Rain Treatment Research Articles

Moss as Bio indicator for Air Quality Monitoring

Air quality monitoring nowadays has become a vital role to assess air quality level, to ensure the health of community are not affected with poor air quality. However, approaches for air quality monitoring either via physical or chemical assessment has built up some constraints. Time consuming, inaccuracy of data due to high maintenance of monitoring devices and only require competent person that able to conduct the monitoring. Therefore, the demand of using bio-indicator, such as moss, for air quality monitoring has risen due to multiple advantages. In this study, moss response and survivability rate towards acidic condition has been physically observed. The color changed and moss grid area were the parameters used to observe moss after acidic treatment. The moss, Leucobryum glaucum, was treated with artificial acid rain at three different pH; pH 3, 4 and 5. The moss was treated with 25 ml of artificial acid rain, once in two days for the duration of over 10 weeks; from week 4 until week 14 during the study period. The result showed that the moss mostly reacted towards lower pH of acid rain, at pH 3. The survivability rate of moss was decreasing when treated with pH 5 to pH 3. The physical observation which is determined by the area covered by moss (per square meter), showed that most of the area that covered by moss are affected at pH 3. The fresh green color that were observed before the artificial acid rain treatment has changed to yellowish color towards the 10 week of treatment. This study suggested that moss could be used by communities as a simple bio-indicator, to monitor air quality, especially for determination of acidic condition in certain area due to any surrounding factors.

Ecophysiological responses of Jatropha curcas L. seedlings to simulated acid rain under different soil types

Acid rain is a global environmental problem. Acid rain can affect plants directly by damaging the leaves and indirectly by soil acidifying. Many studies have been conducted to investigate the impacts of acid rain on plant under a single soil type. However, there is little information on the effect of acid rain on plant under different soil types. Jatropha curcas L. is an energy plant widely distributed in acid rain pollution area with various soil types. In this study, we investigated the effects of acid rain (pH2.5, pH3.5, pH4.5, pH5.6) on the growth, physiology, nutrient elements and bacterial community of J. curcas seedlings under different soil types [Red soils (RS), Yellow soils (YS), Yellow-brown soils (YBS), and Purplish soils (PS)]. Acid rain and soil types significantly influence the growth of J. curcas seedlings, and there was a significant interaction between acid rain and soil types. Acid rain (pH 4.5) was beneficial to the growth of J. curcas seedlings, whereas acid rain (pH 2.5 or 3.5) inhibited growth of J. curcas seedlings. The growth of J. curcas seedlings could resist the stress of acid rain by scavenging and detoxification of active oxygen species in leaves. Combined with the increase in relative growth rate of seedlings treated with simulated acid rain at pH 4.5, we inferred that K can stimulate the growth of seedlings. The lower soil pH, cation exchange capacity and base saturation had stronger inhibitory effects on growth of J. curcas seedlings. YBS and PS were beneficial for growth of J. curcas seedlings by higher buffering capacity under acid rain treatments. The phylum Proteobacteria was found to predominate in rhizosphere soils. YBS was favorable to support Proteobacteria growth and reproduction. The redundancy analysis showed that the Cyanobacteria were favorable to growth of J. curcas seedlings.

Physiological responses of Elaeocarpus glabripetalus seedlings exposed to simulated acid rain and cadmium

Combined effects of cadmium (Cd) and acid rain on physiological characteristics in Eleocarpus glabripetalus seedlings were investigated under controlled conditions. The single Cd treatment and the combined Cd and acid rain treatment increased growth at low Cd concentrations, while decreased growth and photosynthesis at high Cd2+ concentrations. A low Cd2+ concentration (50 mg kg-1) combined with different acid rain treatments increased the seedling biomass. A high Cd2+ concentration (100 mg kg-1) under different acid rain treatments significantly decreased the biomass, the Fe content, chlorophyll fluorescence and photosynthetic parameters. Relative electric conductivity, malondialdehyde (MDA) content and peroxidase (POD) activity were increased while the reduced glutathione (GSH) content and catalase (CAT) activity were significantly lower at high Cd2+ concentration under acid rain. The results indicated that the combination of a high concentration of Cd2+ and acid rain aggravated the toxic effect of Cd2+ or acid rain alone on the growth and physiological parameters of E. glabripetalus due to serious damage to the chloroplast structure. These results provide novel insights into the combined effects of Cd2+and acid rain on woody plants and might also serve as a guide to evaluate forest restoration and biological safety in areas with Cd2+and acid rain pollution.

Response of Soil Respiration and Its Components to Simulated Acid Rain in a Typical Forest Stand in the Three Gorges Reservoir Area

In order to study the effects of acid rain on forest soil respiration, three plots were selected in the conifer/broad-leaved mixed forests in the Three Gorges Reservoir area of the Jinyun Mountain (Chongqing) from January 2016 to April 2017. Two groups of treatments were set up:a trenched treatment and an untrenched treatment. Each group was treated with four simulated acid rain gradients of pH 4.5 (control), 4.0, 3.25 and 2.5. The characteristics of total soil respiration and heterotrophic respiration under the four simulated acid rain treatments were measured. Soil temperature and moisture were measured during the respiration measurements, and soil samples were collected to study the effects of soil pH, the carbon-nitrogen ratio, and fine root biomass on soil respiration. The results indicated that the total soil respiration and heterotrophic respiration of trenched and untrenched plots showed a similar seasonal variation trend. The annual mean soil respiration rates of the CK, T4.0, T3.25, and T2.5 treatments were 1.89, 1.88, 1.75, and 1.74 μmol·(m2·s1)-1, respectively, and the annual mean soil respiration rates of the RCCK, RCT4.0, RCT3.25 and RCT2.5 treatments were 1.37, 1.32, 1.19, 1.08 μmol·(m2·s1)-1, respectively. There was no significant differences between the quarterly average of the total soil respiration and heterotrophic respiration before June 2016 (P>0.05). However, after October 2016, the difference was significant (P<0.01) with CK > pH 4.0 > pH 3.25 > pH 2.5. The cumulative soil CO2 emissions of the T4.0, T3.25, and T2.5 treatments in 2016 decreased by 3.89%, 9.64%, and 11.24% respectively, compared with the control, and the RCT4.0, RCT3.25, and RCT2.5 treatments decreased by 6.79%, 13.23%, and 25.56%, respectively. The simulated acid rain treatments reduced the ratio of heterotrophic respiration in the total soil respiration, and the degree of reduction increased with the pH of the simulated acid rain, indicating that the effect of acid rain on the inhibition of heterotrophic respiration exceeded that of autotrophic respiration. Although the simulated acid rain treatments increased the temperature sensitivity of soil respiration (Q10), it had no significant effect on soil temperature and humidity (P>0.05). The soil carbon-nitrogen ratio and fine root biomass were significantly greater in comparison to the control after October 2016. Soil respiration was significantly positively correlated with fine root biomass and significantly negatively correlated with the soil carbon-nitrogen ratio. Soil temperature and water contributed only slightly to soil respiration under the four simulated acid rain treatments. Fine root biomass and the soil carbon-nitrogen ratio were critical factors for variation of soil respiration under acid rain.

SISTEM MONITORING PENGAIRAN OTOMATIS DENGAN METODE LOGIKA FUZZY

Rice plant which is a source of food for the people, it needs enough temperature, air humidity and high water for maximum growth. The irrigation system is a major requirement in the field of agriculture, especially for rice plant. Some constraints in conventional irrigation, so they need irrigation system automatically. Some previous studies about automatic irrigation were only used one or two parameters and only used fuzzy or IoT. The method offered in this study uses fuzzy logic using 3 inputs and combines the monitoring system in real time based on IoT. The purpose of this study is to determine the effectiveness of fuzzy logic using three inputs to control the automatic irrigation system byreal time monitoring usingIoT. Data obtained by testing in themorning, afternoon, evening, night and using heat and rain treatment then compared using Matlab calculation. From the tool testing, the average precision of the tool comparison using the calculation is 77.13%.

The effects of simulated acid rain on internal nutrient cycling and the ratios of Mg, Al, Ca, N, and P in tea plants of a subtropical plantation.

Acid rain alters nutrient cycling in tea plantations. However, the acquisition of Mg and Ca by plants and their nutrient interactions with Al, N, and P in response to acid rain are poorly understood. Experimental treatments simulating acid rain at various acidities (pH4.5, 3.5, and 2.5) were performed within a red soil tea plantation in China. The available Mg, Al, Ca, N, and P were analyzed in the rhizosphere and bulk soils. Further, these elements were measured in absorptive, transportive, and storative roots in addition to twigs, tea, and mature leaves. Available soil Mg and Ca exhibited negative and positive rhizosphere effects, respectively, but the levels of both decreased due to acid rain treatment. In addition, average Mg and Ca concentrations generally decreased in plant tissues with increasing acidity. In contrast, average Al concentration increased across all plant tissues with increasing acidity treatment. Meanwhile, the ratios of Al/Mg and Al/Ca increased with increasing acidity but that of N/Al decreased in twigs and roots. Lastly, the ratios of N/Al, P/Ca, and N/P were all altered by acid treatment in tea and/or mature leaves. Taken together, these results indicated that elevated acidity increased the internal cycling of Al in plants but decreased Mg and Ca fluxes between soils and roots. Further, the response of interactions among the five measured elements to different acidities varied with tea plant tissue. Our findings may advance our understanding of plant adaptation to increasing soil acidification and atmospheric acid deposition around the world.

Acid rain decelerates the decomposition of Cunninghamia lanceolata needle and Cinnamomum camphora leaf litters in a karst region in China

AbstractAcid rain is generally believed to inhibit litter decomposition, but this inhibition effect often depends on local soil environmental factors such as nutrient and physicochemical property. Karst ecosystem is typically characterized by rich CaCO3, which can potentially react with H+ from acid rain. However, it is unknown whether the effect of acid rain on litter decomposition will be mitigated by this potential reaction. To investigate the effect of acid rain on decomposition, we undertook a field experiment on the decomposition of litters of Cunninghamia lanceolata needle and Cinnamomum camphora leaf during 1 year in a karst region in subtropical China. Contrary to hypothesis, litter decomposition was significantly decelerated by acid rain for the two litter types. For C. lanceolata litter, at the end of incubation, we noted that moderate acid rain resulted in the highest loss in mass (43%), while severe one showed the lowest loss (39%); for C. camphora litter, the mass loss was as follows: ambient treatment (66%) &gt; moderate treatment (56%) &gt; severe treatment (42%). Also microbial activities (including CO2 flux, fungal biomass and microbial degrading enzymes) showed similar variation patterns among acid rain treatments to mass loss. These responses indicated that the deceleration effect of acid rain on litter decomposition did not depend on calcareous soil as well as litter quality. Together, these results suggest that acid rain had a predominant controlling of litter decomposition over soil and litter qualities, and this information may be useful for predicting functional responses of karst ecosystem to environmental factors.

Experimental Study of the Mechanism of Acid Rain-Gabbro Interaction

As a common natural disaster, acid rain could not only cause serious environmental pollution, but also endanger the engineering properties of rock due to water-rock interactions. The failure of slopes of mafic igneous or ultramafic igneous rock is not unusual in areas affected by acid rain, but the specific mechanism of instability remains to be studied. In this study, fresh gabbro samples were processed, and a simulated acid rain treatment of pH 3.0 in the laboratory was carried out. Then the shear strength parameters were evaluated on samples before and after the acid rain test. Finally, the samples were analyzed by X-ray Diffraction (XRD), Polarizing Microscope and Scanning Electron Microscope (SEM) to analyze the mechanism of acid rain-gabbro interaction. Overall, this study provided useful insights toward the evaluation of engineering properties of mafic igneous and ultramafic igneous rocks in acid rain area.

Comparison of phosphor removal efficiency of rain treatment materials containing illite

Artificial lakes constitute more than 40% of drinking water sources, and can be easily eutrophicated by accumulation of phosphor, nitrogen, and nutrition salts introduced by various industrial and domestic origins after 10–30 years of their construction. Specifically, the concentration of phosphor is considered as an important factor that influences eutrophication, and causes seven times the eutrophication of nitrogen. In the present study, porous ceramics were fabricated with bottom ashes (BA) from power plants for recycling purposes and illite, which is known to be an efficient absorption material for phosphor in water. The phosphor removal efficiency reached up to 59% when the composition rate of illite to BA was 4 to 6. The study indicates the possibility of developing phosphor absorbing porous ceramics by using spent materials such as BA as substitutes for expensive illite without a significant decrease in phosphor removal efficiency.

Effects of sulfuric, nitric, and mixed acid rain on Chinese fir sapling growth in Southern China

The influence of acid rain on plant growth includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in root growth. In addition, the concentration of NO3- in acid rain increases along with the rapid growth of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO42-/NO3- (S/N) ratios, which were 1:0, 5:1, 1:1, 1:5 and 0:1, on Chinese fir sapling growth from March 2015 to April 2016. Results showed that Chinese fir sapling height growth rate (HGR) and basal diameter growth rate (DGR) decreased as acid rain pH decreased, and also decreased as the percentage of NO3- increased in acid rain. Acid rain pH significantly decreased the Chlorophyll a (Chla) and Chlorophyll b (Chlb) content, and Chla and Chlb contents with acid rain S/N 1:5 were significantly lower than those with S/N 1:0 at pH 2.5. The chlorophyll fluorescence parameters, maximal efficiency of Photosystem II photochemistry (Fv/Fm) and non-photochemical quenching coefficient (NPQ), with most acid rain treatments were significantly lower than those with CK treatments. Root activities first increased and then decreased as acid rain pH decreased, when acid rain S/N ratios were 1:1, 1:5 and 0:1. Redundancy discriminant analysis (RDA) showed that the Chinese fir DGR and HGR had positive correlations with Chla, Chlb, Fv/Fm ratio, root activity, catalase and superoxide dismutase activities in roots under the stress of acid rain with different pH and S/N ratios. The structural equation modelling (SEM) results showed that acid rain NO3- concentration and pH had stronger direct effects on Chinese fir sapling HGR and DGR, and the direct effects of acid rain NO3- concentration and pH on HGR were lower than those on DGR. Our results suggest that the ratio of SO42− to NO3− in acid rain is an important factor which could affect the sustainable development of monoculture Chinese fir plantations in southern China.

The effect of simulated acid rain on the stabilization of cadmium in contaminated agricultural soils treated with stabilizing agents.

Stabilization technology is one of widely used remediation technologies for cadmium (Cd)-contaminated agricultural soils, but stabilized Cd in soil may be activated again when external conditions such as acid rain occurred. Therefore, it is necessary to study the effect of acid rain on the performance of different stabilizing agents on Cd-polluted agriculture soils. In this study, Cd-contaminated soils were treated with mono-calcium phosphate (MCP), mono-ammonium phosphate (MAP), and artificial zeolite (AZ) respectively and incubated 3months. These treatments were followed by two types of simulated acid rain (sulfuric acid rain and mixed acid rain) with three levels of acidity (pH = 3.0, 4.0, and 5.6). The chemical forms of Cd in the soils were determined by Tessier's sequential extraction procedure, and the leaching toxicities of Cd in the soils were assessed by toxicity characteristic leaching procedure (TCLP). The results show that the three stabilizing agents could decrease the mobility of Cd in soil to some degree with or without simulated acid rain (SAR) treatment. The stabilization performances followed the order of AZ < MAP < MCP. Acid rain soaking promoted the activation of Cd in stabilized soil, and both anion composition and pH of acid rain were two important factors that influenced the stabilization effect of Cd.

Role of rain intensity and soil colloids in the retention of surfactant-stabilized silver nanoparticles in soil

Undisturbed outdoor lysimeters containing arable loamy sand soil were used to examine the influence of either heavy rain events (high frequency of high rain intensity), steady rain (continuous rainfall of low rain intensity), and natural rainfall on the transport and retention of surfactant-stabilized silver nanoparticles (AgNP). In addition, the AgNP–soil associations within the Ap horizon were analyzed by means of particle-size fractionation, asymmetrical flow field-flow fractionation coupled with UV/Vis-detection and inductively coupled plasma mass spectrometer (AF4-UV/Vis-ICP-MS), and transmission electron microscopy coupled to an energy-dispersive X-ray (TEM-EDX) analyzer. The results showed that AgNP breakthrough for all rain events was less than 0.1% of the total AgNP mass applied, highlighting that nearly all AgNP were retained in the soil. Heavy rain treatment and natural rainfall revealed enhanced AgNP transport within the Ap horizon, which was attributed to the high pore water flow velocities and to the mobilization of AgNP–soil colloid associations. Particle-size fractionation of the soil revealed that AgNP were present in each size fraction and therefore indicated strong associations between AgNP and soil. In particular, water-dispersible colloids (WDC) in the size range of 0.45–0.1 μm were found to exhibit high potential for AgNP attachment. The AF4-UV/Vis-ICP-MS and TEM-EDX analyses of the WDC fraction confirmed that AgNP were persistent in soil and associated to soil colloids (mainly composed of Al, Fe, Si, and organic matter). These results confirm the particularly important role of soil colloids in the retention and remobilization of AgNP in soil. Furthermore, AF4-UV/Vis-ICP-MS results indicated the presence of single, homo-aggregated, and small AgNP probably due to dissolution.

南亚热带森林土壤碳库稳定性与碳库管理指数对模拟酸雨的响应

PDF HTML阅读 XML下载 导出引用 引用提醒 南亚热带森林土壤碳库稳定性与碳库管理指数对模拟酸雨的响应 DOI: 10.5846/stxb201610312219 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（41573077，31428001，41430529）；中国科学院前言科学重点研究项目（QYZDJ-SSW-DQC003） Effects of simulated acid rain on soil labile organic carbon and carbon management index in subtropical forests of China Author: Affiliation: Fund Project: 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:通过对土壤总有机碳（SOC）、易氧化有机碳（ROC333、ROC167、ROC33）、颗粒有机碳（POC）、微生物量碳（SMBC）、溶解性有机碳（DOC）的测定，探讨模拟酸雨（pH 3.0、pH 3.5、pH 4.0、对照CK）对鼎湖山三个不同演替阶段森林（季风常绿阔叶林、针阔混交林、马尾松针叶林）土壤碳库稳定性及碳库管理指数的影响。结果表明：模拟酸雨增加了总有机碳的含量和各组分活性有机碳的含量（P<0.05），但酸雨在一定程度上抑制了土壤中微生物量与活性。土壤中各组分活性有机碳与总有机碳呈显著相关，其中ROC333和POC的含量与SOC关系最为密切，相关系数分别为0.853、0.846；碳库管理指数（CMI）结果表明，碳库活度（L）及碳库活度指数（LI）随森林的正向演替有下降的趋势，CPI与CMI呈现相反的趋势。在土壤有机碳及部分活性碳组分增加，碳库活性降低的前提下，土壤碳库稳定性增加。从各项指标的变化幅度可以得出：南亚热带森林土壤随森林群落正向演替而对模拟酸雨响应有更加敏感的趋势，各指标间的敏感性表现为CMI > R333 > POC > SMBC > R167 > R33 > LI > DOC > CPI > SOC。 Abstract:Four gradients of simulated acid rain treatment[pH 3.0, 3.5, 4.0 and CK (lake water)] were designed to determine the effects of simulated rain on soil carbon stabilization and the carbon management index (CMI) in three subtropical forests at different successional stages. The stages are, a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF), and an old grow-growth broadleaved forest (BF) at the Dinghushan Nature Reserve. The soil organic carbon (SOC), readily oxidation organic carbon (ROC), particulate organic carbon (POC), microbial biomass carbon (MBC), dissolved organic carbon (DOC), and soil properties were analyzed. The results showed that the SOC, ROC, and POC contents increased with acid treatment. However, simulated acid rain restrained the activity of microorganism while the SMBC content showed the opposite trend. The analysis showed that ROC333 and POC with SOC had highly significant correlations, with correlation coefficients of 0.853 and 0.846 respectively. Our results also indicated a significant correlation between other labile fractions and the SOC. The value of L and LI decreased with the progressive succession of forests while the rangeability of L and LI showed the same trend. It's indicated the proportion of labile portion to non-labile portion decreased. The results also showed CPI and CMI increased with the progressive succession of forests and, thus, the BF soil pool was more stable. That's due to BF soil has higher C sequestration and lower lability than MF and PF forests, so the carbon is easily to sequestrate and more stable if the carbon lability index decreased. Moreover, the LI was more sensitive than the carbon cool index (CPI) was. From the variation of indicators of the three forests, we can conclude that the response sensitivity of acid rain showed an increasing trend with the progressive succession of forests. All the parameters investigated showed the following order of decreasing sensitivity:CMI > R333 > POC > SMBC > R167 > R33 > LI > DOC > CPI > SOC. 参考文献 相似文献 引证文献

Influence of simulated acid rain on nitrogen and phosphorus contents and their stoichiome-tric ratios of tea organs in a red soil region, China

A 25-year-old tea plantation in a typical red soil region was selected for an in situ simulated acid rain experiment treated by pH 4.5, 3.5, 2.5 and water (control, CK). Roots with different functions, leaves and twigs with different ages were collected to measure nitrogen (N) and phosphorus (P) contents in the third year after simulated acid rain treatment. The N/P and acid rain sensitivity coefficient of tea plant organs were also calculated. The results indicated that with the increase of acid rain intensity, the soil pH, NO3--N and available P decreased, while the absorption root N content increased. Compared with the control, the N content in absorption root was increased by 32.9% under the treatment of pH 2.5. The P content in storage root significantly decreased with enhanced acid rain intensity, and the acid rain treatment significantly enhanced N/P of absorption root. Young and mature leaf N, P contents were not sensitive to different intensities of acid rain, but the mature leaf N/P was significantly increased under pH 3.5 treatment compared with the control. The effects of acid rain treatments differed with tea twig ages. Compared with the control, low intensity acid treatment (pH 4.5) significantly increased young twig N content and N/P, while no signi-ficant differences in old twig N content and N/P were observed among four acid rain treatments. Acid rain sensitivity coefficients of absorption root, young leaf and twig N contents were higher than that of storage root, old leaf and twig, respectively. And the storage root and leaf P had higher acid rain sensitivity coefficient than other tea organs. In sum, tea organs N content was sensitive to acid rain treatment, and moderate acid rain could increase young organ N content and N/P, and change the cycle and balance of N and P in tea plantation.

Effects of Simulated Acid Rain on Soil Respiration and Heterotrophic Respiration in a Secondary Forest

In order to investigate the effects of simulated acid rain on soil respiration and heterotrophic respiration in a secondary forest, a field experiment was carried out. A split-plot experiment was arranged in field. There were 4 blocks; each block had two main plots which were trenched and un-trenched plots. In each main plot, 4 simulated acid rain treatments of control (CK), pH 4.0 (A1), pH 3.0 (A2), and pH 2.0 (A3) were randomly assigned. Soil respiration in the un-trenched plots and heterotrophic respiration in the trenched plots were measured weekly. Soil temperature and moisture at a depth of 5 cm were measured during the respiration measurements. The results indicated that different simulated acid rain treatments exhibited similar seasonal patterns of soil respiration and heterotrophic respiration. Heterotrophic respiration in the trenched plots was significantly lower than soil respiration in the un-trenched plots. The annual mean soil respiration rates for the CK, A1, A2, and A3 treatments in the un-trenched plots were (2.47±0.31), (2.52±0.22), (2.38±0.17), and (2.43±0.22) μmol·(m2·s)-1, respectively, while the annual mean heterotrophic respiration rates for the 4 treatments in the trenched plots were (1.55±0.10), (1.65±0.22), (1.77±0.08), and (1.78±0.27) μmol·(m2·s)-1, respectively. ANOVA showed that simulated acid rain had no significant effects on soil respiration in the un-trenched plots and heterotrophic respiration in the trenched plots. Regression analysis suggested that there was a significant linear regression relationship between soil respiration and heterotrophic respiration. Simulated acid rain significantly (P<0.001) decreased the ratio of soil respiration to heterotrophic respiration. Soil temperature was the main controlling factor regulating the seasonal patterns of soil respiration and heterotrophic respiration for each of the SAR treatment, while soil moisture had no significant effects on the seasonal variability in soil respiration and heterotrophic respiration.

Effects of experimental snowmelt and rain on dispersal of six plant species

AbstractWater flows affect dispersal of propagules of many plant species, and rivers and streams are therefore very important dispersal vectors. However, small water flows such as trough rain and snowmelt are much more common, but their effects on dispersal are barely studied. The importance of this form of dispersal deserves attention, especially when considering that climate change is predicted to change the amounts of rain and snow worldwide. Dispersal through melting snow and rain was addressed experimentally, using artificial soils mounted on slopes with different angles and subjected to a melting snow pack or an equivalent amount of dripping water. Seeds on the soil moved on average 3·02 cm (±1·81 SE) in rain treatments and 0·23 cm (±0·3 SE) in snowmelt treatments. Tracking plastic granules in field conditions further showed that snowmelt exhibited minimal dispersal capacity. Dispersal distances by rain were enhanced by increasing slope angles and with decreasing seed volume. Given that many species in cold environments have small seeds, dispersal by rain could provide an important (secondary) dispersal mechanism in these habitats. © 2016 The Authors. Ecohydrology published by John Wiley &amp; Sons Ltd.

Combined effects of simulated acid rain and lanthanum chloride on chloroplast structure and functional elements in rice.

Acid rain and rare earth element (REE) pollution exist simultaneously in many agricultural regions. However, how REE pollution and acid rain affect plant growth in combination remains largely unknown. In this study, the combined effects of simulated acid rain and lanthanum chloride (LaCl3) on chloroplast morphology, chloroplast ultrastructure, functional element contents, chlorophyll content, and the net photosynthetic rate (P n) in rice (Oryza sativa) were investigated by simulating acid rain and rare earth pollution. Under the combined treatment of simulated acid rain at pH 4.5 and 0.08mM LaCl3, the chloroplast membrane was smooth, proteins on this membrane were uniform, chloroplast structure was integrated, and the thylakoids were orderly arranged, and simulated acid rain and LaCl3 exhibited a mild antagonistic effect; the Mg, Ca, Mn contents, the chlorophyll content, and the P n increased under this combined treatment, with a synergistic effect of simulated acid rain and LaCl3. Under other combined treatments of simulated acid rain and LaCl3, the chloroplast membrane surface was uneven, a clear "hole" was observed on the surface of chloroplasts, and the thylakoids were dissolved and loose; and the P n and contents of functional elements (P, Mg, K, Ca, Mn, Fe, Ni, Cu, Zn and Mo) and chlorophyll decreased. Under these combined treatments, simulated acid rain and LaCl3 exhibited a synergistic effect. Based on the above results, a model of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis was established in order to reveal the combined effects on plant photosynthesis, especially on the photosynthetic organelle-chloroplast. Our results would provide some references for further understanding the mechanism of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis.

不同酸度酸雨对小麦花后氮硫代谢和籽粒蛋白组分的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 不同酸度酸雨对小麦花后氮硫代谢和籽粒蛋白组分的影响 DOI: 10.5846/stxb201408261692 作者: 作者单位: 南京农业大学,南京农业大学,南京农业大学,南京农业大学,南京农业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目(31170475,31471445,30700483) Effect of different acidities of acid rain on nitrogen and sulfur metabolism and grain protein levels in wheat after anthesis Author: Affiliation: Nanjing Agricultural University,Nanjing Agricultural University,Nanjing Agricultural University,Nanjing Agricultural University,Nanjing Agricultural University Fund Project: 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:酸雨是中国重要的环境问题,为研究酸雨对小麦籽粒品质的可能影响,以小麦品种扬麦15和汶农17为材料开展盆栽试验,研究了不同酸度(pH2.5、pH4.0和pH5.6)酸雨对小麦花后氮硫代谢关键酶活性和籽粒蛋白质含量及组分的影响。结果显示:酸雨处理抑制叶片硝酸还原酶(NR)活性,提高了扬麦15整个灌浆期及汶农17灌浆中后期叶片谷氨酰胺合成酶(GS)活性,促进了叶片蛋白的降解,降低了叶片可溶性蛋白含量。不同酸度酸雨提高了成熟期籽粒中蛋白质含量,酸度越强,增加幅度越大,籽粒中各蛋白组分含量和大部分氨基酸含量也有明显提高。酸雨提高了扬麦15叶片丝氨酸乙酰转移酶(SAT)和O-乙酰丝氨酸硫裂解酶(OAS-TL)活性,但对汶农17硫代谢关键酶活性影响较小,酸雨处理还提高了籽粒中二硫键和含硫氨基酸含量。可见酸雨对小麦氮硫代谢有不同程度影响,进而影响了小麦籽粒蛋白质含量和组成,酸度越强影响越大,但不同品种对酸雨响应有一定差异。 Abstract:Recently, acid rain has become a serious environmental problem in China. Acid precipitation has occurred in about 40% of the entire area, especially in the rapidly developing industrial regions, such as the many areas around the Yangtze River. Acid rain is formed when sulfur dioxide (SO2) and nitrogen oxides (NOx) react with water in the atmosphere to produce H2SO4 and HNO3 and deposit as acid precipitation. Most studies have focused on the effect of acid rain on seed germination, plant morphology, plant carbon metabolism, and grain yield. However, the impacts of acid rain on plant nitrogen and sulfur metabolisms and grain quality have rarely been investigated, although SO42- and NO3-are known to be the main components of acid rain. Wheat (Triticum aestivum L.) is a staple food and plays an important role in food security. It is sensitive to biotic and abiotic stresses from flowering to maturity. In this study, a pot experiment was performed to determine the effects of spraying of acid rain with varying acidities (pH, 2.5, 4.0, and 5.6) after anthesis on the activities of key enzymes related to nitrogen and sulfur metabolisms and amino acid and protein contents in wheat grains. Two winter wheat cultivars (Yangmai 15 and Wennong 17) were used in this study. The results showed that acid rain inhibited nitrate reductase activity and decreased the soluble protein content of leaves. At 10 days after anthesis, the soluble protein content in Wennong 17 and Yangmai 15 subjected to acid rain (pH 2.5) decreased by 26.58% (P < 0.05) and 21.31% (P < 0.05), respectively, compared with that in the control. Glutamine synthetase activity in the leaves was increased in Yangmai 15 during the entire grain filling stage and in Wennong 17 only during the late grain filling stage. Acid rain gradually decreased the free amino acid content from the beginning of grain filling stage up to the later stages. The contents of protein and most essential amino acids in mature gains were increased by acid rain and were the highest after treatment with acid rain of higher pH. Acid rain increased the activities of serine acetyltransferase and O-acetylserine(thiol)lyase in Yangmai 15, but had little effect on the activity of key enzymes related to sulfur metabolism in Wennong 17. Acid rain treatment also increased the contents of disulfide bonds and amino acids containing sulfur in the wheat grains of both the cultivars. Thus, acid rain had different influences on wheat sulfur and nitrogen metabolisms, thereby affecting the protein content and composition of wheat grains, and thus its nutritional quality. 参考文献 相似文献 引证文献

Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China

With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China.

Nitrogen Retention in Salt Marsh Systems Across Nutrient-Enrichment, Elevation, and Precipitation Regimes: a Multiple-Stressor Experiment

In the Northeastern USA, multiple anthropogenic stressors, including changing nutrient loads, accelerated sea level rise, and altered climatic patterns, are co-occurring and are likely to influence salt marsh nitrogen (N) dynamics. We conducted a multiple-stressor mesocosm experiment to assess impacts of climate change and nutrient load on N uptake by the ecosystem dominant species. The New England salt marsh plant Spartina alterniflora was planted at mean high water (MHW) and 15 cm above and below MHW in tanks plumbed to mimic tides. The experiment consisted of two nutrient treatments (enriched, unenriched), three precipitation treatments (rain, storm, and no precipitation or control), and three elevations (low, mean, and high), with four replicate pots for each. A quarter of the way into the experiment (1 month), an N stable isotope tracer was added to a portion of the precipitation events received by the rain and storm treatments to assess how N is retained by the different components of each treatment. At the completion of the experiment, Spartina pots in the rain treatments retained far more tracer than the pots receiving the twice monthly storms, with the most tracer recovered at the highest elevation in all precipitation treatments as these pots received direct tracer input to stems and sediment surface. Experimental results suggest that the elevation of the marsh as well as the timing and delivery of rainfall may be important factors in how salt marshes intercept, retain, and transform N.