Search Results (17)

This study explores the health status of veteran Zelkova serrata trees (average age 300 years) in the Pohang region in the context of long-term climatic trends and local environmental variability. Eleven nationally designated veteran trees were monitored using physiological indicators Soil Plant Analysis Development (SPAD) values and live crown ratio (LCR), internal structural assessment (sonic tomography-derived decay ratio), and environmental parameters including meteorological records and Landsat-derived Land Surface Temperature (LST) data from 2000 to 2025. While recent years showed localized heat-extreme events, most sites displayed spatially heterogeneous yet gradually increasing LST trends, with 2024 recording the highest values at more than half the locations. Tree vitality differences were more strongly associated with site specific microclimatic conditions than with uniform long-term climate shifts: trees in cooler or less urbanized zones showed higher SPAD values and lower decay levels, whereas those in warmer, edge-influenced sites exhibited signs of physiological stress. The results indicate that rising summer surface temperature—and their interaction with atmospheric drying—intensify water-stress impacts, but the actual tree responses are modulated by local land-cover and soil stability contexts. These findings underscore the need for integrated, multi-scale assessment of veteran tree health and suggest that conservation practices should incorporate microclimate-based intervention strategies. Full article

This study aimed to determine whether canopy and air temperature difference (ΔT) as an existing simple normalizing index can be used to detect an increase in canopy temperature induced by soil drought in urban parks, regardless of the unique energy balance and three-dimensional (3D) structure of urban trees. Specifically, we used a thermal infrared camera to measure the canopy temperature of Zelkova serrata trees and compared the temporal variation of ΔT to that of environmental factors, including solar radiation, wind speed, vapor pressure deficit, and soil water content. Normalization based on a 3D energy-balance model was also performed and used for comparison with ΔT. To represent the 3D structure, a terrestrial light detection and ranging-derived 3D tree model was used as the input spatial data. The temporal variation in ΔT was similar to that of the index derived using the energy-balance model, which considered the 3D structure of trees and 3D radiative transfer, with a correlation coefficient of 0.85. In conclusion, the thermal-image-based ΔT performed comparably to an index based on the 3D energy-balance model and detected the increase in canopy temperature because of the reduction in soil water content for Z. serrata trees in an urban environment. Full article

The remediation and exploitation of sandy saline soils, an underutilized resource, can be enhanced by a greater comprehension of the impact of plants and microorganisms on nutrient cycling. However, there is scant research information on the capacity of different trees and shrubs to improve carbon and nitrogen cycling in saline soils at different depth layers. This study investigated the effect of the trees Zelkova serrata (ZS) and Ligustrum lucidum (LL) and shrub Hibiscus syriacus (HS) on the carbon and nitrogen fractions, soil enzyme activities and microbial communities in sandy saline soils. Planting ZS, LL or HS improved soil quality, increased soil carbon and nitrogen content, changed rhizosphere soil metabolites and enhanced soil enzyme activities and microbial abundance and diversity. Compared to values in the bare soil, the highest reduction in soil salinity was noticed under Zelkova serrata (49%) followed by Ligustrum lucidum (48%). The highest increase in total soil organic carbon (SOC) was noted under Ligustrum lucidum and Hibiscus syriacus (62% each), followed by Zelkova serrata (43%), as compared to levels in the bare soil. In the 0–10 cm soil layer, the total N in bare soil was 298 ± 1.48 mg/kg, but after planting LL, ZS or HS, the soil total N increased by 101%, 56% and 40%, respectively. Compared with that of the bare soil, cbbL sequencing showed that the relative abundance of Bradyrhizobium increased and that of Bacillus decreased due to planting. Similarly, the nifH sequencing results indicated that the relative abundance of Bradyrhizobium and Motiliproteu increased and that of Desulfuromonas and Geoalkalibacter decreased. These findings suggested that soil microorganisms could play a pivotal role in the carbon and nitrogen cycle of saline soils by influencing the content of soil carbon and nitrogen. Full article

Urbanization and industrialization have escalated air pollution into a critical global issue, particularly in urban areas. Urban green infrastructures (GIs), such as parks and street trees, play a vital role in mitigating air pollution through dry deposition, the process by which air pollutants are removed by deposition onto plant surfaces or through plant uptake. However, existing studies on the dry-deposition capacity of urban green spaces are limited in their ability to reflect variations at the tree-species level, hindering comprehensive evaluations and effective management strategies. This study aims to quantitatively assess the dry-deposition capacity of the urban green spaces of Beijing and Shanghai for six major air pollutants in using an improved dry-deposition model and tree-species-specific data. Results showed that Shanghai’s urban green spaces had a monthly average dry-deposition rate of 5.5 × 10⁻⁶ s m⁻¹, slightly higher than Beijing’s rate of 5.3 × 10⁻⁶ s m⁻¹. Significant seasonal variations were observed, with summer showing the highest deposition rates due to favorable meteorological conditions. Broad-leaved species such as Zelkova serrata in Beijing and Photinia serratifolia in Shanghai exhibited superior dry-deposition capacities compared to coniferous species. Temperature significantly influenced dry-deposition rates for gaseous pollutants, while particulate-matter deposition was primarily affected by pollutant concentrations. This study provides critical insights into the air = purification functions of urban green spaces and underscores the importance of species selection and strategic green-space planning in urban air-quality management, informing the development of optimized urban-greening strategies for improved air quality and public health. Full article

Objectives: In the “dual evaluation” of land space, the evaluation of the importance of ecosystem service functions and residential areas is important, playing a significant role in plants acting as carbon sinks and thereby achieving the transformation of low-carbon settlements. Methods: The paper compares and analyzes five models for quantifying carbon sink benefits and focuses on the national tree benefit calculator (NTBC) model, which is suitable for the carbon sequestration benefits of plants in residential areas, to (i) estimate and compare the economic benefits brought by trees and shrubs in residential areas, (ii) analyze the reasons for the differences between the current data and data for the next 20 years, and (iii) comprehensively evaluate the technical points related to the plant landscape in residential areas to assess whether they comply with the “Green Settlement Standard.” The index system was scored according to the standard. Result: The current data collected for existing trees and shrubs include the following: When the trees are in good condition, the order of the trees according to their economic benefits in the current year is Zelkova serrata > Cedrus deodara > Sapindus saponaria > Sophora japonica > Cinnamomum camphora > Prunus cerasifera > Magnolia grandiflora > Ulmus pumila > Acer L. > Lagerstroemia indica L. > Sapium sebiferum > Sabina > Punica granatum L. > Acer palmatum > Sapium sebiferum > Celtis sinensis Pers > Bambusa multiplex > Cycas > Melia azedarach L. > Pinus parviflora, and that of the trees in the next 20 years is Zelkova serrata > Cinnamomum camphora > Sophora japonica > Sapindus saponaria > Ulmus pumila > Cedrus deodara > Prunus cerasifera > Magnolia grandiflora > Acer L. > Sapium sebiferum > Cycas > Punica granatum L. > Lagerstroemia indica L. > Acer palmatum Thunb > Sabina > Bambusa multiplex > Broussonetia papyrifera > Celtis sinensis Pers > Melia azedarach L. > Pinus parviflora. The order of shrubs according to their economic gain in the current year is Photinia beauverdiana > Pittosporum tobira > Ligustrum lucidum > Viburnum odoratissimum > Buxus cephalantha, and that of the shrubs in the next 20 years is Ligustrum lucidum > Photinia beauverdiana > Pittosporum tobira > Buxus cephalantha > Viburnum odoratissimum. Conclusion: Using plants, the construction ideas, community structure and landscape maintenance of the carbon sink estimation system of residential areas should be updated according to three aspects to promote the quantification of the carbon sink benefits of green areas in urban settlements and the development of low-carbon settlements in China. Full article

With the intensification of coastal erosion, damage to coastal shelterbelts has gradually increased. Arbuscular mycorrhizal fungi (AMF) can improve the salinity tolerance and productivity of plants in saline–alkali soils using various strategies including nutrient uptake, osmotic regulation, soil shaping, etc. Thus, the application of AMF to alleviate the impacts of salinization for these shelterbelts has become a research hotspot. For this study, we investigated the effects of inoculation with different AMF strains on the growth and nitrogen (N) utilization of Gleditsia sinensis Lam. and Zelkova serrata (Thunb.) Makino leaves under different salt concentrations. As the salt concentration increased, the growth rates and leaf areas of the autoclaved AMF inoculant (CK) treatment exhibited a decreasing trend for both G. sinensis and Z. serrata, while Funneliformis mosseae (FM) and Corymbiglomus tortuosum (CT) treatments weakened this trend. Between them, on average, FM increased the G. sinensis height growth rate by 396.9%, ground diameter growth rate by 99.0%, and Z. serrata leaf area by 29.1%. At a salt concentration of 150 mM, the chlorophyll content and nitrate reductase activities of leaves under the FM treatment for both tree species were significantly higher than for CK, with an average increase in chlorophyll content of 106.1% and nitrate reductase activities by 74.6%. Moreover, the AMF inoculation significantly reduced the leaf N content and photosynthetic N-use efficiency of G. sinensis in contrast to Z. serrata. Further, in contrast to G. sinensis, the photosynthetic N-use efficiency was significantly positively correlated with the growth rate and leaf area of Z. serrata. Meanwhile, the nitrate reductase activity contributed most to the growth rate and leaf area of Z. serrata. Our results suggest that the issues with coastal shelterbelts might be effectively alleviated through appropriate AMF–plant combinations, which is of great significance for the optimization of forestry production. Full article

Poor seedling establishment and growth can be a result of the limitation of light and soil resources in the forest understory. Here, we investigate the interacting effects of stand and soil characteristics on the seedling growth of deciduous species (Fraxinus rhynchophylla and Zelkova serrata) and evergreen species (Pinus koraiensis) through a 3-year intersite experiment in two contrasting forest stands. Seedlings were grown in both oak and pine stands using two different soil types, i.e., gray-brown forest soil (GB) and red-yellow forest soil (RY). Soil physicochemical properties, light intensity, tree-seedling height, root-collar diameter (RCD), and biomass growth were analyzed between two stands and/or soil types. Light availability was generally more abundant in the pine stand (mean: 1074.08 lx or 20.25%) than the oak stand (mean: 424.33 lx or 9.20%) throughout the year. The height and RCD growth of fast-growing and deciduous F. rhynchophylla and Z. serrata were higher in the pine than in the oak stand, particularly in GB soil. The growth of the slow-growing and evergreen P. koraiensis was not affected by the forest stand, except for its higher root growth in the oak stand and RY soil. Therefore, abundant light availability can enhance the growth and seedling establishment of F. rhynchophylla and Z. serrata in the pine-stand understory. Contrarily, P. koraiensis may be planted in the understory regardless of light condition, but with a slower growth rate. Full article

As anthropogenic greenhouse gas emissions intensify global climate change, plantations have become an important tool to mitigate atmospheric CO₂. Our aim in this study was to estimate carbon assimilation and clarify the impact of environmental factors on the photosynthesis of Zelkova serrata (Thunb.) Makino, an important plantation species that is extensively planted in low altitude regions of East Asia. We measured monthly gas exchange parameters and leaf area index to estimate carbon assimilation. The results showed that gas exchange was significantly affected by vapor pressure deficit and temperature, especially in the dry season, and both photosynthetic rate and carbon assimilation decreased. Lower daytime assimilation and higher nighttime respiration during the dry season, which caused a 43% decrease in carbon assimilation in Z. serrata plantations. Z. serrata exhibited lower photosynthetic rate and lower carbon assimilation following planting in a tropical monsoon climate area. Therefore, the effects of extreme weather such as high temperature and vapor pressure deficit on Z. serrata forest carbon budget could be stronger in the future. Leaf area showed seasonal variation, and severe defoliation was caused by a typhoon in the summer. The annual carbon assimilation was estimated at 3.50 Mg C ha⁻¹ year⁻¹ in the study area. Full article

Street trees are integral components of urban green infrastructure. The importance of benefits provided by street trees has motivated the development of various tools to quantify the value of ecosystem services. The i-Tree Eco is a widely applied method for quantifying urban forest structure, ecosystem services, and values. Since its first release in 2006, i-Tree Eco has been successfully utilized in over 100 countries around the world. This study described one of the first applications of the i-Tree Eco international project in Kyoto, Japan, by customizing the models and parameters to enhance the accuracy of analysis results. Kyoto’s street trees are prominently dominated by Ginkgo (Ginkgo biloba L.), Trident Maple (Acer buergerianum Miq.), Japanese Zelkova (Zelkova serrata (Thunb.) Makino.), Tuliptree (Liriodendron tulipifera L.), Flowering dogwood (Cornus florida L.), London Planetree (Platanus × acerifolia), Plum/cherry (Prunus spp.), and Weeping willow (Salix babylonica), which account for 92% of the 1230 sample trees and deliver ecosystem service benefits at US$71,434.21 annually or US$58.07/tree/year. The annual value of each function was estimated at US$41.34/tree for carbon storage and sequestration, US$3.26/tree for stormwater runoff reduction, US$11.80/tree for adverse health mitigation effects, and US$1.67/tree for energy savings. The street tree species of Kyoto city that produce the highest average annual benefits are among the largest trees currently in the population, including P. × yedoensis (US$225.32/tree), Z. serrata (US$123.21/tree), S. babylonica (US$80.10/tree), and P. × acerifolia (US$65.88/tree). Our results demonstrated a comprehensive understanding of street trees benefits for Kyoto city, providing baseline information for decision-makers and managers to make effective urban trees management decisions, developing policy, and setting priorities. Full article

Predicting the geographic distribution of a species together with its response to climate change is of great significance for biodiversity conservation and ecosystem sustainable development. Zelkova serrata is an excellent shelterbelt tree species that is used for soil and water conservation due to the fact of its well-developed root system, strong soil fixation, and wind resistance. However, the wild germplasm resources of Z. serrata have been increasingly depleted due to the fact of its weak ability to regenerate naturally and the unprecedented damage humans have caused to the natural habitats. The present work using Maxent aimed to model the current potential distribution of this species as well as in the future, assess how various environmental factors affect species distribution, and identify the shifts in the distribution of this species in various climate change scenarios. Our findings show habitat in provinces in the southern Qinling and Huai river basins have high environmental suitability. Temperature seasonality, annual precipitation, annual mean temperature, and warmest quarter precipitation were the most important factors affecting its distribution. Under a climate change scenario, the appropriate habitat range showed northeastward expansion geographically. The results in the present work can lay the foundation for the cultivation and conservation of Z. serrata. Full article

Potentials of tree species as biofilters depend on appropriate selection based on their tolerance to air pollution, which is usually evaluated by the air pollution tolerance index (APTI) and anticipated performance index (API). Thus, these index values need as a means of scientific understanding to assess the role of urban trees for better greenspace planning/management to mitigate impacts of gaseous air pollution such as ozone (O₃) and sulfur dioxide (SO₂). O₃ exposure to Chionanthus retusus, Pinus densiflora, and Ginkgo biloba showed higher stomatal O₃ flux than the others, finally resulting in both favoring stomatal movement and maintaining carbon fixation. In contrast, despite the whole tree enhanced SO₂ uptake under excess SO₂ exposure, the carbon assimilation capacity was only found in Taxus cuspidata and Zelkova serrata as a consequence of no stomatal sluggishness. On the basis of API, P. densiflora and Prunus × yedoensis were good performers for developing greenspace, while Z. serrata and G. biloba were moderate performers; however, C. retusus and T. cuspidata were estimated to be poor and very poor performers, respectively, for reducing the air quality injury caused by air pollutants. The present study suggests that an integration of both APTI and API based on stomatal absorption flux is needed for selecting sound tree-species in greenspace planning/construction to control gaseous air pollutions. Full article

Although urban trees are proposed as comparatively economical and eco-efficient biofilters for treating atmospheric particulate matter (PM) by the temporary capture and retention of PM particles, the PM removal effect and its main mechanism still remain largely uncertain. Thus, an understanding of the removal efficiencies of individual leaves that adsorb and retain airborne PM, particularly in the sustainable planning of multifunctional green infrastructure, should be preceded by an assessment of the leaf microstructures of widespread species in urban forests. We determined the differences between trees in regard to their ability to adsorb PM based on the unique leaf microstructures and leaf area index (LAI) reflecting their overall ability by upscaling from leaf scale to canopy scale. The micro-morphological characteristics of adaxial and abaxial leaf surfaces directly affected the PM trapping efficiency. Specifically, leaf surfaces with grooves and trichomes showed a higher ability to retain PM as compared to leaves without epidermal hairs or with dynamic water repellency. Zelkova serrata (Thunb.) Makino was found to have significantly higher benefits with regard to adsorbing and retaining PM compared to other species. Evergreen needle-leaved species could be a more sustainable manner to retain PM in winter and spring. The interspecies variability of the PM adsorption efficiency was upscaled from leaf scale to canopy scale based on the LAI, showing that tree species with higher canopy density were more effective in removing PM. In conclusion, if urban trees are used as a means to improve air quality in limited open spaces for urban greening programs, it is important to predominantly select a tree species that can maximize the ability to capture PM by having higher canopy density and leaf grooves or trichomes. Full article

Arbuscular mycorrhizal fungi (AMF) play an important role in the establishment and maintenance of plant communities in forest ecosystems. Most previous studies about AMF have been conducted in natural forests, and little attention has been paid to trees in planted forests. This study investigated AMF associated with tree species and the relationships between edaphic factors and AMF communities in a planted forest of eastern China. We found high total AMF colonization rates in the roots of Carya illinoensis (Wangenh.) K. Koch, Zelkova serrata (Thunb.) Makinoz, Taxodium ‘zhongshansha’, Eucommia ulmoides Oliv., and Elaeagnus pungens Thunb., ranging from 62.07% to 100%, indicating that AMF can establish effective symbiotic relationships with these tree species. The AMF colonization rate was significantly and negatively correlated with soil phosphorus, while AMF colonization intensity was significantly and negatively correlated with soil moisture content, total carbon, and organic matter content. Spore density was in the range of 4.38 to 76.38 spores per g soil. In total, 35 AMF species from 10 genera were identified. Glomus and Acaulospora were the dominant genera. Acaulospora foveata and Septoglomus constrictum were the dominant species. AMF communities differed among the tree species and were closely related to edaphic factors, and AMF diversity was significantly related to soil carbon and pH. Our results revealed the colonization, community, and diversity of AMF associated with tree species, as well as their relationships with edaphic factors, in planted forests. Our findings can be used to provide insight on the utilization and management of AMF to maintain sustainable management of planted forests. Full article

Salinity is the primary restriction factor for vegetation conservation and the rehabilitation of coastal areas in Eastern China. Arbuscular mycorrhizal fungi (AMF) have been proved to have the ability to alleviate salt stress in plants. However, the role of AMF in relieving salt stress among indigenous trees species is less well known, limiting the application of AMF in the afforestation of local area. In this study, a salt-stress pot experiment was conducted to evaluate the effects of AMF on Zelkova serrata (Thunb.) Makino, a tree species with significant potential for afforestation of coastal area. The Z. serrata seedlings inoculated with three AMF strains (Funneliformis mosseae 1, Funneliformis mosseae 2, and Diversispora tortuosa) were subjected to two salt treatments (0 and 100 mM NaCl) under greenhouse conditions. The results showed that the three AMF strains had positive effects, to a certain extent, on plant growth and photosynthesis under normal condition. However, only F. mosseae 1 and F. mosseae 2 alleviated the inhibition of growth, photosynthesis, and nutrient uptake of Z. serrata seedlings under salt stress. The two AMF strains mitigated salt-induced adverse effects on seedlings mainly by increasing the leaf photosynthetic ability and biomass accumulation by reducing Na⁺ content, increasing P, K⁺, and Mg²⁺ content, as well as by enhancing photosynthetic pigments content and the stomatal conductance of leaves. These results indicated that AMF inoculation is a promising strategy for the afforestation of coastal areas in Eastern China. Full article

To explore the relationship between arbor root density and corresponding physical soil properties (total porosity, non-capillary porosity, specific weight, bulk density, moisture content, and permeability), noninvasive methods such as Tree Radar Unit (TRU) were utilized to detect the root systems of 10 species of tree that are commonly used in Shanghai green spaces with more than 70% frequency of occurrence. Using TRU and soil investigation, root density and soil porous features were determined for different tree species, depth slices, and distances. The relationships among root density, soil porosity, and non-capillary porosity were identified using variance analysis and regression analysis. The results indicated that root density decreased with increasing distance from the trunk and soil depth. Soil porosity and non-capillary porosity had significantly positive and linear correlations with root density. Compared with lawns, trees such as Zelkova serrata, Koelreuteria paniculata, Cinnamomum camphora, and Metasequoia glyptostroboides had the greatest effects on soil improvement through soil porosity and non-capillary porosity. Due to the spatial distribution of root systems, trees could be divided into three types based on their influence at various soil depths. Full article