variations in amino acid sequence between thick stem lines and thin stem lines. Expression pattern analyses of these genes also showed a significant difference between thick stem and thin stem lines. This study laid the foundation for gene cloning and molecular mechanism study of cucumber stem development.

Monitoring how plant biomass changes with environmental conditions is critical for evaluating ecosystem carbon storage and understanding the underlying mechanisms of carbon dynamics. Usually destructive methods require a lot of time and cost. And the non-destructive methods to repeatedly estimate the biomass of herbaceous plants across large scale environmental conditions are still limited. Leymus chinensis, as an important constructive species, constitutes a unique community type in the eastern Eurasian steppe across the semi-humid, semi-arid and arid areas in the middle temperate and warm temperate zones. Therefore, it is necessary to analyze the driving factors and establish a unified estimation equation of the aboveground biomass (AGB) of L. chinensis across large scale. In this study, for the first time, we combined climatic factors and plant characteristics to analyze the individual AGB of L. chinensis in northern China, and established a non-destructive prediction model that can accurately quantify the AGB of L. chinensis across large scale in China. 33 sites across different climate conditions with L. chinensis as the constructive species in China were sampled to measure plant traits of L. chinensis individual, including leaf thickness (LT), stem diameter (SD), stem length (SL), plant height (PH), etc. We found that plant traits (PH,SD) were the main factors driving the AGB of L. chinensis individuals, and climate factors mainly affected AGB of L. chinensis individuals indirectly by affecting plant traits. Then, we established the AGB estimation equation of L. chinensis individuals across large scale for the first time. The equation was: AGB = −0.638 + 0.405*SD + 0.017*PH, which had a high predictive ability. The result is not only helpful to quickly and conveniently measure the AGB of L. chinensis individuals in non-destructive experiments, but also important to evaluate the productivity and carbon storage of L. chinensis community across large scale. At the same time, it also laid the foundation for the subsequent non-destructive estimation of the aboveground biomass of individual plants.

Greenhouse microclimate (light, temperature, relative humidity and CO2) and irrigation are important factors for plant growth, development and quality in ornamental horticulture. To optimize plant growth, actual stem diameter growth can be measured and compared with a desired growth pattern. Using the deviation between measured and simulated stem diameter growth, growers can decide whether and in which way the microclimate or irrigation needs to be adjusted. Together with this decision, costs associated with climate control and irrigation must also be taken into account. This will help growers to find a proper balance between cultivation costs and plant growth. In this study, Ficus benjamina was grown from cutting to mature plant in a controlled greenhouse environment. Growing conditions, microclimate as well as plant spacing, closely resembled the ones used in commercial greenhouses. Microclimate, soil water content, leaf temperature, sap flow, stem diameter variation and leaf thickness were continuously measured on three plants. In addition, discrete measurements of leaf area, projected crown surface area, stem water potential, photosynthesis, transpiration and stomatal conductance were performed. These measurements were used to further extend a mechanistic plant model, which allows simulation of long-term stem diameter variation.

The abuse of fertilizer results in tall rice plants that are susceptible to lodging and reduced plant yield. Hence, it is important to identify and utilize the quantitative trait loci (QTLs)/genes for lodging resistance breeding. Oryza longistaminata exhibits a strong stem and high biomass productivity, which could be a candidate gene pool for cultivars lodging resistance improvement. Here, a set of 152 BC2F20 lines derived from a cross between a cultivated line 93-11 and O. longistaminata was evaluated for lodging resistance. QTL mapping analysis combined with single-nucleotide polymorphism (SNP) marker derived from high-throughput sequencing identified 12 QTLs for stem diameter (SD), 11 QTLs for stem length (SL), and 3 QTLs for breaking strength (BS). Of which, 14 QTLs were first identified from O. longistaminata. A major QTL, qLR1, which was delimited to a region ∼80 kb on chromosome 1, increased stem diameter, stem length, and breaking strength. Another major QTL, qLR8, that was delimited in an interval ∼120 kb on chromosome 8, significantly enhanced the breaking strength. These results provide evidence that O. longistaminata can be exploited to develop lodging-resistant rice lines.

Cornelian cherry (Cornus mas L.) is still not a very popular fruit plant in Poland. Fruit growers have been recently increasingly interested in the cultivation of plants with fruits that can be widely used in processing. Fruits of Cornelian cherry can be eaten raw, and processed in various ways: for tinctures, juices, jams, silage, candied, etc. Both the fruits and preserves are characterised by high pro-health properties due to the content of vitamins, anthocyanins, and loganic acid. Cornus mas adapts well to the climate and soil conditions in Poland. The only limitation of its broader cultivation is lack of good planting material. The experiment investigated the efficiency of budding on two-year-old seedlings (Cornus mas L.) of several cultivars and genotypes of Cornelian cherry. Moreover, the height of plants, stem diameter, average number of shoots, number of leaves on selected shoots, and quality of roots were determined. The cornelian cherry maidens obtained by budding with dormant bud in August on two-year-old seedlings of Cornelian cherry (Cornus mas L.) constitutes high quality material suitable for establishing commercial plantations. Maiden trees of particular cultivars and genotypes of cornelian cherry significantly differ in height, diameter, number of branches and leaves, as well as the size of the root system. The diameter of the trunk is a good indicator of the quality of Cornelian cherry maiden, because it is closely positively correlated with the height of plants and the number of shoots.

Pectin is a major polysaccharide component that promotes plant growth and fiber elongation in cotton. In previous studies, the galacturonosyltransferase-like (GATL) gene family has been shown to be involved in pectin synthesis. However, few studies have been performed on cotton GATL genes. Here, a total of 33, 17, and 16 GATL genes were respectively identified in Gossypium hirsutum, Gossypium raimondii, and Gossypium arboreum. In multiple plant species, phylogenetic analysis divided GATL genes into five groups named GATL-a to GATL-e, and the number of groups was found to gradually change over evolution. Whole genome duplication (WGD) and segmental duplication played a significant role in the expansion of the GATL gene family in G. hirsutum. Selection pressure analyses revealed that GATL-a and GATL-b groups underwent a great positive selection pressure during evolution. Moreover, the expression patterns revealed that most of highly expressed GhGATL genes belong to GATL-a and GATL-b groups, which have more segmental duplications and larger positive selection value, suggesting that these genes may play an important role in the evolution of cotton plants. We overexpressed GhGATL2, GhGATL9, GhGATL12, and GhGATL15 in Arabidopsis and silenced the GhGATL15 gene in cotton through a virus induced gene silencing assay (VIGS). The transgenic and VIGS lines showed significant differences in stem diameter, epidermal hair length, stamen length, seed size, and fiber length than the control plant. In addition, the pectin content test proved that the pectin was significantly increased in the transgenic lines and reduced in VIGS plants, demonstrating that GhGATL genes have similar functions and act on the pectin synthesis to regulate plant growth and fiber elongation. In summary, we performed a comprehensive analysis of GhGATL genes in G. hirsutum including evolution, structure and function, in order to better understand GhGATL genes in cotton for further studies.

Stems serve as key determinants of plant development by connecting and supporting parts of the plant body, transporting nutrients important for long-distance communication that affect crop yield, and producing new organs. Nonetheless, studies on the regulation of stem development in crops are rather limited. Here, we found a significant correlation (P, SD1, mainly expressed at the cambium and selected during tomato improvement, encodes a kinase-interacting protein that positively regulates stem development by controlling the size and number of secondary phloem cells.

Internode length and stem diameter are the primary traits affecting the lodging resistance of rice. Traits related to the length of the panicle (LP), uppermost internode (LUI), second internode (LSI), third internode (LTI), fourth internode (LFI), lowest internode (LLI) as well as stem diameter at the uppermost internode (SDUI), second internode (SDSI), third internode (SDTI), fourth internode (SDFI), and lowest internode (SDLI) in 120 Cheongcheong/Nagdong doubled haploid population were investigated using a quantitative trait locus (QTL) analysis. Thirty-four QTL regions affected LP and the length of each internode. Twenty-six QTL regions were associated with the stem diameter of each internode. RM12285-RM212 on chromosome 1 contained 10 QTLs related to the internode length, which have overlapped for over 2 years. Twenty-three candidate genes were screened using mark interval. Among the candidate genes, Os01g0803900, named OsCYPq1, which is in the Cytochrome P450 family, might be involved in gibberellins (GA) synthesis. GA is an essential plant growth regulator that affects plant height. OsCYPq1 catalyzes oxidation steps in the middle part of the GA pathway. OsCYPq1 is expected to provide valuable information to improve the marker assessment for target traits and QTL gene cloning in rice.

The liana species Derris trifoliata is an associate species in mangroves, but in recent years, its biomass and abundance have increased. The biomass estimated for Derris trifoliata is vital for determining the carbon stores in mangrove habitats. And the allometric equations are insufficient but essential for lianas. We collected 132 samples of D. trifoliata to produce a regression analysis, following which allometric equations of biomass (root, stem, leaf, ground, and total biomass) were obtained. The allometric equations we obtained based on basal diameter have a better effect to predict stem biomass, ground biomass, and total biomass, and the adjusted R2 for these measures was 0.5258, 0.5287, and 0.5397, respectively. When leaf biomass was simultaneously added as another independent variable, the accuracy of the prediction of the total biomass (adjusted R2 = 0.6715) and stem biomass (adjusted R2 = 0.6163) improved. The ratio of root biomass to total biomass, stem biomass to total biomass, and leaf biomass to total biomass was 0.208–0.430, 0.394 to 0.643, and 0.146 to 0.199, respectively. The biomass accumulation increased with the increase of basal diameter and the ratio of root biomass to ground biomass decreased with the increase of basal diameter, which is likely due to the limited light resources. We measured the stem diameter where the raceme was located and a total of 304 raceme or fruit spur samples were selected. Finally, we found that the number of raceme or fruit spur increased first and then decreased with the increase of stem diameter. The stem diameter, to some extent, represents the age class of the stem: thinner stems have a greater chance of sexual reproduction than thicker stems. The models provided in this paper will facilitate the estimation of the productivity of forests and the amount of carbon sequestered by forests, and the relationship between the generation of inflorescences and stem diameter can predict sexual reproduction and diffusion in the present D. trifoliata distribution area.

Ramie fibres are harvested from the stem bark of the plant, and thus two stem traits—the stem length (SL) and the stem diameter (SD)—are important components of fibre yield in this crop. A recently developed high-density genetic map using an F2 agamous line population derived from two parents, Qingdaye (QDY) and Zhongzhu 1 (ZZ1) laid the basis for dissection of the genetic basis of fibre yield-related traits. However, the genetic basis of the two fibre yield-related stem traits presented here is still uncharacterized in this population. In this study, quantitative trait locus (QTL) analysis for SL and SD traits was performed using the population of QDY/ZZ1, resulting in the identification of four SL and six SD QTLs. Among these 10 QTLs, one was detected in both environments, and six demonstrated a significant environmental correlation. Three DELLA genes were identified to cluster in the region of the stem length QTL qSL11b, and their encoding proteins displayed either amino acid-substitutions or amino acid-insertion/deletion in the functional GRAS domain between two parents. Because the DELLA protein is a negative regulator of the gibberellin signalling pathway and plays a central role in regulating the stem elongation, the mutations in the GRAS domain-encoding region of these three genes potentially influence stem growth. The identification of the QTLs for two stem traits will help improve the fibre yield in ramie breeding programmes by marker-assisted selection. The three identified DELLA genes are candidate genes for cloning the qSL11b locus in future studies.

Article Saabunud / Received 07.01.2019 ; Aktsepteeritud / Accepted 12.03.2019 ; Avaldatud veebis / Published online 05.04.2019 ; Vastutav autor / Corresponding author: Margit Olle e-mail: margit.olle@gmail.com Effective microorganisms (EM) comprise a mixture of live natural cultures of microorganisms isolated from fertile soils that are used to improve crop production. The purpose was to assess the influence of EM on the growth and nutrient content of leaf celery transplants. Two treatments were compared: 1) EM treatment comprised of seed soaking in EM 1:500 solution, sowing in EM treated peat and watering the plants weekly with EM solution. 2) Control treatment included similar treatments with water. Leaf celery transplants grown with EM were significantly shorter and had thicker stems than those grown without EM. The contents of nitrogen, phosphorus, potassium and calcium increased in transplants grown with EM compared to those grown without EM. The contents of nitrates and magnesium did not show statistically significant differences. Conclusion: EM improves the growth and increases nitrogen, phosphorus, potassium and calcium contents of leaf celery transplants.

QUANTITATIVE TRAIT LOCI ASSOCIATED WITH LODGING, STEM STRENGTH, YIELD, AND OTHER IMPORTANT AGRONOMIC TRAITS IN DRY FIELD PEAS By Jamin Smitchger and Norman Weeden In pea, lodging changes canopy structure, increases disease pressure, reduces yield, and reduces harvest efficiency. In order to discover the quantitative trait loci (QTLs) influencing lodging resistance and other important agronomic traits in pea, a recombinant inbred line (RIL) population was created from a relatively wide cross between the commercial variety Delta and an unnamed pea variety. The RIL population was grown for 6 site-years in Bozeman and Moccasin, MT, USA, and phenotypic data was collected for 22 quantitative morphological traits and seven categorical traits which were thought to be associated with lodging resistance. Genotypic data was derived from genotype by sequencing, microsattelite markers, and cleaved amplified sequence tagged sites. QTL analysis identified a total of 135 putative QTLs for the 22 traits examined in the study. There were 12 specific regions where 115 QTLs co-located, indicating that as few as 12 genes may be responsible for multiple pleiotropic effects. Ten QTLs were found for lodging resistance. Due to the large amount of phenotypic data collected, the putative mechanism of lodging resistance was determined for each QTL. In nearly every case, lodging resistance was associated with reduced plant height, a change in tendril number, or increased stem strength. This conclusion was supported by mathematical modeling. Branch number, which determines the number of tendrils per plant, was also positively associated with lodging resistance during all site-years, indicating that increasing tendril number also increases lodging resistance. Yield was controlled by eight QTLs. All QTLs for yield had pleiotropic effects on lodging resistance and yield per plant. Seed size was not correlated with yield, and a model was created which explained why no association between yield and seed size was found.

Studies on plant population size structure provide important baseline information for monitoring and conservation. Traditionally, inverse J-shaped size class distributions (SCD) were considered indicative of ‘healthy’, stable plant populations; however, this may not hold true for long-lived, slow-growing species. This study assessed the population size structure of 19 populations of Aloe plicatilis, a Cape fynbos endemic tree aloe, and quantified population size and density. A strong positive linear relationship between stem diameter (SDr) and height was used to align SDr and height SCD bins, and to harmonize stage and size classes. Onset of reproduction occurs at ~ 15 cm SDr and ~ 0.8 m in height. Some A. plicatilis individuals appear to display a ‘bonsai effect’ whereby the growth of individuals in very rocky sites is suppressed. Stunted plants may be non-reproductive ‘suppressed juveniles’ or ‘reproductive dwarfs’. The short, shrub-like growth form of many individuals may also result from height restrictions imposed by persistent strong winds. Population size, extent and density ranged from 31 to > 110 000 individuals, 0.05–103 ha and 75–3000 plants/ha respectively. Bell-shaped SCDs were the most common (50% of populations). The SDr and height SCDs for all populations combined were also bell-shaped. Seven populations displayed irregular SCDs, but were similar in structure to the bell-shaped SCDs, both of which were attributed to an adult-persistence population survival strategy. This study challenges the suitability of the inverse J as the only SCD indicative of healthy, stable populations for long-lived, slow-growing species. The study provides baseline demographic data on A. plicatilis across its distribution for long-term monitoring, and provides insights useful for examining trends in the demographics of other long-lived, slow-growing species.

Detailed 3D plant architectural data have numerous applications in plant science, but many existing approaches for 3D data collection are time-consuming and/or require costly equipment. Recently, there has been rapid growth in the availability of low-cost, 3D cameras and related open source software applications. 3D cameras may provide measurements of key components of plant architecture such as stem diameters and lengths, however, few tests of 3D cameras for the measurement of plant architecture have been conducted. Here, we measured Salix branch segments ranging from 2–13 mm in diameter with an Asus Xtion camera to quantify the limits and accuracy of branch diameter measurement with a 3D camera. By scanning at a variety of distances we also quantified the effect of scanning distance. In addition, we also test the sensitivity of the program KinFu for continuous 3D object scanning and modeling as well as other similar software to accurately record stem diameters and capture plant form (6 mm, Asus Xtion may provide a novel method for the collection of 3D data on the branching architecture of woody plants. Improvements in camera measurement accuracy and available software are likely to further improve the utility of 3D cameras for plant sciences in the future.

Accurate vehicle localization in forest environments is still an unresolved problem. Global navigation satellite systems (GNSS) have well known limitations in dense forest, and have to be combined with for instance laser based SLAM algorithms to provide satisfying accuracy. Such algorithms typically require accurate detection of trees, and estimation of tree center locations in laser data. Both these operations depend on accurate estimations of tree trunk diameter. Diameter estimations are important also for several other forestry automation and remote sensing applications. This paper evaluates several existing algorithms for diameter estimation using 2D laser scanner data. Enhanced algorithms, compensating for beam width and using multiple scans, were also developed and evaluated. The best existing algorithms overestimated tree trunk diameter by ca. 40%. Our enhanced algorithms, compensating for laser beam width, reduced this error to less than 12%.

Jatropha curcas L., Jatropha mollissima (Pohl) Baill e Jatropha gossypiifolia L. são Euforbiáceas com potencial para produção de biodiesel e uso na indústria farmacêutica e em cosméticos. Objetivou-se, com este trabalho, avaliá-las em termos de crescimento e fenologia em pesquisa de campo. Adotou-se o delineamento experimental em blocos casualisados contendo na parcela 18 plantas e tendo área útil de 15 m². Nos estudos fenológicos das plantas foram consideradas as seguintes fases: estabelecimento/crescimento vegetativo, floração, frutificação e maturação/colheita. As fases fenológicas das espécies diferiram cronologicamente. Jatropha mollissima cresceu mais do que as outras espécies em altura de plantas enquanto Jatropha curcas cresceu mais em diâmetro caulinar. As maiores taxas de crescimento relativo em altura de plantas ocorreram durante o crescimento vegetativo com os maiores valores sendo registrados em Jatropha mollissima enquanto as maiores taxas de crescimento relativo, também no crescimento vegetativo, foram registradas em Jatropha curcas. As menores taxas de crescimento relativo em altura de plantas e diâmetro caulinar das espécies estudadas coincidiram com as fases reprodutivas. Jatropha curcas L., Jatropha mollissima (Pohl) Baill and Jatropha gossypiifolia L. are Euphorbiaceae with potential for biodiesel production and use in pharmaceutical and cosmetic industries. The aim of this study was to evaluate these species in terms of growth and phenology in a field experiment. In this study an experimental design of randomized blocks was adopted. The experimental plot had 18 plants and a useful plot area of 15 m². In the phenological studies of plants the following phases were considered: establishment/vegetative growth, flowering, fruiting and ripening/harvest. The phenological stages of the species differed chronologically. Jatropha mollissima outgrew the others in plant height, while Jatropha curcas outgrew the others in stem diameter. The highest relative growth rates in plant height occurred during vegetative growth, with the highest values being recorded in Jatropha mollissima, while the greatest relative growth rates also in vegetative growth were recorded in Jatropha curcas. The lowest relative growth rates in plant height and stem diameter of the studied species coincided with the reproductive phases.

Advanced backcross QTL analysis was used to identify QTLs for seven yield and yield-related traits in a BC2F2 population from the cross between a popular Oryza sativa cv Swarna and O. nivara IRGC81848. Transgressive segregants with more than 15% increased effect over Swarna were observed for all the traits except days to heading and days to 50% flowering. Thirty QTLs were detected for seven yield and yield-related traits using interval and composite interval mapping. Enhancing alleles at 13 (45%) of these QTLs were derived from O. nivara, and enhancing alleles at all the QTLs for stem diameter and rachis diameter were derived from O. nivara. Three stem diameter QTLs, two rachis diameter QTLs and one number of secondary branches QTL identified by both Interval and composite interval mapping contributed more than 15% of the total phenotypic variance. The QTL epistasis was significant for stem diameter and plot yield. The most significant QTLs qSD7.2, qSD8.1 and qSD9.1 for stem diameter, qRD9.1 for rachis diameter and qNSB1.1 for number of secondary branches are good targets to evaluate their use in marker-assisted selection. O. nivara is a good source of novel alleles for yield related traits and reveals major effect QTLs suitable for marker-assisted selection.

Tree biometrics was measured: stem diameter at breast height (DBH), tree height, as well as crown diameter and length on 15 plots of Siberian spruce urban plantations were in Yekaterinburg-city. The diameter (DBH) distribution of trees was determined based on the statistics and their errors. Variation in stem and crown parameters of the trees and height to diameter ratio was found to be lower in urban plantations than in natural forest stands. DBH variation coefficient is decreased with tree spacing increase. There is a strong relationship between maximum H:D ratio values and tree spacing. It is established that the most favourable conditions in Siberian spruce urban plantations are created if tree spacing is more than 3 m. The relationships between tree parameters in urban plantations where inter-tree competition is lower than in natural forest stands were determined to be linear ones. The accuracy of equations to evaluate tree parameters increases if a second determining factor is included: if tree spacing is included in the tree height and the crown diameter equations, and if tree height is included in the crown volume equation. The study results show that urban plantations can be considered as a unique subject of forest taxation. © Published under licence by IOP Publishing Ltd.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:50:18Z No. of bitstreams: 1 S0100-69162010000600009.pdf: 126776 bytes, checksum: e46d112e85018d380788b6c98fabbd71 (MD5) Made available in DSpace on 2013-08-22T18:50:18Z (GMT). No. of bitstreams: 1 S0100-69162010000600009.pdf: 126776 bytes, checksum: e46d112e85018d380788b6c98fabbd71 (MD5) Previous issue date: 2010-12-01 Made available in DSpace on 2013-09-30T17:51:06Z (GMT). No. of bitstreams: 2 S0100-69162010000600009.pdf: 126776 bytes, checksum: e46d112e85018d380788b6c98fabbd71 (MD5) S0100-69162010000600009.pdf.txt: 29173 bytes, checksum: 4efe215706609340447038aed2214b88 (MD5) Previous issue date: 2010-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:13:46Z No. of bitstreams: 2 S0100-69162010000600009.pdf: 126776 bytes, checksum: e46d112e85018d380788b6c98fabbd71 (MD5) S0100-69162010000600009.pdf.txt: 29173 bytes, checksum: 4efe215706609340447038aed2214b88 (MD5) Made available in DSpace on 2014-05-20T13:13:46Z (GMT). No. of bitstreams: 2 S0100-69162010000600009.pdf: 126776 bytes, checksum: e46d112e85018d380788b6c98fabbd71 (MD5) S0100-69162010000600009.pdf.txt: 29173 bytes, checksum: 4efe215706609340447038aed2214b88 (MD5) Previous issue date: 2010-12-01 A necessidade de estudar a utilização dos resíduos de podas de árvores é de grande importância ambiental para solucionar os problemas de resíduos sólidos existentes nas áreas urbanas junto com os resíduos de lixos domésticos. O estudo destes materiais foi avaliado com o desenvolvimento de mudas de ipê-amarelo (Tabebuia Chrysotricha (Mart. Ex. Dc.) sandl) em diferentes misturas de substratos e tipos de água para irrigação. O experimento foi instalado no Departamento de Engenharia Rural da Faculdade de Ciências Agrárias e Veterinárias - UNESP, Câmpus de Jaboticabal. Foram realizados dois experimentos, avaliados juntamente com delineamento experimental em blocos casualizados, de oito substratos, duas qualidades de águas e quatro repetições, totalizando 64 parcelas. Cada parcela foi composta por 30 plantas (cinco linhas de seis plantas), sendo consideradas como úteis as três linhas de quatro plantas centrais da parcela. Foram testados oito substratos, resultantes da combinação de substrato comercial, composto de lixo e composto de poda de árvores com dois tipos de água de irrigação (água potável e residuária) e quatro repetições. Para acompanhar o desenvolvimento das mudas de ipê-amarelo, foram avaliados a altura da parte aérea das plantas (H) e o diâmetro do colmo (D). As características foram avaliadas aos 21; 42; 63 e 84 dias após a emergência. da análise dos resultados, possibilitou-se concluir que os substratos estudados promoveram diferenças significativas para a altura média das plantas e o diâmetro de colmo, em todos os períodos de avaliação. Os substratos 4 e 5 e a água residuária apresentaram os melhores resultados no desenvolvimento das mudas de ipê-amarelo. The need to study the use of waste of tree pruning is of great importance to solve the environmental problems of solid waste in the urban areas along with the household waste. The study of these materials was evaluated with the development of seedlings of yellow- ipe (Tabebuia Chrysotricha (Mart. Ex DC.) Sandl) in different types of substrate mixtures and water for irrigation. The experiment was installed at the Department of Rural Engineering in the Faculty of Agricultural Sciences and Veterinary - UNESP, Jaboticabal Campus, in a randomized block design, with 8 substrates, 2 qualities of water and 4 repetitions, totaling 64 plots. Each plot was composed of 30 plants (5 lines of 6 plants), being regarded as useful, the 3 lines of 4 plants of the central plot. Eight substrates were tested, resulting from the combination of commercial substrate, composed of garbage and of trees pruning with 2 types of irrigation water (clean water and residuary) with 4 repetitions. To track the development of the yellow- ipe seedlings, were evaluated the height of the shoots (H) and the diameter of the stem (D). The characteristics were evaluated at 21, 42, 63 and 84 days after the emergency. The analysis of the results allowed to conclude that the substrates studied promoted significant difference in average height and diameter of the stems in all periods of assessment. The substrate 4, 5 and the residuary water showed the best results in the development of the yellow-ipe seedlings. UNIFEB UNESP Faculdade de Ciências Agrárias e Veterinárias UNESP FCAV Departamento de Ciências Exatas UNESP Faculdade de Ciências Agrárias e Veterinárias UNESP FCAV Departamento de Ciências Exatas

Stem lodging is a risk to sunflower production in Argentina, and may contribute to fixing the upper limit to commercially viable crop population density, since yield is known to increase up to densities higher than those currently used. Reputedly, crops are particularly susceptible to stem lodging during grain filling and at harvest maturity, but the temporal and spatial unpredictability of lodging events under field conditions has hampered systematic research on this issue. In this study we used mechanical lodging to examine the relationships between stem failure moment of force and stem structure in plants of two sunflower hybrids of contrasting susceptibility to stem lodging grown at each of three crop population densities (5.6 plants m-2, 10 plants m-2 and 16 plants m-2). Measurements were performed at mid- and near-end of grain filling and at harvest maturity in crops grown in three separate seasons at two locations. Stem failure moment of force at all three developmental stages was significantly (p < 0.05) greater in the lodging-resistant hybrid than in the lodging-susceptible hybrid used in these experiments at 5.6 plants m-2, and fell with increasing crop population density and between 90% grain filling and harvest maturity in both hybrids. At harvest maturity differences in stem failure moment of force between hybrids were significant (p < 0.05) at all three crop population densities. Stem flexural rigidity (ability of the stem to resist bending) and stem deformation (horizontal displacement from the vertical of the stem immediately prior to breakage) exhibited responses to hybrid, crop population density and developmental stage that were broadly consistent with those of stem failure moment of force. Stem diameter at the breakage point fell with crop population density, but there was little difference between hybrids except at the harvest maturity, when the susceptible hybrid at the two highest crop population densities had smaller diameters than the resistant hybrid. Measured at the breakage point, the thickness of the epidermis plus cortex tissues (i.e., the effective thickness of the stem wall) which surround the friable stem pith fell with crop population density and between end of grain filling and harvest maturity in both hybrids. Differences in effective thickness of the stem wall between hybrids were small and often not significant, but there was a tendency for the susceptible hybrid to exhibit greater thickness of the effective stem wall, particularly at the two higher population densities. Stem failure moment of force was linearly related to thickness of the effective stem wall in both hybrids, the slope of the relationship being significantly greater for the resistant hybrid. We conclude that, within limits, the thickness of the effective stem wall may prove to be useful as a guide to genotype susceptibility to stem lodging in breeding programs and may offer a simple approach to modelling susceptibility. This work has also served to highlight the need to investigate the origins (presumably related to stem anatomy and/or cell wall properties) of the genotypic effects on the stem failure moment of force/the effective stem wall relationship. Finally, the demonstration of the existence of genotype differences in tolerance to stem lodging should encourage the execution of a broader survey aimed at identifying sources of tolerance to stem lodging at high crop population densities in sunflower. © 2009 Elsevier B.V. All rights reserved. Fil: Hall, Antonio Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina Fil: Sposaro, Mariano M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina Fil: Chimenti, Claudio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina

Conduziu-se este trabalho, em condições de viveiro e de campo para avaliar o efeito do boro sobre o crescimento em altura e diâmetro e a sobrevivência de mudas de eucalipto. O delineamento experimental utilizado foi o de blocos casualizados em esquema fatorial 5 x 2: cinco doses de boro (0, 0,325, 1,3, 5,2 e 20,8 mg L-1) na forma de octaborato e duas espécies de eucalipto (Eucalyptus grandis w. Hill ex Maiden e Eucalyptus saligna Sm), com cinco repetições. Pelos resultados, verifica-se que as mudas cultivadas com 5,2 e 20,8 mg L-1 de B apresentam redução significativa no crescimento em altura e no diâmetro do caule. Nas condições de campo, a aplicação de até 20,8 mg L-1 não afeta a sobrevivência das mudas das duas espécies de eucalipto. Observou que, nas condições de viveiro, o E. saligna é mais sensível à fitotoxidez de boro do que o E. grandis. The objective this work carried out under nursery and field conditions was determine the development and survival by eucalypts seedlings under boron rates. The randomized blocks experimental design in a 5 x 2 factorial scheme was used: five rates of boron (0, 0.325, 1.3, 5.2 and 20.8 mg L-1) and two species (Eucalyptus grandis w. Hill ex Maiden and Eucalyptus saligna Sm), with five replicates. The results showed that in two conditions, the eucalypts seedlings grown with 5.2 and 20.8 mg L-1 of boron had significative reduction in diameter and height. The application at 20.8 mg L-1 of boron did not affect the two eucalypts species survival in the field. The Eucalyptus saligna was more sensible than Eucalyptus grandis to boron rates under nursery conditions.

Resumen Se hizo una caracterización morfológica de 12 genotipos de chile dulce con frutos de forma cónica cultivados en invernadero, tanto a nivel cualitativo (cinco variables) como cuantitativo (ocho variables). Se presentaron diferencias estadísticamente significativas entre genotipos en el caso de las variables cuantitativas. Los datos muestran una amplia variabilidad en cuanto a la altura de la planta (1,26-1,71 m), área foliar (100,49-158,91 cm2), diámetro del tallo (12,5115,83 mm), longitud del tallo (25,75-36,88 cm), ancho del fruto (4,97-6,19 cm), longitud del fruto (11,24-19,43 cm), relación largo/ancho del fruto (1,82-3,49) y espesor de la pared del fruto (4,06-5,44 mm). Esta información es útil para los productores en el proceso de selección del genotipo que utilizarán en su sistema productivo, según el nicho de mercado de interés. Abstract A morphological characterization of 12 sweet pepper genotypes of conical fruit shape grown under greenhouse conditions was conducted, considering both qualitative (five) and quantitative (eight) variables. There were statistically significant differences between genotypes for quantitative variables. Data show a wide variability with respect to plant height (1,26 - 1,71 m), foliar area (100,49 - 158,91 cm2), stem diameter (12,51 - 15,83 mm), stem length (25,75 - 36,88 cm), fruit width (4,97 - 6,19 cm), fruit length (11,24 - 19,43 cm), fruit length/width ratio (1,82 - 3,49), and fruit wall thickness (4,06 - 5,44 mm). This information is useful for growers to choose the best variety for their particular market purposes.

UMR1334 AGAP : Equipe AFEF ‘Architecture et Fonctionnement des Espèces fruitières’ ; Team AFFS ‘Architecture and Functioning of Fruit Species’; Premise of the study: Accurate and reliable predictive models are necessary to estimate nondestructively key variables for plant growth studies such as leaf area and leaf, stem, and total biomass. Predictive models are lacking at the current-year branch scale despite the importance of this scale in plant science. [br/]Methods: We calibrated allometric models to estimate leaf area and stem and branch (leaves + stem) mass of current-year branches, i.e., branches several months old studied at the end of the vegetative growth season, of four mango cultivars on the basis of their basal cross-sectional area. The effects of year, site, and cultivar were tested. Models were validated with independent data and prediction accuracy was evaluated with the appropriate statistics. [br/]Key results: Models revealed a positive allometry between dependent and independent variables, whose y -intercept but not the slope, was affected by the cultivar. The effects of year and site were negligible. For each branch characteristic, cultivar-specifi c models were more accurate than common models built with pooled data from the four cultivars. Prediction quality was satisfactory but with data dispersion around the models, particularly for large values. [br/]Conclusions: Leaf area and stem and branch mass of mango current-year branches could be satisfactorily estimated on the basis of branch basal cross-sectional area with cultivar-specifi c allometric models. The results suggested that, in addition to the heteroscedastic behavior of the variables studied, model accuracy was probably related to the functional plasticity of branches in relation to the light environment and/or to the number of growth units composing the branches.

The stable isotopes of hydrogen and oxygen (delta H-2 and delta O-18, respectively) have been widely used to investigate tree water source partitioning. These tracers have shed new light on patterns of tree water use in time and space. However, there are several limiting factors to this methodology (e.g., the difficult assessment of isotope fractionation in trees, and the labor-intensity associated with the collection of significant sample sizes) and the use of isotopes alone has not been enough to provide a mechanistic understanding of source water partitioning. Here, we combine isotope data in xylem and soil water with measurements of tree's physiological information including tree water deficit (TWD), fine root distribution, and soil matric potential, to investigate the mechanism driving tree water source partitioning. We used a 2 m(3) lysimeter with willow trees (Salix viminalis) planted within, to conduct a high spatial-temporal resolution experiment. TWD provided an integrated response of plant water status to water supply and demand. The combined isotopic and TWD measurement showed that short-term variation (within days) in source water partitioning is determined mainly by plant hydraulic response to changes in soil matric potential. We observed changes in the relationship between soil matric potential and TWD that are matched by shifts in source water partitioning. Our results show that tree water use is a dynamic process on the time scale of days. These findings demonstrate tree's plasticity to water supply over days can be identified with high-resolution measurements of plant water status. Our results further support that root distribution alone is not an indicator of water uptake dynamics. Overall, we show that combining physiological measurements with traditional isotope tracing can reveal mechanistic insights into plant responses to changing environmental conditions.

Data from five studies on the relationships between dendrometric measurements and leaf area of Eucalyptus globulus Labill. plantations were pooled and analyzed to develop regression models for the estimation of leaf area of individual trees. The data, collected at two sites in west-central and southwestern Portugal, varied in age from 2 to 19 years and in plant density from 481 to 1560 trees/ha and included both first and second rotation coppice stands. A total of 29 nonlinear regression models were tested and ranked with a multicriteria evaluation (MCE) procedure, based on goodness-of-fit statistics, predictive ability statistics, and collinearity diagnostics. The best models were validated using an independent data set. The final model selection was based on comparisons of prediction residuals data, statistical tests, and silvicultural and physiological considerations. One model is proposed as adequate for leaf area estimation of E. globulus plantation trees. This model contains four parameters and independent variables that quantify stem diameter, crown size, and stand density.