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1.
王素霞 《山西水土保持科技》2016,(3):41-42
原平市西部风能资源丰富,为风电项目建设提供了基础条件。目前,原平市有3项风电建设项目,2项已经竣工验收并投产运行,1项正在建设当中。风电项目位于土石山区,项目建设给原本就脆弱的生态环境造成了新的破坏。在对风电建设项目不同阶段水土流失特点分析的基础上,论述了水土保持措施防护体系,总结了当前存在的问题,提出了今后的水土保持工作重点。 相似文献
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内蒙古开发建设项目水土流失特点与监测技术探讨 总被引：1，自引：0，他引：1
"十一五"期间,内蒙古自治区大规模的开发建设活动在推动全区经济快速发展的同时,对生态环境造成了极大的压力,人为水土流失呈现出上升趋势,开发建设活动造成的水土流失呈现出水土流失范围广、类型多样、危害大、治理难度大等特点。水土流失监测是开发建设项目水土保持监测的核心,自《开发建设项目水土保持设施验收管理办法》颁布实施以来,开发建设项目水土保持监测工作已逐渐被社会所接受,但据2009年的统计资料,全区开发建设项目水土保持监测率还不到24%。针对内蒙古自治区开发建设项目的不同水土流失类型,阐述了适用的监测方法,并建议应在充分了解项目建设内容与规模、建设活动扰动方式、项目区自然条件和水土流失特点、建设活动对水土流失的影响等因素的基础上,确定具体开发建设项目的水土流失监测方法,选择一种或多种监测方法,或不同方法交替运用。 相似文献
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公路建设项目水土保持方案编制初探 总被引：8，自引：1，他引：7
通过对公路建设水土保持特点及可能造成的水土流失类型及部位的分析,初步探讨了公路水土保持防治责任范围的界定,并对公路建设项目水土流失的防治进行了探讨。 相似文献
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风电场通常位于高海拔山地区，水土流失风险高、危害大，其水土流失防治措施体系建设十分重要。以江西省吉安市华润峡江玉峡风电场工程为例，从扰动面积、水土流失、挖填方量等方面分析山地风电场水土流失动态特征，探讨山地风电场水土流失防治措施体系建设和防治重点。结果显示：风电场风电机组区和道路工程区是新增扰动面积和水土流失量的主要区域，也是风电场水土流失防治的重点区域；水土保持措施应在施工期第1年布设完毕，这样才能起到有效防止水土流失的作用；单台风机挖填方量、造成的水土流失均小于同地区其他风电项目，表明其水土流失防治措施体系取得了显著成效；挡土埂和挂网喷播植草是两种有效的边坡防护措施，可为同地区其他风电项目水土保持设计提供参考。 相似文献
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《开发建设项目水土流失防治标准》(GB 50434—2008)建立的水土流失防治标准体系,广泛应用于生产建设项目水土保持方案编制、水土保持方案技术评审、水土保持监测评价和水土保持设施验收,对有效预防和治理生产建设活动导致的水土流失,减少水土流失危害起到了重要的作用。随着经济社会发展,新时代对水土保持工作提出了新任务和新要求,现行生产建设项目水土流失防治标准二类别、三等级、三阶段、六指标体系在某些方面已不适应新时期生产建设项目水土流失防治工作的需要。结合多年的工作实践,提出了完善生产建设项目水土流失防治标准体系的主要思路和体系架构。 相似文献
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高玉凤 《山西水土保持科技》2021,(1):22-23
风电项目在建设过程中,风机箱变安装、输电线路布设、施工检修道路和升压站建设等一系列工程建设活动,会扰动、破坏原地表,损害原有植被,同时开挖活动产生的边坡打破了原始荷载平衡,产生严重的水土流失.在实际监测中发现,风电建设项目水土流失分散,水土保持监测不仅需要加大法律普及力度,更要借助先进技术手段,更好的防水土流失隐患于未... 相似文献
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以哈密十三间房一期风电工程为例,系统介绍了风电工程水土保持设施验收技术评估的主要内容,主要包括水土保持措施总体布局评价、水土保持措施建设情况评价、水土保持工程质量评价、水土保持投资评价、水土保持监测评价、水土保持效果评价等,可供同类生产建设项目水土保持设施验收参考。 相似文献
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The charge characteristics of A1 or Ap and B2 horizon samples of total 23 Ultisols, Alfisols and Oxisols in Korea and Thailand were studied by measuring the retention of NH4+ and NO3? at different pH values (4–8) and NH4NO3 concentrations (0.1–0.005 m ). The magnitude of their negative charge (σ?; meq/100g) was dependent on pH and NH4NO3 concentration (C; m ) as represented by a regression equation: log σ?=apH +blogC +c. The values of the coefficient a (0.04–0.226), b (0.03–0.264) and c (–0.676–1.262) were correlated with the kinds of the soil and horizon and with the region where the soil exists. The retention of NO3? was less than 1 and 2–3 meq/100 g for the A1 or Ap and B2 horizon samples, respectively. The sum of exchangeable base and Al (‘effective’ CEC) was close to and higher than the magnitude of permanent charge (=σ? measured at pH = 4.3 and at C = 0.005 m ) for one-third and two-thirds of samples, respectively. A σ? value of 16 meq/100 g clay at pH = 7 and C = 0.01 m was found appropriate to separate the B2 horizons of Thai Ultisols and Oxisols from those of Korean Ultisols and Alfisols. Korean Alfisols and Ultisols and Thai Ultisols were distinguished from each other on the status of exchangeable base and Al 相似文献
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Quantifying global patterns of forest soil respiration (SR), its components of heterotrophic respiration (HR) and belowground autotrophic respiration (AR), and their responses to temperature and precipitation are vital to accurately evaluate responses of the terrestrial carbon balance to future climate change. There is great uncertainty associated with responses of SR to climate change, concerning the differences in climatic controls and apparent Q10 (the factor by which respiration increases for a 10 °C increase in temperature) over HR and AR. Here, we examine available information on SR, HR, AR, the contribution of HR to SR (HR/SR), and Q10 of SR and its components from a diverse global database of forest ecosystems. The goals were to test how SR and its two components (AR and HR) respond to temperature and precipitation changes, and to test the differences in apparent Q10 between AR and HR. SR increased linearly with mean annual temperature (MAT), but responded non-linearly to mean annual precipitation (MAP) in naturally-regenerated forests. For every 1 °C increase in MAT, overall emissions from SR increased by 24.6 g C m−2 yr−1. When MAP was less than 813 mm, every 100 mm increase in MAP led to a release of 75.3 g C m−2 yr−1, but the increase rate declined to 20.3 g C m−2 yr−1 when MAP was greater than 813 mm. MAT explained less variation in AR than that in HR. The overall emissions in AR and HR for every 1 °C increase in MAT, increased by 12.9 and 16.1 g C m−2 yr−1, respectively. The AR emissions for every 100 mm increase in MAP, increased by 44.5 g C m−2 yr−1 when MAP less than 1000 mm. However, above the threshold, AR emissions stayed relatively constant. HR increased linearly by 15.0 g C m−2 yr−1 with every 100 mm increased in MAP. The Q10 value of SR increased with increasing depth at which soil temperature was measured up to 10 cm and was negatively correlated with HR/SR. Our synthesis suggests AR and HR differ in their responses to temperature and precipitation change. We also emphasized the importance of information on soil temperature measurement depth when applying field estimation of Q10 values into current terrestrial ecosystem models. Q10 values derived from field SR measurements including AR, will likely overestimate the temperature response of HR on a future warmer earth. 相似文献
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Interactions between the N2-fixing bacterium Azospirillum brasilense and the mycorrhizal fungus Glomus mosseae were studied in relation to their effects on the growth and nutrition of Zea mays (C4) and Lolium perenne (C3) plants. Although roots from plants inoculated with Azospirillum exhibited C2H2 reduction activity no significant effect of inoculation on N concentration in the plant shoots was found. With non-mycorrhizal plants, inoculation with Azospirillum resulted in increased dry matter production at the first harvest compared to the effect achieved by supplying N as fertilizer, but this trend was reversed at the last harvest. However, with mycorrhizal maize plants, Azospirillum, which stimulated the development of VA mycorrhiza, was still effective in improving plant growth and nutrient uptake at the last harvest. Azospirillum and N behaved similarly in enhancing the growth and nutrition of mycorrhizal maize. The dual inoculation of maize by Azospirillum and Glomus produced plants of a similar size, N content, and a higher P content, than those supplied with N and P. 相似文献
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Influence of Puroindolines A and B Individually and in Combination on Wheat Milling and Bread Traits
Endosperm texture in wheat (Triticum aestivum L.) is determined by the Pina and Pinb genes located within the Hardness (Ha) locus on chromosome 5D. We have previously shown that Pina and Pinb can act alone to produce intermediate-textured grain or act together to produce soft grain. The objective here was to isolate the role of PINA and PINB individually and in combination on milling and bread traits by analyzing F3 recombinant lines created by crosses between PINA and PINB null cultivars with Pina-D1a and Pinb-D1a overexpressing transgenic lines. Homozygous lines that contained either the Pina-D1b/Pinb-D1a (Pina null) or Pina-D1a/Pinb-D1e (Pinb null) Ha locus with or lacking transgenically added Pina or Pinb were analyzed for milling and bread traits. Addition of Pina-D1a to Pina-D1b/Pinb-D1a and addition of Pinb-D1a to Pina-D1a/Pinb-D1e Ha locus genotypes gave soft grain with lower flour yield, flour ash, and a higher proportion of small flour particles. Addition of Pinb-D1a produced greater negative effects on loaf volume than addition of Pina-D1a. Grain hardness, flour protein, flour ash, and mixograph water absorption were positively correlated, which is indicative of the complex phenotype conditioned by PINs. The results demonstrate that PIN overexpression leads to a reduction in grain hardness and reduced flour yield, flour ash, and flour particle size. PIN expression also results in reduced loaf volume and flour water absorption. 相似文献
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Stefan Trapp Almut Köhler Lars C. Larsen Kim C. Zambrano Ulrich Karlson 《Journal of Soils and Sediments》2001,1(2):71-76
The toxicity of fresh and weathered gasoline and diesel fuel to willow and poplar trees was studied using a tree transpiration toxicity test. Soils were taken from an abandoned filling station. Concentrations in the samples were measured as the sum of hydrocarbons from C5 to C10 (gasoline) and C12 to C28 (diesel). Concentrations ranged from 145 to 921 mg/kg gasoline and 143 to 18231 mg/kg diesel. The correlation between log soil concentration and toxicity to willows(Salix viminalis x schwerinii) was highly significant for the diesel fraction (r2=0.81, n=19) and for the sum of hydrocarbons (r2=0.84, n=19). The EC50 (50% inhibition of transpiration) for the sum of hydrocarbons was determined at 3910 mg/kg (95% C.I., 2900 to 5270 mg/kg) and followed a log-normally distributed sigmoidal curve. The EC10 was 810 mg/kg (95% C.I., 396 to 1660 mg/kg). The results were verified with artificially mixed diesel and gasoline contaminated soils, and two willow and one poplar species(S. viminalis, S. alba and Populus nigra). Fresh diesel at about 1000 mg/kg showed no effect onS. alba, althoughP. nigra was more sensitive. 10000 mg/kg seriously affected the transpiration of all species, silver willow(S. alba) being the least sensitive. Free phase diesel killed all trees within six weeks. Fresh gasoline at 1000 mg/kg was deadly for all trees, hence was more toxic than weathered gasoline. Survival of poplars and willows planted at the abandoned filling station was compared to the laboratory findings. There was some correlation, but in the field, trees also suffered from other stress factors than fuel pollution. 相似文献
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《Journal of plant nutrition》2013,36(7):1227-1242
Abstract Uptake of arsenic (As) and its distribution in Chinese Brake fern (Pteris vittata L.), an As hyperaccumulator, and Boston fern (Nephrolepis exaltata L.), a nonhyperaccumulator, in the presence of phosphorus (P), were characterized by employing a hydroponic experiment with a complete three-factorial design. Two levels of As (100 and 1000 µM) and four levels of P (0, 100, 500, and 1000 µM) were used in this study. Arsenic uptake rates on the basis of root fresh weight for the two ferns were similar at low As concentration (100 µM). At high As concentration (1000 µM), however, As uptake rates (373–987 nmol g?1 f wt h?1) of P. vittata were significantly greater than those of N. exaltata (164–459 nmol g?1 f wt h?1). In both ferns, addition of P reduced their As uptake rate as well as accumulation. Pteris vittata had a greater As TF (Translocation factor = concentration ratio of fronds to roots) than N. exaltata. On the contrary, N. exaltata displayed a greater P TF than P. vittata. As a result, high P/As ratio was observed in the roots of P. vittata, whereas high P/As ratio was observed in the fronds of N. exaltata. The study illustrated that As hyperaccumulation by P. vittata may be facilitated by its high As influx rate and its high molar P/As ratio in the roots resulting from both high As TF and low P TF. 相似文献
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Soil microbial and extractable C and N after wildfire 总被引：12，自引：0，他引：12
The effect of wildfire on soil microbes and extractable C (Cext) and N (Next) changed with respect to the time from burning and soil depth. Initially, microbial biomass C (Cmic) and N (Nmic) were drastically reduced in the soil surface layer (0–5 cm) and reduced by 50% in the subsurface (5–10 cm), whereas Cext increased by 62% in the surface layer and did not significantly change in the subsurface. These parameters were affected
for the following 4 years, during which the average reductions in the soil surface and subsurface layers were, respectively,
60% and 50% for Cmic, 70% and 45% for Nmic, 60% and 40% for the ratio Cmic: organic C (Corg) and 70% and 30% for the ratio Nmic: total N (Ntot), while for Cext the surface layer was the only zone consistently affected and Cext decreased by up to 59%. Immediately after a fire, the Cext : Corg ratio increased by 3.5-fold and 2-fold in the surface and subsurface layers, respectively; thereafter for 2 years, it decreased
in the surface layer (by up to 45%) while the effect on the subsurface layer was not consistent. The effect of burning on
Next lasted 1 year, in which Next increased by up to 7- and 3-fold in the surface and subsurface layers, respectively, while the average Next : Ntot ratio doubled in the surface layer and increased by 34% in the subsurface. During the time in which each parameter was affected
by burning, the soil factor explained a high percentage of variance in the fluctuations of Cmic, Nmic, Cmic : Corg and Nmic : Ntot, while those of Next and Next : Ntot, but not those of Cext and Cext : Corg depended on both the soil and its depth. In the burned soils similar patterns of response were found between the following
parameters listed in pairs: Cmic and Nmic; Cmic : Corg and Nmic : Ntot; Cext and Next; and Cext : Corg and Next : Ntot. However, after the fire relationships found previously between the parameters studied and many other soils properties were
either no longer evident, or were inverted. Although the addition of cellulose to the burned soil favoured fungal mycelium
development and increased Cmic and Cext contents, the negative effect of burning on the microbial biomass and the Cext was not counteracted even under incubation conditions suitable for both microbial growth and C mineralization.
Received: 28 May 1997 相似文献
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Rapid nitrogen（N） transformations and losses occur in the rice rhizosphere through root uptake and microbial activities. However,the relationships between rice roots and rhizosphere microbes for N utilization are still unclear. We analyzed different N forms（NH＋4,NO-3, and dissolved organic N）, microbial biomass N and C, dissolved organic C, CH4 and N2O emissions, and abundance of microbial functional genes in both rhizosphere and bulk soils after 37-d rice growth in a greenhouse pot experiment. Results showed that the dissolved organic C was significantly higher in the rhizosphere soil than in the non-rhizosphere bulk soil, but microbial biomass C showed no significant difference. The concentrations of NH＋4, dissolved organic N, and microbial biomass N in the rhizosphere soil were significantly lower than those of the bulk soil, whereas NO-3in the rhizosphere soil was comparable to that in the bulk soil. The CH4 and N2O fluxes from the rhizosphere soil were much higher than those from the bulk soil. Real-time polymerase chain reaction analysis showed that the abundance of seven selected genes, bacterial and archaeal 16 S rRNA genes, amoA genes of ammonia-oxidizing archaea and ammonia-oxidizing bacteria, nosZ gene, mcrA gene, and pmoA gene, was lower in the rhizosphere soil than in the bulk soil, which is contrary to the results of previous studies. The lower concentration of N in the rhizosphere soil indicated that the competition for N in the rhizosphere soil was very strong, thus having a negative effect on the numbers of microbes. We concluded that when N was limiting, the growth of rhizosphere microorganisms depended on their competitive abilities with rice roots for N. 相似文献
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Yoshimi Sakai Shin Ugawa Shigehiro Ishizuka Masamichi Takahashi Chisato Takenaka 《Soil Science and Plant Nutrition》2013,59(4):526-537
Estimating carbon (C) and nitrogen (N) stocks in deadwood in forests nationwide is required for understanding large-scale C and N cycling. To do so requires estimated values of wood density and C and N concentrations. Additionally, parameters that show variation should be examined. In this study, we clarified the estimated values and the variation in three parameters in each decay class of each of two tree species and examined whether dead log diameter and region contribute to variation in the parameters. Data were collected from 73 Chamaecyparis obtusa (Sieb. et Zucc.) Endl. plantations and 66 Cryptomeria japonica D. Don plantations throughout Japan. Wood densities decreased from 386 to 188?kg?m?3 for C. obtusa and from 334 to 188?kg?m?3 for C. japonica in decay classes 1–4. The variation in wood density increased with decay class, and the coefficient of variance increased from 13.9% to 46.4% for C. obtusa and from 15.2% to 48.1% for C. japonica. The N concentrations increased from 1.04 to 4.40?g?kg?1 for C. obtusa and from 1.11 to 2.97?g?kg?1 for C. japonica in decay classes 1–4. The variation in N concentration increased with decay class, and the coefficient of variance increased from 51.9% to 76.7% for C. obtusa and from 50.3% to 70.4% for C. japonica. Log diameter and region contributed to variations in wood density and N concentration in decay classes 1 and 2 for C. obtusa and C. japonica. However, no relationship was observed between regional climates and the two parameters. In contrast, C concentrations ranged from 507 to 535?g?kg?1 and were stable with much lower coefficients of variance throughout the decay classes for both tree species. Thus, we recommend that the same C concentration can be adapted for all decay classes of both tree species. 相似文献
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Diane E. Allen Ram C. Dalal Rikke Louise Meyer Steven Reeves 《Soil biology & biochemistry》2007,39(2):622-631
We quantified spatial and temporal variations of the fluxes of nitrous oxide (N2O) and methane (CH4) and associated abiotic sediment parameters across a subtropical river estuary sediment dominated by grey mangrove (Avicennia marina). N2O and CH4 fluxes from sediment were measured adjacent to the river (“fringe”) and in the mangrove forest (“forest”) at 3-h intervals throughout the day during autumn, winter and summer. N2O fluxes from sediment ranged from an average of −4 μg to 65 μg N2O m−2 h−1 representing N2O sink and emission. CH4 emissions varied by several orders of magnitude from 3 μg to 17.4 mg CH4 m−2 h−1. Fluxes of N2O and CH4 differed significantly between sampling seasons, as well as between fringe and forest positions. In addition, N2O flux differed significantly between time of day of sampling. Higher bulk density and total carbon content in sediment were significant contributors towards decreasing N2O emission; rates of N2O emission increased with less negative sediment redox potential (Eh). Porewater profiles of nitrate plus nitrite (NOx−) suggest that denitrification was the major process of nitrogen transformation in the sediment and possible contributor to N2O production. A significant decrease in CH4 emission was observed with increasing Eh, but higher sediment temperature was the most significant variable contributing to CH4 emission. From April 2004 to July 2005, sediment levels of dissolved ammonium, nitrate, and total carbon content declined, most likely from decreased input of diffuse nutrient and carbon sources upstream from the study site; concomitantly average CH4 emissions decreased significantly. On the basis of their global warming potentials, N2O and CH4 fluxes, expressed as CO2-equivalent (CO2-e) emissions, showed that CH4 emissions dominated in summer and autumn seasons (82-98% CO2-e emissions), whereas N2O emissions dominated in winter (67-95% of CO2-e emissions) when overall CO2-e emissions were low. Our study highlights the importance of seasonal N2O contributions, particularly when conditions driving CH4 emissions may be less favourable. For the accurate upscaling of N2O and CH4 flux to annual rates, we need to assess relative contributions of individual trace gases to net CO2-e emissions, and the influence of elevated nutrient inputs and mitigation options across a number of mangrove sites or across regional scales. This requires a careful sampling design at site-level that captures the potentially considerable temporal and spatial variation of N2O and CH4 emissions. 相似文献