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The article explores the impact of differential warming on primary and secondary growth in walnut trees, highlighting the lack of coordination mechanisms between primary and secondary growth at the crown scale. The study reveals that elevated temperature affects the resumption and growth rate of primary and secondary meristems differently, leading to asymmetry in canopy growth. Additionally, the response of xylem and phloem to temperature variations may differ, emphasizing the need for further research on the coordination mechanisms between primary and secondary growth in trees. [Extracted from the article]

The study of the variations in Macrophomina phaseolina, the causal agent of charcoal rot, is critical in understanding the ecology of the isolates and the epidemiology of the diseases they cause. This study sought to identify and characterize M. phaseolina isolates using both molecular and morphological approaches and to determine the virulence of the isolates. Macrophomina phaseolina was isolated from cowpea-diseased stem tissues. Eleven M. phaseolina isolates from the major cowpea growing areas (Manga, Nyankpala, Yendi, Damongo, Tumu, Wa, Akomadan and Ejura) were morphologically and molecularly characterized. DNA of the M. phaseolina isolates were amplified using species-specific PCR primers MpKF1 (5'-CCGCCAGAGGACTATCAAAC-3') and MpKR1 (5'-CGTCCGAAGCGAGGTGTATT-3') and sequencing of the M. phaseolina specific amplicons was obtained. This was followed by searching against the NCBI nucleotide sequence database. Isolates were tested for their pathogenicity on a susceptible cowpea cultivar (IT97K-499-35). Virulence of the M. phaseolina isolates was expressed as the percentage of sown seeds that expressed seed rot and damping-off symptoms 14 days after planting. All isolates were confirmed as M. phaseolina based on the amplicon size obtained, and the sequenced amplicons showed an average of 99% homology to the available M. phaseolina sequences. The radial growth of isolates and the percentage of seed rot and damping off they caused on the IT97K-499-35 cultivar varied significantly. The percentage seed rot and damping off were positively correlated (r = 0.74 and 0.75) with the radial growth and colour intensity of the isolates, respectively. Macrophomina phaseolina infection and disease expression may be predicted by the colour and colour intensity of isolates as well as cowpea genotypes. Isolate Mp_3Mc (dense black colour) was the most virulent while isolate Mp_6Ec (grey colour) was the least virulent, resulting in 76.7% and 26.7% seed rot and damping off, respectively. The three clades resolved through the phylogenetic tree matched the distinct colour types of M. phaseolina which correlated with virulence. Isolates of M. phaseolina are diverse and differ in their pathogenicity. Efforts must be geared towards developing cowpea varieties that have resistance to charcoal rot disease. [ABSTRACT FROM AUTHOR]

The complex interplay between primary and secondary growth processes in trees holds paramount significance in unraveling the physiological connections within distinct tree tissues. In this study, we continuously monitored the intra-annual radial growth of Pinus koraiensis, Quercus mongolica, and Betula platyphylla in Changbai Mountain of northeast China using microcore techniques from April to September 2021. Additionally, we used existing leaf phenology models to simulate the seasonal variations of leaf area of three species. Our results revealed substantial difference in radial growth dynamics and leaf expansion patterns among the different wood species. Notably, a synchronization between leaf expansion and radial growth was observed in certain phases for pine and birch, with a significant positive correlation between the rates of leaf expansion and radial growth. Conversely, oak exhibited no synchrony between leaf development and radial growth. Temporal disparities between cambial phenology and leaf phenology were observed. Specifically, for pine, leaf unfolding occurred prior to the onset of wall-thickening, while leaf shedding took place after the cessation of lignification. Oak exhibited a delayed leaf unfolding compared to the initiation of secondary wall formation, and leaf shedding notably occurred later than the cessation of radial growth. In contrast, birch displayed an earlier leaf unfolding in comparison to the onset of radial growth, and the cessation of lignification was later than leaf shedding. These findings indicate the diversity in physiological mechanisms and survival strategies among different wood species. Our results suggest that radial growth in pine and birch appears to be heavily reliant on photosynthetic activity of leaves, while oak places greater emphasis on carbon storage, particularly during early growing season. The findings provide new insights into the complex mechanisms of tree growth and are critical for predicting future species suitability in temperate forests. [ABSTRACT FROM AUTHOR]

The dendrochronological parameters of 97 pedunculate oak (Quercus robur L.) trees including 20 plus trees (142-year-old on average) and four half-sib families for four of them were analyzed considering also specifically years of the most severe droughts that were identified using average monthly air temperature and precipitation data. The tree-ring width (TRW) was mostly affected by air temperature that had the largest cross-dating indices (CDI), up to 78% maximum. However, the 32-year Brückner–Egeson–Lockyer cycle (a climatic cycle of approximately 30–40 years that correlates with sunspot activity) was more reflected in the TRW dynamics in plus trees than precipitation and air temperature. A high-frequency of abnormal TRW was clearly observed during drought periods and in the following 2–3 years. Tree radial-growth reduction due to drought stress varied significantly between families. The resistance to drought based on TRW was higher in the maternal plus oak trees than in progeny. Drought resulted in reduced growth during the subsequent year(s); hence, the minimum growth occurred after the actual climate event. Autumn–winter precipitation and weather conditions were of the greatest importance at the onset of active vegetation in April and May. The influence of air temperature on oak growth was the largest in March (r = 0.39, p < 0.05). The strongest positive correlation between precipitation and growth (with r up to 0.38) was observed in May 2023. Plus trees had a high adaptive potential due to the stability of radial growth during drought with high resistance (Rt = 1.29) and resilience (Rs = 1.09) indexes. The offspring of families 1 (Rt = 0.89, Rs = 0.89) and 2 (Rt = 1.04, Rs = 0.87) had similar resistance and resilience, but the recovery indices (Rc) for offspring in families 1, 2 and 3 exceeded the recovery values for plus trees. For offspring in families 3 and 4, the index values were lower. The revealed responses of wood growth of plus trees to climatic parameters estimated as resistance (Rt), resilience (Rs) and recovery (Rc) indexes and similar responses in their progeny can be used in breeding pedunculate oak for wood growth productivity and drought resistance. [ABSTRACT FROM AUTHOR]

Fires affect forest dynamics in seasonally dry regions such as the Mediterranean Basin. There, fire impacts on tree growth have been widely characterized in conifers, particularly pine species, but we lack information on broadleaf tree species that sprout after fires. We investigated post-fire radial growth responses in two coexisting Mediterranean hardwood species (the evergreen Quercus ilex, the deciduous Celtis australis) using tree-ring width data. We compared growth data from burnt and unburnt stands of each species subjected to similar climatic, soil and management conditions. We also calculated climate–growth relationships to assess if burnt stands were also negatively impacted by water shortage, which could hinder growth recovery. Tree-ring data of both species allowed us to quantify post-fire growth enhancements of +39.5% and +48.9% in Q. ilex and C. australis, respectively, one year after the fire. Dry spring climate conditions reduced growth, regardless of the fire impact, but high precipitation in the previous winter enhanced growth. High June radiation was negatively related to the growth of unburnt Q. ilex and burnt C. australis stands, respectively. Post-fire growth enhancement lasted for five years after the fire and it was a transitory effect because the growth rates of burnt and unburnt stands were similar afterwards. [ABSTRACT FROM AUTHOR]

The study examined the impact of Salicornia supplementation on the biological efficiency and biochemical properties of white Elm oyster mushrooms, Hypsizygus ulmarius. Four substrates were used to cultivate the mushrooms. Wheat straw was used as the main substrate and the Salicornia was used to partially replace the main substrate at the ratios of 5, 10, and 20% while 100% wheat straw was used as the control. The study found that the 20% Salicornia completed the mycelial run earlier (41 days), while the control treatment took the longest (45 days). The 5% Salicornia supplemented treatment and control treatment had the highest and lowest biological efficiencies (126 and 65%) respectively. The elemental concentration was undetectable for Copper (Cu), Lead (Pb), and Cadmium (Cd). The mushrooms from the control had the highest while those from the 20% treatment had the lowest (Zinc (Zn) levels (0.0115 ug/100 g) and 0.0078 ug/100 g). Conversely, Chromium (Cr) levels were highest and lowest in the 20% (0.0022 ug/100 g) and control treatments (0.0007 ug/100 g). Similarly, the total unsaturated fatty acids were highest in the control treatment (78%) and lowest in the 20% treatment (69%) while the opposite was true for the saturated fatty acids (22% and 31%). The mushrooms investigated in this study had higher essential amino acids (44–49%) compared to non-essential amino acids (17–20%). The results from this study suggest that Salicornia is a promising marine resource with the potential to enhance the health-promoting properties of oyster mushrooms. [ABSTRACT FROM AUTHOR]

Climate change and warming will potentially profoundly affect forest growth and yield. However, climate change is not only a threat but also an opportunity for tree species to be more productive or colonize new territories where previously they were fragmented or absent. European beech (Fagus sylvatica L.) is a dominant and significant tree species in European forests with a pronounced ability to grow on a great variety of sites and to form mixtures with other tree species due to its shade tolerance. So far, only a few studies have analysed its growth and reaction to changing climatic conditions outside its natural gradient in the north. The aim of this study was therefore to clarify the main growth patterns and tree ring formation characteristics of beech (outside their natural distribution) in mixed stands with Scots pine (Pinus sylvestris L.) The analyses were carried out in two-layered stands in the western part of Lithuania with tree-ring data measured on stem disks collected at 1 m height that were available from shelter-cut thinning activities in a number of forest stands in the region. Our results show that higher temperatures during the summer months of July and August generally inhibited the radial growth of beech under given site conditions. In contrast, warmer late-autumn and cooler early-winter periods together with warmer springs positively affected the radial increments. Above-average precipitation during the vegetation period contributed to the beech producing additional amounts of radial increments. The increasing temperature trends of the summer months and decreasing monthly amounts of precipitation during the vegetation period in recent decades tend to have adverse effects on the ecological conditions for beech growth and vitality in Lithuania. Despite these results, the European beech successfully grows in the sample region and has produced 200 m3 ha−1 in the analysed stands. [ABSTRACT FROM AUTHOR]

Clarifying the climate change effects on the radial growth of trees has implications for sustainable forest management, especially under global warming. To investigate tree growth responses to regional climate change of Xiaowutai Mountain, four Chinese pine (Pinus tabulaeformis) ring-width index chronologies were established at different elevations (1290–1600 m). Species growth trends were estimated using climate change projections derived from global climate models. The results show: (1) the four ring-width chronologies exhibited strong statistical characteristics, making them suitable for dendroclimatology studies. Radial growth-climate relationships were highly consistent, showing a negative correlation with previous September temperatures and current May–June temperatures, as well as a positively correlated with precipitation and Palmer Drought Severity Index during the corresponding period; and (2) climate change scenarios revealed that temperature will gradually increase on the Xiaowutai Mountain, and only a slight variation in precipitation is expected. Chinese pine radial growth may show a decline under future climate change. [ABSTRACT FROM AUTHOR]

The relationship between tree radial growth and climate factors is intricate and affected by various factors related to global climate change. Chinese fir [Cunninghamia lanceolata (Lamb.) Hook.)] is a crucial fast-growing timber species in subtropical China. Its productivity, primarily determined by radial growth, has been influenced by climate change. Our study aimed to explore growth patterns and elucidate the correlation between radial growth and climate factors in Chinese fir plantations across four distinct climatic regions. Through correlation analysis and structural equation model (SEM), we explained the relationship between radial growth trends and climate factors. The results showed that monthly radial growth differed among the four production areas, with an "unimodal curve" in Fujian and Jiangxi, a "bimodal curve" in Hunan, and a "trimodal curve" in Yunnan. Radial growth was positively correlated with temperature and precipitation. The dryness index had a weak correlation with radial growth in Fujian and Jiangxi but a significant positive correlation in Hunan and Yunnan. SEM analyses indicated path coefficients for biological factors influencing radial growth (0.352 in Fujian, 0.616 in Jiangxi, 0.595 in Hunan, and 0.528 in Yunnan) and climate factors (-0.003 in Fujian, 0.150 in Jiangxi, 0.265 in Hunan, and 0.005 in Yunnan). The factors affecting radial growth were the least in Fujian and the most in Yunnan, indicating greater climate sensitivity in the radial growth of Chinese fir from coastal to inland areas. These results enhance our understanding of climate impacts on forest productivity and offer a scientific basis for sustainably managing subtropical plantations under climate change. [ABSTRACT FROM AUTHOR]

Abstract The study examined the impact of Salicornia supplementation on the biological efficiency and biochemical properties of white Elm oyster mushrooms, Hypsizygus ulmarius. Four substrates were used to cultivate the mushrooms. Wheat straw was used as the main substrate and the Salicornia was used to partially replace the main substrate at the ratios of 5, 10, and 20% while 100% wheat straw was used as the control. The study found that the 20% Salicornia completed the mycelial run earlier (41 days), while the control treatment took the longest (45 days). The 5% Salicornia supplemented treatment and control treatment had the highest and lowest biological efficiencies (126 and 65%) respectively. The elemental concentration was undetectable for Copper (Cu), Lead (Pb), and Cadmium (Cd). The mushrooms from the control had the highest while those from the 20% treatment had the lowest (Zinc (Zn) levels (0.0115 ug/100 g) and 0.0078 ug/100 g). Conversely, Chromium (Cr) levels were highest and lowest in the 20% (0.0022 ug/100 g) and control treatments (0.0007 ug/100 g). Similarly, the total unsaturated fatty acids were highest in the control treatment (78%) and lowest in the 20% treatment (69%) while the opposite was true for the saturated fatty acids (22% and 31%). The mushrooms investigated in this study had higher essential amino acids (44–49%) compared to non-essential amino acids (17–20%). The results from this study suggest that Salicornia is a promising marine resource with the potential to enhance the health-promoting properties of oyster mushrooms.

Introduction: To investigate the differences in the response of radial growth of larch (Larix gmelinii) at varying altitude gradients to climatic factors, this study established tree-ring width chronologies of Larix gmelinii at altitudes of 900 m, 1,120 m and 1,300 m based dendroclimatology. Methods: We also employed R packages including "dplR," "static" and "moving" to determine the correlation between larch at different altitudes and climatic factors and to explore the sensitivity and stability between radial growth and the climate of larch at different altitudes in the northern part of the Greater Khingan Mountains Range in Northeast China. Results: The results revealed the radial growth of larch in high altitude areas to exhibit a downward trend due to climate warming, while the growth of trees in intermediate and low altitude areas showed an upward trend. The growth-- climate relationship exhibited a significant negative correlation between radial growth in low altitude larch (900 m) and temperatures in the current winter (February and March) and growing season (July, October of the current year, and October of the previous year) (p < 0.05). Moreover, high altitude larch (1,300 m) showed a significant negative correlation with temperature in January, March, and October of the current year (p < 0.05). However, in intermediate altitude areas (1,120 m), the radial growth of trees was significantly positively correlated with the temperature of the growing season (May, June and August). Precipitation in April was observed to promote the radial growth of low-altitude larch. Moving correlation analysis revealed that the inhibitory effect of low temperatures in winter and high temperatures in the growing season on the radial growth of larch at three altitudes gradually strengthened, transitioning from significant negative/positive correlations to significant positive/negative correlations along the altitudinal gradient. Discussion: Larch trees in high and low altitudes exhibited an increased sensitivity to winter and spring precipitation, while in the intermediate region, the inhibitory effect of growing season precipitation on larch radial growth continued to intensify. The results of the study have an important reference value for the indepth understanding of the growth dynamics of Larix gmelinii natural forests in the northern part of the Greater Khingan Mountains under climate change. [ABSTRACT FROM AUTHOR]

This study investigated the effects of climatic factors on radial growth of Picea schrenkiana var. tianschanica at various altitudes in Central Tianshan Mountains. Tree-ring core samples were collected at three altitudinal levels (1900, 2 200, 2 500 m) within the practice forest of Xinjiang Agricultural University. Dendrochronological techniques, including temperature, precipitation, the standardized precipitation evapotranspiration index, and the Palmer drought severity index, were employed to analyze meteorological data from 1955 to 2022. The results indicate that at low altitudes, tree-ring width is positively correlated with previous June and current June-August temperatures, previous August precipitation, and the current June-September Palmer drought severity index (P<0.05). At mid-altitudes, tree ring width was positively correlated with the previous June temperature, August precipitation, and previous June-August standardized precipitation evapotranspiration index (P<0.05). At high altitudes, tree-ring width was negatively correlated with the current January temperature and previous November to the current March standardized precipitation evapotranspi- ration index (P<0.05), but positively correlated with the current June-July precipitation (P<0.05). Therefore, in the forest, P. schrenkiana var. tianschanica growth is closely linked to the environmental moisture conditions, which vary with altitude. Precipi- tation is pivotal for radial growth of P. schrenkiana var. tianschanica at low altitudes, whereas temperature and precipitation jointly affected growth at mid-altitudes, with temperature exerting a greater impact than precipitation on radial growth at higher altitudes. [ABSTRACT FROM AUTHOR]

The functioning of a tree is shaped by the neighbouring species through the interspecific interaction and local environments. The functional trait composition of the neighbourhood could provide mechanistic insights into the effects of neighbours on the resource strategies of focal trees.In this study, we deployed an automated high‐frequency measurement of the sap flow density (SFD) and the radial growth of 48 trees of 12 species at BEF‐China, a large‐scale forest biodiversity manipulation experiment, to investigate the consequences and underlying mechanisms of the functional trait composition of the neighbourhood on the sap flow and radial growth of focal trees.We found a positive relationship between SFD and growth, reflecting the important supportive role of sap flow in tree growth. High functional diversity (FD) of the neighbourhood depressed SFD but promoted growth when considering all species, and thus promoted water‐use efficiency. Acquisitiveness of neighbouring trees positively affected growth, suggesting interspecific facilitation. Furthermore, neighbourhood FD benefits evergreen focal trees by promoting growth. However, in deciduous focal trees, neighbourhood FD reduced SFD but had no significant effects on growth.Our findings suggest that considering the functional trait composition of neighbourhood communities will support effective afforestation and forest management. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Summary: Secondary xylem and phloem originate from a lateral meristem called the vascular cambium that consists of one to several layers of meristematic cells. Recent lineage tracing studies have shown that only one of the cambial cells in each radial cell file functions as the stem cell, capable of producing both secondary xylem and phloem. Here, we first review how phytohormones and signalling peptides regulate vascular cambium formation and activity. We then propose how the stem cell concept, familiar from apical meristems, could be applied to cambium studies. Finally, we discuss how this concept could set the basis for future research. [ABSTRACT FROM AUTHOR]

The role of the roots and root systems of Pinus sylvestris L. in the formation of secondary pine forests in the cuttings of the Kola North was studied. It has been established that in pine seedlings in disturbed areas, root and shoot systems are formed quite quickly. Already in age class I, characteristic morphological signs of root systems appear and the feeding areas of trees begin to overlap each other. The bulk of the roots (80–85%) is concentrated in the upper 20-cm soil layer. A linear relationship between the taxation indicators of trees and the mass of root systems has been revealed. The conducted studies have shown that the formation of forest communities of Scots pine in the cuttings of the Kola North and their stability and productivity are directly dependent on the degree of development of individual roots and root systems as a whole. [ABSTRACT FROM AUTHOR]

Anticipating future impacts of climate warming and aridification on drylands requires understanding how coexisting woody plant species respond to climate variability. However, we lack knowledge of the growth resilience capacity of Mediterranean shrubs. Do coexisting trees and shrubs differ in their response to climate? Do coexisting shrub species have comparable post‐drought growth resilience?This study was conducted in two Mediterranean shrublands with sparse trees in semi‐arid north‐eastern Spain. We selected sites situated in formerly agricultural or grassland areas in two regions subjected to semi‐arid Mediterranean climate conditions. We sampled six shrubs' species (Juniperus phoenicea, Juniperus oxycedrus, Pistacia lentiscus, Pistacia terebinthus, Rhamnus lycioides and Rhamnus alaternus) and one tree species (Pinus halepensis) to measure their radial growth and to reconstruct their past growth patterns using dendrochronology. We quantified climate–growth relationships of trees and shrubs, as well as the growth resilience capacity after drought events of the six shrubs.Growth patterns differed between species but a prevalent trade‐off between growth and longevity was found. Growth responses to climate were comparable between species but differed between sites. Most species responded positively to precipitation and negatively to temperature. The most negative correlations of growth with drought severity were found at the driest Valcuerna site. Shrubs differed in their resilience capacity. Across sites, species were more resistant and resilient in Alcubierre, the wettest site. The shrubs P. terebinthus and R. lycioides were more resistant and resilient than the rest of species, which required longer growth recovery times and accumulated stronger growth reductions, particularly J. phoenicea.Synthesis. These results highlight the importance of drought as a driver of growth in Mediterranean scrublands. Growth resilience strategies differed between species with junipers being less resilient to drought than other coexisting shrubs. Further research should investigate how this difference in post‐drought resilience is related to functional traits, particularly those related with plant water‐use strategies. [ABSTRACT FROM AUTHOR]

The Vaganov-Shashkin (VS) and VS-Lite models are the most widely used physiological processes-based models oi tree-ring width. Both models can reveal the intrinsic response mechanism between tree-ring width and external climate iactors. The VS model is commonly applied in climate reconstruction, wood phenology prediction, and the simulation oi cambial activity, while the VS-Lite model is primarily applied in iorecasting growth trends of forest. We collected papers related to the VS and VS-Lite models published between 2005 and 2023, and reviewed the fundamental principles, parameter settings, and historical development oi both models, as well as the their applications in research areas oi dendroclimatology, xylem phenology, and forest ecology. Then, we summarized the current issues with the models and proposed future research directions. To increase confidence in the simulation results, it is essential to optimize the parameter adjustment method of the models, consider the impact of multiple environmental factors on the physiological processes of trees, and strengthen the comparative study of the VS and VS-Lite model with other vegetation ecological models. [ABSTRACT FROM AUTHOR]

Dendrochronological studies with shrubs from arid ecosystems in South America are of great importance due to the scarcity of ecological information that exists in these environments. This approach allows to evaluate the responses of plant species exposed to climate variability under arid conditions. We developed ring width chronologies and evaluated, for the first time for Argentina, the relationship between radial growth and climatic variables (precipitation, temperature and aridity index) of two shrub species characteristic of arid montane environments, Proustia cuneifolia and Hualania colletioides. The chronology of P. cuneifolia recorded a positive correlation with precipitation (May), temperature (October, July and February), and SPEI (June-October). The chronology of H. colletioides showed negative correlation with the temperature of the months of December and February. The results suggest that variations of the annual ring widths of P. cuneifolia are influenced by regional climate, mainly by aridity, while the growth of H. colletioides could be influenced by factors at the scale of microsite. A more extensive network of chronologies is necessary to explore site-climate variability under conditions of a complex topography such as that found in mountainous areas, suggesting the spatial extension of these records in order to understand in more detail the climatic imprint on the annual growth of these shrubs. [ABSTRACT FROM AUTHOR]

Tidal freshwater forests are usually located at or above the level of mean high water. Some Louisiana coastal forests are below mean high water, especially bald cypress (Taxodium distichum (L.) Rich.) forests because flooding has increased due to the combined effects of global sea level rise and local subsidence. In addition, constructed channels from the coast inland act as conduits for saltwater. As a result, saltwater intrusion affects the productivity of Louisiana's coastal bald cypress forests. To study the long-term effects of hydrology and salinity on the health of these systems, we fitted dendrometer bands on selected trees to record basal area increment as a measure of growth in permanent forest productivity plots established within six bald cypress stands. Three stands were in freshwater sites with low salinity rooting zone groundwater (0.1–1.3 ppt), while the other three had higher salinity rooting zone groundwater (0.2–4.9 ppt). Water level was logged continuously, and salinity was measured monthly to quarterly on the surface and in groundwater wells. Higher groundwater salinity levels were related to decreased bald cypress radial growth, while higher freshwater flooding increased radial growth. With these data, coastal managers can model rates of bald cypress forest change as a function of salinity and flooding. [ABSTRACT FROM AUTHOR]

A progressive decline in tree growth may be induced by global warming, affecting tree health and eventually resulting in death, particularly for trees growing in rocky mountainous regions where seasonal droughts have become more pronounced. However, tree growth dynamics in areas experiencing pronounced climate change have received little attention. In this study, a total of 100 (10 m × 10 m) grid plots were investigated in planted forests of Chinese cork oak (Quercus variabilis Blume), which were established in the 1960s and 1970s in a rocky mountainous area near Beijing, northern China. Furthermore, the radial growth of Q. variabilis (a total of 843 trees sampled from the dominant [D], co-dominant [CD], and suppressed [S] crown classes) was analyzed using retrospective dendrochronology and generalized additive models. The effects of meteorological changes between 1962 and 2020 on radial growth across the three crown classes were examined using correlation analysis. The results indicated that the growth of Q. variabilis initially increased and then decreased after 2010 at the regional level, and these trends varied according to crown class. The radial growth of the D trees responded more positively to an increase in temperature and drought severity index (<0 for dry and >0 for wet conditions) compared with that of the CD and S trees. The growth of the D and CD trees continuously increased under higher temperatures during the rainy seasons (June to September); however, the increases were higher for D than for CD trees. In contrast, the radial growth of S trees declined. We confirmed the historical effects of rising temperatures on tree growth and health, which are linked to water availability. Our data suggested that Q. variabilis trees will be considerably affected by intensified droughts. This study furthers our knowledge regarding the impact of climate change on tree and forest growth and provides management strategies for afforestation projects in rocky mountainous areas that are facing climate change. [ABSTRACT FROM AUTHOR]

The phenomenon of divergent responses in tree ring radial growth to climate change has been observed in the mid- and high-latitude regions of the Northern Hemisphere amidst global warming. However, the stability of the responses of the primary conifer species to climate factors in the mountainous regions of northeastern China remains unclear. Additionally, it is uncertain whether the radial growth in this area consistently responds to different competition indices. In our study, we developed tree ring width chronologies for Dahurian larch (Larix gmelinii) and analysed the radial growth responses to the regional climate from 1980 to 2012. This analysis was conducted by correlating meteorological data from different physiological stages of trees. We also evaluated the reliability of competition indices in predicting tree growth by constructing multiple linear regression models. Furthermore, we explored the relationship between the Basal Area Increment (BAI) of each tree and the competition indices in the sample plot over the previous five years. Our results showed that the temperature during the Non-Structural Carbohydrate (NSC) accumulation period and the NSC consumption period was significantly negatively correlated with the Ring Width Index (RWI) of Dahurian larch. Conversely, the RWI was significantly positively correlated with precipitation during these periods. The Standardised Precipitation Evapotranspiration Index (SPEI) at any period had a significantly positive correlation with the RWI. These findings suggest that future radial growth is likely to continue to be constrained by rising temperatures and water scarcity. Our findings also demonstrated that radial growth was less negatively impacted by competition from nearby trees and more influenced by the initial size of the tree. Compared to models that included other indices, models that included the BAL index as a single explanatory variable demonstrated superior statistical effectiveness. Our research suggests that before evaluating the competitive effects of the neighbourhood on radial growth, it is necessary to consider the stand diversity of tree species and the parameters related to spatial structure when selecting an appropriate competition index. [ABSTRACT FROM AUTHOR]

The forest loss and degradation caused by tree heart rot presents an increasingly challenging issue for the protection and utilization of forest resources. Yet, it is questionable whether heartwood-decayed trees can still function on par with healthy trees. Here, using tree ring data, we established basal area increment (BAI) series of healthy and heartwood-decayed fir trees at four sites (Abies spectabilis in Bomi; A. georgei Orr in Deqin as well as the Sygera Mountain; A. fabri Craib in Yajiageng) in the southeastern Qinghai-Tibetan Plateau (QTP). We conducted a comparative analysis of the difference in the BAI, response to climate factors and elasticity under environmental stress between the healthy and decayed fir. The results show that, in QTP, fir susceptibility to decay is uncorrelated with growth rates. However, after decaying occurs in fir trees, their radial growth is restricted in warm and humid areas (i.e., at Bomi and Yajiageng). The average BAI of healthy fir is 70.32 % and 86.32 % higher than that of decayed fir in Bomi and Yajiageng respectively (p 0.05). Moreover, healthy fir exhibits a more pronounced response to climatic conditions. Almost all BAI series of healthy and decayed fir in the southeastern QTP is positively correlated with the temperature and vapor pressure deficit. Under temperature stress, decayed fir trees are less resistant at three sites. This empirical study supports that there is no correlation between conifer trees’ radial growth rate and their likelihood of heartwood decay, and provides a compelling explanation for the constrained growth of decayed fir trees. Our findings can bolster the accurate assessment of carbon sinks and the conservation of forest resources in regions prone to high-decaying risks.

ABSTRACTThe radial growth of trees significantly contributes to climate change mitigation by sequestering carbon into woody biomass. Radial growth trends observed in European temperate forests during the recent period of climate warming vary between growth acceleration due to longer growing seasons and growth declines due to amplified drought stress. Assessing the spatial variation of growth trends is challenging due to the point relevance of available empirical data including forest inventories and tree-ring width chronologies. Here, we used a database of tree-ring width chronologies from 596 sites and spatial models to describe the growth trends of five tree species across the Czech Republic between 1990 and 2018. The resulting map highlights multiple sources of variation in growth trends including differences between species and prominent spatial gradients along elevation, latitude, and longitude. The knowledge of spatially explicit growth trends is essential for the adaptation of the forestry sector to ongoing climate change.

For the native Lithuanian Scots pine (Pinus sylvestris L.) population, rapidly changing climatic conditions raise new issues, related to survivability and resistance of local provenances to biotic and abiotic stressors. The aim of this study is to revise and update the findings of Abraitis & Ericsson (1996) who assessed the productivity of Scots pine provenances following 22 years of growth. In this study, we assessed the productivity of same provenances following 39 years of growth. This study was done based on a long-term pine provenance research experiment established in 1975 in Lithuania, as an integral part of the Prokazyn investigation that was launched across the former USSR. Our results indicate a clear effect of latitude as well as longitude on the mean stand performance values of Scots pine provenances. With increasing latitude, mean height, mean quadratic diameter and the volume of growing trees per hectare had a clear decreasing tendency. Except for the mean squared diameter, the impact of the longitude was the same on the mean stand height and the volume of growing trees per hectare. Ranking of Scots pine provenances based on breeding indices showed that provenances that were identified as the most productive ones by Abraitis & Ericsson (1996) after 17 years of growth, lost their top positions after 39 years of growth. In the case of demand for genetically improved planting material, it could be recommended to use southerner populations which demonstrate higher growth intensity up to 39 years.

The effects of rising atmospheric CO2 concentrations (Ca) with climate warming on intrinsic water-use efficiency and radial growth in boreal forests are still poorly understood. We measured tree-ring cellulose δ13C, δ18O, and tree-ring width in Larix dahurica (larch) and Betula platyphylla (white birch), and analyzed their relationships with climate variables in a boreal permafrost region of northeast China over past 68 years covering a pre-warming period (1951–1984; base period) and a warm period (1985–2018; warm period). We found that white birch but not larch significantly increased their radial growth over the warm period. The increased intrinsic water-use efficiency in both species was mainly driven by elevated Ca but not climate warming. White birch but not larch showed significantly positive correlations between tree-ring δ13C, δ18O and summer maximum temperature as well as vapor pressure deficit in the warm period, suggesting a strong stomatal response in the broad-leaved birch to temperature changes. The climate warming-induced radial growth enhancement in white birch is primarily associated with a conservative water-use strategy. In contrast, larch exhibits a profligate water-use strategy. It implies an advantage for white birch over larch in the warming permafrost regions. [ABSTRACT FROM AUTHOR]

Knowledge regarding the growth of trees is essential to understanding their response to predicted warmer and drier climate scenarios. We used the annual rings of three Mexican pines (Pinus montezumae Lamb., Pinus oocarpa Schiede ex Schltdl., and Pinus monophylla Torr. & Frém) to explore their drought responses. Correlation analyses showed that hydroclimatic factors differentially impact tree species in terms of the intensity and temporality. The negative influence of the maximum temperature and positive effect of the precipitation on the growth indices were notable, with P. montezumae being the most responsive species, followed by P. oocarpa and P. monophylla. The climate–growth relationships were specific and driven by the differential hydrothermal conditions across the study areas. SPEI analyses indicated that P. monophylla is better able to tolerate drought than P. montezumae or P. oocarpa, especially in recent years. The lower resilience of P. montezumae and P. oocarpa could predispose them to a higher mortality risk if warming and drying rates increase. Our findings strengthen the understanding of the responses of tree growth to seasonal drought, which is critical considering the biogeographic shifts that will potentially be experienced by these forests in the future. This knowledge improves the understanding of young Mexican stands and could contribute to the design of management strategies in the face of predicted climatic variations. [ABSTRACT FROM AUTHOR]

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

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

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

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

Southwestern China is a critical biodiversity hotspot area, and many large hydroelectric projects have been established in the valleys in the region. Tree growth in the valleys will be affected by both regional climate and reservoir impoundment. However, it remains unknown whether the radial growth of trees in the valleys has a common response pattern to the regional climate, and it is also unclear whether the response of radial growth to reservoir impoundment can be detected. In this study, we developed tree-ring width chronologies of Pinus yunnanensis Franch. collected at 11 sites with vertical and horizontal gradients to three hydroelectric reservoirs in three riverine valleys in southwestern China. We analyzed the radial growth responses to the regional climate from 1986 to 2017 by correlation with instrumental meteorological data. Tree growth responses to reservoir impoundment were investigated through spatial and temporal comparisons using the change in the Euclidean distance and difference test. We also distinguished their responses at tree-ring sites without influenced by reservoir impoundment including two sites in the valleys and seven sites at high elevations. The results showed that the climate conditions in May and the dry season before the growth season significantly limit the radial growth in the valleys, which is different to that at high-elevation areas in southwestern China. Growth variations in the valleys are related to elevations and the trees in similar slopes positions exhibit similar responses. For trees in the low slope positions, both variance and mean values of radial growth are affected by reservoir impoundment. Trees at relatively low sites (i.e., sites M2, R2, L2), rather than the trees close to the reservoirs (i.e., sites M1, R1, L1), respond more sensitively to reservoir impoundment. [ABSTRACT FROM AUTHOR]

For a class of aggregation models on the integer lattice Z d , d ≥ 2 , in which clusters are formed by particles arriving one after the other and sticking irreversibly where they first hit the cluster, including the classical model of diffusion-limited aggregation (DLA), we study the growth of the clusters. We observe that a method of Kesten used to obtain an almost sure upper bound on the radial growth in the DLA model generalizes to a large class of such models. We use it in particular to prove such a bound for the so-called ballistic model, in which the arriving particles travel along straight lines. Our bound implies that the fractal dimension of ballistic aggregation clusters in Z 2 is 2, which proves a long standing conjecture in the physics literature. [ABSTRACT FROM AUTHOR]

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

(1) Background: Climate change significantly impacts the phenology and dynamics of radial tree growth in alpine dryland forests. However, there remains a scarcity of reliable information on the physiological processes of tree growth and cambial phenology in response to long-term climate change in cold and semi-arid regions. (2) Methods: We employed the process-based Vaganov–Shashkin (VS) model to simulate the phenology and growth patterns of Chinese pine (Pinus tabuliformis) in the eastern Qilian Mountains, northeastern Tibetan Plateau. The model was informed by observed temperature and precipitation data to elucidate the relationships between climate factors and tree growth. (3) Results: The simulated tree-ring index closely aligned with the observed tree-ring chronology, validating the VS model's effectiveness in capturing the climatic influences on radial growth and cambial phenology of P. tabuliformis. The model outputs revealed that the average growing season spanned from mid-April to mid-October and experienced an extension post-1978 due to ongoing warming trends. However, it is important to note that an increase in the duration of the growing season did not necessarily result in a higher level of radial growth. (4) Conclusions: While the duration of the growing season was primarily determined by temperature, the growth rate was predominantly influenced by water conditions during the growing season, making it the most significant factor contributing to ring formation. Our study provides valuable insights into the potential mechanisms underlying tree growth responses to climate change in cold and semi-arid regions. [ABSTRACT FROM AUTHOR]

The article deals with the stages of recreational digression of diff erent biogeocenoses in the Shirokovsky district forestry of the National Park “Buzuluksky Bor” and the peculiarities of radial growth of the common pine as a dominant stand. The aim of the work was to analyze the comparative response of the common pine trees in the zone of active recreation and in undisturbed areas. The presence or absence of undergrowth, understorey, projective cover and dominance of indicator plants were noted. Sub-tree enumeration with averaged data was carried out on temporary sample plots. Using a Flir i7 thermal imager, the presence or absence and localization of stem and root rots of pine from sponges were determined. A decrease in the total projective cover of the living ground cover and the number of forest species was observed, with an increase in the number of cereal species as recreational digression increased. As recreation intensifi es, undergrowth and understorey disappears. It was noted that with increasing stages of digression the monotony of undergrowth species composition appears, the density and height of forest litter decreases, the number of trees infected with rots and infested with stem pests (black pine moustache, pine bark beetles, six-toothed bark beetle, apex bark beetle) increases. Changes in all components of biogeocenosis lead to loss of stability of forest phytocenosis as a whole. Even a simple stay of a large number of people in the forest leads to degradation of plant communities.

Climate change has resulted in a widespread increase in primary productivity in northern regions. This “greening” can alter terrestrial ecosystems dynamics and trigger positive climate feedbacks but often exhibits spatial heterogeneity. Few studies have focused on the differential responses of plant functional groups to warming as a potential driver of heterogeneity in greening rates. Our objective was to determine whether climate–growth relationships are species-specific, and whether they can explain the heterogeneity of the subarctic greening rates. We compared climate–growth relationships and associations to normalized difference vegetation index (NDVI) of the dominant tree (Picea mariana) and shrub (Betula glandulosa) species at two locations in the forest–tundra ecotone in Nunavik (Québec, Canada). Correlation coefficients of the climate–growth relationship varied between species and locations, being higher for P. mariana and at the northernmost location. The lower association between NDVI and P. mariana radial growth at the northernmost location appeared to be compensated by a stronger association between NDVI and B. glandulosa radial growth. Our results show that response to climate varies spatially and between species, both of which could potentially be used to explain the heterogeneity of subarctic greening rates. This improved understanding of the species-specific response to climate change will help predict forthcoming changes in primary productivity and their potential positive feedback on climate change.

The dendrochronological parameters of 97 pedunculate oak (Quercus robur L.) trees including 20 plus trees (142-year-old on average) and four half-sib families for four of them were analyzed considering also specifically years of the most severe droughts that were identified using average monthly air temperature and precipitation data. The tree-ring width (TRW) was mostly affected by air temperature that had the largest cross-dating indices (CDI), up to 78% maximum. However, the 32-year Brückner–Egeson–Lockyer cycle (a climatic cycle of approximately 30–40 years that correlates with sunspot activity) was more reflected in the TRW dynamics in plus trees than precipitation and air temperature. A high-frequency of abnormal TRW was clearly observed during drought periods and in the following 2–3 years. Tree radial-growth reduction due to drought stress varied significantly between families. The resistance to drought based on TRW was higher in the maternal plus oak trees than in progeny. Drought resulted in reduced growth during the subsequent year(s); hence, the minimum growth occurred after the actual climate event. Autumn–winter precipitation and weather conditions were of the greatest importance at the onset of active vegetation in April and May. The influence of air temperature on oak growth was the largest in March (r = 0.39, p < 0.05). The strongest positive correlation between precipitation and growth (with r up to 0.38) was observed in May 2023. Plus trees had a high adaptive potential due to the stability of radial growth during drought with high resistance (Rt = 1.29) and resilience (Rs = 1.09) indexes. The offspring of families 1 (Rt = 0.89, Rs = 0.89) and 2 (Rt = 1.04, Rs = 0.87) had similar resistance and resilience, but the recovery indices (Rc) for offspring in families 1, 2 and 3 exceeded the recovery values for plus trees. For offspring in families 3 and 4, the index values were lower. The revealed responses of wood growth of plus trees to climatic parameters estimated as resistance (Rt), resilience (Rs) and recovery (Rc) indexes and similar responses in their progeny can be used in breeding pedunculate oak for wood growth productivity and drought resistance.

Fires affect forest dynamics in seasonally dry regions such as the Mediterranean Basin. There, fire impacts on tree growth have been widely characterized in conifers, particularly pine species, but we lack information on broadleaf tree species that sprout after fires. We investigated post-fire radial growth responses in two coexisting Mediterranean hardwood species (the evergreen Quercus ilex, the deciduous Celtis australis) using tree-ring width data. We compared growth data from burnt and unburnt stands of each species subjected to similar climatic, soil and management conditions. We also calculated climate–growth relationships to assess if burnt stands were also negatively impacted by water shortage, which could hinder growth recovery. Tree-ring data of both species allowed us to quantify post-fire growth enhancements of +39.5% and +48.9% in Q. ilex and C. australis, respectively, one year after the fire. Dry spring climate conditions reduced growth, regardless of the fire impact, but high precipitation in the previous winter enhanced growth. High June radiation was negatively related to the growth of unburnt Q. ilex and burnt C. australis stands, respectively. Post-fire growth enhancement lasted for five years after the fire and it was a transitory effect because the growth rates of burnt and unburnt stands were similar afterwards.

This scientific commentary discusses the importance of understanding carbon source-sink dynamics in masting tree species, particularly in the context of climate change and drought stress. The authors examine the responses of carbon allocation to environmental constraints in stone pine stands, focusing on reproductive effort, radial growth, and tree-ring isotope composition. They find evidence of a shift from sink-limited to source- and sink-co-limited reproduction, suggesting diminishing carbon resources due to drought stress. However, caution is needed in interpreting the data, and further research is necessary to fully understand carbon allocation in trees. [Extracted from the article]

Background and Aims Plant vascular diseases significantly impact crop yield worldwide. Esca is a vascular disease of grapevine found globally in vineyards which causes a loss of hydraulic conductance due to the occlusion of xylem vessels by tyloses. However, the integrated response of plant radial growth and physiology in maintaining xylem integrity in grapevine expressing esca symptoms remains poorly understood. Methods We investigated the interplay between variation in stem diameter, xylem anatomy, plant physiological response and hydraulic traits in two widespread esca-susceptible cultivars, 'Sauvignon blanc' and 'Cabernet Sauvignon'. We used an original experimental design using naturally infected mature vines which were uprooted and transplanted into pots allowing for their study in a mini-lysimeter glasshouse phenotyping platform. Key Results Esca significantly altered the timing and sequence of stem growth periods in both cultivars, particularly the shrinkage phase following radial expansion. Symptomatic plants had a significantly higher density of occluded vessels and lower leaf and whole-plant gas exchange. Esca-symptomatic vines showed compensation mechanisms, producing numerous small functional xylem vessels later in development suggesting a maintenance of stem vascular cambium activity. Stabilization or late recovery of whole-plant stomatal conductance coincided with new healthy shoots at the top of the plant after esca symptoms plateaued. Conclusions Modified cropping practices, such as avoiding late-season topping, may enhance resilience in esca-symptomatic plants. These results highlight that integrating dendrometers, xylem anatomy and gas exchange provides insights into vascular pathogenesis and its effects on plant physiology. [ABSTRACT FROM AUTHOR]

In this work, we propose that small wood core samples (≤10 cm length), taken from 0.3 m above the soil, represent an accurate means of correlating forest growth with remote sensing data. Short-term correlations between the Normalized Difference Vegetation Index (NDVI) and tree-ring components of the last three to four decades were tested, using 210 Pinus hartwegii wood cores collected at two locations, Tláloc (TLA) and Jocotitlán (JOCO) in central Mexico. The NDVI time series were generated with the Google Earth Engine (GEE) using Landsat 8 images. Also, seasonal trends in NDVI (e.g., spring, summer, autumn, winter) were analyzed through longitudinal analysis. The results showed more statistically significant dendrochronological indices in TLA than in JOCO, but both locations consistently showed an NDVI decrease in 2018 and 2020, indicating a reduction in vegetation vigor. At the two locations, the minimum and maximum NDVI occurred in April and October, respectively. Seasonal NDVI changes for spring were mainly seen at TLA with a decreasing trend, which may be related to a less defined dry season. The significant correlations (p < 0.05) between tree-ring components and the NDVI occurred in the dry season, indicating that the productivity of a given year is defined by the tree vigor shown in April and May, in the case of TLA, and between January and March, for JOCO. Although the NDVI values of JOCO were higher than those of TLA, tree growth, expressed by tree-ring indices, was lower. Our proposed field method to correlate tree-ring information and the NDVI is reliable and can be used in other coniferous forests. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate two strains of fungi, Pleurotus ostreatus and Pleurotus sapidus, on radia growth, biomass production, mushroom production and chemical composition. The treatments to evalua)te radial growth and biomass production were: T1) PDA + P. ostreatus, T2) PDA + P. sapidus, T3) PDA Soybean stubble + P. ostreatus, T4) PDA Soybean stubble + P. sapidus, T5) PDA Rice stubble + P. ostreatus, T6) PDA Rice stubble + P. sapidus, T7) PDA Corn bush + P. ostreatus, T8) PDA Corn bush + P. sapidus. To evaluate the production and chemical composition of the Pleurotus mushroom mushrooms, they were: T1) Soybean stubble + P. ostreatus, T2) Soybean stubble + P. sapidus, T3) Corn tusa + P. ostreatus, T4) Corn tusa + P. sapidus, T5) Rice stubble + P. ostreatus, T6) Rice stubble + P. sapidus. There were differences (≤ 0,05) between the treatments in the variables of radial growth and biomass production, highlighting T3 with better growth and biomass production. In the yield and chemical composition of the Pleurotus mushrooms, there were also differences (≤ 0,05), with T1 being the best compared to the other treatments. These results could be explained because soybean stubble contains a high content of lignocellulosic components since these components are very palatable for the growth of Pleurotus fungi. [ABSTRACT FROM AUTHOR]

The radial growth of trees significantly contributes to climate change mitigation by sequestering carbon into woody biomass. Radial growth trends observed in European temperate forests during the recent period of climate warming vary between growth acceleration due to longer growing seasons and growth declines due to amplified drought stress. Assessing the spatial variation of growth trends is challenging due to the point relevance of available empirical data including forest inventories and tree-ring width chronologies. Here, we used a database of tree-ring width chronologies from 596 sites and spatial models to describe the growth trends of five tree species across the Czech Republic between 1990 and 2018. The resulting map highlights multiple sources of variation in growth trends including differences between species and prominent spatial gradients along elevation, latitude, and longitude. The knowledge of spatially explicit growth trends is essential for the adaptation of the forestry sector to ongoing climate change. [ABSTRACT FROM AUTHOR]

Ice storms can cause substantial damage to tree crowns and lead to growth reduction. However, in uneven-aged stands, the growth of an individual tree may also increase due to crown release caused by the damage or mortality of neighboring trees. Three years after the devastating ice storm in 2014 in mixed uneven-aged Dinaric forests (Croatia), we cored 156 European beech (Fagus sylvatica) and 85 silver fir (Abies alba) trees across 20 permanent sample plots to study the post-storm growth response as a function of tree, stand, site, spatial arrangement and local competition factors. The ice storm damaged over 84% of trees on the sampled plots. Among the cored trees, 52.7% exhibited growth reduction, which on average amounted to -3.1% relative to the pre-disturbance average. Trees with less than 40% crown damage maintained their pre-disturbance growth rates or experienced only minor growth suppression. While 60% of beech trees suffered a growth reduction at an average rate of -7.2%, the average radial increment of fir after the storm was 14.0% higher compared to the pre-storm rate. A linear mixedeffects model suggests that the growth response can largely be explained by the focal and neighboring tree species identity, tree competition pressure, focal and neighboring tree damage, crown size, slenderness index and stoniness. Growth release was positively associated with fir, inverse distance-weighted crown damage of the nearest neighbor, shorter crowns, slenderness, less stony sites and less damaged trees. The analysis suggests that at the same level of local competition load, trees with a broadleaved and damaged nearest neighbor are more likely to experience growth release than those with a coniferous or undamaged nearest neighbor. This implies that unevenaged stands with a substantial presence and mingling of both conifers and broadleaves are expected to be more resilient to ice storms and are less likely to suffer growth reduction. [ABSTRACT FROM AUTHOR]

The present investigation aimed to determine the per cent growth inhibition of different fungicides against Alternaria burnsii, the causal agent of cumin blight. The study was conducted during 2020-21 at the Experiential Unit of Plant Pathology, College of Agriculture, SKRAU, Bikaner. Using the poisoned food technique, eleven fungicides were tested at varying concentrations (100, 200, 300, and 500 ppm). After seven days of incubation, the radial growth and per cent growth inhibition of A. burnsii were measured. The results revealed that increasing the fungicide concentration led to greater inhibition of mycelium growth. Among the tested fungicides, Tebuconazole 50% + Trifloxystrobin 20% WG exhibited the highest mean inhibition (76.94%), followed by Tebuconazole 2DS (65.09%) and Pyraclostrobin 13.30% + Epoxiconazole 5% SE (58.75%). Notably, Tebuconazole 50% + Trifloxystrobin 20% WG at concentrations of 300 ppm and 500 ppm, as well as Tebuconazole 2DS at 500 ppm, demonstrated the highest effectiveness with cent per cent growth inhibition. On the other hand, Chlorothalonil showed the least mean growth inhibition (22.96%). The results demonstrated that as the fungicide concentration increased, there was a corresponding increase in the inhibition of A. burnsii growth. These findings highlight the potential effectiveness of selected fungicides, particularly Tebuconazole 50% + Trifloxystrobin 20% WG and Tebuconazole 2DS for managing cumin blight caused by A. burnsii. [ABSTRACT FROM AUTHOR]

In order to explore the radial growth of Pinus yunnanensis var. tenuifolia in Jinzhongshan of Guangxi and its response to climate, a standard tree-ring chronology of P. yunnanensis var. tenuifolia was established, response analysis was used to explore the relationship between radial growth and climatic factors, and stepwise regression and variance decomposition were used to quantify the effects of climatic factors on radial growth of P. yunnanensis var. tenuifolia. The results were as follows: (1) Sunshine duration in January, August, September and November, and the mean minimum temperature and the mean temperature in October of the previous year were significantly positively correlated with tree-ring width of standard chronology. By contrast, there was a significant negative correlation between the number of days with the amount of precipitation >10 mm in June of the previous year and tree-ring width. Precipitation in February, relative air humidity and the mean minimum temperature in March, sunshine duration in June, and the mean maximum temperature and mean temperature in September of the current year were positively correlated with tree-ring width. (2) The variance decomposition results of the final stepwise regression model revealed that the mean minimum temperature in October of the previous year had the greatest effect on the radial growth of P. yunnanensis var. tenuifolia (explaining 23.35% of the variance), followed by the mean maximum temperature in September of the current year (explaining 10.39% of the variance). Sunshine duration in January and November of the previous year explained 3.94% and 6.58% of the variation in radial growth of P. yunnanensis var. tenuifolia, respectively. In conclusion, autumn temperature and winter light condition are the main climatic factors limiting the radial growth of P. yunnanensis var. tenuifolia in Jinzhongshan. In addition, both drought in early spring and heavy rainfall in rainy season can reduce the radial growth of P. yunnanensis var. tenuifolia.