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Plasmonic materials can generate strong electromagnetic fields to boost the Raman scattering of surrounding molecules, known as surface-enhanced Raman scattering. However, these electromagnetic fields are heterogeneous, with only molecules located at the 'hotspots', which account for ≈ 1% of the surface area, experiencing efficient enhancement. Herein, we propose patterned plasmonic trimers, consisting of a pair of plasmonic dimers at the bilateral sides and a trap particle positioned in between, to address this challenge. The trimer configuration selectively directs probe molecules to the central traps where 'hotspots' are located through chemical affinity, ensuring a precise spatial overlap between the probes and the location of maximum field enhancement. We investigate the Raman enhancement of the Au@Al2O3-Au-Au@Al2O3 trimers, achieving a detection limit of 10−14 M of 4-methylbenzenethiol, 4-mercaptopyridine, and 4-aminothiophenol. Moreover, single-molecule SERS sensitivity is demonstrated by a bi-analyte method. Benefiting from this sensitivity, our approach is employed for the early detection of lung tumors using fresh tissues. Our findings suggest that this approach is sensitive to adenocarcinoma but not to squamous carcinoma or benign cases, offering insights into the differentiation between lung tumor subtypes. SERS spectroscopy critically relies on the accumulation of analyte molecules in electromagnetic 'hotspots'. Here, the authors demonstrate plasmonic trimers with central particles that act as chemical traps, enabling the subtyping of lung tumors using fresh tissue samples. [ABSTRACT FROM AUTHOR]

The quantification of large-scale leaf-age-dependent leaf area index has been lacking in tropical and subtropical evergreen broadleaved forests (TEFs), despite the recognized importance of leaf age in influencing leaf photosynthetic capacity in this biome. Here, we simplified the canopy leaves of TEFs into three age cohorts (i.e., young, mature, and old, with different photosynthesis capacities; i.e., Vc,max) and proposed a novel neighbor-based approach to develop the first gridded dataset of a monthly leaf-age-dependent leaf area index (LAI) product (referred to as Lad-LAI) at 0.25 ∘ spatial resolution over the continental scale during 2001–2018 from satellite observations of sun-induced chlorophyll fluorescence (SIF) that was reconstructed from MODIS and TROPOMI (the TROPOspheric Monitoring Instrument). The new Lad-LAI products show good performance in capturing the seasonality of three LAI cohorts, i.e., young (LAI young ; the Pearson correlation coefficient of R=0.36), mature (LAI mature ; R=0.77), and old (LAI old ; R=0.59) leaves at eight camera-based observation sites (four in South America, three in subtropical Asia, and one in the Democratic Republic of the Congo (DRC)) and can also represent their interannual dynamics, validated only at the Barro Colorado site, with R being equal to 0.54, 0.64, and 0.49 for LAI young , LAI mature , and LAI old , respectively. Additionally, the abrupt drops in LAI old are mostly consistent with the seasonal litterfall peaks at 53 in situ measurements across the whole tropical region (R=0.82). The LAI seasonality of young and mature leaves also agrees well with the seasonal dynamics of the enhanced vegetation index (EVI; R=0.61), which is a proxy for photosynthetically effective leaves. Spatially, the gridded Lad-LAI data capture a dry-season green-up of canopy leaves across the wet Amazonian areas, where mean annual precipitation exceeds 2000 mm yr -1 , consistent with previous satellite-based analyses. The spatial patterns clustered from the three LAI cohorts also coincide with those clustered from climatic variables over the whole TEF region. Herein, we provide the average seasonality of three LAI cohorts as the main dataset and their time series as a supplementary dataset. These Lad-LAI products are available at 10.6084/m9.figshare.21700955.v4 (Yang et al., 2022). [ABSTRACT FROM AUTHOR]

The impacts of enhanced nitrogen (N) deposition on the global forest carbon (C) sink and other ecosystem services may depend on whether N is deposited in reduced (mainly as ammonium) or oxidized forms (mainly as nitrate) and the subsequent fate of each. However, the fates of the two key reactive N forms and their contributions to forest C sinks are unclear. Here, we analyze results from 13 ecosystem-scale paired 15N-labelling experiments in temperate, subtropical, and tropical forests. Results show that total ecosystem N retention is similar for ammonium and nitrate, but plants take up more labelled nitrate ( 20 15 25 %) ( mean minimum maximum ) than ammonium ( 12 8 16 %) while soils retain more ammonium ( 57 49 65 %) than nitrate ( 46 32 59 %). We estimate that the N deposition-induced C sink in forests in the 2010s is 0.72 0.49 0.96 Pg C yr−1, higher than previous estimates because of a larger role for oxidized N and greater rates of global N deposition. A study using paired 15N tracers shows atmospheric N deposited in oxidized form is more likely retained by trees, while the reduced form is retained in soil. The authors argue that this is a greater contribution of deposited N to the global forest C sink than previously reported. [ABSTRACT FROM AUTHOR]

Aims Understanding variation and coordination of leaf traits at multiscales along elevational gradients can help predict the likely responses of dominant species to climate change. We seek to determine the extent to which variation in leaf stomatal, anatomical and morphological traits is associated with environmental factors, and whether ecological strategies of Cyclobalanopsis species shift with elevations. Methods In a tropical forest landscape in Jianfengling, South China, we determined leaf traits related to stomata, anatomy and morphology of six evergreen oak species (Cyclobalanopsis bambusaefolia , C. hui , C. patelliformis , C. fleuryi , C. tiaoloshanica and C. phanera) along a long elevational gradient (400–1400 m above sea level). Important Findings We found that stomatal density and stomatal pore index increased, whereas spongy mesophyll thickness to leaf thickness ratios decreased, significantly with elevation. The leaf area and leaf dry matter content increased and decreased, respectively, with elevation. Variations in stomatal, anatomical and morphological traits were mainly correlated to the mean annual temperature, mean annual sum precipitation and soil pH. At low and high elevations, the oak species exhibited strong stress tolerance combined with competition strategy, while they shifted toward more clearly the competitive strategy at intermediate elevations. And the changes in soil phosphorus concentration and soil pH along the elevation may drive the shift of ecological strategy. The results showed that the dominant oak species in tropical forests respond to environmental change by modulating traits at multiple levels, from that of the individual cell, through tissue and up to the whole leaf scale. [ABSTRACT FROM AUTHOR]

Au nanodots decorated Cu2O nanooctahedrons were fabricated by a facile liquid-phase process combined with a galvanic replacement reaction for nonenzyme glucose detection. A simple rapid test strip based on the nanooctahedrons was proposed to evaluate the possibility of commercial application in nonenzymatic glucose detection. This test strip shows excellent response toward glucose. Linear response was obtained over a concentration ranging from 0.05 mM to 15 mM, and the detection accuracy is 0.05 mM. The good detection performance in selectivity, stability, and feasibility proving the great potential application in human blood glucose monitoring. This study demonstrated the possibility of a high-performance nonenzyme glucose test strip based on metal-oxide nanostructures decorated by catalysts. [ABSTRACT FROM AUTHOR]

The effects of nitrogen (N) deposition on forests largely depend on its fate after entering the ecosystem. While several studies have addressed the forest fate of N deposition using 15N tracers, the long‐term fate and redistribution of deposited N in tropical forests remains unknown. Here, we applied 15N tracers to examine the fates of deposited ammonium (NH4+) and nitrate (NO3‐) separately over 3 years in a primary and a secondary tropical montane forest in southern China. Three months after 15N tracer addition, over 60% of 15N was retained in the forests studied. Total ecosystem retention did not change over the study period, but between 3 months and 3 years following deposition 15N recovery in plants increased from 10% to 19% and 13% to 22% in the primary and secondary forests, respectively, while 15N recovery in the organic soil declined from 16% to 2% and 9% to 2%. Mineral soil retained 50% and 35% of 15N in the primary and secondary forests, with retention being stable over time. The total ecosystem retention of the two N forms did not differ significantly, but plants retained more 15NO3‐ than 15NH4+ and the organic soil more 15NH4+ than NO3‐. Mineral soil did not differ in 15NH4+ and 15NO3‐ retention. Compared to temperate forests, proportionally more 15N was distributed to mineral soil and plants in these tropical forests. Overall, our results suggest that atmospherically deposited NH4+ and NO3‐ is rapidly lost in the short term (months) but thereafter securely retained within the ecosystem, with retained N becoming redistributed to plants and mineral soil from the organic soil. This long‐term N retention may benefit tropical montane forest growth and enhance ecosystem carbon sequestration. [ABSTRACT FROM AUTHOR]

Histone demethylases are promising therapeutic targets as they play fundamental roles for survival of Mixed lineage leukemia rearranged acute leukemia (MLLr AL). Here we focused on the catalytic Jumonji domain of histone H3 lysine 9 (H3K9) demethylase JMJD1C to screen for potential small molecular modulators from 149,519 natural products and 33,765 Chinese medicine components via virtual screening. JMJD1C Jumonji domain inhibitor 4 (JDI‐4) and JDI‐12 that share a common structural backbone were detected within the top 15 compounds. Surface plasmon resonance analysis showed that JDI‐4 and JDI‐12 bind to JMJD1C and its family homolog KDM3B with modest affinity. In vitro demethylation assays showed that JDI‐4 can reverse the H3K9 demethylation conferred by KDM3B. In vivo demethylation assays indicated that JDI‐4 and JDI‐12 could induce the global increase of H3K9 methylation. Cell proliferation and colony formation assays documented that JDI‐4 and JDI‐12 kill MLLr AL and other malignant hematopoietic cells, but not leukemia cells resistant to JMJD1C depletion or cord blood cells. Furthermore, JDI‐16, among multiple compounds structurally akin to JDI‐4/JDI‐12, exhibits superior killing activities against malignant hematopoietic cells compared to JDI‐4/JDI‐12. Mechanistically, JDI‐16 not only induces apoptosis but also differentiation of MLLr AL cells. RNA sequencing and quantitative PCR showed that JDI‐16 induced gene expression associated with cell metabolism; targeted metabolomics revealed that JDI‐16 downregulates lactic acids, NADP+ and other metabolites. Moreover, JDI‐16 collaborates with all‐trans retinoic acid to repress MLLr AML cells. In summary, we identified bona fide JMJD1C inhibitors that induce preferential death of MLLr AL cells. What's new? Histone demethylase JMJD1C represents one of the most promising therapeutic targets for a subtype of acute leukemia with inferior prognosis, MLLr AL. Here, the authors focused on the catalytic Jumonji domain of JMJD1C to screen for potential small molecular modulators from 149,519 natural products and 33,765 Chinese medicine components via virtual screening. They identified structurally‐akin JMJD1C inhibitors with the ability to selectively kill MLLr AL cells, regulate MLLr AL cell metabolism, and collaborate with all‐trans retinoic acid to repress MLLr AL. The findings helped identify the backbone of an inhibitor class that holds promise for the treatment of MLLr AL. [ABSTRACT FROM AUTHOR]

Bacteria are the highest abundant microorganisms in the soil. To investigate bacteria community structures, diversity, and functions, contrasting them in four different seasons all the year round with/within two different forest type soils of China. We analyzed soil bacterial community based on 16S rRNA gene sequencing via Illumina HiSeq platform at a temperate deciduous broad-leaved forest (Baotianman, BTM) and a tropical rainforest (Jianfengling, JFL). We obtained 51,137 operational taxonomic units (OTUs) and classified them into 44 phyla and 556 known genera, 18.2% of which had a relative abundance >1%. The composition in each phylum was similar between the two forest sites. Proteobacteria and Acidobacteria were the most abundant phyla in the soil samples between the two forest sites. The Shannon index did not significantly differ among the four seasons at BTM or JFL and was higher at BTM than JFL in each season. The bacteria community at both BTM and JFL showed two significant (P < 0.05) predicted functions related to carbon cycle (anoxygenic photoautotrophy sulfur oxidizing and anoxygenic photoautotrophy) and three significant (P < 0.05) predicted functions related to nitrogen cycle (nitrous denitrificaton, nitrite denitrification, and nitrous oxide denitrification). We provide the basis on how changes in bacterial community composition and diversity leading to differences in carbon and nitrogen cycles at the two forests. [ABSTRACT FROM AUTHOR]

In most real-world planning domains, it is important to have flexible executive time against uncertainty and disturbance of environment. Execution time can be propagated from dispatchable Simple Temporal Network (STN), which is obtained from filtering the distance graph of STN. To minimise the execution latency, computation of dispatchable STN should be improved. In the previous works, all-pairs shortest paths (APSP) algorithm is used to compute distance graph of STN, so the redundant constraints should be processed in the following filtering process. In this paper, an improved algorithm named Dispatchabile Partial Path (DPP) algorithm, which uses the P3C algorithm to replace APSP and compute the shortest distance of vertices, is presented. To ensure the correctness of dispatchable STN, triangulation uses vertices ordering sorted by execute time. The filtering process is also simplified by time-sorting vertices. Experimental evidence confirms that the DPP algorithm outperforms previous algorithms based on APSP. [ABSTRACT FROM AUTHOR]

An influenza pandemic remains a major public health concern. A key strategy to prevent a pandemic is to stockpile and pre-position stable influenza vaccine to allow rapid deployment in response to an outbreak. However, most influenza vaccines today are formulated as liquids that are stable only within a temperature range of 2°C to 8°C and require use of a cold chain, making vaccine transportation, distribution, and storage complicated and expensive, particularly for developing countries. To support the National Strategy for Pandemic Influenza preparedness in the United States and internationally, we developed two lead dry formulations of stable H1N1 influenza subunit vaccines using freeze-drying technology. The stable formulations contain an excipient combination of a disaccharide, such as sucrose or trehalose, and glycine, in addition to a surfactant and phosphate buffer. The freeze-dried vaccines were shown to be safe and remained immunogenic in an in vivo study in mice. Moreover, the lead formulations demonstrated no significant loss of activity after 40 months at storage temperatures of 25°C and 37°C. This stability can be particularly attractive as it could eliminate the need to use a cold chain for vaccine deployment and facilitate integration of vaccine distribution with general drug distribution where appropriate. These freeze-dried thermostable influenza subunit vaccines could also reduce the frequency of vaccine stockpile turnover, offering a cost-effective option for pandemic preparedness. [ABSTRACT FROM AUTHOR]

Tropical forests play an important role in carbon cycle. However, the temporal and spatial variation in soil carbon dioxide (CO) emission of tropical forest remains uncertain, especially near the Tropic of Cancer. In this research, we studied the annual soil CO fluxes from three tropical montane rainforests on the Hainan Island of China (pristine montane rainforest, PF; secondary montane rainforest, SF; and Podocarpus imbricatus plantation, PP). The results showed a lower annual average soil CO flux as 6.85 ± 0.52 Mg C-CO ha (9.17 Mg C-CO ha in the wet season and 4.50 Mg C-CO ha in the dry season). The CO fluxes exhibited obviously seasonal variation during the study period. Among the three forest types, PF had the highest average CO flux rate of 317.77 ± 147.71 mg CO m h (433.08 mg CO m h in the wet season and 202.47 mg CO m h in the dry season), followed by PP of 286.84 ± 137.48 mg CO m h (367.12 mg CO m h in the wet season and 206.56 mg CO m h in the dry season) and SF of 255.09 ± 155.26 mg CO m h (351.48 mg CO m h in the wet season and 155.71 mg CO m h in the dry season). We found between CO fluxes and soil temperature a highly significant linear relation ( P < 0.01) at 5 cm depth and a highly significant exponential correlation ( P < 0.01) at 10 cm depth for all three forest types; a significant linear relation ( P < 0.05) between CO fluxes and soil moisture content was found for SF and PF, but not for PP ( P > 0.05). The CO flux was significantly correlated ( P < 0.05) with water-filled pore space only for PF. In conclusion, our results suggested soil CO fluxes in the three forest types that exhibit obviously spatial and temporal variation, and the temperature is the major factor affecting soil CO fluxes from this region. [ABSTRACT FROM AUTHOR]

Purpose: Stable vaccines with long shelf lives and reduced dependency on the cold chain are ideal for stockpiling and rapid deployment during public emergencies, including pandemics. Spray drying is a low-cost process that has potential to produce vaccines stable at a wide range of temperatures. Our aim was to develop a stable formulation of a recombinant H1N1 influenza hemagglutinin vaccine candidate and take it to pilot-scale spray-drying production. Methods: Eight formulations containing different excipients were produced and assayed for antigen stability, powder characteristics, and immunogenicity after storage at a range of temperatures, resulting in the identification of four promising candidates. A pilot-scale spray-drying process was then developed for further testing of one formulation. Results: The pilot-scale process was used to reproducibly manufacture three batches of the selected formulation with yields >90%. All batches had stable physical properties and in vitro potency for 6 months at temperatures from −20°C to +50°C. Formulations stored for 3 months elicited immunogenic responses in mice equivalent to a frozen lot of bulk vaccine used as a stability control. Conclusions: This study demonstrates the feasibility of stabilizing subunit vaccines using a spray-drying process and the suitability of the process for manufacturing a candidate product. [ABSTRACT FROM AUTHOR]

Tropical rainforest ecosystems are important when considering the global methane (CH4) budget and in climate change mitigation. However, there is a lack of direct and year-round observations of ecosystem-scale CH4 fluxes from tropical rainforest ecosystems. In this study, we examined the temporal variations in CH4 flux at the ecosystem scale and its annual budget and environmental controlling factors in a tropical rainforest of Hainan Island, China, using 3 years of continuous eddy covariance measurements from 2016 to 2018. Our results show that CH4 uptake generally occurred in this tropical rainforest, where strong CH4 uptake occurred in the daytime, and a weak CH4 uptake occurred at night with a mean daily CH4 flux of −4.5 nmol m−2 s−1. In this rainforest, the mean annual budget of CH4 for the 3 years was −1260 mg CH4 m−2 year−1. Furthermore, the daily averaged CH4 flux was not distinctly different between the dry season and wet season. Sixty-nine percent of the total variance in the daily CH4 flux could be explained by the artificial neural network (ANN) model, with a combination of air temperature (Tair), latent heat flux (LE), soil volumetric water content (VWC), atmospheric pressure (Pa), and soil temperature at −10 cm (Tsoil), although the linear correlation between the daily CH4 flux and any of these individual variables was relatively low. This indicates that CH4 uptake in tropical rainforests is controlled by multiple environmental factors and that their relationships are nonlinear. Our findings also suggest that tropical rainforests in China acted as a CH4 sink during 2016–2018, helping to counteract global warming. [ABSTRACT FROM AUTHOR]

Aims Tropical forest plays a key role in global C cycle; however, there are few studies on the C budget in the tropical rainforests in Asia. This study aims to (i) reveal the seasonal patterns of total soil respiration (RT), litter respiration (RL) and soil respiration without surface organic litter (RNL) in the primary and secondary Asian tropical mountain rainforests and (ii) quantify the effects of soil temperature, soil moisture and substrate availability on soil respiration. Methods The seasonal dynamics of soil CO2 efflux was measured by an automatic chamber system (Li-8100), within the primary and secondary tropical mountain rainforests located at the Jianfengling National Reserve in Hainan Island, China. The litter removal treatment was used to assess the contribution of litter to belowground CO2 production. Important Findings The annual RT was higher in the primary forest (16.73±0.87 Mg C ha−1) than in the secondary forest (15.10±0.26 Mg C ha−1). The rates of RT, RNL and RL were all significantly higher in the hot and wet season (May–October) than those in the cool and dry season (November–April). Soil temperature at 5cm depth could explain 55–61% of the seasonal variation in RT, and the temperature sensitivity index (Q10) ranked by RL (Q10 = 3.39) > RT (2.17) > RNL (1.76) in the primary forest and by RL (4.31) > RT (1.86) > RNL (1.58) in the secondary forest. The contribution of RL to RT was 22–23%, while litter input and RT had 1 month time lag. In addition, the seasonal variation of RT was mainly determined by soil temperature and substrate availability. Our findings suggested that global warming and increased substrate availability are likely to cause considerable losses of soil C in the tropical forests. [ABSTRACT FROM AUTHOR]

Biometric inventories for 25 years, from 1983 to 2005, indicated that the Jianfengling tropical mountain rain forest in Hainan, China, was either a source or a modest sink of carbon. Overall, this forest was a small carbon sink with an accumulation rate of (0.56±0.22) Mg C hayr, integrated from the long-term measurement data of two plots (P9201 and P8302). These findings were similar to those for African and American rain forests ((0.62±0.23) Mg C hayr). The carbon density varied between (201.43±29.38) Mg C ha and (229.16±39.2) Mg C ha, and averaged (214.17±32.42) Mg C ha for plot P9201. Plot P8302, however, varied between (223.95±45.92) Mg C ha and (254.85±48.86) Mg C ha, and averaged (243.35±47.64) Mg C ha. Quadratic relationships were found between the strength of carbon sequestration and heavy rainstorms and dry months. Precipitation and evapotranspiration are two major factors controlling carbon sequestration in the tropical mountain rain forest. [ABSTRACT FROM AUTHOR]

Understanding the successional process from a disturbed forest to a mature forest is essential for species recovery and conservation initiatives. The resource acquisition and drought tolerance of plants can be instructive to predictions of species abundance and distribution for different forests. However, they have not been adequately tested at different successional stages in karst regions. Here, we selected seven dominant species in an early-succession forest and 17 species in a late-succession forest in a karst region of southwestern China. Resource acquisition-related traits such as hydraulic conductivity and photosynthetic rate, and drought tolerance-related traits, including turgor loss point and wood density, were measured. We found that species in the early-succession forest had a higher hydraulic conductance and photosynthetic rate than those in the late-succession forest, while leaf water potential at turgor loss point and wood density showed nonsignificant differences between the two forests. In addition, we observed a significant negative relationship between photosynthetic rate and drought tolerance in the early-succession forest, which was not identified in late-succession forests. Our study indicates that resource acquisition rather than drought tolerance was the key factor explaining plant distributions in forests at different successional stages in karst regions. We also suggest that the resource acquisition and drought tolerance trade-off hypothesis is not always supported for karst region species. Our study could inform about the design of species replacements in successional forests and provide forest management and restoration guidelines for karst regions. [ABSTRACT FROM AUTHOR]

Twenty-three sample plots dominated by Vatica mangachapoi at various elevations in the tropical lowland rainforest in the Jianfengling National Nature Reserve of Hainan Island were established. The interspecific association among the 32 dominant species was analyzed and the division of ecological species groups and functional groups are discussed. The results showed that these dominant populations had an overall positive interspecific association. The species pairs with significant, positive association accounted for only about 10% of the total 496 species pairs. Most of the other species pairs showed weak association or non-association, i.e., the dominant populations investigated had relatively independent distributions. The 32 dominant species were divided into four ecological species groups and ten functional groups according to their interspecific association coefficients, based on a cluster analysis of the species. Recognition characteristics of the ten functional groups are proposed. [ABSTRACT FROM AUTHOR]

Summary Langerhans cells in the epidermis of skin are potent antigen-presenting cells that trigger the immune system to respond to invading microorganisms. We have previously shown that epidermal powder immunization with a powdered inactivated influenza virus vaccine, by targeting the Langerhans cell-rich epidermis, was more efficacious than deeper tissue injection using a needle and syringe. We now report enhanced humoral and cellular immune responses to recombinant hepatitis B surface antigen following epidermal powder immunization. We observed that epidermal powder immunization with unadjuvanted hepatitis B surface antigen elicited an antibody titre equivalent to that induced by the alum-adjuvanted vaccine delivered by intramuscular injection, suggesting that epidermal powder immunization can overcome the need for adjuvantation. We demonstrated that synthetic CpG oligonucleotides (CpG DNA) could be coformulated with hepatitis B surface antigen and delivered by epidermal powder immunization to further augment the antibody response and modulate T helper cell activities. Epidermal powder immunization of hepatitis B surface antigen formulated with CpG DNA formulations resulted in 1.5-2.0 logs higher IgG antibody titres than alum-adjuvanted commercial vaccines administered by intramuscular injection. Formulation of hepatitis B surface antigen with CpG DNA elicited an augmented IgG2a antibody response and increased frequency of IFN-γ secreting cells. In addition, CpG DNA was found to activate epidermal Langerhans cells and stimulate the production of TNF-α and IL-12 cytokines by epidermal cells, explaining its strong adjuvant activity following epidermal powder immunization. These results show that epidermal powder immunization is a safe and effective method to deliver hepatitis B surface antigen and the addition of new adjuvants, such as CpG DNA, may further enhance the efficacy of this vaccine. [ABSTRACT FROM AUTHOR]

Describes epidermal powder immunization (EI) which effectively delivers powdered vaccines to the epidermis by using a helium-powered, needle free PowderJect system. Comparison between EI and needle injection; Challenge experiments; Immunogenicity of influenza vaccine.

Understanding the impacts of nitrogen (N) addition on soil respiration (RS) and its temperature sensitivity (Q10) in tropical forests is very important for the global carbon cycle in a changing environment. Here, we investigated how RS respond to N addition in a tropical montane rainforest in Southern China. Four levels of N treatments (0, 25, 50, and 100 kg N ha−1 a−1 as control (CK), low N (N25), moderate N (N50), and high N (N100), respectively) were established in September 2010. Based on a static chamber-gas chromatography method, RS was measured from January 2015 to December 2018. RS exhibited significant seasonal variability, with low RS rates appeared in the dry season and high rates appeared in the wet season regardless of treatment. RS was significantly related to the measured soil temperature and moisture. Our results showed that soil RS increased after N additions, the mean annual RS was 7% higher in N25 plots, 8% higher in N50 plots, and 11% higher in N100 plots than that in the CK plots. However, the overall impacts of N additions on RS were statistically insignificant. For the entire study period, the CK, N25, N50, and N100 treatments yielded Q10 values of 2.27, 3.45, 4.11, and 2.94, respectively. N addition increased the temperature sensitivity (Q10) of RS. Our results suggest that increasing atmospheric N deposition may have a large impact on the stimulation of soil CO2 emissions from tropical rainforests in China. [ABSTRACT FROM AUTHOR]