Chinese Academy of Forestry

The expansion of Pleioblastus amarus into tea plantations introduces environmental heterogeneity, significantly influencing the growth and quality of bamboo shoots. This study examined the effects of bamboo expansion on the appearance, nutrition, and palatability of bamboo shoots, utilizing partial least squares structural equation modeling (PLS-SEM) to identify key influencing factors. Results revealed that bamboo expansion increased shoot diameter, length, and fresh weight, enhancing overall size and edibility, particularly in the tea-bamboo mixed forest center zone (TBC), where appearance quality peaked. Nutritional analysis revealed substantial increases in protein, fat, starch, and vitamin C content after bamboo expansion, along with the improvements in amino acid score (AAS), essential amino acid index (EAAI), and nutritional index (NI), indicating elevated nutritional value. However, despite the rise in soluble sugars and flavor-enhancing amino acids, higher levels of total acids, oxalic acid, tannins, and cellulose diminished the palatability, notably in TBC site. PLS-SEM further indicated that while bamboo expansion positively influenced shoot appearance and nutrition, soil factors predominantly drove these changes and concurrently detracted from overall palatability. These findings provide a framework for enhancing bamboo shoot quality and optimizing management practices in tea plantation ecosystems.

Wildfires profoundly influence ecosystems, human societies, and economic activities as a global phenomenon. The continuing climate change increases the frequency and intensity of wildfire, resulting in urgent needs in searching for better fire management strategies. This paper aims to pave a pathway towards meeting this challenge through accurately predicting spatiotemporal pattern of global wildfire risk, using an improved Transformer model that integrates information theory and full-attention mechanisms. Experimental results demonstrate that the proposed SimAM modulated Full Attention Network shows superior performances in terms of Accuracy, Recall, and Area Under the Precision-Recall Curve. Furthermore, new discoveries based on the model find out that the wildfire risk in the northern forest region of Australia is influenced by the seasonality of the climate in North America and the Pacific and the dry winter climate in the Canadian region, illuminating the intricate relationship between the global climate and regional wildfire risk. These findings provide new tools and knowledges for understanding the mechanisms in global wildfire risk.

acoustic space for bird vocalization. Passive acoustic monitoring in various urban forests was used to monitor natural and anthropogenic noises, and sounds were classified into three acoustic scenes (bird sounds, human sounds, and bird-human sounds) to determine interconnections between bird sounds, anthropogenic noise, and vegetation structure. Anthropogenic noise altered the acoustic niche of urban forests by intruding into the low-frequency space used by birds, and vegetation structures related to volume (trunk volume and branch volume) and density (number of branches and leaf area index) significantly impact the diversity of bird sounds. Our findings indicate that the response to low and high frequency signals to vegetation structure is distinct. By clarifying this relationship, our results contribute to understanding of how vegetation structure influences bird sounds in urban forests impacted by anthropogenic noise.

Understanding the relationship between forest management and water use efficiency (WUE) is important for evaluating forest adaptability to climate change. However, the effects of thinning and understory removal on WUE and its key controlling processes are not well understood, which limits our comprehension of the physiological mechanisms of various management practices. In this study, four forest management measures (no thinning: NT; understory removal: UR; light thinning: LT; and heavy thinning: HT) were carried out in Pinus massoniana plantations in a subtropical region of China. Photosynthetic capacity and needle stable carbon isotope composition (δ13C) were measured to assess instantaneous water use efficiency (WUEinst) and long-term water use efficiency (WUEi). Multiple regression models and structural equation modelling (SEM) identified the effects of soil properties and physiological performances on WUEinst and WUEi. The results show that WUEinst values among the four treatments were insignificant. However, compared with the NT stand (35.8 μmol·mol−1), WUEi values significantly increased to 41.7 μmol·mol−1 in the UR, 50.1 μmol·mol−1 in the LT and 46.6 μmol·mol−1 in HT treatments, largely explained by photosynthetic capacity and soil water content. Understory removal did not change physiological performance (needle water potential and photosynthetic capacity). Thinning increased the net photosynthetic rate (An) but not stomatal conductance (gs) or predawn needle water potential (ψpd), implying that the improvement in water use efficiency for thinned stands was largely driven by radiation interception than by soil water availability. In general, thinning may be an appropriate management measure to promote P. massoniana WUE to cope with seasonal droughts under future extreme climates.

As promising energy-storage devices, zinc–air batteries (ZABs) exhibit slow reaction kinetics for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) occurring at their electrodes. High-performance bifunctional catalysts must thus be synthesized to accelerate the reversible conversion of oxygen and improve the rate and overall performance of ZABs. Herein, we reported the promising prospects of self-supported composite electrodes composed of wood-derived carbon (WDC) and bimetallic cobalt-iron alloys/oxides (CoFe-CoFe2O4@WDC) as efficient electrocatalysts for alkaline ORR/OER. WDC provided a favorable three-phase interface for heterogeneous reactions owing to its layered porous structure and genetic stability, thereby enabling mass diffusion and improving reaction kinetics. The CoFe2O4 spinel surface was reduced to bimetallic CoFe alloy to form abundant heterostructure interfaces that promote electron transfer. Under alkaline conditions, the optimized composite electrode exhibited a remarkable high half-wave potential of 0.85 V and an exceptionally low overpotential of 1.49 V. It also exhibited stable performance over an impressive 2340 cycles in a ZAB. Theoretical calculations also confirmed that the heterointerface addresses the issue of proton scarcity throughout the reaction and actively facilitates the creation of O–O bonds during the reversible transformation of oxygen. This study introduces a new concept for developing bifunctional and efficient electrocatalysts based on charcoal and encourages the sustainable and high-value use of forest biomass resources.

In this study, the response surface method (RSM) was used to determine the optimal parameters of ultrasonic assisted extraction of Gymnocladus chinensis Baill. polysaccharides (GCBP). The optimal extraction conditions were as follows: a liquid‐solid ratio of 50.4 mL/g, an extraction temperature of 60 °C, an extraction time of 43 min, and an extraction power of 240 W. Under these conditions, the extraction rate of GCBP reached 50.1%. Three fractions of GCBP‐40, GCBP‐60 and GCBP‐80 with sugar contents of 64.33%, 59.16% and 59.46% were obtained by different concentrations of ethanol purification. All the three fractions were consisted of six monosaccharides with different ratio, namely Man, Rha, Gal, Glu, Ara and Xyl. From Congo red test, it is confirmed that all three fractions could have a triple helix structure. In addition, the antioxidant and hypoglycemic experiments showed that all three components had excellent antioxidant activity (DPPH free‐radical scavenging activity, ABTS free‐radical scavenging activity, and OH‐ free‐radical scavenging activity) and hypoglycemic activity (α‐glucosidase inhibitory activity).

Cross breeding is an important way to innovate germplasm. However, the growth performance of hybrid offspring is difficult to predict. Pinus yunnanensis is an important tree species for both timber and industrial raw materials in southwest China, and its genetic degradation is a serious concern. To accelerate the breeding process and diversify the genetic resources, 16 interspecific crosses of P. yunnanensis × P. kesiya and 22 intraspecific crosses of P. yunnanensis were evaluated and selected based on the systematic analysis of nutritional and reproductive growth traits. The results indicated that the differences in traits between the different combinations were significant, suggesting that the interspecific and intraspecific hybrid offspring showed high genetic variation with potential for selection. The interspecific crosses were considerably better than the intraspecific crosses for all phenotypic traits, indicating that the distant hybridization had an advantage of heterosis. Compared with the open-pollinated progeny, the progeny of superior hybrid family significantly improved in nutritional growth traits, and declined in reproductive growth traits. The coefficients of phenotypic variation, genetic variation, family heritability and individual heritability for the phenotypic traits were higher than other Pinus, indicating that the traits were highly variable and under strong genetic control. Nutritional and reproductive growth traits could be selected independently. Five interspecific crosses and one intraspecific cross were selected using a combination of the membership function and an independent selection method. Our findings provided an important material basis and theoretical support for hybrid breeding and genetic improvement of Pinus.

Hylurgus ligniperda (Fabricius) is an important pest that attacks Pinus species in China. It impacts the vitality of local pine vegetation, reduces the ability to prevent windbreak and sand fixation, and causes ecological loss. MaxEnt and ArcGIS are used to predict and analyze the changes in suitable distribution areas of H. ligniperda under current and future climate scenarios, based on 12 climate factor datasets and 1,001 field distribution data points for this pest. The environmental variables used significantly influence the potential distribution of H. ligniperda. Highly suitable areas of this beetle are located in western Europe, central Asia, and the southeastern regions of Oceania, with sporadic occurrences across North America, South America, and Africa. Highly suitable areas in China occur across the east, central south, and southwest regions. There is a significant increase in the high and medium suitability areas, while the area of low suitability decreases under the 4 future climate scenarios (SSP126, SSP245, SSP370, and SSP585). The suitable distribution area for H. ligniperda shows an overall trend of moving northwestward. The purpose of this current study is to provide important theoretical support for the prevention and management of this pest by predicting and analyzing suitable distribution areas under current and future climate scenarios.

Phenolics are essential quality components in pecan nuts, influencing the nutritional value of various varieties. Conventional breeding methods for pecan trees are time-consuming and laborious due to their considerable height and extended juvenile period. Molecular marker-assisted selection offers the potential to expedite the breeding process. In this study, we examined the allelic variations of five phenolics biosynthesis-related genes within a germplasm population. The linkage disequilibrium (LD) values (r²) between single nucleotide polymorphisms (SNPs) of each gene were analyzed, demonstrating a decrease in r² to less than 0.2 within a 1.0 kb distance. The contents of total phenolics, total flavonoids, and condensed tannins in the kernels of each individual were assessed over two consecutive years. Following this, association mapping was conducted. A total of 29 significant marker-trait pairs and eight significant haplotype-trait pairs were observed. Among these, three SNPs in CiPAL4 and two haplotypes in CiCHS3 were consistently identified over both years. The explanation rates of the SNPs for the observed traits ranged from 3.45 to 14.39% (p < 0.05). This study offers valuable insights into the molecular basis underlying phenolic biosynthesis in pecan trees, which will enhance the efficiency of quality improvement in this plant and other species within the Carya genus.

Background and aims Studying the relationship between plant functional groups and soil microbial functional groups, abiotic and biotic factors are important for understanding the mechanisms of species coexistence and ecological processes among biological communities, especially in species-rich tropical rainforests. Methods This study utilized the Competitor, Stress-tolerator, and Ruderal (CSR) theory for plant classification, and FAPROTAX and FUNGuild for soil bacterial and fungal functional guild analysis, and combined with abiotic and biotic factors. We use correlation analysis, multivariate regression analysis, random forest model, redundancy analysis and variance decomposition to analyze the data. Results (1) A total of 316 woody plant species were classified into four functional groups. The intermediate (Int, 53.48%) and competitor (C, 29.75%) functional groups comprised the majority of plant species, while the ruderal (R) functional group was least represented (1.27%). Dominant soil fungal functional groups included undefined saprotrophs, ectomycorrhizal, and soil saprotrophs, while key bacterial groups included chemoheterotrophs, nitrifiers, and nitrogen fixers. (2) Soil saprotrophs were positively correlated with the stress-tolerator (S) functional group but negatively with the Int functional group. The C functional group was positively associated with arbuscular mycorrhizal fungi. (3) Soil bacterial functional groups were the key driving factors affecting the relative abundance of plant functional groups, while abiotic and biotic factors were the important influencing factors. Conclusion This study sheds light on the relationship between plant functional groups and soil microbial functional diversity, biotic and abiotic factors, underlying processes for understanding tropical rainforest community dynamics.

Kiwifruit (Actinidia spp.), celebrated for its unique flavor and rich nutritional content, is a globally popular fruit. This fruit requires post-harvest ripening before consumption. However, the unpredictable ripening pace significantly impacts consumer acceptance and sales, thereby hindering the commercial growth of kiwifruit. To address this, understanding the key molecular mechanisms and metabolites governing postharvest ripening and senescence could offer valuable insights for developing storage strategies and breeding techniques in yellow-fleshed kiwifruits. We constructed two models that integrated these findings with existing theories. The first model suggests that, unlike the T6P-sucrose regulatory mechanism observed in plant leaves, the separation of harvested kiwifruit from the mother plant leads to an insufficient supply of T6P, which activates the SnRK1 kinase. This, in turn, inhibits the TOR kinase signaling pathway, regulating starch metabolism. The T6P-SnRK1-TOR-starch metabolism pathway plays a regulatory role during postharvest ripening, limiting excessive starch degradation that could accelerate aging and decay in yellow-fleshed kiwifruit. The second model highlights the role of abscisic acid (ABA), cytokinins (CKs), and ethylene in regulating the process, inducing the activation of ERFs and cell wall-degrading enzymes, promoting fruit postharvest softening. These findings indicate that at least two models, the T6P-SnRK1-TOR-starch metabolism model and the ABA-CKs-ethylene-cell wall degradation model, regulate postharvest fruit ripening, offering new insights into the artificial regulation of yellow-fleshed kiwifruit ripening speed.

The structural properties of mixed stands and its potential impact on forest carbon sink function have attracted the attention of forest managers. Comprehensively understanding how stand factors and structural diversity influence forest biomass is critical for enhancing carbon management. However, data and information on biomass variability and its relationships to stand structural features are still insufficient. The purpose of this study was to develop models that delineated the relationships between stand biomass (above and below ground) and stand factors, with a particular emphasis on structural diversity in natural mixed forests. Four machine learning (ML) algorithms named support vector machine (SVM), artificial neural network (ANN), random forest (RF) and boosted regression trees (BRT) were trained. The results indicated that SVM and ANN provided more accurate stand biomass estimations than RF and BRT algorithms. The ANN, incorporating tree size diversity, achieved the highest accuracy (R² = 0.9255 ± 0.0421), followed by SVM (R² = 0.9252 ± 0.0385). Structural diversity proved to be a reliable predictor of biomass estimation in mixed stand surpassing stand average height traditionally used. The positive correlation between stand biomass and structural diversity with the relative importance value ranged from 10.21 to 15.32% suggested that complex stand structural diversity facilitated larger biomass accumulation. Thus, our study offered a ML protocol for predicting stand biomass of natural coniferous-broadleaved mixed forests, and suggested that using comprehensive management measures such as properly promoting tree differentiation can help forest managers enhance ecosystem carbon.

Toxicodendron species are economically and medicinally important trees because of their rich sources of natural products. We present three chromosome‐level genome assemblies of Toxicodendron vernicifluum ‘Dali’, Toxicodendron succedaneum ‘Vietnam’, and T. succedaneum ‘Japan’, which display diverse production capacities of specialized metabolites. Genome synteny and structural variation analyses revealed large genomic differences between the two species ( T. vernicifluum and T. succedaneum ) but fewer differences between the two cultivars within the species. Despite no occurrence of recent whole‐genome duplications, Toxicodendron showed evidence of local duplications. The genomic modules with high expression of genes encoding metabolic flux regulators and chalcone synthase‐like enzymes were identified via multiomics analyses, which may be responsible for the greater urushiol accumulation in T. vernicifluum ‘Dali’ than in other Toxicodendron species. In addition, our analyses revealed the regulatory patterns of lipid metabolism in T. succedaneum ‘Japan’, which differ from those of other Toxicodendron species and may contribute to its high lipid accumulation. Furthermore, we identified the key regulatory elements of lipid metabolism at each developmental stage, which could aid in molecular breeding to improve the production of urushiol and lipids in Toxicodendron species. In summary, this study provides new insights into the genomic underpinnings of the evolution and diversity of specialized metabolic pathways in three Toxicodendron cultivars through multiomics studies.

Michelia macclurei Dandy is a valuable plantation species, and its wood is employed extensively in buildings and furniture. In this study, the radial variations in density, crystallinity index and microfibril angle were investigated via XRD and near-infrared spectroscopy. Models were constructed in order to predict the crystallinity and microfibril angle of Michelia macclurei wood. The density and crystallinity exhibited a gradual increase from the pith to the bark, while the microfibril angle demonstrated a gradual decrease. For the collected near-infrared spectrum, “MSC + 1st in the 780-1500 nm spectral range” and “MSC in the spectral range of 780-2500 nm spectral range” were identified as the optimal preprocessing methods for crystallinity and microfibril angle. The correlation coefficients of the crystallinity and microfibril angle calibration models were 0.91 and 0.95, respectively, while the correlation coefficients of the prediction models were 0.91 and 0.98, respectively. The model established in this study allows for rapid and non-destructive prediction of the crystallinity and microfibril angle of Michelia macclurei wood. The findings from this study provide valuable and detailed scientific data that can contribute to the study and prediction of wood properties.

Patchy global data on belowground litter decomposition dynamics limit our capacity to discern the drivers of carbon preservation and storage across inland and coastal wetlands. We performed a global, multiyear study in over 180 wetlands across 28 countries and 8 macroclimates using standardized litter as measures of “recalcitrant” (rooibos tea) and “labile” (green tea) organic matter (OM) decomposition. Freshwater wetlands and tidal marshes had the highest tea mass remaining, indicating a greater potential for carbon preservation in these ecosystems. Recalcitrant OM decomposition increased with elevated temperatures throughout the decay period, e.g., increase from 10 to 20 °C corresponded to a 1.46-fold increase in the recalcitrant OM decay rate constant. The effect of elevated temperature on labile OM breakdown was ecosystem-dependent, with tidally influenced wetlands showing limited effects of temperature compared with freshwater wetlands. Based on climatic projections, by 2050 wetland decay constants will increase by 1.8% for labile and 3.1% for recalcitrant OM. Our study highlights the potential for reduction in belowground OM in coastal and inland wetlands under increased warming, but the extent and direction of this effect at a large scale is dependent on ecosystem and OM characteristics. Understanding local versus global drivers is necessary to resolve ecosystem influences on carbon preservation in wetlands.

The growth of timber assortment is related to site conditions and forest management measures. To our knowledge, however, the effects and relative importance of these factors on the growth of different timber assortments of Chinese fir have not yet been explored. Based on data from long-term fixed observation plots in the northwest of the Chinese fir distribution zone, we examined the effects of planting density and the site index on the timber assortment structure of Chinese fir. Furthermore, we quantified the relative importance of stand factors (age, planting density, stand density index, number of living trees, Gini coefficient, and site index) in determining the growth of various timber assortments. The results showed that the wood yield of all timber assortment types increased as the site quality improved. The outturn and outturn rate of large- and medium-diameter timber were negatively correlated with the planting density. Before the age of 22, planting density had a negative impact on total timber yield and small-diameter timber outturn. After 22 years, planting density had a positive impact on total timber yield and small-diameter timber outturn. SDI (stand density index), age, and SD (stand density) were the most important factors influencing total timber yield and small-diameter timber. The relative importance of age to large-diameter timber was the greatest, followed by SI (site index) and SD. The effects of age, SD, SI, and PD (planting density) on the medium-diameter timber were greater than those of SDI and Gini coefficient. The results indicate small- and medium-diameter timber as the primary target timber assortment types to be cultivated in the study area, while large-diameter timber cannot be effectively produced under the current site conditions. Our findings provide valuable insights for the management of Chinese fir plantations and the directed cultivation of target timber assortments in the northwest of the Chinese fir distribution zone.