Selection of genetically superior Eucalyptus clones that combine high productivity with enhanced ecosystem services is crucial for sustainable plantation management and climate change mitigation. The present investigation assessed fifteen promising Eucalyptus clones cultivated for eight years under the conditions of eastern India with respect to biomass accumulation, carbon sequestration capacity, foliar nutrient concentration, soil fertility status and soil microbial dynamics. Biomass and carbon stocks were quantified through destructive sampling techniques, whereas soil chemical and microbiological attributes were determined using standard analytical methods. Marked differences were observed among the clones for all growth, carbon and soil-related characteristics. Total biomass production varied from 193.92 to 418.59 Mg ha⁻¹, while carbon storage ranged between 96.96 and 209.30 Mg ha⁻¹. Among the evaluated clones, JKSC-ECD exhibited the greatest biomass yield (418.59 Mg ha⁻¹), carbon stock (209.30 t ha⁻¹) and annual carbon sequestration rate (26.16 Mg ha⁻¹ yr⁻¹). This clone also recorded the highest concentrations of foliar nutrients and significantly improved soil quality, attaining maximum values of soil organic carbon (0.67
Visual assessments of growing forest nursery plants are time-consuming and often result in a lack of information at a physiological level. There exists a need for health screening in nurseries, that is fast and efficient, to improve overall health monitoring and nursery productivity. Rapid handheld sensors such as rapid thermal devices, leaf porometers and moisture meters, can provide regular information at a physiological level, that can improve the understanding of the impact of stress on young plant cuttings and their decline in health over time. This paper evaluates the utility and reliability of contemporary sensor technologies, to operationally monitor stress phases in juvenile forest plant cuttings during progressive moisture (dry-down) conditions. Furthermore, to assess whether thermal sensors could be used as an indicator, in conjunction with other variables such as soil water content or stomatal conductance, is needed operationally for fast screening during limited planting windows. Near Infra-Red Analysis (NiRA) data was collected to understand detailed plant functions at a finer reflectance level. A relationship was found where the increase in thermal signals reflects a depletion of water content, resulting in an eventual decline in stomatal conductance and, ultimately, plant mortality. Several algorithms were used in a preliminary test, using RapidMiner software, to discriminate between the four phases of plant health decline using physiological variables and NiRA data. Both Gradient Boosting Trees (GBT) and Deep Learning (DL) showed the best performances, achieving favourable accuracies of 96.8
The Persian oak (Quercus brantii) is a keystone species in Iran’s Zagros forests, but its natural regeneration is severely challenged by soil moisture depletion in the arid and semi-arid climate. This research evaluated the efficacy of a superabsorbent polymer (SAP) in enhancing the growth and survival of one-year-old Persian oak seedlings under controlled drought stress. A factorial experiment was conducted in a completely randomized block design employing 16 treatments, 3 replications, and 2 controls. The treatments consisted of four SAP levels (0
Global climate change is increasing the frequency and intensity of heatwaves, posing a major challenge to forest tree species. Neltuma alba (ex Prosopis alba) is one of the dominant native tree species of the South American Dry Chaco and is recognized for its tolerance to drought and salinity. However, its response to high temperatures remains poorly understood. In this study, we evaluated the physiological responses of N. alba seedlings to heat stress and their capacity for recovery. Six-month-old seedlings were grown in vermiculite, irrigated with Hoagland nutrient solution, and exposed for 7 days to four day/night temperature regimes (26/26 °C, 35/26 °C, 40/26 °C, and 46/26 °C) under a 16-h photoperiod and 60 ± 5
Reduced-impact logging (RIL) has improved operational practices in tropical forests, yet increasing evidence shows that it alone is insufficient to restore commercial timber stocks within realistic cutting cycles. Post-harvest silvicultural interventions in logging gaps have therefore been proposed to accelerate tree growth and shorten rotation lengths. We evaluated the long-term effects of post-harvest silviculture on growth, survival, biomass accumulation, and stem volume of Tachigali glauca, a fast-growing and light-demanding Amazonian timber species. We monitored trees established under three treatments, control (RIL only), tending of natural regeneration, and enrichment planting, across 17 years in logging gaps. Periodic annual increments in diameter, aboveground biomass, and volume were quantified, and growth projections were used to estimate time to reach the minimum cutting diameter of 50 cm. Mortality rates were low within all treatments. In contrast, growth responses differed markedly: enrichment planting resulted in the highest diameter, biomass, and volume increments, followed by tending and control treatments. Diameter class distributions revealed faster structural advance under enrichment planting, with a greater proportion of trees reaching larger size classes by 2023. Growth projections indicated that enrichment planting reduced the estimated time to reach 50 cm DBH to approximately 54 years, compared to 93 years under tending and 175 years under control conditions. Our results demonstrate that post-harvest silviculture (particularly enrichment planting) substantially accelerates growth trajectories and reduces rotation length.
Water limitation during tree seedling cultivation can promote traits that improve drought hardiness. Nurseries apply water limitation mostly during a brief developmental window of seedling growth, which may restrict the range of useful traits achievable through water limitation if phenotypic responses differ across ontogeny. We characterized the diversity of western larch (Larix occidentalis (Nutt.)) seedling traits produced by four factorial combinations of low- and high-watering regimes spanning the first and second years of growth. Seedlings from all watering treatments were exposed to ten days of water withholding during a drought pulse trial at the end of year two preceding destructive measurements. Seedling stem water potential (Ψ) measurements recorded before, during, and after the drought pulse trial suggested that water-limited cultivation in the second year and consecutively across both years resulted in the greatest mid-day Ψ (least moisture stress) during the drought pulse and the greatest integrated water use efficiency. Seedlings cultivated with limited water in the second year and consecutively across both years expressed similar traits and performance during the drought pulse, suggesting that previous exposure to drought did not moderate seedling responses to subsequent water limitation. Water-limited cultivation in year one resulted in a greater number of root branch nodes and mass of egressed roots given ample water in year two, but not when water was limited in year two. Evidence suggests that seedlings express age-dependent phenotypic responses to water limitation that promote belowground growth best when applied during the first year except in dry transplanting environments.
Extending New Zealand’s planting season for Pinus radiata may increase the economic viability of mechanised planting. Doing this could necessitate adding hydrogels or water at planting to buffer dry soil conditions, however, optimizing amendment type and volume for seedling establishment is required. We compared how synthetic polyacrylamide hydrogel (PAM) and nanocellulose hydrogel (NCH) influenced water retention in different forest soils, and found NCH applied to intact soil cores at 0.5
Estimating tree height growth and survival rate are important for characterizing forest growth performance and evaluating dynamic changes during the early development of newly planted forests. This study evaluated tree height growth and survival rates in a newly forested area of Chinese fir (Cunninghamia lanceolata (Lamb) Hook) and Schima superba Gardner Champ. planting from two temporal Unmanned Aerial Vehicle (UAV) images over a four-year period. Individual tree crowns were delineated by visual interpretation, and tree heights were estimated using the local maxima method. Using the 2023 digital surface model (DSM) combined with the 2019 digital terrain model (DTM), UAV-based tree height estimation achieved high accuracy, with a root mean square error (RMSE) of 0.48 m for Chinese fir and 0.37 m for S. superba compared with field survey measurements in 2023. It reduced RMSE by 0.30 m for Chinese fir and 0.50 m for S. superba compared to using the 2023 DTM for ground height estimates. From 2019 to 2023, the survival rates of Chinese fir and S. superba were 92.39
Japan has adopted biodiversity-oriented forest management, necessitating the diversification of extensive conifer plantations and the identification of geographic conditions that favor natural hardwood regeneration. The increasing availability of high-resolution airborne laser scanning (ALS) data provides new opportunities to analyze spatial patterns in forests. In this study, we applied exploratory approaches to quantify the prevalence of natural hardwood regeneration within mature conifer plantations in Kochi Prefecture, southwestern Japan. The study covered an area of approximately 250 km2, enabling spatial analyses at the landscape scale. Hardwood regeneration was defined as areas recorded as conifer plantations in forest registry data (2005–2009) but dominated by hardwoods based on ALS data collected in 2018. Across postwar afforestation sites (1949–1978 planting), hardwood regeneration consistently occupied 20–25
Global warming has emerged as a key driver of global biodiversity loss, substantially impacting on the geographical distribution and richness patterns of species. Picea, a crucial component of China’s forest ecosystem, plays a vital role in ecological functioning and conservation. This study employed the MaxEnt model and integrated distribution data of 22 Picea species in China to predict historical and future diversity patterns and trends. Additionally, using structural equation modeling (SEM), this study revealed how global warming and environmental heterogeneity drive the richness patterns of Picea species in China, and identified relevant diversity hotspots and conservation gaps. Results showed that climate change contracts suitable habitats for some Picea species and drives most taxa upward to higher latitudes and elevations. Environmental energy and water availability directly control Picea richness, whereas environmental heterogeneity dominates richness spatial patterns via strong indirect effects and the largest total effect. Furthermore, the analysis of protection effectiveness revealed that Picea species are well protected within the existing conservation network; however, certain conservation gaps remain. Notably, hotspot regions distributed in the Hengduan Mountains demand focused attention. This study investigated the response patterns of Picea species diversity in China to global warming and environmental heterogeneity under a multi-climate scenario framework. It not only offers insights into the evolutionary mechanisms underlying the distribution patterns of coniferous forests but also provides a scientific foundation for the strategic planning of biodiversity conservation priority areas in the context of climate change.
Poplars are key tree species for shelterbelt construction in China’s Three-North Region but suffer severe damage from the defoliator Hyphantria cunea and stem-borer Anoplophora glabripennis, highlighting the urgent need for insect-resistant germplasm. Here, we evaluated the insect resistance of two hybrid poplar progenies, Populus ‘Shaxin 3’ (PdSPaP_3) and ‘Shaxin 4-1’ (PdSPaP_4), derived from a cross between insect-susceptible Populus alba var. pyramidalis (PaP) and insect-resistant Populus deltoids ‘Shalingyang’ (PdS). For H. cunea, larvae fed on PdSPaP_3 showed a 99.4
Recent climatic trends in the Southern microregion of Nyírség in Hungary indicate an increase in aridity, which threatens the persistence of native woody vegetation over the next 50–100 years. Black locust (Robinia pseudoacacia L.) is gaining ecological and silvicultural importance due to its rapid growth, drought tolerance, and ability to develop and survive in degraded sandy soils. This study evaluated the effects of various organic and inorganic fertilization treatments on the early growth of black locust seedlings and rhizosphere soil properties in a small-plot open-field experiment near Debrecen. Shoot height, basal stem diameter, soil organic carbon (SOC), pH and AL-extractable macro elements (K, P, Ca, and Mg) were monitored over 2.5 years. Low-dose mineral fertilizer, high-dose humic acids, sewage sludge in compost, and wool pellets significantly enhanced growth relative to the control. In contrast, bacterial inoculants showed moderate effects, consistent with slower microbial action. Strong correlations between soil pH, SOC, AL-extractable nutrients—especially Mg—and sapling growth parameters emerged from the second sampling onward. Notably, a positive correlation between soil pH and AL-extractable Ca strengthened over time (1st : r = 0.253, p = 0.63, 2nd : r = 0.311*, p = 0.021; 3rd : r = 0.789**, p < 0.001; 4th : r = 0.874**, p < 0.001). These results highlight the crucial role of soil nutrient availability in the early development of woody plants. Organic amendments, such as sewage sludge compost and wool pellets, offer viable alternatives or supplements to mineral fertilizers, supporting the preservation of soil quality and sustainable nutrient management in reforestation and land reclamation.
The success of tree regeneration following silvicultural interventions depends on its interaction with landscape-scale disturbances. In the mixed Nothofagus forests of northwestern Patagonia (Argentina), this study evaluates how site conditions modulate the recruitment in response to the combined effects of silvicultural management and the mass die-off of Chusquea culeou. We quantified the density, composition, age, height, and mortality of total tree regeneration (diameter at breast height < 10 cm) of Nothofagus dombeyi, N. alpina, and N. obliqua (Nothofagaceae) in managed and unmanaged forests located in West (2200 mm yr− 1 mean precipitation), Middle (1800 mm yr− 1), and East (1400 mm yr− 1) sites. In the West and Middle sites, disturbances acted as compound disturbances, showed higher regeneration density and height in managed compared to unmanaged forest. Segmented regression revealed a regeneration pulse occurring between 2001 and 2017, after C. culeou die-off. In the East site, where C. culeou is naturally sparse, regeneration showed delayed establishment and no mortality. Regeneration of the more light-demanding N. dombeyi and N. obliqua was negatively correlated with C. culeou cover, whereas regeneration of the more shade-tolerant N. alpina declined under high canopy openness. Regarding the density of established regeneration (height > 2 m), the effect of C. culeou on N. dombeyi became positive when canopy openness > 40
Eucalyptus is one of the world’s most widely planted hardwood genera and is increasingly supplying higher-value solid-wood and engineered products. However, wood cell collapse during drying—manifesting as surface waviness, dimensional instability, and internal checks—remains a concern for product and value recovery in many fast-grown taxa. Collapse in Eucalyptus has been studied for over a century, with numerous articles and postgraduate studies describing the collapse mechanisms and industrial pretreatment methods. Yet practically applied and standardised evaluation protocols for cell collapse within tree improvement programs are scarce. This review identifies the mechanisms, measurement approaches, and genetic selection potential for collapse, and outlines operational phenotyping options for breeding programs. Collapse typically initiates above the fibre saturation point (FSP) when capillary tension coincides with peak internal compressive stresses, with evidence indicating that collapse is also governed by the interaction of moisture transport, nanoscale weakening of the cell wall, and anatomical constraints. Across species and sites, density tends to correlate negatively with collapse but is not a reliable sole predictor, while cellulose content and stiffness (MOE) are informative indicators, especially where tension wood is implicated. Increment-core evaluation remains the most practical phenotyping method, although the effects of sample geometry on collapse are not yet fully understood. Technologies such as near-infrared (NIR) spectroscopy enable scalable screening in tree improvement programs. Collapse shows moderate heritability with limited genotype-by-environment interaction in several taxa, indicating that breeding against collapse is feasible, provided phenotyping is robust and comparable across sites. New insights into sap ion effects on permeability/collapse and strong geometry effects highlight the need for standardised test conditions. Process options such as intermittent schedules, reconditioning, and non-capillary dewatering can prevent or facilitate recovery from collapse but are species- and geometry-dependent. Integrating cost-effective, standardised phenotyping with multi-trait selection and genomic tools can materially reduce collapse risk in Eucalyptus breeding while informing drying strategies for value recovery.
Non-destructive testing (NDT) of trees is crucial for the effective management and health assessment of arboreal plantations. Unlike traditional destructive sampling, NDT evaluates the structural integrity and health of trees without damaging their biological functions or aesthetic value. The four-point electrical resistivity (ER) method, alongside electrical resistance tomography (ERT), was applied for the early detection of wood decay and hollows in black afara (Terminalia ivorensis A. Chev.) tropical trees. Fifty standing specimens of black afara trees (T1 to T50) were selected for this study with stem diameters at breast height ranging from 57 to 197 cm. The electrical resistivities of the samples were measured using the four-point ER method. ERT tomograms of four selected trees (T22, T29, T30, and T37) with resistivity anomalies, suggesting internal defects, were generated to validate the ER measurements. The influence of internal defects on the ER of healthy specimens was experimentally examined under controlled conditions. Field data showed a consistent increase in ER from sapwood to heartwood, varying from 75 Ωm to 520 Ωm, in the selected healthy trees. Conversely, unhealthy specimens exhibited irregular resistivity patterns, with decayed trees displaying resistivity values four times lower than those of healthy trees and hollowed trees possessing resistivity values three times higher than those of sound trees. ERT tomograms confirmed the results of the four-point ER technique. The outcome of this research would facilitate efficient management practices and risk evaluation of tree plantations in both forest and urban areas.
Drought and salinity are critical abiotic factors influencing plant emergence, growth, and reproduction, with important implications for domestication and conservation. Although the baobab tree (Adansonia digitata L.) is widely recognized for its tolerance to dry conditions, the relative importance of drought and salinity during seed germination remains insufficiently documented. This study assessed the effects of drought and salinity stress on the germination of baobab seeds from three provenances in Senegal, with particular attention to provenance-specific responses. Under laboratory conditions and using a randomized complete block design, seeds were exposed to three levels of drought stress (0, − 4, and − 8 bars) and three salinity levels (0, 20, and 40 mMol NaCl). Germinated seeds were recorded daily for 28 days. Germination traits, including germination rate, time spread, and mean germination time, were analyzed using log-logistic distributions and generalized linear models. Results showed that drought stress significantly reduced germination rates across all provenances, whereas salinity exerted a comparatively moderate effect, mainly delaying germination without reducing final germination success. No statistically significant interaction between drought and salinity was detected, indicating that these stressors act independently during germination. Provenance-related differences further highlighted the role of local adaptation in shaping germination responses under water-limited conditions. Overall, these findings demonstrated that drought is the primary ecological filter affecting baobab seed germination, while salinity may play a secondary role at early developmental stages. This information is essential for conservation, restoration, and regeneration strategies in dryland ecosystems increasingly affected by climate change.
We welcome the opportunity to respond to Wasowicz et al.‘s (2026) critique of our recent findings on biomass accumulation in Pinus contorta (Riege et al., 2025). We share the fundamental conclusion that a balanced assessment, integrating both potential benefits and ecological effects, is necessary when considering the use of lodgepole pine in forestry, land rehabilitation and carbon sequestration. However, we contend that the response by Wasowicz et al. presents an unbalanced perspective, focusing disproportionately on perceived risks and utilizing terminology that obscures the complexity of ecosystem change and ecosystem dynamics. We contend that Riege et al. reports a more objective, evidence-based assessment of the effects and potential uses of lodgepole pine colonization.
Species with a wide geographic distribution constitute an ideal model system for characterizing the adaptation of secondary chemistry to local climate and testing the generality of hypotheses about how investments in secondary chemistry scale with relative carbon and nutrient availability. We studied needle carbon (CM), nitrogen (NM) and terpenoid contents per dry mass in Pinus sylvestris collected across a broad geographical (38° to 59° N, latitudes 18° to 29° E; Estonia, Sweden, Romania, Turkey) and altitudinal (26-1980) range. In the Turkish samples, a low CM value corresponded to the lowest levels of mono- and sesquiterpenoids. In addition, the Turkish pine needles lacked diterpenoids. The monoterpenoid profiles revealed the presence of two distinct pine chemotypes: the Turkish pines were characterized as ‘(−)-α-pinene pines’, while the Estonian, Swedish, and Romanian samples were identified as ‘(+)-α-pinene - (+)-3-carene pines’. Overall, Northern pine populations were characterized by higher foliage C and terpenoid contents and greater terpenoid diversity. In addition, the direct correlations of foliage C and terpenoid contents were observed for ‘(+)-α-pinene - (+)-3-carene pines’. Our study highlights major variations in composition and content of Scots pine needle terpenoids among geographically distinct populations.
Wild fruit tree species are increasingly recognized for their ecological, genetic, and practical value, particularly in the context of biodiversity conservation and reforestation. Among them, European wild pear (Pyrus pyraster (L.) Burgsd.) and almond-leaved pear (P. spinosa Forssk.) offer promising potential, yet their reproductive biology remains insufficiently understood. This study examines how fruit and seed morphology, alongside fruit chemical composition and environmental and geographical variables, influence germination success and early seedling development. Specifically, we aimed to determine whether these traits can reliably differentiate the species and detect intraspecific variation across provenances. In order to explore these distinctions at both interspecific and intrapopulation levels, fruits were sampled from ten natural populations. We assessed their morphological and chemical characteristics, and conducted a two-year nursery trial to examine germination dynamics and seedling performance. Germination was consistently higher in Pyrus spinosa, while P. pyraster produced more vigorous seedlings. Seed mass showed a strong positive correlation with seedling height and collar diameter, but did not predict germination rate. Fruit stalk length also correlated strongly with seed mass and seedling growth, suggesting indirect genetic and physiological linkages. Significant intraspecific variability was detected in both species, mediated by geographic and ecological structuring of the populations. Indeed, full RDA model revealed a strong joint effect of environmental and geographic predictors on studied traits in both species. These findings highlight how both inherited traits and provenance shape early developmental success, offering practical implications for restoration, nursery propagation, and conservation amid shifting environmental conditions.
Eucalyptus urophylla is widely used in forestry plantations in Mexico. However, its utilization could be optimized if the anatomical characteristics of its wood were better understood. The objective of this research was to evaluate the suitability of its wood for the manufacture of medium-density fiberboard (MDF), sawmilling industry, making pulp for paper, and producing charcoal. Seventy-eight trees of 26 clonal lines were analyzed, measuring diameter at breast height, total height, basic wood density, and fiber morphology (length, diameter, lumen width, and cell wall thickness) in the pith and sapwood at four tree heights. From these variables, indices were calculated to evaluate wood quality. Basic wood density ranged from 435 to 511 kg m⁻3 among clonal lines, with higher values in sapwood (440–542 kg m⁻3) than in pith. Fibers were short, with lengths of 955–1190 µm, diameters of 17.0–20.7 µm, lumen widths of 8.6 to 11.6 µm, and cell wall thicknesses of 3.9–5.0 µm. Wood quality indices showed flexibility coefficients of 51–57
