Pine Forest Research Articles

Early response of soil bacterial communities to soil burn severity in pine and shrub vegetation after wildfire in temperate-humid climate.

Prescribed and natural fire help restore fire-adapted conditions in an Eastern Sierra Jeffrey pine forest

Post-fire seedling recruitment across a range of stand age in bark-beetle impacted lodgepole pine forests: Informing reforestation needs

Effects of seasonal prescribed burns on understory vegetation in a Mediterranean mixed pine forest

Detecting change in belowground carbon stocks: Statistical feasibility and future opportunities from loblolly pine forests

Tree-architectural response to restoration thinning pattern in post-fire Aleppo pine forests – A modular view of tree plasticity

The research assessed the current state of the Mongolian pine forests and revealed the features of their restoration after logging and fires. It was found that the number of Pinus sylvestris L. undergrowth in the cuttings is 15–18 times less than under the canopy of undisturbed stands. Noticeable changes in the cuttings are also observed in the ground cover. So, 5–8 years after harvesting the stand, part of the taiga forest species of the grass-shrub layer disappears in the cuttings and steppe and forest-meadow plant species appear. Changed environmental conditions, intensively developing ground cover and frequently recurring grass-roots fires in cuttings prevent the emergence of seedlings and the formation of undergrowth of the main forest-forming species. The pyrogenic factor is the main anthropogenic factor preventing the natural restoration of forests after their disturbance. Dendrochronological analysis of pine wood samples indicates that fires in the studied area occurred in the past with an average frequency of about 14 years. In the last 20–25 years, during the period of uncontrolled exploitation of forests, forest communities have been exposed to fires once every 7–9 years, and in some tracts much more often. The Scots pine is successfully renewed on burning grounds. The amount of viable undergrowth ranges from 3 to 10 thousand, pcs./ ha. In case of repeated fires in these areas, pine undergrowth and living ground cover are damaged or completely destroyed, shoots in the amount of 4–5 thousand pcs/ha or more appear in places of burnt litter. The age of the undergrowth of the scots pine in the burning is determined, for the most part, by the prescription of the last fire. Haphazard logging of stands and forest fires are most often powerful exogenous factors affecting the formation and development of pine forests in Mongolia.

Soil quality assessment is crucial for monitoring and restoring soil functions and ensuring the soil’s ability to support sustainable production. The present study aimed to assess the soil quality of a pine-forested region in the Engiz basin of Samsun province, Türkiye. We applied the minimum dataset (MDS) and total dataset (TDS) indicator selection method and linear and non-linear scoring approach and integrated with the Fuzzy-analytical hierarchical approach (F-AHP) to evaluate the soil quality of the region. Principal component analysis (PCA) reduced the initial set of 28 soil quality indicators to 12 most representative indicators, namely, sand, silt, structural stability index, organic matter, calcium, potassium, calcium carbonate, copper, manganese, soil respiration, and carbon-to-nitrogen ratio. Regardless of scoring techniques, soil quality obtained based on MDS adequately represented the TDS approach, with a significant correlation coefficient (r > 0.85, P < 0.01) and strong linear association (R² > 0.64). Non-linear (NL) models consistently performed better than linear models, and TDS_NL (sensitivity index (SI): 2.29) emerged as the best model in representing the soil quality of the study area, followed by MDS_NL (SI: 2.23). Repeated 10-fold cross-validation (with 3 random repeats) results showed that random forest models accurately predicted soil quality across all soil types (R² > 0.75), emphasizing their utility in soil quality evaluation studies. Both the observed and predicted soil quality maps, regardless of the indicator selection or scoring method, showed a consistent spatial trend, with lower soil quality mainly concentrated in the southern and southwestern areas, moderate soil quality in the central area, and higher soil quality in the north and northeastern regions. The results of our study approach are expected to offer valuable insights into sustainable forest soil and forest use management in forest-dominated landscapes in similar ecological and climatic conditions.

BackgroundChronic musculoskeletal pain is a prevalent health concern among older workers affecting their quality of life and overall well-being.ObjectiveThis study aimed to assess the combined effects of a short-term intervention involving sea mud application with local heat and complex exercises in a sea pine forest (SPF) setting, compared to a physical modalities group receiving regular physical modality (PM) intervention with stretching exercises.MethodsThe study focused on assessing the impact on pain reduction, improvement in health-related quality of life (HRQoL) measured using the EQ-5D, and reduction in stress scores among older adults dealing with chronic musculoskeletal pain. A total of 24 participants were randomly assigned to either the thalassotherapy or the physical modalities group.ResultsThe results indicated a significant reduction in pain over time in both groups, suggesting that both interventions contributed to pain reduction. Although both interventions led to improvements in HRQoL and stress reduction, a significant difference in HRQoL improvement was observed between the thalassotherapy and physical modalities groups.ConclusionsThese findings highlight the potential benefits of thalassotherapy-based interventions in the management of chronic musculoskeletal pain in older workers.

Bursaphelenchus xylophilus, the pine wood nematode (PWN), is responsible for causing pine wilt disease (PWD), leading to significant ecological and economic damage in pine forests. Endophytes are well-known producers of bioactive secondary metabolites, offering potential for environmentally friendly control agents. This study focused on identifying and evaluating nematicidal compounds from pine tree endophytes active against PWN. A total of 30 endophytes isolated from Korean pine trees were screened for their nematicidal activity and identified as novel nematicidal agents against PWN. Among them, Streptomyces sp. AN140557 showed the highest nematicidal activity. The active compound, murayaquinone, was isolated by nematicidal activity-guided fractionation, and it showed significant dose-dependent nematicidal activity and egg-hatching inhibition against PWN at 3.12, 6.25, 12.5, and 25 μM, respectively. Exposure to 25 μM murayaquinone led to 100% mortality of PWN. Additionally, murayaquinone strongly suppressed egg hatching. In addition, the assessment of the activity against the other four plant parasitic nematodes (Meloidogyne incognita, Ditylenchus destructor, Aphelenchoides subtenuis, and Heterodera trifolii) showed that it has a broad nematicidal spectrum. The greenhouse experiments suggested that the murayaquinone efficiently inhibited the development of PWD in 5-year-old Pinus thunbergii plants. Our results highlight the nematicidal potential of the murayaquinone derived from Streptomyces sp. AN140557. This is the first report of murayaquinone exhibiting biocontrol potential against PWN, suggesting its possibility as a PWD control agent. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Pine Wilt Disease (PWD) is one of the most destructive forest infectious diseases affecting pine trees. Although infected pine trees exhibit subtle physiological changes in the early stages, it is difficult to detect these changes in a timely manner using spectral reflectance alone. Consequently, accurately identifying early-infected pine forests remains a major challenge for disease monitoring. This study explored the physiological and biochemical response mechanisms of PWD at different infection stages and confirmed the application potential of chlorophyll fluorescence combined with sensitive spectral bands for early diagnosis. The results indicate that in the early stage of PWD, minimal fluorescence (Fo) significantly decreases, while non-photochemical quenching (NPQ) increases. These parameters can serve as sensitive indicators for early disease diagnosis. Compared with using only sensitive bands, combining chlorophyll fluorescence parameters with the least absolute shrinkage and selection operator (LASSO) selected bands significantly improved the K-nearest neighbors (KNN) model's classification performance, resulting in a 10% increase in overall accuracy and a 29% increase in early-stage precision. The LASSO-selected bands combined with chlorophyll fluorescence parameters demonstrated optimal performance in the support vector machine (SVM) model, achieved an overall accuracy of up to 96%, with an early-stage precision at 91%. This study determined key chlorophyll fluorescence parameters and diagnostic spectral bands for early detection, and proposed a novel strategy of combining sensitive bands with chlorophyll fluorescence for early identification, effectively overcoming the technical bottleneck in early-stage detection of traditional single-modality data. © 2025 Society of Chemical Industry.

Fire exclusion and encroachment by shade-tolerant, often fire-sensitive and/or opportunistic tree species threaten dominance of fire-dependent, open pine (Pinus spp.) forests throughout the southeastern U.S., largely due to encroaching species’ traits that reduce flammability. To better understand fuels within fire-dependent pine ecosystems undergoing encroachment, we measured loads of varying fuel types (herbaceous, shrub, leaf litter, duff, woody debris) in 96 plots with little to no recent management across a pine dominance gradient at five sites in east-central Alabama, USA in 2022. Across pine-, mixedwoods-, and hardwood-dominated plots, we found similar mean basal area (36.5 – 40.2 m2 ha-1), canopy cover (&gt; 90%), and total fuel loads (20 – 22 Mg ha-1). Encroaching species had lower basal area and density in pine-dominated plots, but their mean leaf litter fuel loads were similar among plot types (0.9 – 1.5 Mg ha-1). However, encroaching species’ relative contribution to leaf litter fuelbeds declined with increasing pine basal area due to a significant linear increase in pine leaf litter fuel loads. Overall, leaf litter was the only fuel to co-vary with pine dominance, suggesting fuel homogenization with encroachment. Future studies experimentally manipulating leaf litter fuels could determine thresholds where encroaching species’ fire-suppressing leaf litter negates pine’s fire-promoting effects.

ABSTRACT Resource Use Efficiency (RUE) serves as a critical indicator of forest ecosystem functionality, reflecting the efficiency of forests in utilizing light, water, and carbon for biomass production. This study investigates the spatiotemporal dynamics of RUE across 14 major Indian forest types from 2014 to 2023 by integrating Light Use Efficiency (LUE), Water Use Efficiency (WUE), and Carbon Use Efficiency (CUE) derived from MODIS satellite products. Using an eco-hydrogeological framework coupled with Random Forest modeling, the study evaluates the influence of climatic, topographic, and hydrological variables on forest productivity. Results reveal considerable spatial heterogeneity and temporal variation in RUE, with the highest efficiencies observed in wet evergreen and semi-evergreen forests and the lowest in dry deciduous and thorn forests. WUE demonstrated substantial variability across forest types and years, particularly impacted by the 2016 drought. CUE was strongly influenced by elevation (R2 = 0.82), and slope emerged as a limiting factor in drier ecosystems. The study highlights that subtropical pine and montane forests exhibit resilience and adaptive efficiency, while arid-zone forests remain vulnerable to climatic stressors. These findings provide actionable insights for site-specific sustainable forest management and climate resilience planning in India’s diverse forest landscapes.

Ectomycorrhizal (ECM) fungi, as major carbon (C) sinks, are critical to plant-soil C cycling. Although C allocation between plants and ECM fungi has been studied extensively, C transport time, the key component of C cycling, remains limited understanding. To address this, we collected new needles (weekly), roots (monthly) and ECM fungi (sporocarps and hyphae) of three genera (Cortinarius, Lactarius, and Russula) in a boreal Scots pines (Pinus sylvestris L.) forest in Finland. We analyzed the natural abundance C isotope composition (δ13C) of sugars or organic matter and observed a strong vapor pressure deficit (VPD) signal in needle sucrose δ13C. We coupled VPD with the δ13C of water-soluble carbohydrates (WSC, δ13CWSC) in sporocarps to determine C transport times. We found Lactarius and Russula, with short hydrophilic mycelia that enable efficient solutes uptake, had transport times of 6-13 days, peaking at 8 days. In contrast, Cortinarius, with extensive hydrophobic mycelia that limit water and solute movement, showed slower transport times of around 18 days. The different transport time is likely attributable to a more extensive mycelial network and potentially higher C demand in Cortinarius compared to Lactarius and Russula. The three genera also showed a marginally significant effect on δ13CWSC in sporocarps (P = 0.06, ANCOVA). This study highlights that natural abundance δ13C analysis offers a practical alternative to pulse-labeling for estimating C transport time in complex plant-fungal interactions where the latter is difficult to implement. The longer transport time of Cortinarius compared to Lactarius and Russula is critical during periods of reduced photosynthesis, when limited C supply makes fast allocation essential for sustaining belowground metabolism. Slower transport may weaken its role and reduce forest productivity in boreal forests with short growing seasons. As global warming favors Cortinarius, its longer C transport time may impede soil C cycling and nutrient turnover.

Abstract. The regulatory role of plant carbohydrate status and root exudation on soil CO2 efflux has been demonstrated, yet the underlying mechanisms, particularly through root respiration, remain largely theoretical. In this study, we analyzed the cospectral variation of soil autotrophic (Ra) and heterotrophic (Rh) respiration components with key physiological and environmental factors, including gross primary productivity (GPP), photosynthetically active radiations (PAR), soil temperature (Ts) and volumetric water content (VWC), to evaluate their relative contributions in a subtropical mature shortleaf pine forest in the southern United States. The findings reveal a strong diurnal relationship between Rh and both GPP and PAR, in contrast to the weaker and more variable associations observed with Ra. This suggests that substrate availability was a key limitation of Rh on a diurnal basis, and that recently assimilated carbohydrates were directly discharged into the soil via root and mycorrhizal exudates. The consistent 2–4 h time lag between Rh relative to GPP is consistent with the propagation rate of phloem pressure-concentration waves. While a diurnal peak in Rh-Ts covariance was also detected, the time lag of Rh in relation to Ts varied between positive and negative values, precluding this from being a causal relationship. Ra had a similarly strong cospectral peak with GPP as Rh, but with inconsistent lag, likely because of carbon availability from local starch reserves.

Archaeorhizomycetes is a class of globally widespread soil-dwelling fungi, originally proposed to be associated with plant roots, but their ecology and nutritional mode are not clearly defined. To increase the knowledge about Archaeorhizomycetes' ecology and biogeography, we investigate how they are distributed along major environmental gradients, as well as different soil compartments. To assess their abundance and diversity, we use both short- and long-read metabarcoding with class-specific primers for the long reads. The short-read sequences revealed that Archaeorhizomycetes is proportionally abundant and a dominant fungal class in alpine vegetation types, as well as boreal spruce and pine forests. The long-read sequences revealed high phylogenetic diversity of Archaeorhizomycetes, with 120 OTUs grouping into 13 clades with potentially differing ecologies and biogeographic distributions. Vegetation types and climate primarily structure the Archaeorhizomycetes community, while community composition was similar in litter, soil, and roots. However, Archaeorhizomycetes were significantly more abundant in soil and plant roots than litter, supporting the idea that Archaeorhizomycetes depend on the presence of plant roots. Our study illustrates that targeted group-specific amplification coupled with long-read sequencing is a powerful approach for exploring the diversity and ecology of specific fungal groups.

This case study evaluates an innovative methodological approach that integrates soil chemical analysis (including pH, organic matter, total nitrogen, and grain size composition) with tree-ring δ¹³C measurements to assess long-term forest soil acidification processes. The study was conducted in Nang Pine Forest, located in Phong Nha - Ke Bang National Park, central Vietnam. Soil grain size analysis reveals a predominance of fine particles over coarse particles. There is a difference in the distribution of soil components at depth. The results indicate that the soil tends to be acidic, with a low pH that increases in depth, while it contrasts with the total nitrogen content. This acidity may result from natural processes and human activities, such as the release of acid rain. The findings also highlight the influence of topography and climate on soil properties. Furthermore, soil pH was negatively correlated with δ¹³C in pine tree rings in central Vietnam. This relationship could serve as a valuable tool for assessing past soil degradation processes, reconstructing historical environmental changes, or analyzing the connection between δ¹³C content in pine tree rings and climate change in the region. The results suggest that mitigating soil acidity and supporting healthier tree growth are essential to improve soil pH through the planting of suitable tree species and effective vegetation management in the study area. This study's integrated approach provides both current assessments and historical reconstructions, establishing a replicable and cost-effective methodological framework applicable to other tropical forest ecosystems under acidification stress. This framework provides valuable insights to advance both research and conservation management.

In the Central Himalayas' tropical and sub-alpine regions, a study was conducted to analyze the impact of soil on natural vegetation. The study took place in the Dolakha and Sindhupalchowk districts and involved ecological sampling in six different forest types at various elevations. The random sampling method with circular plots of different radius viz. 10m, 2.5m &amp; 1m to sample trees, shrubs, and herbs were utilized respectively. The study examined various soil properties, including texture, pH, water holding capacity, sticky point, water rising and percolation. The analysis revealed that the Mixed Broadleaf Forest soil had the highest water holding capacity (86.97%), while the Sal Forest in Sukute had the lowest. In terms of soil pH, the Rhododendron-dominated Forest had the least acidic soil with a pH of 6.45, whereas the Pine Forest and Taxus wallichiana-dominated forest had more acidic soil with a pH of 5.6. The study also found that the sticky point of the Mixed Broadleaf Forest soil was 47.46%, indicating it was much drier, while the Sal Forest in Sukute soil was very wet with a sticky point of 22.73%. The results of this study suggest that vegetation patterns are influenced by a combination of topographic, edaphic factors and change in climatic conditions.

Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) are among the most valuable tree species in the Lithuanian forests. Pure stands, which comprise approximately one-quarter of Lithuania’s forest area, provide an important framework for studying tree responses to thinning and susceptibility to species-specific diseases and damage. This study investigated stem health and quality in two experimental Scots pine stands (32 and 39 years old) and four experimental Norway spruce stands (36–43 years old) to assess the influence of the initial stand density and thinning intensity. Each stand consisted of five plots with different initial densities and was subjected to varying thinning regimes from stand establishment. Tree locations were mapped using the pseudolite-based positioning system TerraHärp, and local tree density was calculated. Stem health and damage were assessed using ICP-Forests methodology. Our results showed that across initial densities of 1000–4400 trees ha−1, tree dimensions (diameter and height) were similar, regardless of thinning intensity. The highest levels of stem damage and competition-induced mortality occurred in the densest, unthinned stands, with deer browsing and scraping from fallen trees being the most common damage agents. In contrast, thinned stands exhibited a higher incidence of stem rot (Heterobasidion annosum (Fr.) Bref.), particularly for Norway spruce. Finally, stand density alone did not consistently explain the patterns of tree mortality in either the pine or spruce stands. These findings suggest that cultivating Scots pine and Norway spruce at lower initial densities with minimal thinning may reduce the damage and losses caused by fungal infection. Finally, novel techniques, such as the pseudolite-based positioning system for geolocating trees and drone imaging for assessing tree health, have proven valuable in facilitating field surveys.

ABSTRACT Forest fires have the potential to greatly impact both flora and fauna and are therefore one of the key regulators of ecosystem sustainability. The primary aim of this research was to assess the impact of forest fires on plant nutrients and weight in Scots pine (Pinus sylvestris) forests in the Northeastern Türkiye. Plant samples were collected from designated burned and control plots in the research region in May and August season. The weight of the plants was measured both after drying in an oven and after air-drying. Subsequently, the plant samples were analyzed to determine the levels of Ca, Fe, Mg, Na, K, C, H, N, and S nutrients. The results revealed that the levels of all nutrients were greater in the burned area compared to the control plots. Furthermore, Ca, Fe, Mg, H, and N content exhibited statistically significant disparities when compared to the control plots. The N% content in the burned area during the month of May was 5.57, while in the control plot it was 4.97. This study also demonstrated that prescribed fire may effectively enhance plant nutrients contents and a tool for sustainable use of forest resources.