Soil fungi participate in various ecosystem processes and are important factors driving the restoration of degraded forests. However, little is known about the changes in fungal diversity and potential functions under the development of different vegetation types during natural (secondary forest succession) and anthropogenic (reforestation) forest restoration. In this study, we selected typical forest succession sequences (including Pinus densiflora Siebold & Zucc., pine-broadleaf mixed forest of P. densiflora and Quercus acutissima Carruth., and Q. acutissima), as well as natural secondary deciduous broadleaved mixed forests and planted forests of Robinia pseudoacacia on Kunyu Mountain for analysis. We used ITS rRNA gene sequencing to characterize fungal communities and used the FUNGuild database to predict fungal functional groups. The results showed that forest succession affected fungal β-diversity, but not the α-diversity. There was a significant increase in Basidiomycota and a decrease in Ascomycota in the later successional stage, accompanied by an increase in the functional groups of ectomycorrhizal fungi (ECM). Conversely, planted forests exhibited decreased fungal α-diversity and altered community compositions, characterized by fewer Basidiomycota and more Ascomycota and Mucoromycota. Planted forests led to a decrease in the relative abundances of ECM and an increase in animal pathogens. The TK content was the major factor explaining the distinction in fungal communities among the three successional stages, whereas pH, AP, and NH4 + were the major factors explaining community variations between natural and planted forests. Changes in vegetation types significantly affected the diversity and functional groups of soil fungal communities during forest succession and reforestation, providing key insights for forest ecosystem management in temperate forests.

Fungi are key decomposers of deadwood, but the impact of anthropogenic changes in nutrients and temperature on fungal community and its consequences for wood microbial respiration are not well understood. Here, we examined how nitrogen and phosphorus additions (field experiment) and warming (laboratory experiment) together influence fungal composition and microbial respiration from decomposing wood of angiosperms and gymnosperms in a subtropical forest. Nutrient additions significantly increased wood microbial respiration via fungal composition, but effects varied with nutrient types and taxonomic groups. Specifically, phosphorus addition significantly increased wood microbial respiration (65%) through decreased acid phosphatase activity and increased abundance of fast-decaying fungi (e.g., white rot), while nitrogen addition marginally increased it (30%). Phosphorus addition caused a greater increase in microbial respiration in gymnosperms than in angiosperms (83.3% vs. 46.9%), which was associated with an increase in Basidiomycota:Ascomycota operational taxonomic unit abundance in gymnosperms but a decrease in angiosperms. The temperature dependencies of microbial respiration were remarkably constant across nutrient levels, consistent with metabolic scaling theory hypotheses. This is because there was no significant interaction between temperature and wood phosphorus availability or fungal composition, or the interaction among the three factors. Our results highlight the key role of tree identity in regulating nutrient response of wood microbial respiration through controlling fungal composition. Given that the range of angiosperm species may expand under climate warming and forest management, our data suggest that expansion will decrease nutrient effects on forest carbon cycling in forests previously dominated by gymnosperm species.

We conducted analyses on 253 protein sequences (Pfam00257) derived from 25 woody plant species, including trees, shrubs, and vines. Our goal was to gain insights into their architectural types, biochemical characteristics, and potential involvement in mitigating abiotic stresses, such as drought, cold, or salinity. The investigated protein sequences (253) comprised 221 angiosperms (85 trees/shrubs and 36 vines) and 32 gymnosperms. Our sequence analyses revealed the presence of seven architectural types: Kn, KnS, SKn, YnKn, YnSKn, FSKn, and FnKn. The FSKn type predominated in tree and shrub dehydrins of both gymnosperms and angiosperms, while the YnSKn type was more prevalent in vine dehydrins. The YnSKn and YnKn types were absent in gymnosperms. Gymnosperm dehydrins exhibited a shift towards more negative GRAVY scores and Fold Indexes. Additionally, they demonstrated a higher Lys content and lower His content. By analyzing promoter sequences in the angiosperm species, including trees, shrubs, and vines, we found that these dehydrins are induced by the ABA-dependent and light-responsive pathways. The presence of stress- and hormone-related cis-elements suggests a protective effect against dehydration, cold, or salinity. These findings could serve as a foundation for future studies on woody dehydrins, especially in the context of biotechnological applications.

Allergic rhinitis, caused by airborne pollen, is a common disease with a great impact on the quality of life for patients and high costs for society. Prevention of high pollen concentrations in the air is relevant for creating a safe environment for allergic patients. Due to climate change, the heat in cities during the summer is a recurring problem. The local climate can be improved by using the cooling properties of trees, providing shade and cooling by evapotranspiration. When deciding which tree species will be planted, it is important to take into account the allergenicity of the pollen that the tree produces. Available guides, used all over the world, on the allergenicity of pollen are very divers in content and interpretation and not applicable for the Netherlands. In this study a method is described to develop a guide for the allergenic potential of tree pollen in a region, in this case the Netherlands. For the most common tree species in the Netherlands the scientific knowledge on the allergenicity of the pollen was collected, followed by an inventory on regional pollen abundance. Subsequently, the sensitization pattern in a patient group with possible inhalation allergy was analyzed. Based on these data allergenicity of the tree pollen was classified into five classes. Eight tree species/genera of the 61 most planted tree species in the Netherlands are considered to have a very strong to moderate allergenic potential. We propose to use this methodology to develop regional-specific guides classifying the allergenic potential of tree pollen.

Urban forests are essential for maintaining urban ecological stability. As decomposers, soil microorganisms play an indispensable role in the stability of urban forest ecosystems, promoting the material cycle of the ecosystems. This study used high-throughput sequencing technology to explore the bacteria in six forest stands, including Phyllostachys edulis (ZL), Metasequoia glyptostroboides (SSL), Cornus officinalis (SZY), mixed broad-leaved shrub forest (ZKG), mixed pine and cypress forest (SBL), and mixed broad-leaved tree forest (ZKQ). Meanwhile, the differences in fungal communities were investigated. The results show that ZL has the highest alpha diversity of bacterial communities, while its fungal community is the lowest; Proteobacteria is the most abundant bacterial phylum in the six forest stands; ZKQ has the highest fungal diversity. In addition, soil microbial communities are affected by environmental factors. Soil pH, organic matter (SOM), and available phosphorus (AP) significantly influence the compositions of urban forest soil microbial communities. This study revealed the differences in bulk soil (BS) microbial community structures among six forest stands and the relationship between environmental factors and soil microbial communities, which has important guiding significance for creating healthy and stable urban forests with profound ecological benefits.

Urban forests play a crucial role in the overall health and stability of urban ecosystems. Soil microorganisms are vital to the functioning of urban forest ecosystems as they facilitate material cycling and contribute to environmental stability. This study utilized high-throughput sequencing technology to examine the structural characteristics of bacterial and fungal communities in the bulk soil of six different forest stands: Phyllostachys pubescens (ZL), Metasequoia glyptostroboides (SSL), Cornus officinalis (SZY), mixed broad-leaved shrub forest (ZKG), mixed pine and cypress forest (SBL), and mixed broad-leaved tree forest (ZKQ). Soil samples were collected from each forest stand, including the corners, center, and edges of each plot, and a combined sample was created from the first five samples. The results revealed that among the bacterial communities, ZKG exhibited the highest alpha diversity in spring, while ZL demonstrated the highest alpha diversity in both summer and autumn. Proteobacteria was the most abundant bacterial phylum in all six forest stand soils. The dominant fungal phylum across the six forest stands was identified as Ascomycota. Notably, the microbial community diversity of SBL bulk soil exhibited significant seasonal changes. Although ZL exhibited lower bacterial community diversity in spring, its fungal community diversity was the highest. The bulk soil microbial diversity of ZL and SSL surpassed that of the other forest stands, suggesting their importance in maintaining the stability of the urban forest ecosystem in the Zhuyu Bay Scenic Area. Furthermore, the diversity of the bulk soil microbial communities was higher in all six stands during spring compared to summer and autumn. Overall, this study provides valuable insights into the seasonal variations of bulk soil microbial communities in urban forests and identifies dominant tree species, offering guidance for tree species\' selection and preservation in urban forest management.

Polycyclic aromatic hydrocarbons (PAHs) are among the most studied organic compounds in urban environments, due to their known threat to human health. This study extends the current knowledge regarding the ability of different vegetative parts of different tree species to accumulate PAHs. Moreover, exposure intensity to PAHs in areas frequented by population susceptible to adverse health effects of air pollution is evaluated. For this, leaves and barks of Sambucus nigra (S. nigra) and Acacia melanoxylon (A. melanoxylon) were collected at urban areas in the Andean city of Quito, at seven points near hospitals and schools. A methodology, previously developed, for the extraction, purification, and quantification of PAHs associated with the leaves and bark of S. nigra was employed and also validated for leaves and bark of A. melanoxylon. The total PAH level varied from 119.65 ng g-1 DW (dry weight) to 1969.98 ng g-1 DW (dry weight) with naphthalene (Naph), fluoranthene (Flt), pyrene (Pyr), chrysene (Chry), and benzo[a]pyrene (BaP) predominating in all samples. The results indicate that the leaves and bark of tree species studied have certain abilities to bio-accumulate PAH according to their molecular weight. The leaves of S. nigra and bark of A. melanoxylon showed the highest ability to accumulate PAHs, mainly those with high and medium molecular weight, respectively. The highest incidence of light molecular weight PAHs was found in the leaves of A. melanoxylon. Furthermore, coal combustion, biomass burning, and vehicle emissions were identified as the main PAHs sources. Concentrations of PAHs associated with tree species suggest an affectation in areas frequented by populations susceptible to air pollution. This fact shows the importance of regulatory scheme to significantly improve the air quality in the city integrating a knowledge-based decision-making.

Leaves can specifically uptake trace elements from the surrounding environment. And tree leaves are a good biological indicator for air pollution. Therefore, chemical analysis of leaf specifications can be used to reproduce a historical record of air pollution. To better understand the history of urban air pollution from the 1920s to the 2020s in Nanjing, China, leaf samples of two woody plants, Platanus × hispanica and Pittosporum tobira, were collected in this study as environmental indicators from different historical periods. These included historical herbarium specimens and current leaves from live trees. The concentrations of 10 trace elements were determined in the samples using ICP‒MS. Pollution indices were calculated, yielding the key findings. The historical leaf samples showed continuously increasing mean concentrations of the 10 trace elements over time, which significantly correlating with automobile quantities and the number of large-scale industrial enterprises (p < 0.05). Moreover, modern leaf trace element concentrations were significantly correlated with PM10, PM2.5, automobiles, large-scale industrial enterprises, and atmospheric factors, confirming these as sources. In addition to the historical growth trend, spatial heterogeneity was revealed in historical Platanus × hispanica leaf samples from the 14 sites in Nanjing. Changes in heavy metal trace element pollution distributions were consistent with transportation and industrial expansion, with homologous patterns across elements. Specifically, post 1980s increases were observed in the representative NJ2 (Zhongshan Botanical Garden) and the NJ5(Nanjing University) sites, with higher concentrations occurring at in the NJ5 contaminated site than at the NJ2 uncontaminated site. After 2009, the 10 element (except Cd) pollution indices in Platanus × hispanica leaves fluctuated but declined overall. This reconstruction of Nanjing\'s air pollution history demonstrates that ample environmental information can be extracted from plant leaf markers over time and space.

To explore the contribution of microorganisms to forest ecosystem function, we studied the ectomycorrhizal (ECM) fungal and soil bacterial community of the five typical tree species (Pinus massoniana, PM; Castanopsis carlesii, CC; Castanopsis eyrei, CE; Castanopsis fargesii, CF; and Keteleeria cyclolepis, KC) at the Junzifeng National Nature Reserve. The results indicated that the ECM fungal and soil bacterial diversity of CC and CF was similar, and the diversity rates of CC and CF were higher than those of PM, CE, and KC. Cenococcum geophilum and unclassified_Cortinariaceae II were the most prevalent occurring ECM fungi species in the five typical tree species, followed by unclassified_Cortinariaceae I and Lactarius atrofuscus. In bacteria, the dominant bacterial genera were Acidothermus, Bradyrhizobium, Acidibacter, Candidatus_Solibacter, Candidatus_Koribacter, Roseiarcus, and Bryobacter. EMF fungi and soil bacteria were correlated with edaphic factors, especially the soil pH, TP, and TK, caused by stand development. The results show that the community characteristics of ECM fungi and bacteria in the typical tree species of the Junzifeng National Nature Reserve reflect the critical role of soil microorganisms in stabilizing forest ecosystems.

We assessed the diversity and composition of fungal communities in different functional tissues and the rhizosphere soil of Pinus sylvestris and Picea abies stands along the latitudinal gradient of these tree species distributions in Europe to model possible changes in fungal communities imposed by climate change. For each tree species, living needles, shoots, roots, and the rhizosphere soil were sampled and subjected to high-throughput sequencing. Results showed that the latitude and the host tree species had a limited effect on the diversity and composition of fungal communities, which were largely explained by the environmental variables of each site and the substrate they colonize. The mean annual temperature and mean annual precipitation had a strong effect on root fungal communities, isothermality on needle fungal communities, mean temperature of the warmest quarter and precipitation of the driest month on shoot fungal communities, and precipitation seasonality on soil fungal communities. Fungal communities of both tree species are predicted to shift to habitats with a lower annual temperature amplitude and with increasing precipitation during the driest month, but the suitability of these habitats as compared to the present conditions is predicted to decrease in the future.