Diameter Increment Research Articles

Habitat association and demographic rates for large tree species: implications for native tree species used in forestry

AbstractExotic tree species, though widely used in forestry and restoration projects, pose great threats to local ecosystems. They need to be replaced with native species from natural forests. We hypothesized that natural forests contain large, fast-growing, dominant native tree species that are suitable for specific topographic conditions in forestry. We tested this hypothesis using data from a 50-ha forest dynamics plot in subtropical China. We classified the plot into the ridge, slope, and valley habitats and found that 34/87 species had significant associations with at least one topographic habitat. There were 90 tree species with a maximum diameter ≥ 30 cm, and their abundances varied widely in all habitat types. In all habitat types, for most species, rate of biomass gain due to recruitment was < 1% of its original biomass, and rate of biomass gain due to tree growth was between 1 and 5% of its original biomass. For most species, biomass loss due to tree mortality was not significantly different than biomass gain due to recruitment, but the resulting net biomass increment rates did not significantly differ from zero. The time required to reach a diameter of 30 cm from 1 cm diameter for Altingia chinensis in the slope habitat, for Quercus chungii and Morella rubra in the ridge habitat and for Castanopsis carlesii in all habitats could be as short as 30 years in our simulations based on actual distributions of tree growth observed in the forest. Principal component analyses of maximum diameter, abundance and net biomass increment rates suggested several species were worthy of further tests for use in forestry. Our study provides an example for screening native tree species from natural forests for forestry. Because native tree species are better for local ecosystems, our study will also contribute to biodiversity conservation in plantations.

Diameter Increment Estimations of Open-Grown Stone Pine (Pinus pinea L.) Trees in Urban Parks in Istanbul, Türkiye

Open-grown trees in cities can improve environmental conditions by providing sustainable ecosystem services. Reliable data are necessary for assessing the functions of urban trees. The diameter at breast height (DBH), diameter increment, and annual ring measurements are the main parameters in the development of reliable models. To model periodic mean diameter increments calculated for different time periods (5, 10, 15, 20, and 25 years), a total of 43 open-grown stone pines (Pinus pinea L.) of different diameter classes were sampled in several urban parks in Istanbul, Türkiye. The DBH was measured, and increment cores were extracted from each tree at 1.30 m stem height using an increment borer. Tree age at breast height was determined by counting annual rings, and periodic mean diameter increments were calculated for different periods based on the measured tree-ring widths. The periodic mean increments of different periods were related to the inside-bark diameter at breast height and tree age. Since there was no significant relationship between tree age and periodic mean increments for each period’s length, as shown in the correlation analysis, models used to estimate the periodic mean increments of inside-bark DBH were developed using the least squares regression and quantile regression (QR) techniques. As the period length increased, the estimation success of the diameter increment models increased while the mean absolute percentage error (MAE) values decreased from 40 to 32%. The best model was the one used for the last 25-year period with the quantile value q = 0.50 which estimated the diameter increment with an RMSE = 1.391 mm/year and MAE = 32.27%.

Radiocarbon ageing of Indigenous culturally‐significant trees for bushfire management on Minjerribah (North Stradbroke Island), southeast Queensland

SummaryPartnerships between Indigenous People and governments for joint management of ancestral lands, designated as protected conservation areas for biodiversity and cultural heritage, provide an opportunity to leverage accumulated traditional land management knowledge with emerging science. In Australia, veteran or large old trees in natural landscapes are of significant ecological importance, and among the Indigenous communities, they are living monuments to historical cultural practices, but their survival, endurance and long lives are rarely acknowledged to afford them protection. In sub‐tropical Australia, the lack of consistent annual growth rings in stem wood makes it difficult to estimate the age of large trees using methods such as the periodic diameter increment. Ngugi et al., 2020 published radiocarbon (14C) dates using wood core (‘pith‐wood’) samples from 12 Indigenous culturally‐significant trees covering five species on Minjerribah (North Stradbroke Island). Due to the imprecise calendar age results of the single samples used in the original study (Ngugi et al., 2020), subsequent radiocarbon dating of an additional three wood core samples from each tree was undertaken to age the trees more precisely. The revised tree ages ranged from 63 to 531 years and suggest an important role of past Indigenous land management practices into protecting Bugari (Cypress Pine, Callitris columellaris F. Muell.) from deadly crown scorching fires. These results underscore the importance of incorporating Indigenous practices in current fire management strategies and plans. Estimating tree ages based on the periodic diameter increment method overestimated the age relative to that derived from radiocarbon dating. New bias correction factors were developed for adjusting the recorded periodic tree diameter increments.

Особенности роста сосны обыкновенной в условиях Красноярской лесостепи

The growth peculiarities of Scots pine (Pinus sylvestris L.) have been studied by the example of an even-aged pine stand of high density. A long-term research has been conducted on a permanent sample plot. The data has been collected from the stand aged from 37 to 55 years. The characteristics of individual trees and the entire stand during the growth period in the absence of external influences (cutting, windfalls, pest damage, etc.) and after improvement cuttings have been analyzed. The influence of the amount of resource available to a tree on the formation of crowns, root systems and stem wood has been investigated. The size of the available resource has been the square of the dominance area. The root system of the pine trees of the studied stands is compact in size and, despite the high stand density, due to the high content of nutrients in the soil and the absence of moisture deficiency, it sufficiently ensures intensive tree growth corresponding to the conditions of the I quality class. It has been found that under these conditions, the average area of the root system is proportional to the average square of the dominance area. It has been shown that the stem diameter at a height of 1.3 m in the absence of external influences significantly depends on the square of the dominance area. The correlation coefficient of these indicators for the studied stand at the age of 37 is 0.89. The influence of cuttings on annual radial increment has been studied using dendrochronology methods. It has been revealed that in the year following the cutting, it has increased by 1.3–2.0 times, depending on the increase in the square of the dominance area. A method has been proposed for calculating the competition coefficient as a share of the resource required for the free growth of a tree, which is redistributed between its closest neighbours. Long-term observations have shown that with competition coefficients exceeding 0.6–0.7, the stem diameter increment rate decreases significantly, and the trees develop a sparse crown extending less than 40 % of the tree height. This, in turn, leads to growth retardation and a transition to a depressed state. This, in turn, leads to growth retardation and a transition to a depressed state.

Hunting for Early Melanomas With a Maximum Clinical Surface Diameter up to 6 mm: A Prospective Study of Reflectance Confocal Microscopy Features in 68 Consecutive Cases.

Early diagnosis of melanoma and prompt effective therapy optimizes prognosis. Reflectance confocal microscopy (RCM) facilitates diagnosis by providing immediate 3D single cell resolution down into the papillary dermis. Consecutive cases were examined using a Vivascope 1500 confocal microscope at a single referral medical practice in Sydney, Australia 2019-2023. Melanoma clinical surface diameters were recorded by 0.1 mm increments up to 6.0 mm. The RCM features recorded were: pagetoid single cells or nests, pleomorphic cell shape, atypical dendritic cells, non-edged papillae, variation in melanocyte size and confluent sheets of cells. All cases required diagnostic agreement by two dermatohistopathologists using hematoxylin and eosin staining followed by SOX 10 and/or PRAME stains if required. Total cases were 68: 38 males (mean age 57) and 30 females (mean age 64). Melanoma in situ (n = 65) compared to invasive melanoma (n = 3), all males, invasion depth (0.4-0.5 mm). Most frequent RCM features found in 50% or more of cases within all diameter increments were: pagetoid single cells n = 64/68 (94%), pleomorphic cell shape n = 63/68 (93%), epidermal disarray n = 58/68 (85%), and atypical dendritic cells n = 45/68 (66%). Non-edged dermal papillae were n = 42/68 (62%). Melanoma RCM features were found throughout the diameter ranges. Confocal examination may facilitate early melanoma recognition in these ranges.

The Impact of Different Thinning Regimes on the Growth Dynamics of Pure Norway Spruce Stands in Lithuania

Forest growth under changing environmental conditions has been a major concern worldwide. The estimations of forests’ growth trends may provide significant insight on changing the value of Norway spruce (Picea abies (L.) H. Karst.) forests. The purpose of this study was to estimate the growth dynamics of thinned and un-thinned spruce stands in Lithuania by assessing their standing volume, gross volume yield, and stand density. For this purpose, two pure Norway spruce sites, established in 1990 and 1992, were selected. The thinning treatment scheme for each trial, comprised of five distinct stand density variants and eight different yield parameters, were analysed for each plot. Control plots exhibited the smallest growth in diameter, whereas stands that had been thinned once at a young age displayed the largest diameter increment (peak—1.4 cm/year). An increasing trend in tree stem volume was registered in all thinning treatment plots. The greatest competition index was found in the control plots, indicating an exceptionally high competition (peak—4.6–5.1) between trees for growth space. The competition index was four times smaller (2.0) in the moderately thinned stand. Intensifying natural mortality rate and signs of growth stabilization in the control plots (un-thinned) cannot guarantee them the positions of the highest productivity and accumulated stand volume in the future compared with thinned spruce stands.

Indiferentní reakce sazenic borovice lesní a buku lesního ošetřených hydroabsorbenty

Super-absorbents are expected to amend soils as they are capable of retaining water, which turns dry loose powdery substances (also capsule) into hydrogel. These were applied to prevent an artificial regeneration failure due to drought events. Four commercially-available products were mixed with soil from planting holes (the capsule was put to the soil) in order to support bare-root Scots pine and European beech seedlings after a spring planting on eleven clear-cut sites in 2020–2021. The plantations were designed as rows with 4 × 150 plants treated with four hydrogels plus 150 plants without hydrogel as a control. The performance evaluation of new plantations was based on attributes such as mortality/survival and relative height and root-collar diameter increments. The plants, which lost their initial size, due to pine weevil damage, dry tops and damage by game, were excluded from the evaluation. Besides the plant response to the applied super-absorbents, the planting operations were evaluated from economic point of view. The 2020 plantations showed higher mortality than 2021 ones; both years showed an excessive loss. The hydrogels did not help the plants to survive better compared to control and growth data also showed ambiguous results. Therefore, from commercial perspective, the application of all tested super-absorbents just increased the renewal costs.

Effects of Planting Density and Nitrogen Fertilization on Growth Traits and Leaf and Wood Characteristics of Three Poplar Clones

A comprehension of the effects planting density and nitrogen (N) fertilization have on the physiological and morphological characteristics of trees is critical for optimizing the require size and characteristics of wood products. We evaluated the growth traits and the leaf and wood characteristics of three clone poplars including Populus simonii × P. nigra ‘Xiaohei’, ‘Xiaohei-14’ and ‘Bailin-3’ under five planting densities (1666, 1111, 833, 666, and 555 tree ha−1) and four N fertilization rates (0, 100, 160, and 220 g tree−1 year−1). The results show that the clone type significantly affected all observed indicators, while planting density and N fertilization treatments had a significant effect on growth traits and leaf characteristics, but not on wood characteristics. Specifically, the clone ‘Bailin-3’ exhibited the largest annual increments in tree height and diameter at breast height (DBH), leaf width, N content, and soluble protein content. A decrease in initial planting density (from 1666 to 555 tree ha−1) led to an increased annual incremental tree height and DBH, regardless of clone type and N fertilization treatment. N fertilization treatment significantly impacted the annual increment in DBH, but not that of tree height. Further, the annual increments in tree height and DBH were positively correlated with leaf width, N content, chlorophyll content, and soluble protein content, and negatively correlated with hemicellulose content. In addition, the chlorophyll and soluble protein contents were identified as the most reliable predictors of the annual increments in tree height and DBH. Our results demonstrate the clone ‘Bailin-3’ with 555 tree ha−1 under 160 g N tree−1 yr−1 showed superior growth traits and leaf characteristics. Thus, it is recommended for future poplar silviculture of larger diameter timber production at similar sites. The results contribute to understanding of the effects of planting density and fertilization on the growth traits and the leaf and wood characteristics of three poplar clones, offering valuable guidance for the sustainable development and long-term productivity of poplar plantations.

Influence of meteorological variables on the development in plantation of Tachigali vulgaris L.G. Silva & H.C. Lima (tachi-branco)

The objective of this work was to evaluate the influence of meteorological variables on height and diameter increment in a Tachigali vulgaris plantation fertilized with NPK. The meteorological data were recorded by the agroclimatological station of Embrapa Amazônia Oriental, located in Igarapé-Açu, in the period from March 2016 to June 2018. The monitoring of the increment rate in height and diameter of the plants was done. The data collected were: monthly temperature, average maximum temperature, average minimum temperature andprecipitation. The maximum quarterly periodic increment in height occurred in the June-September 2017 quarter, while the highest diameter increment occurred in the June-September 2016 quarter. Principal component analysis showed that the first three factors together explained 94% of the total variance of the species’ growth, where the unfolding analysis of the first two principal components showed that the variables that contributed most to explain the species’ stand development correlated with the climate measures observed in this study, were mean and maximum temperatures and precipitation, followed by height, diameter and minimum temperature. It was concluded that the weather variables positively influenced the increment in height and diameter of plants Tachi, with precipitation being the variable with the greatest contribution to predicting tree growth.

Early selection efficiency in a progeny test of timber species Cordia trichotoma (Vell.) Arráb. ex Steud

One of the key obstacles in forest breeding routines is the time-consuming steps of selection and recombination of superior genotypes owing to the long life cycle of trees. Considering the increase in global temperature and constant climate alterations, the quick selection of genetic materials is crucial to ensure the effectiveness of genetic improvement programs. Early selection studies on other forest species are scarce, barring eucalyptus and pine, which are well-studied crops. In this context, this study aimed to understand the efficiency of early selection in a progeny test of Cordia trichotoma (Vell.) Arráb. ex Steud to evaluate age-age trends, genetic variability, and potential gains. A progeny test was conducted and measured at three, six, and eight years of age for growth traits, diameter, and volume increment. The experiment included 21 open-pollinated families of C. trichotoma arranged in a 4 × 4 m experimental design grid with a single-tree plot distributed into 10 blocks. The genetic correlations among the three measurements for genitor selection were greater than 0.90 for all the traits. For every ten progenies selected at three years of age, approximately seven were determined to be similarly top-ranked at eight years of age, taking into account an early selection assertiveness rate of approximately 0.70 for progenies. Considering the high age-age genetic correlation found in the C. trichotoma progeny test, there is a significant possibility of improving genetic gains per unit of time through early selection. The general mean of volume increment was 18 m3 ha−1 year−1, with productive genotypes showing a volume greater than 30 m3 ha−1 year−1 and representing an estimated general gain of 66 %. Superior genotypes of C. trichotoma are highly competitive in terms of volumetric yield, can generate considerable gains, and are used in the forest industry. Early selection of C. trichotoma is efficient, with a high rate of assertiveness.

Meta-regression of idiopathic full-thickness macular holes diameter and anatomical closure rate: Implications to intraoperative technique

PurposePrimary surgery failure of macular holes causes poor visual acuity outcomes. Several studies indicate that small-medium idiopathic full-thickness macular holes (iFTMH) have consistent and high anatomical closure rates after vitrectomy and internal limiting membrane (ILM) peeling, regardless of iFTMH diameters. However, there is no systematic analysis examining the relationship between iFTMH diameters and anatomical closure rates. MethodsIn this systematic review and meta-regression, we searched PubMed, Embase, and Web of Science databases on October 24th, 2022. We included studies regarding iFTMH, with ILM peeling/inverted flap technique, long-lasting gas tamponade, and face-down position after surgery. Univariable meta-regression with a restricted cubic spline model and component-plus-residual plot after covariables adjustment were used to explore non-linear association. ResultsA total of 7257 participants from 19 randomized controlled trials and 49 observational studies were included in this meta-analysis. In ILM peeling group, every 100-μm increment in diameter was associated with a 3.8 % (95 % confidence interval [CI], 1.8%–5.7 %, P < 0.001) relatively lower anatomical closure rate. Yet, among studies using the inverted flap technique, baseline iFTMH diameter was not associated with a lower anatomical closure rate (0.2 %, 95%CI, −4.2 %–4.5 %, P > 0.9). The restricted cubic spline model and component-plus-residual plot controlling for age, sex, and symptom duration prior to surgery showed no evident non-linearity in both surgical techniques. ConclusionsThe iFTMH diameter is linear and inversely associated with the anatomical closure rate after the ILM peeling technique, but not with the inverted flap technique. The present study supports the use of advanced techniques, e.g., inverted flap technique, in small-medium iFTMH to improve anatomical closure rates.

Individual tree diameter growth modelling for natural secondary forest in Changbai Mountains, Northeast China

Individual modelling is a foundational approach to study the natural forest growth and in this paper, we develop a serial distance-depended individual tree model for some species in natural forest which would provide prediction and characteristics for natural species. The data used to develop individual model for natural mixed forests were collected from 712 remeasured 10-year periodic permanent sample plots of in Baihe Forest Bureau of Changbai Mountains, northeast China. Based on analyzing relationship between diameter increment of individual trees with tree size, competitive status, and site condition and finding out the major independent variables, the growth models for individual trees of 15 species in the natural mixed forests, that have good predicting precision, and easily applicable, were developed using stepwise regression method. The individual growth model developed in this study can reflect the tree increment of 15 species and be generally well suited for simulating tree and stand growth for natural mixed forests in Changbai Mountains. The research results for individual trees growth model of each species showed that main variable to influence on diameter increment of individual trees for natural mixed forests were tree size (D) and then competition index. The site condition was not related with diameter increment. The natural logarithm of DBH (lnD) and square diameter (D2) were included in the predicting models of diameter increment for all 15 species. The diameter increment was directly proportional to tree diameter for each species. For the competitive indexes in growth model, the relative diameter (RD), canopy closure (P), and the ratio of diameter of subject tree with maximum diameter (DDM) were related to diameter increment and the stand density measures were not significantly influenced on diameter increment. As canopy closure increase, tree increment decreases. The site conditions were performance less of factors in increment predictions in the model.

PERTUMBUHAN DAN PERKEMBANGAN TANAMAN SAMAMA(Anthocepalus macrophyllus) DI DEMPLOT SUMBER BENIH DESA HATUSUA KECAMATAN KAIRATU KABUPATEN SERAM BAGIAN BARAT

The aim of this research is to determine the diameter increment and height increment, growth and development of Samama Plants (Anthocepalus marcophyllus) as well as environmental factors that influence the growth of Samama Plants (Anthocepalus marcophyllus). This research was carried out in Block III of Samama Plants (Anthocepalus marcophyllus) in the Seed Source Demonstration Plot in Hatusua Village, Kairatu District, West Seram Regency. Initial data was taken in January 2022 and continued with final data collection in July 2022. This research uses a quantitative analysis method by calculating the Average Annual Increment (MAI), current annual increment (CAI) and analysis simple regression. The results of further research show that the growth of Samama (AnthocepHalus marcopHyllus) plants in the seed source demonstration plot of Hatusua village, West Seram Regency with a Current Annual Rate (CAI) diameter in 2022 is 1.2 (cm/tnm/yr) and an average annual increase (MAI) diameter is 3.05 (cm/tnm/yr), current annual increment (CAI) is high, namely 1.77 (m/tnm/yr) and average annual increment (MAI) is high, namely 2.93 (m /tnm/yr). The development of the Samama plant in measurements in 2022, the walnut plant has developed. From the results of research in 2022, the growth of the Samama plant is at the pole and tree level. There are 8 trees on the pole with diameters ranging from 14.5 – 20.

Numerical investigation on flow-induced wall shear stress variation of metastatic cancer cells in lymphatics with elastic valves

Hematogenous metastasis occurs when cancer cells detach from the extracellular matrix in the primary tumor into the bloodstream or lymphatic system. Elucidating the response of metastatic tumor cells in suspension to the flow conditions in lymphatics with valves from a mechanical/fluidic perspective is necessary. A physiologically relevant computational model of a lymphatic vessel with valves was constructed using fully coupled fluid–cell–vessel interactions to investigate the effects of lymphatic vessel contractility, valve properties, and cell size and stiffness on the variations in magnitude and gradient of the flow-induced wall shear stress (WSS) experienced by suspended tumor cells. Results indicated that the maximum WSSmax increased with the increments in cell diameter, vessel contraction amplitude, and valve stiffness. The decrease in vessel contraction period and valve aspect ratio also increased the maximum WSSmax. The influence of the properties of the valve on the WSS was more significant among the factors mentioned above. The maximum WSSmax acting on the cancer cell when the cell reversed the direction of its motion in the valve region increased by 0.5–1.4 times that before the cell entered the valve region. The maximum change in WSS was in the range of 0.004–0.028 Pa/µm depending on the factors studied. They slightly exceeded the values associated with breast cancer cell apoptosis. The results of this study provide biofluid mechanics-based support for mechanobiological research on the metastasis of metastatic cancer cells in suspension within the lymphatics.

Repeated Mild Summer Drought in Crataegus monogyna Jacq. Provokes Compensation Growth in the Following Year

Water limitations will pose significant challenges to forest ecosystems across Europe. To gain a deeper understanding of the potential impacts, we investigated the response of the common shrub Crataegus monogyna to two summer droughts, each followed by rewatering. The experimental design consisted of a common garden with potted saplings from a local Belgian (n = 48), a Swedish (n = 47), and a Spanish-Pyrenean provenance (n = 48). We quantified the effects on growth and leaf phenology, focusing on the legacies in the year following the droughts. Responses were influenced by the severity of the drought and by its timing. Most strikingly, height increment was enhanced by 24% (p = 0.046) in comparison to the controls in the year following the droughts in the group of plants that endured the two drought treatments, each time without developing visible stress symptoms. Only one such mild drought, whether early or late summer, did not lead to this response, suggesting stress memory acting as a growth promoter. A late summer drought that resulted in visible drought symptoms led to a reduced diameter increment in the year following the droughts, independent of the preceding treatment (severe, mild, or no drought), whereas this was not the case for a similar drought in early summer. Minor leaf phenological responses were detected in the year following the droughts. Finally, the non-local provenances did not respond in a deviating way to the droughts compared to the local provenance. Our findings contribute to the prediction of carbon sequestration in forests and other woody vegetations in the temperate regions of Europe.

Study of urologic exposure dose in selective organ's cell & behavior of Wistar rats

BackgroundRadiologic fluoroscopy procedures have been imposing considerable exposure dose to staff with serious consequences relative to dose quantity which is still continuing as challenge of studies, hence the aims were to assess the animal behavior, quantify blood components and red blood cells morphology after exposure to x-ray urologic fluoroscopy doses (0.3, 0.8, 1.8 and 2.5 mSv). Methodsurologic exposure doses measured by TLDs chips and TLD reader Model 5500 from selected hospitals. These doses used to expose Wister male rats weighted (275 ± 2.0 g). The collected data were animal behavior, quantity of blood components and cellular changes in RBCs, kidneys, liver & testicles then analyzed by SPSS- 20 (SPSS Inc., Chicago, IL, USA) Resultsshowed that a dose of 2.5 mSv decreased significantly (p value = 0.00) the motor activity of rats. and the blood components decreased as follows: WBC (30.2%), Lymphocytes (40%.0), Neutrophils (35.7%), RBC (37.9%), MCV (32.2%) and RCDW (31.5%). At exposure dose of 0.3 mSv a mild morphological changes as circular shape deformity and loss of bi-concavity of RBCs. At 0.8 mSv RBCs diameter increment (10 ± 0.4 μm) and formation of spikes. At 1.8 mSv RBC underwent anisocytosis and poikilocytosis. While at 2.5 mSv the RBC showed intensive spikes, clustering and some underwent hemolysis. Morphological changes were induced also, at 2.5 mSv for the followings: The renal cortex showed bleeding & congestion at 2.5 mSv. The Renal medulla showed bleeding at 2.5 mSv. The liver texture showed bleeding and congestion with two nuclei- Kupffer cells hyperplasia, ballooning of hepatocytes with Acidophilic bodies at 2.5 mSv. the testicles tissues developed congestion and bleeding. Conclusionfluoroscopic urologic exposure dose can induce significant behavioral, RBCs changes and reduction in blood components.

Effects of needle cast diseases on the growth of a 33-year-old Douglas-fir provenance plantation in northwestern Bulgaria

Abstract In this study, the effects of defoliation caused by fungal pathogens on the tree vitality and growth of a 33-year old Douglas-fir (Pseudotsuga menziesii) provenance plantation in northwestern Bulgaria was presented. The results of the conducted surveys in 2011 and 2020 showed that there were significant differences between the individual provenances of Douglas-fir concerning their susceptibility to the needle cast diseases, caused by the fungal pathogens Rhabdocline pseudotsugae and Phaeucryptopus gaeumannii. The extent of damage, expressed as the amount of Douglas-fir needles cast, varied among provenance groups in individual years. A serious degree of defoliation was assessed among all continental provenances. In 2011, all examined trees from the group of continental provenances had severe symptoms of the needle cast disease. In 71.5% of them, the defoliation of the crowns was over 25% – moderately to severely affected. The average degree of defoliation varied from 18.3% (32 Wаrm Springs) to 89.3% (55 Alamogordo). In 2020, severe defoliation was found among all continental provenances. Both fungal pathogens were found as causes of the defoliation of 64.3% of the trees. The growth indicators: average height, average diameter at breast height, average height- and diameter increment for survived provenances in 2011 (at age 24) and 2020 (at age 33) were evaluated. The loss of needles and the reduced physiological function of the trees affected their vitality in the following years. Relationships between the average current annual height and diameter increment by provenance groups for 2003–2011 and 2011–2020 were calculated. It was found that with an increase in the degree of defoliation, the height and diameter increment of the provenances decreases.

Restoring a dry tropical forest through assisted natural regeneration: enhancing tree diversity, structure, and carbon stock

Deforestation is a key factor in global climate change, severely impacting ecosystem services. Effective implementation of reducing emissions from deforestation and forest degradation (REDD+) initiatives is essential for mitigating this change. Reforestation is a sustainable way to mitigate deforestation effects. We studied the impact of assisted natural regeneration (ANR) on restoring dry forest land, increasing biodiversity, structure, and carbon stock. Reforestation units were established at a multiple row planting system in a dry tropic region. We selected 63 plots, each 20 m × 20 m, categorized into multiple row–mixed plantation (MRMP) and multiple row–unmixed plantation (MRUP). We measured tree height and diameter at breast height (DBH) and evaluated biodiversity indices, including the Shannon–Weiner Index (SWI), species richness, evenness, and Important Value Index (IVI). Carbon stock was estimated using allometric equations. We identified 931 individual trees representing 27 species, 24 genera, and 14 families. MRMP showed significantly higher biodiversity, species richness, and evenness than MRUP. Terminalia arjuna was the most dominant species (IVI=124.45), followed by Khaya senegalensis (53.84). Survival rates exceeded 90 % for T. arjuna, K. senegalensis, Madhuca longifolia, and Pongamia pinnata (p<0.001). No significant differences were observed in tree DBH, tree height, tree density, basal area, and carbon stock among the plantation categories. The species Albizia saman exhibited a high diameter increment rate (4.07 ± 1.55 cm/year), followed by K. senegalensis (3.83 ± 0.43 cm/year). A mean value of 5.63 ± 1.13 MgC/ha of carbon stock was stored, while 20.66 ± 4.13 Mg/ha of atmospheric CO2 was sequestered. The results highlight that promoting mixed tree species in multiple rows to enhance biodiversity and optimize carbon regulation. This technique should be popularized to restore the dry forest landscape across the region.

Scale Effects of Individual Tree Thinning in Chinese Fir Plantations

Thinning is a crucial approach to the near-natural conversion of plantations, contributing to the sustainability of forest management. However, over a rotation, the effects of thinning on tree growth, structure, and species diversity, as well as their scale-dependent outcomes, remain unclear. Ten years after conducting individual tree thinning in a Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) monoculture in southwest China, we analyzed the thinning effects within the influence zone (r = 0–2.5 m) centered around stumps and center trees. The results indicate that (1) individual tree thinning did not significantly promote the increment of diameter at breast height, volume, and biomass of Chinese fir. The four nearest Chinese fir around stumps and center trees were in a state of random distribution, high mixing, and dominance; (2) individual tree thinning significantly promoted the formation of species abundance and richness at r = 2–2.5 m. With increased scale, more species were found, leading to increased stability in diameter and species distribution. Linear and nonlinear relationships between diameter classes, mingling, and dominance became more stable; (3) later-coming populations within both modes exhibited a common characteristic of random distribution, high mixing, and disadvantage at each scale, but with significant differences in species composition (kj = 0.22–0.61). These results suggest that individual tree thinning has limited impacts on the growth and structure of retained trees in Chinese fir plantations but significantly enhances the formation of species diversity, demonstrating scale effects. This underscores the feasibility of individual tree thinning in the near-natural conversion of plantations.

Effect of prostaglandin treatment on the estrus behaviour, follicular and luteal morphometry and serum hormone profile in sub-estrus buffaloes during non-breeding season.

Sub-estrus buffaloes do not exhibit estrus signs despite being cyclic contributing to extended service periods and inter-calving intervals causing significant economic loss. The present study described the effect of synthetic prostaglandin (PGF2α) on estrus behaviour, follicular and luteal morphometry, and serum estradiol (E2) and progesterone (P4) profile in sub-estrus buffaloes during the non-breeding season. The incidence of sub-estrus was 38.4% during the non-breeding season. The sub-estrus buffaloes (n = 33) were divided into two groups, viz., Control (n = 16) and PGF2α treatment (Inj. Cloprostenol 500 μg, i.m., n = 17). Estrus induction response was significantly greater in the treatment (100 vs. 18.75%, p < .001), and a relatively greater proportion of animals conceived in the treatment group (29.41 vs. 6.25%, p = .08). The time elapsed to induction of estrus and insemination following treatment was significantly lower in the treatment group than control. A significant increment in the follicle diameter (9.72 ± 0.45 vs. 13.00 ± 0.45 mm, P < .0001) and serum estradiol (E2) concentration (66.01 ± 11.92 vs. 104.9 ± 13.21 pg/mL, p = .003) observed at the post-treatment period in the PGF2α treatment group. At the same time, CL diameter was reduced significantly at a higher regression rate in the PGF2α treated buffaloes than those of control. Of the responded buffaloes, only 30% showed high-intensity estrus attributed to the expulsion of cervico-vaginal mucus (CVM), uterine tonicity, micturition, and mounting response by a teaser bull. From this study, it can be concluded that the administration of PGF2α could induce estrus in the sub-estrus buffaloes during the non-breeding season. Behavioural changes, along with sonographic observation of POF, regressing CL, and serum E2 and P4 concentration would be useful to determine the right time of insemination in sub-estrus buffaloes during non-breeding season.