Subtropical Forests In China Research Articles

Germination of shrub species from Chinese subtropical forests: implications for restoration.

Incorporating native shrubs into restoration projects can improve biodiversity conservation and enhance the sustainability of ecosystem functions. Shrubs grow under different forest canopy structures, having varied microclimatic conditions according to forest type and composition. Currently, there is a lack of information on propagation from seed and planting material availability for the utilization of shrubs in forest restoration. In the present study, we evaluated the effects of temperature and light on germination of ten shrub species (Ardisia japonica, Callicarpa cathayana, Callicarpa giraldii var. subcanescens, Deutzia schneideriana, Fraxinus sieboldiana, Hydrangea chinensis, Maesa japonica, Rhododendron simsii, Spiraea japonica var. fortunei and Weigela japonica var. sinica) occurring in subtropical forests in China. No seeds of any species germinated in the coolest thermal regime (5/10 °C), while optimal temperature requirements varied from 10/20 °C to 25/35 °C. Seeds of small-seeded species had higher germination percentages in the light treatments, while larger seeds were not photoblastic. There was no relationship between germination in the light and the seed shape index. Our results may assist in identification of seed traits and suitable shrub species for restoration in specific forest types, thus aiding native forest recovery of structure and composition. Successful recovery leads to enhanced biodiversity, reestablishment of microhabitats and ecological interactions in the forest understorey.

Complementary belowground strategies underlie species coexistence in an early successional forest.

Unravelling belowground strategies is critical for understanding species coexistence and successional dynamics; yet, our knowledge of nutrient acquisition strategies of forest species at different successional stages remains limited. We measured morphological (diameter, specific root length, and root tissue density), architectural (branching ratio), physiological (ammonium, nitrate, and glycine uptake rates) root traits, and mycorrhizal colonisation rates of eight coexisting woody species in an early successional plantation forest in subtropical China. By incorporating physiological uptake efficiency, we revealed a bi-dimensional root economics space comprising of an 'amount-efficiency' dimension represented by morphological and physiological traits, and a 'self-symbiosis' dimension dominated by architectural and mycorrhizal traits. The early pioneer species relied on root-fungal symbiosis, developing densely branched roots with high mycorrhizal colonisation rates for foraging mobile soil nitrate. The late pioneer species invested in roots themselves and allocated effort towards improving uptake efficiency of less-mobile ammonium. Within the root economics space, the covariation of axes with soil phosphorus availability also distinguished the strategy preference of the two successional groups. These results demonstrate the importance of incorporating physiological uptake efficiency into root economics space, and reveal a trade-off between expanding soil physical space exploration and improving physiological uptake efficiency for successional species coexistence in forests.

Effects of multispecies restoration on soil extracellular enzyme activity stoichiometry in Pinus massoniana plantations of subtropical China

Multispecies restoration is considered a feasible practice to tackle the decline in ecosystem services provided by monocultures. However, our understanding of how multispecies restoration influences microbial catabolic and anabolic pathways in coniferous monocultures based on enzymatic stoichiometry remains limited. Here, to assess the microbial resource limitation and carbon (C) use efficiencies in topsoil and subsoil after multispecies restoration, we compared the soil enzyme activities and stoichiometry of two multispecies plantations (broadleaf-oriented transformation and replenishment with local broadleaved trees), two stand ages of Pinus massoniana monocultures, and secondary forests in subtropical China. According to the specific enzyme activities, the labile C decomposition was suppressed but the recalcitrant C decomposition was stimulated in the subsoil in multispecies restorations. Additionally, the vector analysis and microbial acquisition ratios consistently indicated that multispecies plantations aggravated the co-limitation of C and phosphorus (P) in the subsoil and that the limitation was equal to the level of secondary forests. We also found significant decreases in C use efficiencies in multispecies plantations compared with pine monocultures. These findings suggested a trade-off between obtaining multiple nutrients and increasing C use efficiency in the subsoil of forests with different restoration approaches. Furthermore, the microbial acquisition ratios and C use efficiencies were mainly influenced by soil pH and microbial biomass stoichiometry. Overall, our study integrated the microbial resource limitation and C use efficiency to provide an enzymatic perspective for underground C-cycling and nutrient mineralization after forest restoration, highlighting the critical role of multispecies plantations in inducing strong shifts in microbial metabolism, especially in the subsoil.

A ‘Get‐Save‐Return’ process continuum runs on phosphorus economy among subtropical tree species

Abstract Plants allocate nutrients to new leaves via making a cost–benefit trade‐off between root nutrient absorption (‘get’) and leaf nutrient resorption (‘save’). This active trade‐off in nutrient acquisition pathways may cause a passive trade‐off between resorption and decomposition (‘return’). However, whether these nutrient‐associated processes are linked and form a ‘get‐save‐return’ (GSR) continuum, and its linkages with the above‐ground leaf economics spectrum (LES) and the below‐ground mycorrhizal association remain unclear. Here, we present the first empirical evidence of a direct link among multiple nutrient‐associated processes and tested this continuum hypothesis by synchronously integrating root nutrient absorption, leaf nutrient resorption and leaf litter decomposition of 15 co‐occurring tree species hosting either arbuscular mycorrhizal or ectomycorrhizal fungi in subtropical forests of China. Across species, there was an active trade‐off between phosphorus (P) absorption and resorption, which further caused a passive trade‐off between P resorption and leaf litter decomposition, indicating that the GSR continuum exists and runs on P economy. However, these processes associated with nitrogen economy were not well linked. Interestingly, the loading scores of species on the LES were positively correlated with root P absorption, negatively with leaf P resorption and positively with leaf litter decomposition. These linkages indicate that species running in the ‘fast lane’ had greater root P absorption, lower leaf P resorption and faster leaf litter decomposition than species running in the ‘slow lane’, and that the process‐based GSR continuum follows the trait‐based ‘fast‐slow’ LES. Furthermore, the continuum on P economy emerged evidently in the ectomycorrhizal tree species rather than in the arbuscular mycorrhizal tree species, indicating critical control of mycorrhizal association over the continuum. Synthesis. Overall, these results demonstrate the existence of the GSR continuum on tree P economy, which conforms to the economics spectrum theory but varies with mycorrhizal association type. Our findings provide a process‐based framework for mechanistic understanding of the whole plant nutrient economy and ecosystem nutrient cycling, and facilitate improved predictions of biogeochemical models.

Novel Weighting Method for Evaluating Forest Soil Fertility Index: A Structural Equation Model.

Understanding nutrient quantity and quality in forest soils is important for sustainable management of forest resources and maintaining forest ecosystem services. In this study, six soil nutrient indicators, including soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) were measured in five different aged stands of Chinese fir forests in subtropical China. A structural equation model (SEM) was developed based on these soil nutrients indicators in order to better evaluate the soil fertility index (SFI) in these studied forests. The results show that soil nutrient contents changed with the soil depth in different age groups. The SOM decreased in a specific order: over mature > mature > near mature > middle > young stands. The TN content of the soil gradually decreased with increased soil depth throughout all age groups. The SEM indicated that the TN had the highest weight of 0.4154, while the TP had the lowest weight at 0.1991 for estimating the SFI. The weights of other indicators (AN, SOM, AP, and AK) ranged 0.2138−0.3855 in our study. The established SEM satisfied the fitness reference values and was able to accurately describe the forest soil nutrient status through the SFI. The overall SFI values were significantly higher in over mature stands than in young-aged stands and in topsoil than in deeper soil in all examined forests. Soil TN, AP, and AK were the most important nutrient indicators to the evaluation of the SFI in the study sites. The results confirmed that the SEM was suitable to estimate the weights of the SFI and better describe the soil nutrient status in forests. Our research provides an innovative approach to assess a soil nutrient status and soil fertility and provides a scientific basis for accurate implementation of soil nutrient assessment in forest ecosystems.

Mechanisms Underlying Aboveground and Belowground Litter Decomposition Converge over Time under Nutrient Deposition

Decomposition is vital for nutrient cycling and is sensitive to atmospheric nutrient depositions. However, the influences and underlying mechanisms of nutrient deposition on the long-term decomposition of leaves and absorptive roots remain unclear. Here, we explored the responses of leaves and absorptive roots to nutrient deposition (control, +N, +P, and +NP) in Pinus massoniana and Schima superba forests in subtropical China based on two stages (early-stage (1-year) and late-stage (3-year)) of a decomposition experiment. The chemical factions (acid-unhydrolysable residue (AUR), cellulose, and hemicellulose concentrations) and microbial enzymatic activities (hydrolase and oxidase) were also determined. The +N treatment had persistent negative effects on absorptive root decomposition, except for P. massoniana during the late stage. The +P treatment had a positive effect on leaf decomposition in all stages. The +NP treatment had a positive effect on leaf decomposition during the late stage. The increasing decomposition rates of foliar under +P treatment were more correlated with the increasing acid phosphatase activity than chemical factions, indicating a microbial mechanism. The decreasing decomposition rates of roots under +N treatment were weakly correlated with increasing AUR concentrations and strongly correlated with decreasing oxidase activity during the late stage, indicating both chemical and microbial mechanisms. Overall, our findings highlight that, despite contrasting responses to nutrient deposition, the mechanisms underlying aboveground and belowground decomposition tend to converge as decomposition progresses.

Species diversity pattern and its drivers of the understory herbaceous plants in a Chinese subtropical forest

Understory herbaceous plants are an important component of forest ecosystems, playing important roles in species diversity and forest dynamics in forests. However, the current understanding of the biodiversity of forest communities is mostly from woody plants, and knowledge of community structure and species diversity for understory herbaceous plants remains scarce. In a subtropical forest in China, we investigated understory vascular herbaceous diversity from 300 plots (5 × 5 m) in the main growing season. In this study, we analyzed the community structure and diversity pattern of the understory herbaceous community and linked the species diversity pattern to both abiotic and biotic environments. We found a rich diversity of understory herbaceous communities in this forest (81 species belonging to 55 genera), and floristic elements at the genus level were dominated by tropical elements, followed by temperate elements. The diversity pattern of the understory herbaceous showed a significant habitat preference, with the highest diversity in the lowland valleys and then followed by in middle slopes. In addition, herbaceous diversity was significantly affected by both abiotic factors (such as terrain convexity) and biotic factors (such as the diversity of surrounding woody plants). Our study indicated that species diversity of understory herbaceous showed a remarkable habitat preference, such as lowland valleys, and highlighted the importance of both abiotic and biotic environments in driving herbaceous diversity patterns in the subtropical forest understory.

Litter, Root, and Mycorrhiza Input Affected Soil Microbial Community Structure in Schima superba Pure Forest in Subtropical China

During forest vegetation rehabilitation, changes in aboveground litter and underground root inputs affect soil microbial communities. Clarifying the effects of forest ecosystem carbon inputs on soil microbial community structure can provide a theoretical basis for the microbial driving mechanism of soil fertility evolution and ecosystem rehabilitation of vegetation rehabilitation in degraded red soil. Our research focuses on a Schima superba pure forest recovered from eroded and degraded red soil in a subtropical region. Five treatments were set as follows: control treatment (CT), mycorrhiza (M), root + mycorrhiza (RM), litter + root + mycorrhiza (LRM), and double litter + root + mycorrhiza (DLRM). We used Illumina HiSeq technology to study the effects of different organic carbon inputs on soil microbial community structure. The results showed that all organic carbon input treatments reduced the total population of soil bacteria by 55–79%; M, RM, and DLRM treatments increased the quantity of operational taxonomic units (OTUs) by 25–37%, ACE index by 25–34%, and Chao1 index by 28–39%. Acidobacteria, Proteobacteria, and Actinobacteria were the dominant bacteriophyta in the Schima superba pure forest soil. The relative abundance of Alphaproteobacteria decreased by 55% under LRM treatment, and Thermoleophilia increased by 81% under M treatment. The dominant fungal phyla were Basidiomycota and Ascomycota. RM, LRM, and DLRM treatments reduced the relative abundance of Sordariomycetes by 46–64% and increased the relative abundance of Mortierellomycetes by 251–615%. The order of effects of different organic carbon inputs on the bacterial community composition at the phylum level was LRM > RM > M > DLRM and that on the fungal community composition was DLRM > LRM and RM > M. Alphaproteobacteria, Thermoleophilia, Sordariomycetes, and Mortierellomycetes were the main microbial groups affected by changes in organic carbon inputs. Soil organic carbon and total nitrogen were the key factors affecting the change of Mortierellomycetes. The bacterial community mainly affected the activity of soil acid invertase, while the fungal community affected the activities of various enzymes, with positive or negative effects. We concluded that the organic carbon inputs changed the species and quantity of soil microorganisms in the Schima superba forest, and the influence of organic carbon input on the fungal community structure was greater than that of bacteria.

Environmental heterogeneity determines beta diversity and species turnover for woody plants along an elevation gradient in subtropical forests of China.

To understand how diversity change with environmental gradients is a fundamental aim for clarifying biodiversity pattern and underlying mechanisms. Here, we studied the characteristics of beta diversity and its partitioning components for woody plant communities along an elevation gradient in subtropical forests of China, and thus explored the effects of environment and space on beta diversity. By using the Classification Method, we divided the species of Daiyun Mountain into four groups, namely generalists, high-elevation specialists, low-elevation specialists and rare species. We then calculated beta diversity, and partitioned it into species turnover and species nestedness. dbRDA was conducted to analyze the impact of spatial and environmental distance on the beta diversity and its partitioning components. Beta diversity comprised of two components: species turnover and species nestedness. Species turnover was the larger contributor to total beta diversity, and it tended to increase as elevation changed. This pattern can be attributed to environmental heterogeneity, resulting in the differentiation of specialized species and an increase in species turnover and beta diversity. Environmental factors, specifically the air temperature and slope, played a significant role in explaining the variation of turnover and beta diversity. However, spatial variables did not have a significant influence on these patterns. The maintenance of biodiversity in Daiyun Mountain was mainly governed by environmental filtering. Future conservation efforts should focus on strengthening the protection of specialized species in high elevation areas.

臭氧污染对亚热带森林生产力和生物量的影响——以鼎湖山为例

PDF HTML阅读 XML下载 导出引用 引用提醒 臭氧污染对亚热带森林生产力和生物量的影响——以鼎湖山为例 DOI: 10.5846/stxb202110313054 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（41971135）；国家自然科学基金项目（41801082）；国家自然科学基金项目（41630532）；中国地质大学（武汉）科研启动基金资助项目（162301192642） Impact of ozone pollution on productivity and biomass of subtropical forests: A case study in Dinghushan Author: Affiliation: Fund Project: China Postdoctoral Science Foundation 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:全球气候变化背景下，我国近地面臭氧浓度不断增加，已严重威胁到森林生态系统。但是，目前臭氧污染影响我国亚热带森林生物量的研究仍然具有较高的不确定性。本研究比较了不同模型和不同参数化方案评估的鼎湖山森林和林下草地生物量损失率的差别，比较了鼎湖山阔叶林和针叶林以及林下草地的生物量损失率与总初级生产力（GPP）损失率的一致性。2015-2016年臭氧污染造成的鼎湖山阔叶林生物量损失率为11.3%-11.69%，针叶林生物量损失率为3.97%-3.68%，草地生物量损失11.2%-14.6%；不同参数化方案估计的鼎湖山阔叶林的生物量损失率在9%-13%之间，针叶林的生物量损失率在3.68%-4.4%之间变化，草地在11.2%-14.6%之间。基于臭氧剂量响应关系模型估算的阔叶林GPP损失率为10%-12.6%，针叶林GPP损失率为1.81%-2.6%，草地GPP损失率为3.2%-3.3%。总的来看，鼎湖山阔叶林和针叶林的生物量和GPP损失具有较高的一致性，阔叶林生物量和GPP的损失率明显高于针叶林生物量和GPP的损失率。 Abstract:In the context of global climate change, the increasing surface ozone concentration in China has seriously threatened the forest ecosystem. However, the research on the effects of ozone pollution on the biomass of subtropical forests in China is still uncertain. In this study, we compared the difference of biomass loss rate between forest and understory grassland assessed by different models and different parameterization schemes, and compared the consistency of biomass loss rate and total primary productivity (GPP) loss rate between broad-leaved forest and coniferous forest and understory grassland in Dinghushan. The biomass loss rates of broad-leaved forest, coniferous forest and grassland were 11.3% to 11.69%, 3.97% to 3.68% and 11.2% to 14.6%, respectively, caused by ozone pollution in Dinghushan during 2015-2016. The biomass loss rate of broad-leaved forest, coniferous forest and grassland varied from 9% to 13%, 3.68% to 4.4% and 11.2% to 14.6%, respectively. The GPP loss rate of broad-leaved forest, coniferous forest and grassland was estimated to be 10% to 12.6%, 1.81% to 2.6% and 3.2% to 3.3% based on ozonometry response model. In general, the biomass and GPP loss of broad-leaved forest and coniferous forest in Dinghushan had a high consistency, and the loss rate of broad-leaved forest biomass and GPP was significantly higher than that of coniferous forest. 参考文献 相似文献 引证文献

Ice storm damage to oak forests in subtropical China

Ice storms, as important sources of frequent and injurious disturbances, drive forest dynamics in the Northern Hemisphere. However, stand-level differential vulnerability to ice storms and the associated factors that predispose forest stands remain unclear. This is particularly concerning in the subtropics where the frequency of ice storms is predicted to increase with global warming. Here we assessed how the impact on three forest stands (early and late secondary-growth forests, and old-growth forests) differed after an extreme ice storm during 20–21 March 2022, and identified the abiotic and biotic factors that determine the damage intensity in the Shennongjia World Natural Heritage Site, a biodiversity conservation hotspot in central China. We found a stand-specific ‘mid-domain effect’ where the late secondary-growth forest sustained the most severe damage, the early secondary-growth forest sustained the least, and the old-growth forest suffered an intermediate amount. ‘Crown broken’ was the most severe damage type across all three forest stands, although the proportion of ‘branch broken’ was also high in the old-growth forest. Topography played a significant role in determining the vulnerability of the early secondary-growth forest to severe ice storms whereas the forest structure and composition were important factors in explaining the damage rates in the old-growth forest, although they differed among the damage categories. In contrast, topography, forest structure and composition generally explain the intensity of damage in the late secondary-growth forests. Our results highlight that, in subtropical forests, the intensity of damage caused by severe ice storms and related determining factors are stand-level dependent. We also suggest exploring potential management strategies (e.g., slow-growing hardwood species that can resist storms should be the main species for reforestation in early secondary-growth forests) to mitigate the risk of future severe ice storms, as well as other wind-related climatic extremes.

Assessing the Potential Distribution of a Vulnerable Tree under Climate Change: Perkinsiodendron macgregorii (Chun) P.W.Fritsch (Styracaceae)

Species adaptation and their response to the warming climate offer understanding into the present geographical distribution and may assist in improving predictions regarding the expected response to future climate change. As a result, assessing the distribution and potentially suitable habitats is key for conserving important vulnerable species such as Perkinsiodendron macgregorii, a rare tree species of high ornamental value distributed only in the subtropical forests of China. In this study, 101 sampling points distributed in China and 11 climatic variables were selected and imported into the maximum entropy model (MaxEnt). We simulated the spatiotemporal dynamics of potential habitats under past, current, and future (2050s and 2070s) scenarios and found that the total suitable area for P. macgregorii is 1.67 × 106 km2 in recent times. This area is mainly located in seven provinces of southern China (Zhejiang, Anhui, Jiangxi, Fujian, Hunan, Guangdong, and Guangxi). The habitat centroid of P. macgregorii has been in Jiangxi province from the past to the 2070s. In both the lowest and the highest emission scenarios (RCP2.6 and RCP8.5), the potential distribution of P. macgregorii will slightly increase in the 2070s, indicating that climate change may have little effect on its distribution. The precipitation of the warmest quarter (bio_18) is the most important climatic factor, with an optimum range of 487.3–799.8 mm. Our work could help make scientific strategies for in situ and ex situ conservation of P. macgregorii.

Effects of on- and off-year management practices on the soil organic C fractions and microbial community in a Moso bamboo (Phyllostachys edulis) forest in subtropical China.

On- and off-year management practices are usually adopted in Moso bamboo (Phyllostachys edulis) forests to achieve higher productivity. However, little is known about the effects of these management practices on soil C sequestration and microbial community structure. In the present study, soil nutrient content, organic C fractions, and bacterial and fungal communities were comparatively investigated in on- and off-year bamboo stands. The results showed that soil organic C (SOC), alkali-hydrolyzable N (AN), and available P (AP) in the on-year were significantly lower (p ≤ 0.05) than those in the off-year. Among the different soil organic C fractions, easily oxidizable organic C (EOC), microbial biomass C (MBC), Ca-bound SOC (Ca-SOC), and Fe/Al-bound SOC (Fe/Al-SOC) also had significantly higher contents in the off-year than in the on-year, with MBC and EOC decreasing by 56.3% and 24.5%, respectively, indicating that both active and passive soil organic C pools increased in the off-year. However, the alpha diversities of both soil bacteria and fungi were significantly lower in the off-year soils than in the on-year soils. The bacterial taxa Actinobacteria, Planctomycetes, WPS-2, Acidothermus, Candidatus_Solibacter, Burkholderia-Caballeronia-Paraburkholderia, and Candidatus_Xiphinematobacter were increased in off-year soils relative to on-year soils. Meanwhile, fungal taxa Ascomycota, Mortierella, Hypocrea, Cryptococcus, Clitopilus, and Ceratocystis were significantly increased in on-year soils. Soil pH, SOC, AP, MBC, EOC, and Ca-SOC were significantly correlated with bacterial and fungal communities, with soil pH being the most important driving factor for the shift in bacterial and fungal communities. Our findings showed that the studied bamboo forest possessed an inherent restorative ability in the off-year, which can reverse the soil nutrient and C depletion in the on-years and ensure soil fertility in the long term.

Impact of Aspect on Arbuscular Mycorrhizal Fungal Diversity and Community Composition in a Natural Toona ciliata var. pubescens Forest in Subtropical China

The aspect can affect plant communities and soil physical and chemical properties through different microclimates. However, little is known about the effect of aspect on arbuscular mycorrhizal (AM) fungal diversity and community composition, although AM fungi are beneficial for plant nutrient absorption and natural restoration. In this study, AM fungal community and diversity distribution patterns in the rhizosphere soil and roots of seven widespread plants in a natural Toona ciliata var. pubescens (Tc) forest on the north-facing (NF) aspect and south-facing (SF) aspect were investigated using Illumina PE250 high-throughput sequencing in the Guanshan National Nature Reserve, Jiangxi Province, China. Our results exhibited that aspect did not affect AM fungal diversity but significantly affected AM fungal community structure and composition. Glomeraceae was the most common and abundant family in the Tc natural forest. The Glomeromycota sequence proportion of root AM fungal community was significantly larger on NF than on SF (p < 0.05). The relative abundance of Acaulosporaceae of root AM fungal community differed significantly with aspect, being greater on NF than on SF (p < 0.05). In addition, the number of Glomeromycota sequences was significantly larger on SF than on NF, while the number of OTUs and the relative abundance of unclassified fungi in rhizosphere soil in Tc showed the opposite trend (p < 0.05). The soil properties (organic matter, nitrogen, potassium, phosphorus, and pH) were significantly correlated with these changes. These findings indicate that the habitat of NF with low insolation, high soil moisture, and high nutrient content might promote the functional realization of AM fungi; the habitat of SF with high insolation, low soil moisture, and low soil nutrient content might be beneficial for the proliferation and preservation of AM fungal groups. This study provides important information on the ecological processes of AM fungal community construction and microbiological mechanisms in natural Tc forests.

Soil Fungal Diversity and Functionality Changes Associated with Multispecies Restoration of Pinus massoniana Plantation in Subtropical China

Soil fungi play a critical role in the carbon and nutrient cycling of forest ecosystems. Identifying the composition of soil fungi in response to the broadleaf restoration of Pinus massoniana plantation is essential for exploring the mechanistic linkages between tree species and ecological processes, but remains unexplored. We compared the shifts in soil fungal diversity and guilds by high–throughput sequencing between two P. massoniana plantations at different stand ages, two modes of restoration with broadleaf trees, and a secondary forest in subtropical China. We found that soil fungal taxonomic and functional compositions significantly differed among forests. The highest Chao 1, Shannon, and phylogenetic diversity indices were consistently observed in the two P. massoniana monocultures, followed by the two modes of broadleaf mixing, and the secondary forests. Fungal communities transitioned from Ascomycota-dominated at P. massoniana plantations to Basidiomycota-dominated at other forests in the topsoil. Furthermore, saprotrophs and symbiotrophs were favoured in plantations and secondary forests, respectively. Soil pH exerted the most significant effect on the relative abundance of Ascomycota and Rozellomycota, as well as the saprotrophs. Moreover, the dominant phyla of Ascomycota, Mucoromycota, and Rozellomycota were negatively related to soil microbial biomass nitrogen, ammonium nitrogen, and total nitrogen contents; however, Mortierellomycota benefited from the elevated soil ammonium nitrogen content. On the other hand, soil nitrate nitrogen and available phosphorus contents strongly and negatively influenced the ectomycorrhizal fungi, while the other fungal guilds were mainly affected by soil pH. Our findings guide an evaluation of the consequences of forest restoration and contribute to an improved understanding of the mechanisms behind soil biogeochemical cycling in subtropical forest ecosystems.

Tree diversity increases soil C and N stocks of secondary forests in subtropical China

Carbon (C) and nitrogen (N) stocks are important for food security and mitigation of climate change, also could be likely affected by tree diversity. However, a detailed evaluation of the relationships between tree species diversity and stand biomass C (AGC), and the C and N stocks of stand litter and soil is still scant, especially in secondary forests. Thus, we assessed the associations between tree species diversity (i.e., Shannon-Wiener index) and the AGC stock, the C and N stocks in stand litter and soil [soil organic carbon (SOC), N, microbial biomass fractions (MBC and MBN), heavy fractions (HFOC and HFON) and mineral associated factions (MAOC and MAON)] at the plot level (25 m × 25 m) in mature secondary forests in subtropical China. We also used the structural equation model (SEM) to explore the underlying mechnism by which tree diversity drives the AGC stock and the C and N stocks in stand litter and soil. We found that the tree species diversity decreased AGC stock via the dominant tree biomass C stock. However, the tree species diversity enhanced the C and N stocks in stand litter mainly via affecting conifer proportion, and the SOC and N stocks at the depth of 0–40 cm via increasing their stable factions (i.e., heavy fractions and mineral associated factions). We also observed the tree species diversity had positive effects on the stocks of MBC, HFOC and HFON in soil epipedon, and had non-significant effects on the stocks of MBN, MAOC and MAON. Our results revealed that tree species diversity can elevate the soil C and N stocks and their stability in the subtropical secondary forests of China.

Temporal Acoustic Patterns of the Oriental Turtle Dove in a Subtropical Forest in China

There is an abundance of bird species in subtropical areas, but studies on the vocal behavior of non-passerines in subtropical regions are limited. In this study, passive acoustic monitoring was used to investigate the temporal acoustic patterns of the vocal activities of the Oriental Turtle Dove (Streptopelia orientalis) in Yaoluoping National Nature Reserve (YNNR) in eastern China. The results show that the vocal production of the Oriental Turtle Dove exhibited a seasonal variation, peaking in the period April–August. Additionally, its diurnal vocal activity displayed a bimodal pattern in late spring and summer, with the first peak in the morning and a secondary peak at dusk. Among weather factors, temperature significantly affected the temporal sound pattern of the Oriental Turtle Dove, instead of humidity and precipitation. This study, which was focused on sound monitoring technology, provides knowledge for further research on bird behavior and ecology. In the future, long-term sound monitoring could be used for managing and conserving bird biodiversity.

Community of soil-inhabiting myxomycetes shares similar assembly mechanisms with fungi, and is affected by bacterial community in subtropical forests of China

Myxomycetes (Myxogastrea) are found in soil as myxamoebae and are a major component of the soil protist flora. Yet, our understanding of the drivers of myxamoebae community assembly lags far behind that of other protist groups. In this study we simultaneously investigate the spatial patterns of myxamoebae and their prey (bacteria and fungi communities) across eight subtropical forests in China, and aim to identify the ecological processes that determine the community assembly of myxamoebae. We found that all three microbial communities exhibited significant distance–decay relationships, with a higher degree of community concordance between myxamoebae and fungi than between myxamoebae and bacteria. The community turnover of both myxamoebae and fungi was primarily influenced by deterministic processes, whereas bacterial assembly was dominant by stochastic processes. Variation partitioning analysis showed that bacterial community structure explained the largest portion of the community turnover of myxamoebae, followed by spatial factors. Co-occurrence network analyses further revealed that myxamoebae had more potential interactions with bacteria than fungi, but did not target specific bacterial or fungal taxa. Overall, the significant effects of biotic and spatial factors on myxamoebae community assembly are critical to deciphering the distribution and function of these ecologically important microorganisms in soil environments.

The morphological and anatomical study of Wisteria sinensis leaves

Chinese wisteria (Wisteria sinensis), Glycine chinensis, is a genus of treelike deciduous lianas from the legume family (Fabaceae). In natural conditions, Glycine chinensis is found in the subtropical forests of China, Korea and Japan. Nowadays, the plant is widely cultivated in European countries. Leaves of the plant exhibit the antioxidant,cytostatic effect, flowers inhibit the growth of tubercle bacilli. The seeds are used in Chinese medicine to treat cardiovascular diseases and as a diuretic. Aim. To study macro- and microscopic features of Chinese wisteria leaves for standardization of the medicinal plant raw material and development of the quality control method. Materials and methods. The study object was the leaves of Chinese wisteria harvested in the period of mass flowering in the Kyiv region and the Autonomous Republic of Crimea. The morphological features were studied visually. Preparations from the leaf surface were prepared according to conventional methods. Results and discussion. The main morphological and anatomical features of Chinese wisteria leaves have been determined. Macroscopic features include complex unpaired leaves that have a common petiole and its continuation – rachis, on which there are five pairs of opposite leaves and one apical one. The leaves are large, do not have a toothed edge, pubescent at first, but eventually become smooth; microscopic signs are the dorso-ventral type of theleaf blade structure. The epidermis is covered with a cuticle. The cells of the upper epidermis are parenchymal, slightly convoluted, with evenly thickened membranes. Above the vein, the cells are prosenchymal, elongated along the vein. The lower epidermis is represented by cells of various shapes, parenchymal or having a somewhat elongated shape, sinuous-walled, polygonal. Stomata are frequent and oval. The stomatal apparatus is of anisocyte type. There are numerous hairs along the central vein and on the petiole. The petiole of the leaf has a rounded shape. In the center there is a single conductive bundle surrounded by parenchymal cells. The epidermis consists of small erect cells. There are numerous simple unicellular hairs. The cross-section of the rachis has an oval-triangular shape, the tubercles are ribshaped. Stomata are present. Conclusions. As a result of the studies, the main macroscopic and microscopic features of Chinese wisteria leaves have been determined; they will be used to standardize the medicinal plant raw material and develop the quality control method.

Soil organic carbon primarily control the soil moisture characteristic during forest restoration in subtropical China

Soil organic carbon (SOC) is a crucial component of the soil carbon pool that regulates fundamental soil properties and water status. In the global context of restoring vegetation, the soil carbon-water coupling relationship has gained attention. In particular, the regulatory mechanism of SOC on soil moisture requires further research. In this study, three typical forests in subtropical China were chosen as restoration sequences to investigate the changes in SOC and soil moisture during subtropical forest restoration and its regulation mechanisms: broadleaf-conifer mixed forest (EF), broad-leaved forest (MF), and old-growth forest (LF). The soil water content (35.71 ± 1.52%), maximum water holding capacity (47.74 ± 1.91%), capillary water holding capacity (43.92 ± 1.43%), and field water holding capacity (41.07 ± 1.65%) in LF were significantly higher than those in EF (p < 0.01). As forest restoration progressed, the amount of litter returning to the soil increased gradually, and the SOC content (0–100 cm) increased from 9.51 ± 1.42 g/kg (EF) to 15.60 ± 2.30 g/kg (LF). The SOC storage increased from 29.49 ± 3.59 to 42.62 ± 5.78 Mg/ha. On one hand, forest restoration led to a change in SOC content, which optimizes the soil structure and enhances soil porosity (path coefficient of 0.537, p < 0.01), further leading to a change in soil water content (path coefficient of 0.940, p < 0.01). On the other hand, the increase in SOC influenced the change in soil nutrient content, i.e., total nitrogen (TN) and total phosphorus (TP) (path coefficient of 0.842, p < 0.01). Changes in SOC and soil nutrients stimulated changes in the stoichiometric ratio, i.e., C:P and N:P (path coefficients of 0.988 and –0.968, respectively, p < 0.01), and the biological activity in soil changed appropriately, which eventually led to a change in soil water content (path coefficient of –0.257, p < 0.01). These results highlight the changes in SOC and soil water content (SWC), as well as the mechanism of SOC controlling SWC as a result of vegetation restoration, which is of tremendous importance for advancing our understanding of the eco-hydrological process of subtropical forest restoration.