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Real-time semantic segmentation is a challenging task as both segmentation accuracy and inference speed need to be considered at the same time. In this paper, a Dual Context Network (DCNet) is presented to address this challenge. It contains two independent sub-networks: Region Context Network and Pixel Context Network. Region Context Network is main network with low-resolution input and features re-weighting module to achieve sufficient receptive field. Meanwhile, Pixel Context Network with location attention module is to capture the location dependencies of each pixel for assisting the main network to recover spatial detail. A contextual feature fusion is introduced to combine output features of these two sub-networks. The experiments show that DCNet can achieve high-quality segmentation while keeping a high speed. Specifically, for Cityscapes test dataset, it can achieve 76.1% Mean IOU with the speed of 82 FPS on a single GTX 2080Ti GPU when using ResNet50 as backbone and 71.2% Mean IOU with the speed of 142 FPS when using ResNet18 as backbone. [ABSTRACT FROM AUTHOR]

Environmental change factors can significantly affect the composition and physiology of soil microbes. How the resulting changes in the community composition are related to microbial functions, however, remains poorly understood. We investigated the effects of climate warming (+ 1.4°C of air temperature and + 0.75°C of soil temperature at 10 cm depth) and reactive nitrogen (N) input (12 g N m–2 year–1) on the community composition and physiologies of soil bacteria in a semiarid Loess grassland. Soil bacterial communities were assessed by Miseq sequencing of 16S rRNA gene amplicons while their physiological properties were assessed by microbial metabolic quotients (qCO2, microbial respiration per unit of microbial biomass) and microbial community-level physiological profiles (CLPPs). Our results showed that N input, but not warming, altered bacterial community structure, although both warming and N input significantly affected the abundances of certain phyla. While phyla Verrucomicrobia and Chloroflexi were sensitive to warming, Saccharibacteria, Bacteroidetes and Actinobacteria were primarily responsive to N input. Both warming and N input increased microbial metabolic quotients, but only warming significantly impacted soil microbial CLPPs with L-cysteine, oxalic acid, oxoglutaric acid and aminobutyric acid being the sensitive C sources. Structural equation modeling showed that warming and N input influenced soil bacterial phyla through soil moisture, soil NO3––N and plant biomass. The sensitive bacterial phyla, not the whole community property, were significantly correlated with qCO2 and microbial C utilization. Our findings suggest that responses of bacterial groups sensitive to environmental change factors, rather than the whole community, may exert dominant effects on soil microbial functions under future climate change scenarios. [ABSTRACT FROM AUTHOR]

This study aimed to prepare effervescent tablets of traditional Chinese medicine Xianganfang with fresh juice using a semi-solid 3D printer with three cartridge holders to seperate acid and alkali source by drug paste through model design to avoid sticking impact and premature effervescence during the tableting in the conventional preparation process. The powder of Xianganfang including fresh juice of Phyllanthus emblica and licorice extract was obtained by vacuum freeze-drying with 50% mannitol as cryoprotectant. Then, the formulation of 3D-printed effervescent tablets was investigated. Further 5% HPMC hydroalcoholic gel was mixed with sodium bicarbonate and freeze-dried Xianganfang powder to prepare alkali source and drug paste respectively while 30% PVP ethanol solution was mixed with tartaric acid to prepare acid source paste; these three pastes had good printability. The pastes of drug, acid, and alkali were loaded into three syringe cartridges separately and numbered as "3," "5," and "7," according to cartridge holders of the 3D printer, and printed in the order of "537,353,735" for separating acid and alkali by drug to avoid premature effervescence. And the basic printing parameters were optimized. The tablets were evaluated by the appearance, tablet weight variation, hardness, disintegration time, friability, pH, and stability. The physicochemical properties all conformed to the Chinese Pharmacopoeia 2020 edition. The content of the active ingredient gallic acid was 0.769 ± 0.019 mg/g. This study provided a new method to prepare effervescent tablets of traditional Chinese medicine with fresh juice using 3D printing technology. [ABSTRACT FROM AUTHOR]

Background: Forest succession is an important ecological process and has been studied for more than a century. However, changes in nitrogen (N) availability during succession remain unclear as they may lead to either N saturation or N limitation. Here, we propose a conceptual model to illustrate changes in N availability during four stages of secondary succession using the natural abundance of 15N in plant leaves (foliar δ15N). We predicted that N availability would decline in the early stages of succession and then increase in late stages, coinciding with the changes in foliar δ15N, with the inflection point varying in different climate zones. Data on foliar δ15N from 16 succession sequences were synthesized to explore changes in N availability during forest succession. Results: The compiled data were consistent with the proposed conceptual model. Foliar δ15N in boreal and temperate forests decreased significantly in the first two stages of succession (estimated to last at least 66 years in temperate forests), at a rate of 0.18‰ and 0.38‰ per decade, respectively, and decreased slightly in tropical forests in the first 23 years. Foliar δ15N is projected to increase in later stages in all forests, which is supported by observations in both temperate and tropical forests. The inflection points of N availability when N limitation peaked during succession were different in different climate zones, implying different ecosystem N turnovers. Conclusions: Our study reconciles the controversies regarding changes in N availability during forest secondary succession. Our findings are also useful for predicting the recovery of N and carbon accumulation during succession. Nonetheless, studies on forest secondary succession using foliar δ15N have thus far been limited, and more research should be conducted to further verify the conceptual model proposed here. [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]

Resource integration of coal enterprises is conducive to reducing pollution and carbon emissions, thus alleviating environmental problems such as global warming. Government regulation has a great influence on enterprise behavior. Therefore, it is necessary to analyze the strategies of government and coal enterprises in resource integration. Based on the perspective of government regulation, this paper discusses how to guide and restrict coal enterprises to conduct resource integration behavior, and whether the government supervises this behavior. First, through empirical research, government regulations of coal enterprises are given practical policy implications. Second, using evolutionary game and simulation technology, from the perspective of government regulation, we explore the complex behavioral interaction mechanism between the dominant and inferior coal enterprises, the mechanism between the government and coal enterprises, and analyze the impact of key factors on the dynamic evolution process. Finally, the sensitivity analysis of the selected parameters is discussed in details, which provides useful decision-making suggestions for the government and enterprises. In addition, this paper further analyzes the impact of different government policies on coal enterprises' green innovation strategies. Results demonstrate that (1) when the power gap between enterprises is large, the probability of dominant enterprises choosing resource integration converges to 1, while the probability of inferior enterprises converges to 0. Therefore, government regulations are invalid for inferior enterprises; (2) the combination of government regulations can help improve the efficiency of coal enterprises' strategic choices. With the increase in the intensity of government rewards and punishments, the probability of enterprise resource integration evolves from 0 to 1; (3) excessive government regulations make the choice between the government and coal companies tend to swing, because the probability of the two is between 0 and 1. Therefore, excessive government regulations cannot effectively achieve resource integration and government regulation. (4) The government subsidy strategy is less effective than the government's pollution penalty strategy in promoting the green innovation of enterprises. Our research shows that the government should choose different policy combinations and intensities to regulate resource integration according to the market power of coal enterprises, which provides theoretical reference and practical guidance for the government to regulate corporate resource integration behavior. [ABSTRACT FROM AUTHOR]

Urbanization negatively impacts the diversity of aquatic insect assemblages in headwater streams and can lead to the homogenization of insect communities at the regional level. However, less is known about the impact of urbanization on insects in headwater streams within smaller cities that have significant upstream portions outside of urban land use. We collected insects monthly from April to September in 2014 and 2015 from five streams that flowed from rural upstream through urban downstream land use, plus two rural reference streams, in Greater Binghamton, New York, in the northeast USA. While urbanization was associated with lower insect taxonomic richness ( α ¯ ) and elevated stream water conductivity, the regional diversity (γ) was similar among urban and rural land use. This corresponded to higher dissimilarity among urban sites (β) than among rural sites. To our knowledge, this is the first report of higher urban stream insect community β-diversity. Our results suggest that urbanization in this medium-sized city negatively impacts stream insect richness, but the change of community assemblages is not homogenous across the urban landscape. Connectivity between upstream rural sites and downstream urban sites may provide some relief from the impacts of urbanization in smaller cities. [ABSTRACT FROM AUTHOR]

Urban wetlands can serve to reduce flooding and improve water quality, yet we know little about their plant communities. Our study aims to characterize the vegetation and soil parameters of these important ecosystems, and to compare these features to those of previously sampled natural wetlands in south-central New York. Vegetation and soil characteristics were sampled in eight urban wetlands and compared to six forested wetlands, five scrub-shrub wetlands, and seven emergent wetlands. Urban sites had significantly lower species richness and a higher percent cover of invasives, including Typha x glauca, Phalaris arundinacea, and Lythrum salicaria. However, non-invasive species were also common in urban flora, including Leersia oryzoides, Ludwigia palustris, and Sagittaria latifolia. Urban wetlands had a high percentage of obligate wetland species, and most closely resembled emergent wetlands in their vegetation composition. Soil pH and soil electrical conductivity were significantly higher in urban sites, but potential net N-mineralization rates were significantly lower. Urban wetland vegetation and soil characteristics are different than those in nearby natural wetlands, and our increased knowledge of these urban ecosystems will lead to more successful restoration and creation projects. [ABSTRACT FROM AUTHOR]

Background and aims: Forest restoration has been proposed as an effective strategy for the sequestration of atmosphere CO. Understanding the mechanisms of soil organic carbon (SOC) dynamics in afforestation is important to quantifying and enhancing carbon (C) sequestration. Methods: After 70 years afforestation with two conifer and three broadleaf tree species in monocultures in Northeast USA, we measured soil C pools as well as C fractions in these plantations and nearby pasture control. Results: Soil C stored in forest floor was increased by afforestation, especially in conifer stands. Total C stock in mineral soils was not statistically different among species, but C fractions had been altered. Compared to pasture land, afforestation decreased coarse particle organic C (cPOC) fraction, while increased recalcitrant mineral associated SOC (mSOC) fraction. Afforestation decreased the macro-aggregate C fraction in the 0-5 cm soil, but increased the micro-aggregate C fraction in the 5-15 cm soil. Conclusions: 1) Afforestation using conifers could improve the whole soil-profile carbon stock compared to broadleaves when the forest floor is included; 2) Even though the overall mineral soil C stock was not changed, afforestation could improve soil C stabilization through increasing mSOC fraction and forming more micro-aggregate C fraction in deeper soils. [ABSTRACT FROM AUTHOR]

Roadside plants have the potential to accumulate pollutants and safeguard waterways. To assess growth and pollutant accumulation of roadside plants, the willow Salix miyabeana was grown (a) in a greenhouse on soil collected at different distances from an interstate highway to test the longer-term effects of pollutant deposition as manifested in soil, and (b) in the field on reference soil placed at different distances from that highway to test the shorter-term effects of proximity to pollutant sources during a single growing season. In the first experiment, relative growth rate (RGR) increased 150 % with distance of soil collection from the roadway, from a baseline near the highway to 100 m away. Relative nitrogen and phosphorus accumulation rates were positively correlated with RGR ( P <0.0001), and total contents of zinc, strontium, copper, nickel, cadmium, and lead in new shoots were also positively correlated with RGR ( P <0.05). Thus more rapidly growing plants accumulated more N, P, and metals. Reduced growth for plants grown on soils collected near the roadway was associated with very high tissue concentrations of sodium and soil concentrations of chloride, implicating the deposition of deicing agents in this northern temperate roadside ecosystem. In contrast, S. miyabeana showed the opposite pattern on reference soil in the field, with RGR decreasing 31 % as distance from the roadside increased. The latter trend appears to have resulted from greater soil moisture and reduced shading near the highway. We suggest that reducing road salt applications will promote growth and pollutant accumulation by roadside vegetation. [ABSTRACT FROM AUTHOR]

Since wetland construction projects are becoming more commonplace, meaningful follow-up studies are needed to evaluate how these systems change over time. To that end, the objective of our study was to examine the temporal changes in plant community composition and water chemistry in two constructed wetlands. We investigated two wetland sites that were constructed in 2003 in northern Otsego County, NY, a county that is largely dominated by agriculture. Site 1 was previously an active cow pasture and site 2 was previously a wet meadow surrounded by agricultural fields. No active plant introduction was made during the construction; however, both sites were located in areas with many remnant wetlands and were connected to through-flowing streams. In 2004 (Year 1) and 2010 (Year 7), the plant community composition and nitrogen retention were assessed. We found that both sites experienced site-wide declines in plant species richness, including the loss of upland and facultative upland species and the unanticipated loss of facultative wetland and some obligate species. We propose that high water levels, which, at their maximum depth were >1.5 m deeper than in Year 1, maintained by landowners in the years after the initial survey, may have been responsible for the unexpected loss of wetland species. We also found that site 1 exhibited considerable nitrogen retention in both Year 1 and Year 7; however, N concentrations were low at site 2 in both years. [ABSTRACT FROM AUTHOR]

This paper attempted the feasibility to determine firmness and soluble solid content (SSC) in intact pears using Fourier transform near infrared (FT-NIR) spectroscopy coupled with multivariate analysis. Principal component analysis and independent component analysis were employed comparatively to extract latent vectors from the original spectra data. Extreme learning machine (ELM) was performed to calibrate regression model. Some parameters of ELM model were optimized according to the lowest root mean square error of cross-validation in the calibration set. Moreover, the root mean square error of prediction of the calibration model was finally corrected for making it more closed to the true prediction error due to the effect of reference measurement error existing in the pear sample attribute value on the prediction error of the model. Experimental results showed that the $$ R_p^2 $$ and ratio performance deviation (RPD) in the prediction set were achieved as follows: $$ R_p^2 $$ = 0.81 and RPD = 2.28 for the firmness model when ICs = 6 and $$ R_p^2 $$ = 0.91 and RPD = 3.43 for the SSC model when ICs = 5. This study demonstrates that the predictive precision of the calibration model can be effectively enhanced in measurement of firmness and SSC in intact pears by use of FT-NIR spectroscopy combined with appropriate chemometrics methods. [ABSTRACT FROM AUTHOR]

Background and aims: The relationship between tree species and soil nutrient availability is critical for evaluating plantation succession and promoting forest restoration. This study was conducted to evaluate the impact of exotic and native tress species on soil nutrient availability. Methods: Four exotic species ( Eucalyptus urophylla, E. tereticornis, Acaia auriculaeformis, A. mangium) and four native species ( Castanopsis fissa, Schima superba, C. hystrix, Michelia macclurei) were planted and grown for one-year. Soil solution (DOC, DON, NH−N, NO−N) was sampled and analyzed during the study. After the experiment, soil properties were determined, and plant tissues were analyzed. Results: DOC levels were greater in soils with trees planted than controls without trees. Compared to native species, exotic species had much faster growth rates and greatly reduced DON and NO−N concentrations. Exotic species always had less P concentrations in leaves and stems than native species. Furthermore, N-fixing A. auriculaeformis led to greater soil available P compared to other species. Conclusions: Based on these findings, we provide some recommendations for afforestation practice. This study highlights that a better understanding of the pros and cons of exotic species would be beneficial to advance afforestation in China and the world. [ABSTRACT FROM AUTHOR]

Atmospheric nitrogen (N) deposition in subtropical metropolitan regions has increased greatly because of rapid urbanization, and such increase could lead to N-related changes in soil properties and plant diversity in remnant forests of urban ecosystems. To investigate the pattern of atmospheric N deposition along an urban-rural gradient in metropolitan Guangzhou, southern China, and to assess the potential influence of N deposition on soil properties and understory plant diversity in remnant forests, precipitation, and soil samples were collected and vegetation was surveyed from four forest sites between March 2010 and March 2011. The atmospheric inorganic nitrogen deposition (DIN) decreased with increasing distance from the urban center: DIN inputs were 43.3, 41.2, 35.2, and 30.1 kg N ha year in two urban sites, a suburban site and a rural site, respectively. However, forest soil N status (NH-N, NO-N, and total nitrogen) showed the opposite pattern. Understory herb-layer diversity was negatively correlated to DIN input and positively correlated to soil calcium (Ca) and potassium (K) concentrations and pH; with highest herb-layer diversity found in the rural site receiving the lowest amount of DIN input. These results indicated that higher DIN along with soil acidification and leaching of base cations (Ca and K) might change the current N status and increase nutrients leaching and thereby cause reductions in understory plant diversity. A regional policy linking atmospheric pollution and land protection is needed to protect the most N-sensitive herb species (e.g., forbs and ferns) in these remnant forests. [ABSTRACT FROM AUTHOR]

Background and aims: The impacts of atmospheric nitrogen (N) deposition on terrestrial ecosystem processes remain controversial, mostly because of the uncertainty regarding the fates of deposited N. We conducted a 16-week simulated deposition study to experimentally trace N in a greenhouse plant-soil system. Methods: Using a two-way factorial design, we added (NH)SO solution twice a week to pots containing different soil organic matter (SOM) content and with or without a live plant ( Salix dasyclados). The recoveries of N in soil, plant biomass, and leaching solution were quantified. Results: We found most N was retained in soil (18.0-59.2%), with significantly more N recovered from high-SOM soils than from low-SOM soils. Plant presence significantly increased N retention in soil. Plant biomass accounted for 10-20% of the N input, with proportionally more N assimilated when plants were grown in low-SOM soils. Leaching loss of N was relatively low (10-17%). Conclusion: Our study suggests that SOM content and plant presence significantly affect the fates of deposited N. Indeed, N would be preferentially retained in soils with high SOM content and live plant, while plants would assimilate more deposited N when grown in low SOM soils. Global biogeochemical models thus need to incorporate such soil-specific N retention and plant N assimilation. [ABSTRACT FROM AUTHOR]

OBJECTIVE To provide evidence for breast cancer prevention and control through epidemiological analysis of the incidence, mortality and survival rate of female breast cancer patients in Beijing. METHODS The female registration data in the Beijing urban area from 1982 to 2001 were retrospectively reviewed. The incidence, mortality and survival rate of female breast cancer patients were analyzed using routine and life-table statistical methods. RESULTS During the period of 1982 to 2001, there was a trend of an average annual increase of female breast cancer incidence of 4.6% in urban Beijing, and of 4.9% in the world-population standardized incidence. The epidemiological features of urban Beijing female breast cancer showed: (1) The incidence distribution of different age groups from 25 to 80 years elevated with two peaks at ages of 45– and 70– years; (2) There was an elevation in each age group over the last 20 years; (3) The incidence rate at ages of 35 to 64 reached 95.3/105, causing breast cancer to become the number one cancer in fomales. The changes in the survival rate showed the following: the 5-year observed survival rate (OSR) increased from 62.0% in 1982–1983 to 68.7% in 1987–1988, and the relative-survival rate (RSR) increased from 66.3% to 74.2%. The 10-year OSR and RSR in 1987–1988 were 60.3% and 65.1%, and at 15 years 57.5% and 61.3%, respectively. The mortality rate of breast cancer patients fluctuated from 8 to 10 per 105 population over the 20 years of study. CONCLUSION There is a trend of an annual increase in female breast cancer in Beijing. The 5-year survival is being improved gradually while the mortality remains stable. The results demonstrate that the principles of "early prevention, diagnosis and treatment" for breast cancer are effective in Beijing. [ABSTRACT FROM AUTHOR]

The effects of live and dead roots on soil fungi were investigated experimentally in a spodosolic soil of the New Jersey Pinelands. Field mesocosm plots were constructed to have a layer of either C- and N-rich organic soil or a vermiculite substitute overlying a layer of sandy mineral soil with a very low organic content. The plots were also supplied with live pitch pine and blueberry roots or dead pitch pine roots in varying quantities based on anturally occurring densities (half, same, and double the ambient quantities). All plots were sampled 1 year after construction (June 1991), and three more times in two subsequent years (November 1991, June 1992, June 1993). In the presence of live roots, fluorescein diacetate-determined (FDA-active) fungal hyphae, total fungal hyphae, and soil moisture decreased significantly in the organic material, while no change was associated with the dead roots. The FDA-active fungal length in the live-root plots ranged from 40 to 165 mg soil, and from 55 to 335 mg soil in the dead-root plots. While the total fungal length in live-root plots remained constant over time (∼3000 mg soil), the total fungal length in the dead-root plots increased from an initial value of 3000 to >4000 mg soil at the conclusion of the study. Fungal lengths in mineral soil were higher under organic material than under the vermiculite substitute. Soil moisture was higher in the presence of live roots in mineral soils, but this did not increase the fungal abundance. Inputs of dead roots did not alter the fungal abundance. Overall, we demonstrated that live and dead roots had different effects on fungal abundance in soils with contrasting qualities, and in a spodosolic forest soil, roots could have ecosystem effects very different from those in agricultural soils. [ABSTRACT FROM AUTHOR]

Roads and highways play an important function in the human-dominated Earth landscape and strongly affect the environment. Roadside ecosystems receive a number of pollutants, including deicing salt and inorganic nitrogen (N) from automobiles. We investigated how soil carbon (C) and N cycling were impacted by the application of salt (NaCl) and nitrate (NO3−) to experimental plots in a field that is adjacent to Interstate 81, in Binghamton, NY. Experimental plots were constructed on two parallel transects; one was adjacent to the highway (0-m) and the other 50 m away from the highway (50-m). We hypothesized that the 0-m transect was exposed to roadway-derived pollutants over a long-term period of time, while the 50-m transect was exposed to fewer pollutants due to its distance from the road. Soils were collected in July and November 2011 and June and October 2012. Salt significantly decreased the rates of soil C mineralization and in situ soil respiration in both 0- and 50-m transects (p < 0.001), though it did not discernibly affect the rates of N mineralization or nitrification. Applications of NO3− had no significant impact on soil C or N mineralization. The effects of roadway pollutants were reflected in higher soil conductivities and pH at the 0-m transect. Under experimental salt treatment, C mineralization was reduced by 75% in the 50-m transect, compared to 20% reduction in the 0-m transect. We conclude that microbial communities near roads might have evolved to better withstand the impacts of roadway pollutants. Nevertheless, roads and vehicle traffic have strong impacts on the environment, and the application of road salt has important environmental consequences. [ABSTRACT FROM AUTHOR]

Background and aims: Growing evidence has shown that nitrogen (N) deposition can lead to soil acidification and tree nutrient imbalance. Tree species-specific differences in plant-soil interactions may render different forest types exhibiting contrasting responses to N deposition, yet this remains largely untested.We conducted N addition experiments (0 and 50 kg N ha−1 yr−1) separately in a larch (Larix kaempferi) forest and an adjacent larch-broadleaf mixed forest, and examined whether soil N availability, soil acid–base chemistry, leaf nutrients and stoichiometry of these two forests responded differently to four-year N addition.We found that N addition increased soil nitrate concentrations at four soil layers (i.e. Oa + e, 0–10, 10–20, and 20–40 cm), and resulted in soil acidification at Oa + e and 0–10 cm layers characterized by decreased pH and exchangeable base cations and increased hydrolyzing cations in the larch forest. In contrast to soil chemical properties, larch leaf nutrient stoichiometry except the C:N ratio showed no significant responses to N addition in the larch forest. Moreover, N addition did not significantly affect soil inorganic N concentration, soil acid–base chemistry, and tree leaf nutrients in the larch-broadleaf mixed forest.Our results suggest the higher resistance of larch-broadleaf mixed forests than larch forests against soil acidification under N addition, and highlight the establishment of conifer-broadleaf mixed forests is an important silvicultural practice to alleviate soil acidification induced by N deposition.Methods: Growing evidence has shown that nitrogen (N) deposition can lead to soil acidification and tree nutrient imbalance. Tree species-specific differences in plant-soil interactions may render different forest types exhibiting contrasting responses to N deposition, yet this remains largely untested.We conducted N addition experiments (0 and 50 kg N ha−1 yr−1) separately in a larch (Larix kaempferi) forest and an adjacent larch-broadleaf mixed forest, and examined whether soil N availability, soil acid–base chemistry, leaf nutrients and stoichiometry of these two forests responded differently to four-year N addition.We found that N addition increased soil nitrate concentrations at four soil layers (i.e. Oa + e, 0–10, 10–20, and 20–40 cm), and resulted in soil acidification at Oa + e and 0–10 cm layers characterized by decreased pH and exchangeable base cations and increased hydrolyzing cations in the larch forest. In contrast to soil chemical properties, larch leaf nutrient stoichiometry except the C:N ratio showed no significant responses to N addition in the larch forest. Moreover, N addition did not significantly affect soil inorganic N concentration, soil acid–base chemistry, and tree leaf nutrients in the larch-broadleaf mixed forest.Our results suggest the higher resistance of larch-broadleaf mixed forests than larch forests against soil acidification under N addition, and highlight the establishment of conifer-broadleaf mixed forests is an important silvicultural practice to alleviate soil acidification induced by N deposition.Results: Growing evidence has shown that nitrogen (N) deposition can lead to soil acidification and tree nutrient imbalance. Tree species-specific differences in plant-soil interactions may render different forest types exhibiting contrasting responses to N deposition, yet this remains largely untested.We conducted N addition experiments (0 and 50 kg N ha−1 yr−1) separately in a larch (Larix kaempferi) forest and an adjacent larch-broadleaf mixed forest, and examined whether soil N availability, soil acid–base chemistry, leaf nutrients and stoichiometry of these two forests responded differently to four-year N addition.We found that N addition increased soil nitrate concentrations at four soil layers (i.e. Oa + e, 0–10, 10–20, and 20–40 cm), and resulted in soil acidification at Oa + e and 0–10 cm layers characterized by decreased pH and exchangeable base cations and increased hydrolyzing cations in the larch forest. In contrast to soil chemical properties, larch leaf nutrient stoichiometry except the C:N ratio showed no significant responses to N addition in the larch forest. Moreover, N addition did not significantly affect soil inorganic N concentration, soil acid–base chemistry, and tree leaf nutrients in the larch-broadleaf mixed forest.Our results suggest the higher resistance of larch-broadleaf mixed forests than larch forests against soil acidification under N addition, and highlight the establishment of conifer-broadleaf mixed forests is an important silvicultural practice to alleviate soil acidification induced by N deposition.Conclusions: Growing evidence has shown that nitrogen (N) deposition can lead to soil acidification and tree nutrient imbalance. Tree species-specific differences in plant-soil interactions may render different forest types exhibiting contrasting responses to N deposition, yet this remains largely untested.We conducted N addition experiments (0 and 50 kg N ha−1 yr−1) separately in a larch (Larix kaempferi) forest and an adjacent larch-broadleaf mixed forest, and examined whether soil N availability, soil acid–base chemistry, leaf nutrients and stoichiometry of these two forests responded differently to four-year N addition.We found that N addition increased soil nitrate concentrations at four soil layers (i.e. Oa + e, 0–10, 10–20, and 20–40 cm), and resulted in soil acidification at Oa + e and 0–10 cm layers characterized by decreased pH and exchangeable base cations and increased hydrolyzing cations in the larch forest. In contrast to soil chemical properties, larch leaf nutrient stoichiometry except the C:N ratio showed no significant responses to N addition in the larch forest. Moreover, N addition did not significantly affect soil inorganic N concentration, soil acid–base chemistry, and tree leaf nutrients in the larch-broadleaf mixed forest.Our results suggest the higher resistance of larch-broadleaf mixed forests than larch forests against soil acidification under N addition, and highlight the establishment of conifer-broadleaf mixed forests is an important silvicultural practice to alleviate soil acidification induced by N deposition. [ABSTRACT FROM AUTHOR]