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Subtropical evergreen broadleaved forests distributed in montane zones of southern China experience seasonal droughts and winter frost. Previously, studies have recognized that xylem anatomy is a determinant of its vulnerability to embolism caused by drought and freezing events. We hypothesized that there is a coordination of xylem resistance to freeze-thaw and drought-induced embolism for the subtropical montane evergreen broadleaved tree species because they are influenced by common xylem structural traits (e.g., vessel diameter). We examined the branch xylem anatomy, resistance to drought-induced embolism (P 50 ), and the percent loss of branch hydraulic conductivity after a severe winter frost (PLC winter ) for 15 evergreen broadleaved tree species in a montane forest in South China. Our results showed that P 50 of the studied species ranged from -2.81 to -5.13 MPa, which was not associated with most xylem anatomical properties except for the axial parenchyma-to-vessel connectivity. These tree species differed substantially in PLC winter , ranging from 0% to 76.41%. PLC winter was positively related to vessel diameter and negatively related to vessel density, vessel group index, and vessel-to-vessel connectivity, but no coordination with P 50 . This study suggests that hydraulic adaptation to frost is important to determine the distributional limit of subtropical montane evergreen woody angiosperms., (© 2024 Scandinavian Plant Physiology Society.)

Forests, the largest terrestrial carbon sinks, play an important role in carbon sequestration and climate change mitigation. Although forest attributes and environmental factors have been shown to impact aboveground biomass, their influence on biomass stocks in species-rich forests in southern China, a biodiversity hotspot, has rarely been investigated. In this study, we characterized the effects of environmental factors, forest structure, and species diversity on aboveground biomass stocks of 30 plots (1 ha each) in natural forests located within seven nature reserves distributed across subtropical and marginal tropical zones in Guangxi, China. Our results indicate that forest aboveground biomass stocks in this region are lower than those in mature tropical and subtropical forests in other regions. Furthermore, we found that aboveground biomass was positively correlated with stand age, mean annual precipitation, elevation, structural attributes and species richness, although not with species evenness. When we compared stands with the same basal area, we found that aboveground biomass stock was higher in communities with a higher coefficient of variation of diameter at breast height. These findings highlight the importance of maintaining forest structural diversity and species richness to promote aboveground biomass accumulation and reveal the potential impacts of precipitation changes resulting from climate warming on the ecosystem services of subtropical and northern tropical forests in China. Notably, many natural forests in southern China are not fully stocked. Therefore, their continued growth will increase their carbon storage over time., Competing Interests: The authors declare no conflict of interest., (© 2024 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.)

Ferns are primitive vascular plants with diverse morphologies and structures. Plant anatomical traits and their linkages can reflect adaptation to the environment; however, these remain are still poorly understood in ferns. The main objective of this study was to explore whether there was structural coordination among and within organs in fern species. We measured 16 hydraulically related anatomical traits of pinnae, petioles, and roots of 24 representative fern species from the tropical and subtropical forest understory and analyzed trait correlation networks. In addition, we examined phylogenetic signals for the anatomical traits and analyzed co-evolutionary relationships. These results indicated that stomatal density and all petiole anatomical traits exhibited significant phylogenetic signals. Evolutionary correlations were observed between the tracheid diameter and wall thickness of the petiole and between the water transport capacity of the petiole and stomatal density. Conversely, anatomical traits of roots (e.g., root diameter) showed no phylogenetic signals and were not significantly correlated with those of the pinnae and petioles, indicating a lack of structural coordination between the below- and above-ground organs. Unlike angiosperms, vein density is unrelated to stomatal density or pinna thickness in ferns. As root diameter decreased, the cortex-to-stele diameter ratio decreased significantly (enhanced water absorption) in angiosperms but remained unchanged in ferns. These differences lead to different responses of ferns to climate change and improve our knowledge of the water adaptation strategies of ferns., (© 2024 Scandinavian Plant Physiology Society.)

Tropical karst habitats are characterized by limited and patchy soil, large rocky outcrops and porous substrates, resulting in high habitat heterogeneity and soil moisture fluctuations. Xylem hydraulic efficiency and safety can determine the drought adaptation and spatial distribution of woody plants growing in karst environments. In this study, we measured sapwood-specific hydraulic conductivity (Ks), vulnerability to embolism, wood density, saturated water content, and vessel and pit anatomical characteristics in the branch stems of 12 evergreen tree species in a tropical karst seasonal rainforest in southwestern China. We aimed to characterize the effects of structural characteristics on hydraulic efficiency and safety. Our results showed that there was no significant correlation between Ks and hydraulic safety across the tropical karst woody species. Ks was correlated with hydraulic vessel diameter (r = 0.80, P < 0.05) and vessel density (r = -0.60, P < 0.05), while the stem water potential at 50 and 88% loss of hydraulic conductivity (P50 and P88) were both significantly correlated with wood density (P < 0.05) and saturated water content (P = 0.052 and P < 0.05, respectively). High stem water storage capacity was associated with low cavitation resistance possibly because of its buffering the moisture fluctuations in karst environments. However, both Ks and P50/P88 were decoupled from the anatomical traits of pit and pit membranes. This may explain the lack of tradeoff between hydraulic safety and efficiency in tropical karst evergreen tree species. Our results suggest that diverse hydraulic trait combination may facilitate species coexistence in karst environments with high spatial heterogeneity., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

The concentration and sorption behavior of 237 Np on the bottom sediments of water bodies in the Far East region of Russia (Lake Khanka and Peter the Great Bay) were studied for the first time. The 237 Np concentrations vary from 1.06 × 10 -6 to 4.43 × 10 -5 mBq g -1 in the bottom sediments of Lake Khanka and from 1.05 × 10 -4 to 2.52 × 10 -3 mBq g -1 for Amur Bay. The experiment on the adsorption of Np on marine and lake sediment showed that it is sorbed through complexation with silicates (albite, leucite). The Np sorption isotherm on marine sediments is described by the Langmuir equation; the distribution coefficients (Kd) of Np vary from 57 to 588 mL g -1 . For lake sediments, the isotherm is described by the Henry equation; the Kd value reaches 935 mL g -1 ., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kuzmenkova Natalia reports financial support was provided by Russian Science Foundation. Hou Xiaolin reports financial support was provided by National Natural Science Foundation of China. Co-author is an assocaited editor in Journal of Environmental radioactivity., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objective: To explore the expression of microRNA-3162-3p in different clinical stages of childhood primary immune thrombocytopenia (ITP) and its significance., Methods: Ninety-six children with ITP were enrolled and divided into new diagnosis group ( n =40), persistent group ( n =30) and chronic group ( n =26) according to the course of disease. 80 healthy children were selected as the control group. Peripheral blood mononuclear cells (PBMNC) of ITP children and healthy children were isolated and cultured, and the expression of microRNA-3162-3p in PBMNC of subjects was detected by real-time fluorescence quantitative PCR. The contents of IL-17, IL-23, IL-10 and TGF-β in PBMNC of subjects were determined by ELISA. The correlation between microRNA-3162-3p and platelet count, IL-17, IL-23, IL-10 and TGF-β was analyzed., Results: Compared with the control group, the expression of microRNA-3162-3p and IL-10 in PBMNC and platelet count of ITP children were significantly decreased（ P < 0.05）, while IL-17, IL-23 and TGF-β were significantly increased ( P < 0.05). With the prolongation of the disease course, the expressions of microRNA-3162-3p and IL-10 in PBMNC and platelet count were significantly decreased（ P < 0.05）, while the expressions of IL-17, IL-23 and TGF-β were significantly increased ( P < 0.05). The expression of microRNA-3162-3p in PBMNC was positively correlated with platelet count and IL-10 ( r =0.716, 0.667), and negatively correlated with IL-17, IL-23, and TGF-β ( r =-0.540, -0.641, -0.560)., Conclusion: MicroRNA-3162-3p expression is significantly reduced in PBMNC of children with ITP, and is involved in the regulation of Th17/Treg imbalance, which can be used as a potential therapeutic target of ITP.