Diameter Increment Research Articles

Grey alder at the regeneration stage: Long-term effects on soil nitrogen and carbon pools and Norway spruce growth

Increasing soil N availability is an effective way to enhance soil organic carbon (SOC) sequestration and biomass production in N-limited ecosystems such as boreal Norway spruce forests. Alder has a root nodule symbiosis with Frankia, an N2-fixing bacterium, and can thus add considerable amounts of N to soil mainly through its N-rich leaf litter. The objective of this study was to determine whether the presence of grey alder at the regeneration stage had any long-term effects on soil C and N cycling and stocks and spruce growth. The study sites were two relatively fertile 40-year-old Norway spruce stands (Luhdansuo and Porkkola) in Southern Finland. At both study sites, half the spruce stand had an admixture of grey alders for approximately 10–15 years after regeneration (alder treatment), but no alder had been present in the other half (control treatment). Alders were cut from the alder treatment 25 (Luhdansuo) or 30 (Porkkola) years before the measurements. At Porkkola, alder treatment received ash fertilisation 13 years ago. We observed no significant differences in the plant-available N fluxes, measured with a microdialysis technique, or SOC stocks between treatments. The total N stock (organic horizon + 0–30 cm mineral soil) and organic horizon thickness were larger, while the microbial biomass C:N and C mineralisation rate were lower in the alder versus the control treatment at Luhdansuo. The annual ring widths of spruces were larger in the alder versus the control treatment for up to six years after alder removal at both sites, but no differences were observed in the current tree diameters or diameter increments. In conclusion, most of the current soil or tree properties did not differ significantly between treatments, possibly because the effect of alder had faded out over the 25–30 years since its removal, and because the sites were initially relatively fertile.

Usability of fractometer for the purpose of a practical preliminary assessment tool for wood density of Pinus brutia

The fractometer is a device that breaks increment cores to measure fracture strength. The advantages of the device are that it is relatively fast, easy to use in the field, and it can perform direct strength measurements on increment cores. The main purpose of the study was to evaluate the usability of the fractometer as a preliminary evaluation tool for wood density traits of standing Turkish Pinus brutia (red pine) trees. Fracture strength was measured on 5 mm diameter increment cores, and X-ray densitometry was used for density measurements. Due to the high correlation between the two traits (fracture and density), a model was built using linear regression. Fifty trees were sampled to build the statistical model (r2: 0,74), and an equal sample size was used to test the model. The density value obtained from the model was 0,546 gcm-3, while the density value averaged by the X-ray method for the same group was 0,543 gcm-3. When considering mean values, it can be said that the model provides a good prediction. Based on personal experience and research results, some trees exhibited better growth and wood quality traits than others. Breeding from these trees could offer improvement in timber production and performance for Pinus brutia (red pine). As a general consequence, the fractometer and increment core sampling can be used for pine tree breeding programs for the preliminary assessment of wood density.

Effects of fertilization on radial growth of Pinus pinea explored hourly using dendrometers

BackgroundStone pine (Pinus pinea), a drought-resistant species, has significant socio-economic benefits and increasing interest for the establishment of productive plantations in several countries, especially in a climate change context. Monitoring hourly stem diameter variations contributes to the understanding of the tree-growth response to changes in environmental conditions and management. By monitoring the diameter expansion of tree stems, high-resolution band dendrometers were used to study the development of adult trees growing in a semi-arid coastal environment of central Chile under fertilized and non-fertilized soil conditions through the span of a year.ResultsShort cycles (< 21 h) were few in fertilized and non-fertilized trees (6 and 4, respectively), whereas long cycles (> 28 h) occurred at a higher frequency in fertilized trees (16 vs 6). Most of the circadian cycles were regular (24 ± 3 h). The longest cycle duration (59 h) was observed in fertilized trees during spring. In all seasons, each phase of the circadian cycle, especially during the stem diameter increment phase (P3, irreversible growth), started earlier in fertilized than in control trees. P3 duration was significantly longer in fertilized than in control trees in springtime. The maximum shrinkage (P1) was observed in summer for both treatments. Stem diameter increased faster in fertilized than in control trees throughout the year, with the highest accumulation occurring in spring and the lowest in autumn. The daily variability pattern showed lower growth under high temperature across seasons.ConclusionsThis study highlights the importance of fertilization in enhancing stone pine diameter growth. This cultural practice should be further explored to contribute to the mitigation of climate change effects in semi-arid environments.

Impact of light conditions on the early development of Cinchona officinalis

Cinchona officinalis, a native plant species known in Peru as the cinchona tree, has civic importance because it represents the plant wealth of this nation and medicinal importance since it was for more than 300 years the only cure for malaria, and is currently threatened. The aim was to determine the effect of light conditions on the percentage of mortality, height increase, and diameter increase of Cinchona officinalis. In the community of La Cascarilla (5°39’48.87 “S 78°54’35.24 “W), two treatments were installed, forest massif (FM) and enrichment bands (EB). For each treatment, three replicates and 16 plants per replicate were used. Monthly evaluations were carried out in which the number of dead plants, plant height, and diameter were recorded. These parameters were correlated with precipitation, temperature, and photoperiod records of the study area. The results showed that mortality in FM was 27.1% higher than that reported in EB, while the increase in height and diameter increment in the FM plot was 45.5 and 25.1% higher than that obtained in EB. In addition, a negative correlation was observed between the percentage of mortality and precipitation (rs=-0.54), and between the increase in height and diameter increment with the maximum temperature (rs=-0.73 and rs=-0.60, respectively) for the FM treatment, while for the EB treatment, there was a negative correlation between the increase in height and precipitation (rs=-0.55) and a positive correlation between the diameter increment and the minimum temperature (rs=0.53). In general, shaded conditions allow a higher survival rate at the cost of reducing height and diameter increment.

Models for simulating the temporal development of black cottonwood (Populus balsamifera L. ssp. trichocarpa (Torr. &amp; Gray ex Hook.) Brayshaw) plantations in Iceland

Black cottonwood (Populus balsamifera ssp. trichocarpa) was initially introduced to Iceland in 1944 from the Kenai Peninsula in Alaska and has been widely planted in shelterbelts and afforestation projects since the 1980s. There is currently much interest in increasing the planting of black cottonwood, especially in carbon sequestration projects, because of its rapid growth at an early age. Growth models simulate the growth of a forest over time and are important tools for forest managers, researchers, and policymakers. This study presents, for the first time, site index, individual-tree diameter increment and tree height models for even-aged black cottonwood stands in Iceland. The data were collected from Icelandic national forest inventory (NFI) plots and from three plots from a network of permanent sample plots (PSP). The NFI data were collected during 2005–2022, and the PSP data were collected between 2009 and 2022. The model of McDill and Amateis was selected for predicting site index and dominant height development, and the model of Schumacher was selected for predicting tree height. For diameter increment modelling, an optimization-based modelling approach was found to be more suitable than non-linear regression analysis. The models developed in this study can be used in forestry practice and in optimization studies for thinned black cottonwood stands. The models produced simulation results that corresponded to measured stand development.

Early tree growth and crop yields under and Prosopis cinerariaAilanthus excelsa based agroforestry system in north western India

A field experiment was initiated in 2017 to evaluate the effect of tree species and tree spacing on intercrop productivity and tree growth with advancing age of and in an agroforestry Prosopis cinerariaAilanthus excelsasystem at Bikaner, Rajasthan. Both and were planted at three spacings: 4m × 4m, 6m × P. cinerariaA. excelsa6m and 8m × 8m; and L. Taub. (Cluster bean) was grown as intercrop during the Cyamopsis tetragonolobakharifA. excelsa seasons of 2018 and 2023. At 24 months after planting (MAP), trees were significantly taller and thicker in wider spacings of 6m × 6m and 8m × 8m compared to closer spacing of 4m × 4m; while in P. cineraria, different spacings did not significantly affect tree height and collar diameter. In this period, collar diameter and height of increased by 10.9 and 6.9-fold in 6m × 6m and 9.9 and 6.8-fold in 8m × 8m A. excelsaspacing, respectively. Percent increment in tree growth parameters were higher during initial growth period (6-12 MAP), and decreased in the subsequent months for both . Among the different A. excelsa and P. cinerariaspacings, higher percent increment in collar diameter in both the species at 24 MAP was recorded in 6m × 6m spacing. The intercrop yield in both the years was not significantly affected by different tree species and spacings. The study indicated that could be established and grown faster in arid region at wider A. excelsaspacings to get maximum tree growth

Transpiration rates from mature Eucalyptus grandis × E. nitens clonal hybrid and Pinus elliottii plantations near the Two Streams Research Catchment, South Africa

Abstract. Pine plantations are the dominant species currently planted within the South African commercial forestry industry. Improvements in bio-economy markets for dissolving wood pulp products have seen an expansion in fast-growing Eucalyptus plantations due to their higher productivity rates and better pulping properties than pine. This has raised concerns regarding the expansion of Eucalyptus plantations and how they will affect water resources as they have been reported to have higher water use (quantified using transpiration rates) than pine. We measured transpiration rates (mm yr−1), diameter at breast height (quantified as quadratic mean diameter, Dq, m) and leaf area index of an 8-year-old Eucalyptus grandis × Eucalyptus nitens clonal hybrid (GN) and a 20-year-old Pinus elliottii. Transpiration rates were measured for two consecutive hydrological years (2019/20 and 2020/21) using a heat ratio sap-flow method, calibrated against a lysimeter. In the 2019/20 year, annual transpiration for P. elliottii exceeded GN by 28 %, while for the 2020/21 hydrological year, there was no significant difference between the transpiration of the two species, despite a 17 % and 21 % greater leaf area index for P. elliottii than GN in 2019/20 and 2020/21 measurement years respectively. Quadratic mean diameter increments were statistically similar (p &gt; 0.05) in 2019/20, whereas the 2020/21 year produced significant differences (p&lt;0.05). Tree transpiration is known to be influenced by climatic variables; therefore, a random forest regression model was used to test the level of influence between tree transpiration and climatic parameters. The soil water content, solar radiation and vapour pressure deficit were found to highly influence transpiration, suggesting these variables can be used in future water-use modelling studies. The profile water content recharge was influenced by rainfall events. After rainfall and soil profile water recharge, there was a rapid depletion of soil water by the GN trees, while the soil profile was depleted more gradually at the P. elliottii site. As a result, trees at the GN site appeared to be water stressed (reduced stem diameters and transpiration), suggesting that there was limited access to alternative water source (such as groundwater). The study concluded that previous long-term paired catchment studies indicate that eucalypts use more water than pine; however, periods of soil water stress and reduced transpiration observed in this study must be accommodated in hydrological models. Long-term total soil water balance studies are recommended in the same region to understand the long-term impact of commercial plantations on water resources.

PCL/Fe3O4 magnetic electrospun yarn composites as a novel nanomaterial for biomedical applications

Magnetic composite structures were fabricated by embedding iron oxide nanoparticles (Fe3O4) into polycaprolactone (PCL) nanofibers through an electrospinning process. The PCL nanofibers incorporating 0.5 and 1 wt. % Fe3O4 were electrospun with various yarn and membrane architectures. SEM images of the fabricated fibers revealed diameter increment by raising the Fe3O4 proportion. Additionally, elongation at break, in tandem with the ultimate strength of the electrospun PCL yarn was improved by 63 and 67% through embedding 0.5 and 1 wt. % Fe3O4, respectively. The saturation magnetization results depended on the number of magnetic nanoparticles loaded in the electrospun fibers, as well as the architectural design of the electrospun fibers. The magnetic response of the fibrous yarns was enhanced by increasing the Fe3O4 mass fraction from 0.5 to 1 wt. %. The highest saturation magnetization of 5.38 emu/g was obtained for the electrospun yarn containing 1 wt. % Fe3O4, corroborating 13.6 times greater features than that of the fibrous membrane with a similar chemical composition. The obtained results implied that the as-spun fibrous yarn could be a great candidate as a surgical suture with the release capability of bioactive agents under a magnetic field.

Variation of Physical and Mechanical Properties of Pinus Sylvestris L. Wood in the Boreal Zone of the European Northeast

The study considers variational aspects of physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood depending on conditions and growth areas in the boreal zone of the European Northeast. Anatomical traits of xylem and its strength properties were analyzed. Based on the data received, statistical processing of the material was carried out using correlation and multivariate analysis. The impact of hazardous air emissions on variation of linear dimensions in structural elements of the annual height increment in the trunk diameter was estimated. A varying nature of the influence of environmental factors on the formation of strength properties of P. sylvestris wood in growth areas was attested. The variation value of basic wood density decreases as soil and hydrological conditions of growth improve. A significant negative correlation between basic wood density and distance to sources of hazardous air emissions in the areas of concentration of industrial enterprises was established. The results of multivariate analysis make it possible to reveal the weight of the influence of environmental factors and biometric characteristics of wood on volumetric and strength properties of pine wood. Growth in the impact zone of air emissions from large industrial enterprises in the study area does not produce a significant effect on the dynamics of wood strength properties, taking into account various growth conditions. For Scots pine growing in the European Northeast, the study determined a significant impact of the size and structure of the annual height increment of the trunk in terms of diameter, as well as the position of the wood sample in terms of trunk volume, on strength properties of pine wood.

Survivorship and Field Growth Characteristics of Four Selected Bamboo Species for The Development of Bamboo Industry in Sarawak, Malaysian Borneo

The Sarawak State Government has assigned the Sarawak Timber Industry Development Corporation (STIDC) to lead the development of the bamboo industry in Sarawak. Since bamboo research in Sarawak has received meagre attention, baseline information on the early survival rate and field growth characteristics of bamboo are essential for the development of the bamboo industry. A study to evaluate the survivorship and field growth characteristics of a three-year-old bamboo was conducted at the Sarawak Bamboo Pilot Project site in Sabal, Malaysia. Study plots were established at bamboo plantation areas with four different potential bamboo species grown in Sarawak, namely Bambusa vulgaris (Buluh minyak), Gigantochloa levis (Buluh beting), Gigantochloa hasskarliana (Buluh beti), and Dendrocalamus asper (Buluh betong). Survival rate and field growth characteristics in terms of the number of culms per clump, the number of new shoots, culm diameter, culm height, mean annual increments of diameter (MAID), and height (MAIH) were measured and quantified quarterly in the year of 2021. The findings revealed that the highest mean survival rate (88%) was found in G. levis, and the lowest survival rate (70%) was found in G. hasskarliana. However, the lowest mean culm diameter was observed in G. levis at 2.66 cm, and the highest was in B. vulgaris at 4.51 cm. Notwithstanding, B. vulgaris remained with the greatest mean culm height of 12.61 m. Nonetheless, G. hasskarliana depicted the highest number of culms per clump and shoots with 91 culms and 3 shoots, respectively. The MAID and MAIH of B. vulgaris were significantly higher than the other species with 1.69 cm year-1 and 4.72 m year-1, respectively. The scientific information and findings from this study would be useful as guidelines for bamboo industry players, managers, nursery practitioners, and policymakers to begin and carry out the development of the bamboo industry, mainly in Sarawak.

Nutrient and Growth Response of Fagus sylvatica L. Saplings to Drought Is Modified by Fertilisation

The increased frequency of climate change-induced droughts poses a survival challenge for forest trees, particularly for the common beech (Fagus sylvatica L.). Drought conditions adversely affect water supply and nutrient uptake, yet there is limited understanding of the intricate interplay between nutrient availability and drought stress on the physiology, growth, and biomass accumulation in young trees. We aimed to address this knowledge gap by examining the effects of irrigation and fertilisation and their interaction with various parameters in common beech saplings, including foliar and root N, P, and K concentrations; height and diameter increments; and aboveground and belowground biomass production. Our findings revealed that a higher fertilisation dose increased nutrient availability, also partially mitigating immediate drought impacts on foliar N concentrations. Also, higher fertilisation supported the post-drought recovery of foliar phosphorus levels in saplings. Prolonged drought affected nitrogen and potassium foliar concentrations, illustrating the lasting physiological impact of drought on beech trees. While drought-stressed beech saplings exhibited reduced height increment and biomass production, increased nutrient availability positively impacted root collar diameters. These insights have potential implications for forest management practices, afforestation strategies, and our broader understanding of the ecological consequences of climate change on forests.

Study of diameter and height increment of Nipa (Nypa fruticans) fronds for the sustainability of mangrove forests management in Pagar Batu Island, Mahakam River Estuary, East Kalimantan

Nipa (Nypa fruticans) is a type of plant that lives in many mangrove forests. The potential of nipa palm has been used as a source of income for the community, such as through the production of nipa plants and their fronds. However, harvesting carried out by the community has the potential to cause damage to nipa palm forests. This research aims to determine the increase in height and diameter of nipa palm fronds until they are ready to be harvested and to ensure that nipa palm harvesting is in accordance with the principles of desire. Sampling was carried out randomly on 30 palm clumps, and diameter and height measurements were carried out repeatedly every ten days for 40 days. The results showed that the average increase in front height was 16.71 cm per day, and the average increase in diameter was 0.18 cm per day. After 40 days of age, the front diameter reaches an average of 7.5 cm and a height of 6.7 m, making it suitable for harvesting in accordance with the principles of sustainable forest management.

Vegetation dynamics of permanent plot in dipterocarp forest Bukit Bangkirai, East Kalimantan, Indonesia

Vegetation dynamics in dipterocarp forest permanent plots after fire (1997-1998) is important to monitor due to the successional process. Monitoring was conducted from 2001 to 2013 to record tree individuals with a more than 4.8 cm diameter. The highest species diversity was found in 2013 (249 species), then decreased in 2022 (237 species). Dominant species during monitoring change from Macaranga gigantea (Euphorbiaceae) and Madhuca kingiana (Sapotaceae) (2001-2002) to M. gigantea (Euphorbiaceae) and Vernonia arborea (2005-2013) and then M. gigantea (Euphorbiaceae) and M. kingiana (Sapotaceae) (2022). Shannon-Wiener diversity index (H’) in 2022 indicates that species diversity in this permanent plot is high (4.85). The class diameter of trees in the permanent plot is dominated by small individuals (DBH <10 cm). The highest diameter increments are M. gigantea (0.42 cm year-1) and V. arborea (0.41 cm year-1) in the 5-10 cm diameter class. The highest tree recruitment found in 2005 (41.62%). Mortality rate from 2013-2022 was 3.16%, with high contribution from M. gigantea (141 individuals). Carbon storage value from 2001 to 2022 increased from 38.91 tons ha-1 (2001) to 114.29 tons ha-1 (2022). Successional process in this permanent plot needs to be monitored to assess forest health.

Tree height and stem growth dynamics in a Scots pine dominated boreal forest

Tree growth is a key forest ecosystem service and essential for carbon sequestration and biomass production. However, the intra-seasonal dynamics of tree height and stem diameter growth have been difficult to measure hampering the understanding of the interplay between these processes. Here, we investigated the feasibility of a laser scanning system in monitoring tree height development, aiming to study how tree height and stem diameter growth dynamics vary and interact, and how environmental variables explain the tree growth dynamics within a growing season. The experimental design consisted of 40 boreal trees equipped with dendrometers measuring changes in the stem diameter at 15-minutes intervals while a laser scanner fixed to a 35-meter tower was used to measure tree height near-daily during the monitoring period from May to mid-August 2021. We found that vertical changes in the tree-segmented point clouds enabled monitoring of tree height increment and investigation of the temporal dynamics of changes in tree height and stem diameter, when coupled with dendrometer measurements. The experiments revealed that, on average, height increment occurred ahead of diameter increment and deviated more towards the late season. Norway spruce showed more delayed diameter increment than Scots pine during the late season. Silver birch experienced diameter increment ahead of height increment. Based on the dendrometer measurements, we computed a radial change response function that aimed at characterizing the current state of stem diameter development, whether it was increasing or decreasing from its past state. When these radial change responses were compared against environmental variables, we found that the radial change response was mostly controlled by balance between precipitation and evapotranspiration, soil water content, minimum daily temperature, and vapor pressure deficit. Our findings support the utilization of laser scanning time series for measuring intra-seasonal changes in tree height and increase our understanding of the interactions between tree height and stem diameter growth processes.

Container volume and doses of maximum technical efficiency of controlled-release fertilizer on the morphological quality of Cordia alliodora seedlings in Roraima

The objective of this study was to determine the correlation between the morphological characteristics of Cordia alliodora seedlings produced as a function of container volume and controlled-release fertilizer (CRF) doses under nursery conditions in Northern Amazon. The experimental design was a 2 x 6 factorial scheme, corresponding to two container volumes (1.8 and 2.2 L) and six doses of Forth Cote® (0, 1, 2, 4, 8, and 12 g L-1 in medium sand), with five replicates. The evaluations were: height (H), stem diameter (SD), shoot dry mass (SDM), root dry mass (RDM), total dry mass, increment in stem diameter (ΔSD) and increment in height (ΔH) obtained from the data collected every fifteen days, from transplanting, encompassing the period of plant growth until the end of the experiment (three months), in addition to Dickson quality index (DQI). Container volume of 2.2 L is suitable for the formation of good-quality Cordia alliodora seedlings at 90 days after transplanting. Controlled-release fertilizer doses from 8.0 g L-1 are not indicated to obtain seedlings of this species in the northern region of Brazil, with quality, regardless of the container volume.

Damage analysis of deployable thin-walled composite shell structure during coiling up

Thin-walled coilable composite shells have been successfully used in deployable space payloads due to their high storage efficiency and stiffness-to-weight ratio. However, in real-life applications the deployable composite shells requiring repeatable coiling up and deployment are easy to be damaged, and their damage or failure behaviors due to large deformations has been rarely studied. This paper aims to investigate their damage and failure behaviors during the snap through, equal-sense and opposite-sense coiling up. First, multiscale models are established to compute the mechanical properties of plain-woven fabrics and unidirectional prepregs with consideration of stiffness reduction of the composites. Then, damages of each ply within the thin-walled shell are studied during snap through and coiling up. Simultaneously, effects of hub diameter on the damage of the thin-walled shell were investigated, followed by experimental verification using strain gauges and a scanning electron microscope (SEM). Simulation and experimental results show that the dominated damage of the thin-walled shell is failure of matrix. The SEMs of the edge damaged show failures of both resin and carbon fibers. Tensile damages of matrix can be relieved as the increment of the hub diameter, and no obvious failure is observed at the hub diameter of 50 mm.

Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees

The influence of canopy structure on tropical tree growth has been scantly studied because of the difficulties making field measurements in these dense multi-layered ecosystems. The recent advent of unmanned aerial vehicles (UAVs), has made it easier to collect canopy data, so offering a way to gain a better understanding of forest productivity and thereby improve forest management. In this study, we assessed tree growth prediction using UAV-derived crown measurements as an alternative for field data.Four experimental 9 ha plots were sampled in two forest sites, Yoko in the Democratic Republic of the Congo and Loundoungou in the Republic of Congo. Field inventories were made between 2015 and 2020. For each tree, we computed the diameter increment (DBHI) using censuses and diameter-based competition indices (diameter-based CIs) using the first census. High-resolution orthoimages and digital surface models were acquired with UAVs in 2016 and 2018 in the two sites. They gave estimates of crown characteristics (size, relative elevation, shape) and crown-based competition indices (crown-based CIs). Co-recorded UAV and field measurements were obtained for 1558 trees. The diameter increment of these trees was then modelled using supervised component generalized linear regression, and 20 % of trees were kept for cross-validation.Combined field and UAV data predicted tree DBHI twice better than either taken separately. Diameter at breast height (DBH) and crown area (CA) were found to be complementary predictors. Crown-based CIs significantly improved predictions of models already containing DBH and CA. Adding diameter-based CIs to models containing DBH, CA, and crown-based CIs only marginally improved growth predictions, showing that tree competition can be well-described with UAV data. The model calibrated at one site predicted the growth at the other site well, suggesting that a general model could be devised for multiple sites. Growth variance was better explained in the site (Yoko) where the crown density was higher and the crown smaller. Further data are now needed from multiple sites with ranging stand structures and compositions to build a general model.

Environment-induced growth changes in forests of Finland revisited - a follow-up using an extended data set from the 1960s to the 2020s

After a rising trend for 1971 – 2013, during which the annual volume growth of the forests of Finland increased by more than 70 %, a recent reduction has been observed. We analyzed the development of annual growth in the forest of Finland, focusing on the component not explainable by changes in growing stock. The data originate from nine consecutive Finnish National Forest Inventories. In the data, diameter increments were measured from increment cores and tree height increments from standing sample trees in the field. We developed models predicting periodic (5 years) annual volume increment per hectare with properties of the trees and stands as predictor variables. Deviations from model-predicted values were interpreted to be induced by environmental variation. The development was analyzed for all tree species combined and separately for three species groups: Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.) and broadleaves. We observed a rising growth trend not solely explainable by increased growing stock. The species groups produced rather a similar pattern in different parts of Finland: from the 1960s to the mid-1990s, the observed volume increment was mainly below the model-predicted level, thereafter above it. During the current century, the difference between observed and predicted annual volume increment has shown a downward trend for Scots pine. For Norway spruce, the difference has continued to increase in southern Finland, but shows little change in the north. For broadleaved species, the difference between measured and predicted increment shows a recent increase as well, though not as large as for Norway spruce. The geographical pattern of the environment-induced increment component was described in more detail via maps using a 75 km × 75 km grid. The changing environment has enhanced forest productivity in Finland over a period of nearly six decades, but recent years have not been favorable for Scots pine, which represents 50 % of the growing stock volume of the forests of Finland.

Significant unfavorable geometrical changes in ascending aorta despite stable diameter at follow-up

ObjectiveThe clinical importance of following up on the ascending aortic diameter lies in the fundamental presumption that wall pathology eventually manifests as a change in shape. However, the diameter describes the vessel locally, and the 55 mm criterion fails to prevent most dissections. We hypothesized that geometric changes across the ascending aorta are not necessarily imprinted on its diameter; i.e. the maximum diameter correlates weakly and insignificantly with elongation, surface stretching, engorgement, and tortuosity. MethodsTwo databases were interrogated for patients who had undergone at least 2 ECG-gated CT scans. The absence of motion artifacts permitted the generation of exact copies of the ascending aorta which then underwent three-dimensional analysis producing objective and accurate measurements of the centreline length, surface, volume, and tortuosity. The correlations of these global variables with the diameter were explored. ResultsTwenty-two patients, 13 male and 9 female, were included. The mean age at the first and last scan was 63.7 and 67.1 y, respectively. The mean diameter increase was approximately 1 mm/y. There were no dissections, while 7 patients underwent preemptive surgery. The yearly change rate of the global variables, normalized to height if applicable, showed statistically insignificant, weak, or negligible correlation with diameter increments at follow-up. Most characteristically, a patient's aorta maintained its diameter, while undergoing 1 mm/y elongation, 151 mm2/(y·m) stretching, 2366 mm3/(y·m) engorgement, and 0.02/y tortuosity. ConclusionMaximum diameter provides a local description of the ascending aorta and cannot fully portray the pathological process across this vessel. Following up the diameter is not suggestive of length, surface, volume, and tortuosity changes.

Influence of Foliar Spray with Urea and GA3 on Some Vegetative Growth Characteristics of Mandarin Saplings cv.Clementine.

The experiment was conducted in the lath house affiliated with the College of Agriculture / University of Anbar to investigate the effect of foliar spray of urea and GA3 on some vegetative growth traits of mandarin saplings cv. Clementine, during the period from April 2021 to December 2021, spraying urea(46% N) included 0(spray with distilled water as control), 4, 8 and 12 g.l-1 ; on the other hand, spraying GA3 included 0(spray distilled water as control), 30 and 60 mg.l-1 . The results showed that urea spray significantly increased all vegetative traits, especially 12 g.l-1 , compared to the control. In the same context, GA3 at 60 mg.l-1 spray increased all vegetative growth characteristics, like plant height, leaves number increment, leaves area, shoot number, shoot length and rootstock diameter increment, compared to the lowest value in control. Keywords: Foliar Spray, Urea, Nitrogen, GA3, Vegetative Growth, Mandarin.