Search Results (16)

Abies nephrolepis and Picea jezoensis are native Pinaceae trees distributed in high mountainous regions of Northeast Asia (typically above ~1000 m a.s.l. on the Korean peninsula, northeastern China, Sakhalin, and the Russian Far East) and southern boreal forests, vulnerable to climate change and human disturbances, necessitating accurate habitat identification for effective conservation. While protected areas (PAs) are essential, merely expanding existing ones often fail to protect populations under human pressure and climate change. Using species distribution models with current and projected climate data, we mapped potential habitats across Northeast Asia. Spatial clustering analyses integrated with PA and land cover data helped identify optimal sites and priorities for new conservation areas. Ensemble species distribution models indicated extensive suitable habitats, especially in southern Sikhote-Alin, influenced by maritime-continental climates. Specific climate variables strongly affected habitat suitability for both species. The Kamchatka peninsula consistently emerged as an optimal habitat under future climate scenarios. Our study highlights essential environmental characteristics shaping the habitats of these species, reinforcing the importance of strategically enhancing existing PAs, and establishing new ones. These insights inform proactive conservation strategies for current and future challenges, by focusing on climate refugia and future habitat stability. Full article

Specialized research on large trees in Northeast China is rare. To strengthen the understanding of local large trees, a survey of 4055 tree individuals from 75 plots in southeastern Jilin Province was conducted. The individual number and species composition of large trees in the community, as well as large individual standards in diameter at breast height (DBH) and population structures of typical tree species, were analyzed. By setting a DBH ≥ 50 cm as the threshold, 155 individuals across all the recorded trees were determined as large trees in the community, and 32.9% (51/155) of them were national second-class protected plant species in China. By setting the top 5% in DBH of a certain tree species as the threshold of large individuals of that tree species, the large individual criteria of six typical tree species were determined. The proportion of basal area of large trees to all trees was 30.4%, and the mean proportion of basal area of large individuals across the six typical tree species was 23.9% (±4.0%). As for the population characteristics, Abies nephrolepis and Picea jezoensis had large population sizes but relatively thin individuals, Tilia amurensis and Pinus koraiensis had small population sizes but relatively thick individuals, while Betula costata and Larix olgensis had medium population sizes and medium-sized individuals. Full article

Ectomycorrhizal (EcM) fungi are critical mediators of forest succession, yet the relative contributions of stochastic (neutral) and deterministic (niche-based) processes in shaping their communities are still poorly understood. We investigated the assembly processes in root EcM fungal communities across juvenile and adult coniferous (Abies nephrolepis, Picea jezoensis, and Pinus koraiensis) and broadleaf (Acer mono, Betula platyphylla, and Quercus mongolica) tree species in northeastern China. Employing neutral theory modeling, alpha and beta diversity metrics, and a random forest analysis, we identified patterns of EcM fungal community assembly and the specific taxa associated with developmental stages of various hosts. Neutral processes contributed to the variation in fungal communities, with adult trees showing a higher explanation power (more than 33% of variation) compared to juvenile trees (less than 7% of variation), reflecting a successional shift in assembly mechanisms. Dispersal dynamics was pronounced in juveniles but diminished with host age. Additionally, alpha diversity increased with host age and was slightly moderated by host identity, while beta diversity reflected stronger effects of host age (PERMANOVA R² = 0.057) than host identity (R² = 0.033). Host age and identity further structured communities, with distinct taxa varying between juvenile vs. adult, and coniferous vs. broadleaf hosts. Our results demonstrate that host maturity drives a transition from deterministic to stochastic assembly, modulated by tree species identity, improving our understanding of plant–fungal dynamics during forest succession. Full article

Herein, we explored the ecologic niches of generalist and specialist species within the subalpine vegetation zone, a habitat of Abies sp. distributed throughout South Korea and China. We included Abies sp. habitats in inland areas of South Korea and parts of the Manchurian region of China. Rhododendron schlippenbachii Maxim., Acer pseudosieboldianum (Pax) Kom., Picea jezoensis (Siebold & Zucc.) Carrière, Betula ermanii Cham., Acer komarovii Pojark., Pinus koraiensis Siebold & Zucc., Betula davurica Pall., Betula costata Trautv., Quercus mongolica Fisch. ex Ledeb, and Sorbus commixta Hedl. were selected as generalist species. Betula chinensis Maxim., Betula platyphylla var. japonica (Miq.) H. Hara, Euonymus pauciflorus Maxim., Salix maximowiczii Kom., Cornus walteri F.T. Wangerin, Carpinus laxiflora (Siebold & Zucc.) Blume, Populus davidiana Dode, Philadelphus tenuifolius Rupr. & Maxim., Rhododendron brachycarpum D. Don ex G. Don, and Larix olgensis var. koreana (Nakai) Nakai were selected as specialist species. NMS ordination analysis showed that specialist, generalist, and other plant species distribution correlated with basal area at breast height, stand density, and species diversity index. Generalist species could be grouped based on Quercus sp., Betula sp., and Acer sp. niche spaces. Specialist species shared ecological niches with plant species found in the limestone zone, sedimentary rock zone, and valley area. Full article

To describe the characteristics and dynamics of the Picea jezoensis (PJ) community, a survey of 48 forest plots containing PJ trees was conducted in Northeast China. Methods of community grouping, analysis of variance, and linear regression, and indicators of relative basal area (RBA, reflecting the dominance degree of species in the community) and temporary stability (TS, reflecting the stability of forest plant community), were employed. The objectives were to describe the dominant species composition and environment of the PJ community and to quantify the changes in PJ’s dominance status. Communities with PJ trees were divided into four groups: PJ as the first dominant species; PJ as the second dominant species; PJ being co-dominant but ranked third or lower; and PJ as a non-dominant species. Among them, the PJ community (i.e., where PJ is the first dominant species) occupied sites at the highest elevation with a mean value of 1408 m, on gentle slopes ≤ 10°, where the tree species occurring with PJ mainly included Betula costata and Abies nephrolepis. A linear relationship was found between the TS and RBA. The threshold for PJ shifting between being the first and second dominant species in the community was RBA = 0.387. This study provides a scientific basis for judging the attributes and status of PJ community and the protection and restoration of PJ forests. These findings also provide comparable information for ecological research and conservation of PJ forests in other areas. Full article

Picea jezoensis (Siebold & Zucc.) Carrière forests are distributed in Korea and China and are crucial for phytogeographical research. Implementing conservation policies encompassing multiple species is necessary to conserve endangered species, particularly monitoring coexisting species and their interactions within an ecological network. Here, we identified plants within P. jezoensis forests in East Asia as generalist species to contribute foundational data for biodiversity conservation. We examined 91 standardized sites through the Braun-Blanquet method, while generalist indices were calculated using Levin’s method. The top 5% of generalists in the P. jezoensis forests were Acer komarovii (0.7409), Betula ermanii (0.7214), Asarum sieboldii (0.7002), Lepisorus ussuriensis (0.6977), Acer pseudosieboldianum (0.6915), Tripterygium regelii (0.6876), Thelypteris phegopteris (0.6771), Dryopteris expansa (0.6745), Sorbus commixta (0.6642), and Rhododendron schlippenbachii (0.6625). Correlation analysis between ecological factors and generalist species revealed that the coverage of Abies spp., Acer spp., and Rhododendron spp. and the species diversity index were influenced by altitude. Convex hull analysis revealed that pteridophytes and broad-leaved plants regenerated through stump sprouts occupy ecological niche spaces, indicating diverse habitats within P. jezoensis forests. This study highlights the importance of the simultaneous monitoring of multiple species to conserve ecosystem health and offers broader implications for ecological understanding. Full article

Climate change significantly influences forest communities, even leading to their complete transformation. In the case of boreal and temperate forests, it is particularly important to understand how dominant tree species respond to climate changes, as they largely determine the structure of forest communities. In this study, we focus on the Jezo spruce (Picea jezoensis (Siebold & Zucc.) Carriere), which is widespread in Northeast Asia. We investigated the climate parameters affecting the radial growth of Jezo spruce and how their influence changes along environmental gradients. For the research, 500 tree cores were collected from 10 sites located at elevations ranging from 460 to 1060 m. We found a negative response of Jezo spruce radial growth to precipitation in July–August and SPEI in July of the current year, maximum temperatures in July–August and November of the previous year. On the other hand, we observed a positive response to the maximum temperatures in January of the current year. Furthermore, we established that the influence of these climatic parameters depends on local topography, with 74.3% of the variance in response values being explained by elevation, slope, and the Topographic Position Index. The results obtained demonstrate that the reaction of Jezo spruce radial growth to climate change will be complex, and the balance between negative and positive effects will depend significantly on local topography. Full article

Adequate seed provenance is an important guarantee for the restoration of the mixed Korean pine (Pinus koraiensis) and broadleaf forest (MKPBF). However, the commercial harvest exclusion in natural forests has led to a sharp decline in economic income from timber. Given the economic value of Korean pine seeds, predatory seed harvesting (PSH) has become increasingly serious in the past 20 years and has significantly reduced the seed and seedling bank, which might seriously threaten the restoration and sustainable management of the MKPBF. How the historical PSH has affected the future of the MKPBF is unclear at the landscape scale. In this study, we quantified the effects of seed harvesting at the landscape scale by a forest landscape model LANDIS PRO, and then assessed the legacy effects of the historical PSH on the composition and structure of the MKPBF in the Xiaoxing’an Mountains, Northeast China. Our results showed that the historical PSH decreased the Korean pine basal area of all age cohorts, with an average decrease of 0.06 to 0.19 m² ha⁻¹ but insignificantly altered the age structure diversity of Korean pine throughout the simulation. Our results indicated that the historical PSH remarkably decreased the dominance of Korean pine by 11.1%, but significantly increased the dominance of spruce (Picea koraiensis and Picea jezoensis) and fir (Abies nephrolepis) by 3.8% and 4.5%, respectively, and had an insignificant effect on the other tree species over the simulation. We found that the historical PSH evidently changed the succession trajectories of the disturbed stands, which would result in the transition from the succession pattern dominated by Korean pine to that dominated by spruce and fir. The historical PSH decreased the importance value of Korean pine by 12.2% on average but increased it by 5.1% and 6.0% for spruce and fir, respectively, and resulted in an average 33.2% increase in the dissimilarity index compared with the initial state during the whole simulation period. Future forest management should strictly limit the intensity and rotation of seed harvesting to protect the seed provenance of Korean pine and consider how to ensure the recovery and sustainable management of the MKPBF through direct seeding or seedling planting. Full article

Spruce taiga forests in Northeast Asia are of great economic and conservation importance. Continued climate warming may cause profound changes in their distribution. We use prognostic and retrospective species distribution models based on the Random Forest machine learning method to estimate the potential range change of the dominant taiga conifer Jezo spruce (Picea jezoensis (Siebold & Zucc.) Carrière) for the year 2070 climate warming scenarios and for past climate epochs–the Last Glacial Maximum (LGM) (~21,000 years before present) and the mid-Holocene Climatic Optimum (MHO) (~7000 years before the present) using the MIROC-ESM and CCSM4 climate models. The current suitable climatic conditions for P. jezoensis are estimated to be 500,000 km². Both climatic models show similar trends in past and future ranges but provide different quantitative areal estimates. During the LGM, the main part of the species range was located much further south than today at 35–45° N. Projected climate warming will cause a greater change in the distributional range of P. jezoensis than has occurred since the MHO. Overlapping climatic ranges at different times show that the Changbai Mountains, the central parts of the Japanese Alps, Hokkaido, and the Sikhote-Alin Mountains will remain suitable refugia for Jezo spruce until 2070. The establishment of artificial forest stands of P. jezoensis and intraspecific taxa in the future climate-acceptable regions may be important for the preservation of genetic diversity. Full article

Predicting future stand conditions based on tree age is crucial for natural forest management. The objective of this study was to model and predict the future age distribution of Picea jezoensis, Abies sachalinensis, and broad-leaved trees by assessing the past and current survival trends of preserved stands located at the University of Tokyo Hokkaido Forests (UTHF), Furano, Japan. This study analyzed forest census data of four plots (927 trees) in a preserved permanent area over 30 years (1989–2019). Individual tree-ring data were identified using a resistograph to determine the current tree age of the targeted trees. The predicted age distributions nearly converged to the shape of the survival probability curve. Among the scenario predictions, the multimodal age class distribution of P. jezoensis was predominant among all prediction scenarios. In contrast, the exponential shape of A sachalinensis and the age distribution of broad-leaved trees in the 100% scenario gradually shifted to the multimodal shape at the 50% scenario prediction. The species composition of conifer and broad-leaved trees and their age distribution would reach stable states in the long run by reaching a climax state. Therefore, it is theoretically possible to maintain stands under the pre-climax stage by allowing high growth rates at the stand level. The suggested age class-prediction of living and dead trees can improve the natural forest management of UTHF. Full article

Genome-wide single nucleotide polymorphism (SNP) markers were obtained by genotyping-by-sequencing (GBS) technology to study the genetic relationships, population structure, gene flow and selective sweeps during species differentiation of Picea wilsonii, P. neoveitchii and P. likiangensis from a genome-wide perspective. We used P. jezoensis and P. pungens as outgroups, and three evolutionary branches were obtained: P. likiangensis was located on one branch, two P. wilsonii populations were grouped onto a second branch, and two P. neoveitchii populations were grouped onto a third branch. The relationship of P. wilsonii with P. likiangensis was closer than that with P. neoveitchii. ABBA-BABA analysis revealed that the gene flow between P. neoveitchii and P. wilsonii was greater than that between P. neoveitchii and P. likiangensis. Compared with the background population of P. neoveitchii, the genes that were selected in the P. wilsonii population were mainly related to plant stress resistance, stomatal regulation, plant morphology and flowering. The genes selected in the P. likiangensis population were mainly related to plant stress resistance, leaf morphology and flowering. Selective sweeps were beneficial for improving the adaptability of spruce species to different habitats as well as to accelerate species differentiation. The frequent gene flow between spruce species makes their evolutionary relationships complicated. Insight into gene flow and selection pressure in spruce species will help us further understand their phylogenetic relationships and provide a scientific basis for their introduction, domestication and genetic improvement. Full article

Stilbenes are plant phenolic secondary metabolites that show beneficial effects on human health and possess high antifungal activity against plant pathogens. Currently, a search for plant sources with high stilbene levels is relevant, since stilbene content in various plant species can vary substantially and is often at a low level. In this paper, the bark and wood of Picea jezoensis were analyzed for the content and composition of stilbenes and compared with other known stilbene sources. The HPLC-MS analysis of P. jezoensis bark and wood extracted with different solvents and at different temperatures revealed the presence of 11 and 5 stilbenes, respectively. The highest number of stilbenes of 171 and 229 mg per g of the dry weight (mg/g DW) was extracted from the bark of P. jezoensis using methanol or ethanol at 60 °C for 2 h. Trans-astringin, trans-piceid, and trans-isorhapontin prevailed over other stilbenoids (99% of all detected stilbenes). The most abundant stilbene was trans-isorhapontin, reaching 217 mg/g DW or 87% of all stilbenes. An increase in the extraction time from 2 to 6 h did not considerably increase the detected level of stilbenes, while lower extraction temperatures (20 and 40 °C) significantly lowered stilbene yield. The content of stilbenes in the P. jezoensis bark considerably exceeded stilbene levels in other stilbene-producing plant species. The present data revealed that the bark of P. jezoensis is a rich source of stilbenes (primarily trans-isorhapontin) and provided effective stilbene extraction procedures. Full article

Scientifically sound methods are essential to estimate the survival of trees, as they can substantially support sustainable management of natural forest resources. Tree mortality assessments have mainly been based on forest inventories and are mostly limited to planted forests; few studies have conducted age-based survival analyses in natural forests. We performed survival analyses of individual tree populations in natural forest stands to evaluate differences in the survival of two coniferous species (Abies sachalinensis (F. Schmidt) Mast. and Picea jezoensis var. microsperma) and all broad-leaved species. We used tree rings and census data from four preserved permanent plots in pan-mixed and sub-boreal natural forests obtained over 30 years (1989–2019). All living trees (diameter at breast height ≥ 5 cm in 1989) were targeted to identify tree ages using a Resistograph. Periodical tree age data, for a 10-year age class, were obtained during three consecutive observation periods. Mortality and recruitment changes were recorded to analyze multi-temporal age distributions and mean lifetimes. Non-parametric survival analyses revealed a multi-modal age distribution and exponential shapes. There were no significant differences among survival probabilities of species in different periods, except for broad-leaved species, which had longer mean lifetimes in each period than coniferous species. The estimated practical mean lifetime and diameter at breast height values of each coniferous and broad-leaved tree can be applied as an early identification system for trees likely to die to facilitate the Stand-based Silvicultural Management System of the University of Tokyo Hokkaido Forest. However, the survival probabilities estimated in this study should be used carefully in long-term forest dynamic predictions because the analysis did not include the effects of catastrophic disturbances, which might significantly influence forests. The mortality patterns and survival probabilities reported in this study are valuable for understanding the stand dynamics of natural forests associated with the mortality of individual tree populations. Full article

Environmental factors that drive carbon storage are often used as an explanation for alpine treeline formation. However, different tree species respond differently to environmental changes, which challenges our understanding of treeline formation and shifts. Therefore, we selected Picea jezoensis and Betula ermanii, the two treeline species naturally occurring in Changbai Mountain in China, and measured the concentration of non-structural carbohydrates (NSC), soluble sugars and starch in one-year-old leaves, shoots, stems and fine roots at different elevations. We found that compared with P. jezoensis, the NSC and soluble sugars concentrations of leaves and shoots of B. ermanii were higher than those of P. jezoensis, while the starch concentration of all the tissues were lower. Moreover, the concentration of NSC, soluble sugars and starch in the leaves of B. ermanii decreased with elevation. In addition, the starch concentration of B. ermanii shoots, stems and fine roots remained at a high level regardless of whether the soluble sugars concentration decreased. Whereas the concentrations of soluble sugars and starch in one-year-old leaves, shoots and stems of P. jezoensis responded similarly changes with elevation. These findings demonstrate that compared with P. jezoensis, B. ermanii has a higher soluble sugars/starch ratio, and its shoots, stems and fine roots actively store NSC to adapt to the harsh environment, which is one of the reasons that B. ermanii can be distributed at higher altitudes. Full article

In this study, ring-width chronology of Picea jezoensis var. microsperma from the Changbai Mountain (CBM) area, Northeast China, was constructed. Growth/climate responses suggested that mean maximum temperature (T_max) was the limiting factor affecting radial growth of PJ trees in the study region. According to the correlation analysis between the ring-width index and meteorological data, a June–July mean maximum temperature (T_max6–7) series between 1772 and 2004 was reconstructed by using the standard chronology. For the calibration period (1959–2004), the explained variance of the reconstruction was 41.6%. During the last 233 years, there were 36 warm years and 34 cold years, accounting for 15.5% and 14.7% of the total reconstruction years, respectively. Cold periods occurred in 1899–1913, 1955–1970, and 1975–1989, while warm periods occurred in 1881–1888. The reconstructed temperature series corresponded to the historical disaster records of extreme climatic events (e.g., drought and flood disasters) in this area. Comparisons with other temperature reconstructions from surrounding areas and spatial correlation analysis between the gridded temperature data and reconstruction series indicated that the regional climatic variations were well captured by the reconstruction. In addition, multi-taper method spectral analysis indicated the existence of significant periodicities in the reconstructed series. The significant spatial correlations between the reconstructed temperature series and the El Niño–Southern Oscillation (ENSO), solar activity, and Pacific Decadal Oscillation (PDO) suggested that the temperature in the CBM area indicated both local-regional climate signals and global-scale climate changes. Full article