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1.
本文对环江肯福环境移民安置示范区所采 88个表层土样及 4个剖面土样有机质 ,全氮 ,全磷 ,全钾 ,水解氮 ,速效磷 ,速效钾 ,pH等指标进行了测定。结果表明该区表层土壤有机质含量较高 ,土壤氮相对丰富 ,钾含量偏低 ,磷严重缺乏 ,pH偏酸性。土壤剖面发育完整 ,在土壤剖面中有机质、氮、速效磷、交换性钾主要聚集在 2 0cm的表层土壤中 ,全磷随深度的增加而降低 ,全钾和 pH值则随土壤深度增加而上升  相似文献   

2.
The agricultural lands of typic tundra of the Yamal Peninsula in Russia are pastures for reindeer (Rangifer tarandus sibiricus Murr.) herds. Currently, degradation of tundra soil cover is mainly caused by mechanical impacts of tracked vehicles used in construction operations. The objective of this study was to evaluate changes in morphological, micro-structural, and physical properties of Cryozems and Cryogenic peaty soils affected by these tracked vehicles. Soil samples were taken from the surface and underlying horizons before and 5 years after four and 100 passes of tracked vehicles. Surface horizons (0–10 cm) of the undisturbed Cryozems and Cryogenic peaty soils were organogenic. Passage of tracked vehicles caused mixing of these horizons with lower sandy loam and loam mineral horizons. Properties of the organomineral horizons formed in this way differed essentially from those of the surface horizons of the undisturbed soils. Microaggregates were completely disturbed, even after only four passes of tracked vehicles. Large inter-aggregate pores disappeared and thin pores or cracks formed as a result of vehicle-induced mechanical impacts. Humification of plant residues was observed to be faster in the compacted organomineral horizons of disturbed soils compared with undisturbed ones. The organic substances formed in the compacted organomineral horizons readily moved downward within the soil profile or were lost during runoff events. High correlation coefficients of organic carbon content with both specific surface area and water retention showed that the above-mentioned organic substances were hydrophilic. Specific surface area and water retention of the disturbed soils rose with increasing organic carbon content. The results obtained in this study demonstrated a high susceptibility of Cryozems and Cryogenic peaty soils to mechanical impacts.  相似文献   

3.
以毛乌素退化湿地为研究对象,采集芦苇滩地、灌草地、沙地3个不同退化时期9个土壤剖面样本,研究土壤有机碳、全氮、全磷垂直分布,并进行有机碳-全磷、有机碳-全氮Pearson相关性分析和Spearman秩相关分析。结果表明:不同类型退化湿地土壤有机碳、全氮、全磷含量差异明显,随土层深度增加含量减少,并呈现分层特征。研究发现,在土壤剖面深度100cm左右且有黑色泥炭层存在情况下,有机碳、全氮、全磷含量增加。样地土壤有机碳与全氮呈显性线性相关(R=0.989),Spearman秩相关系数为0.944。样地土壤有机碳与全磷呈显性线性相关(R=0.938),Spearman秩相关系数为0.698。  相似文献   

4.
川西北高寒地区土壤有机碳含量垂直分布特征   总被引:3,自引:0,他引:3  
本论文研究了川西北高寒地区三种典型土壤(亚高山草甸土、泥炭草甸土和冲积土)在不同土壤深度有机碳含量、全氮含量、全磷含量、C/N以及C/P的变化,探讨了有机碳含量和全氮含量、全磷含量、C/N以及C/P之间的相关关系。试验结果表明:冲积土和亚高山草甸土有机碳含量、全氮含量和全磷含量随土壤深度的增加都有下降的趋势;但是泥炭草甸土有机碳含量和全氮含量都是随土壤深度增加先下降后升高,在20~40 cm土壤深度时含量最低,而全磷含量随土壤深度的增加而下降。亚高山草甸土、泥炭草甸土和冲积土的有机碳含量都与全氮含量显著相关,其相关系数分别为0.999、0.965和0.992;而冲积土的有机碳含量还与全磷含量和C/P显著相关,相关系数分别为0.902和0.982。  相似文献   

5.
The dynamics of the content and microbiological transformation of carbon and nitrogen compounds in the surface horizons of mountain tundra soils are considered in the postpyrogenic succession. The contents of total and labile carbon and nitrogen increase in the course of postpyrogenic soil evolution. At the same time, in the surface organic horizons, the carbon reserves, as compared to the nitrogen ones, are restored faster. The aerobic transformation of carbon compounds prevails at all the stages of the succession. The tolerance of soil organic matter toward mineralization increases as the ecosystem recovers after fire. However, this parameter reaches the values characteristic of the control soils no earlier than 60 years after the fire. The microbial communities of the podburs (Folic Podzols, Haplic Podzols) restore their functional activity fast enough after the fire (about three years). In the remote future, the effect of fire leads to an increase in the availability of soil nitrogen and in the soil ability to fix atmospheric nitrogen. Despite the temporary increase in the availability of mineral nitrogen (including nitrates) at early stages of the postpyrogenic restoration of soil systems, denitrification does not play a significant role in the biogeochemical cycle of nitrogen.  相似文献   

6.
Soil fertility is the basis for production of high green mass, which has numerous essential benefits in urban areas. This study aimed to investigate the soil fertility of urban land. This was done by comparing soils from a vegetable garden and its surrounding arable land. A local brickwork dump was included. The soils were Hortisols, slightly stagnogleyic Luvisols, and a Regosol from sandy loamy silt. The location of the study was in the center of one of the world’s largest urban, hard-coal mining and heavy industry areas, the Ruhr area in Germany. The investigations for identifying the characteristic features of the soil fertility involved determination of the profile horizons, texture, pH, bulk density, C/N ratio, content and stocks of organic carbon, total nitrogen, available phosphorus and potassium, and soil water by field capacity. As they are expected to become construction land, the sites were already in a derelict state. The results show that all three soil types had high fertility characteristics. However, the fertility of the garden soils was much greater than that of the local arable land. This was due to the strong and deep accumulation of organic carbon due to compost application. The available phosphorus and potassium contents and field capacity were also distinctly increased in the garden soils. The spatial distribution and distribution with depth of pH, bulk density, organic carbon, nitrogen, available phosphorus, and potassium were extremely heterogeneous among the individual garden soils. In contrast, in the arable land, they were uniform. The organic carbon accumulation in the dump was in the range of that of the garden soils, but the nutrient contents were lower. These results show that the diversity of properties of urban soils is much higher than that of arable soils. The dereliction of arable, garden, and dump soil and vegetation by bushes and trees also affect the soil properties. There should be greater awareness of the high fertility of urban soils, such as vegetable garden soils. Vegetable garden soils have a high potential for contributing to solving urban problems by producing high volumes of biomass and storing water. Therefore, it should be demanded that vegetable garden soils receive a high protection status, and they should not be used for the establishment of construction.  相似文献   

7.
成都典型区水稻土有机碳组分构成及其影响因素研究   总被引:3,自引:0,他引:3  
农田生态系统土壤有机碳对农业生产、生态平衡和全球气候变化至关重要,有机碳组分构成及平均驻留时间对深入了解土壤有机碳特征及演变规律意义重大。通过土壤呼吸培养实验和三库一级动力学方程,模拟分析了成都典型区水稻土有机碳组分构成特征;利用土壤定量化属性与有机碳各组分相关及回归分析,建立研究区土壤有机碳各组分预测模型。结果表明,有机碳组分的活性碳、慢性碳和惰性碳含量在表层(0~20 cm)分别为0.42、6.13、11.43 g kg-1,均高于亚表层(20~40 cm)的0.23、4.09、7.50 g kg-1,两土层间有机碳组分含量具有显著性差异,但有机碳组分比例没有显著性差异。剖面(0~100 cm)有机碳组分含量随着深度增加而减小,活性碳和慢性碳比例随着深度增加而降低,惰性碳比例则随着深度增加显著升高。容重、全氮和全磷对有机碳各组分含量,质地对活性碳组分含量、比例及平均驻留时间,p H对慢性碳和惰性碳组分比例均具有显著影响;活性碳和惰性碳组分含量与土壤全氮、碳氮比、p H以及土壤细粉粒(0.02~0.002 mm)含量间存在显著线性关系,可用来预测水稻土有机碳各组分含量,研究结果对其他地区土壤有机碳各组分研究及预测具有积极启示作用。  相似文献   

8.
Volcanic ash soils along the western edge of the Omiya tableland, Japan, are covered with thick anthropogenic soil horizons. The formation of anthropogenic soil horizons occurs because of the soil dressing practice known as “Dorotsuke,” where alluvial soil materials are deposited on fields and mixed with volcanic ash topsoil by tillage over the years. To clarify the chronology of this anthropedogenesis, carbon-14 (14C) age profiles were estimated using humic acid fractions from three pedons: an anthropogenic soil, an undressed Andosol, and a Fluvisol. Soil charcoal fragments were also dated to estimate maximum burial age. Charcoal fragments displayed vertically random age distributions, indicating that the fragments may have had multiple origins. However, the age of charcoal in the lower part of the anthropogenic soil horizons indicated that the initiation of anthropedogenesis occurred later than the late 13th century. The 14C age profile of humic acid in the Andosol exhibited little variation in age with depth in the subsoil. The 14C age profile of humic acid in the Fluvisol suggested that the humic acid fraction included allochthonous old carbon (C), although the soil itself had been formed from recent sediments. The 14C age profile of humic acid in the anthropogenic soil showed features of its two component soils. The 14C ages in the volcanic ash subsoil matched with those in the Andosol, whereas the ages increased in the anthropogenic soil horizons because of supplementation with old C from alluvial soil materials. However, the peak 14C ages occurred in the lower part of the anthropogenic horizons, whereas the middle part on the peak position displayed a gradual age-depth gradient. This feature was interpreted as a sign of 14C activity equilibrium throughout anthropedogenesis. On the basis of this postulated 14C activity equilibrium, the linear age-depth gradient at the peak position was derived from differences in burial time, and burial ages were calculated by estimating steady-state 14C. The calculated ages were lower than the charcoal ages. These age estimates suggest that anthropedogenesis was initiated in the Middle Ages and reached an intermediate stage before or during the first half of the Edo period.  相似文献   

9.
白洋淀典型台田湿地土壤生源元素剖面分布特征   总被引:2,自引:0,他引:2  
研究了在人为干扰作用下白洋淀典型台田湿地土壤中碳氮磷等生源元素的剖面分布特征.结果表明,台田湿地土壤有机碳随土层深度增加呈现先增加后减少的趋势,累积峰出现在10~20 cm土层;无机碳大致呈先减小后增加的趋势,而全碳大致呈先增加后减小的趋势;各形态氮和全氮含量随深度的增加出现较大的波动,但总体上呈现出深层土壤含量高于上部土层的趋势;土壤C/N比较低,C/N比与有机碳含量有显著的相关性,与全氮无显著的相关性;有效磷含量随着土层加深呈现增加趋势.全磷含量总体上呈现波动性变化,存在两个累积峰.  相似文献   

10.
贵州毕节地区不同石漠化程度土壤理化性质特征   总被引:4,自引:0,他引:4  
为揭示喀斯特地区不同石漠化程度土壤理化性质特征及其影响机制,以贵州毕节石漠化地区土壤为研究对象,在雨季前、中、后对潜在、轻度、中度、强度石漠化程度的土壤进行了为期4年的监测,分析了不同石漠化程度土壤理化性质及其各项指标之间的相关性特征。结果表明:同一石漠化程度下,土壤有机质、全磷、有效磷、全氮和水解氮含量表现为雨季中雨季后雨季前。随着石漠化程度的加深,土壤田间持水量、毛管持水量、毛管孔隙度和总孔隙度升高,全磷、有效磷和有机质含量减少。与潜在石漠化程度相比,轻度、中度和强度石漠化程度的土壤全氮含量分别增加5.6%,20.9%,26.6%,水解氮含量分别增加3.5%,18.3%,36.2%,全钾含量分别增加15.8%,30%,46.3%,速效钾含量分别增加3.9%,11.3%,16.5%。相关性分析结果显示,土壤有机质、全磷、全氮含量、土壤容重、总孔隙度、毛管持水量之间相关性显著(p0.05),其中土壤有机质含量、全氮含量、容重、总孔隙度间相关性极显著(p0.01)。研究结果为石漠化综合治理工作提供理论与科学依据。  相似文献   

11.
以天山北坡为研究区域, 采用野外调查与试验分析相结合的方法, 选取5个土壤养分指标: 有机质、速效氮、速效磷、速效钾和总盐, 应用多元统计分析方法, 分析了天山北坡3个区段(昭苏-特克斯、新源-巴音布鲁克、巴里坤-伊吾)林沿土壤不同层位(0~5 cm、5~20 cm、20~40 cm)养分含量的分布特征及差异性。结果表明: 天山北坡西段(昭苏-特克斯、新源-巴音布鲁克)土壤养分含量比天山北坡东段(巴里坤-伊吾区域)高。3个区段不同深度土壤有机质、速效氮、速效磷、速效钾含量均存在明显差异, 其中0~5 cm土层有机质、速效氮、速效磷、速效钾的平均含量均比5~20 cm、20~40 cm高; 5~20 cm土层有机质、速效氮、速效磷、速效钾的平均含量均比20~40 cm高; 总盐含量不具有明显的垂直分层现象。按全国第2次土壤普查标准, 天山北坡3个区段土壤均属肥沃级。昭苏-特克斯区段、新源-巴音布鲁克区段0~5 cm、5~20 cm、20~40 cm土壤养分各指标含量变化具有一定的规律, 而巴里坤-伊吾区段土壤养分各指标含量变化具有良好的独立性。天山北坡西段(昭苏-特克斯、新源-巴音布鲁克)植被类型较多, 植被覆盖度较高, 土壤较为肥沃, 大部分区域为夏牧场, 人类活动以放牧为主, 对该区段土壤要防止过度放牧所造成的植被退化与水土流失。天山北坡东段(巴里坤-伊吾)因土壤中砾石较多, 植被类型较少, 植被覆盖度较低, 人类活动包括放牧、林业种植与旅游, 与西段相比东段土壤的养分含量较低, 所以应以保持生境原貌为主, 避免人为扰动后的生境退化。  相似文献   

12.
三江平原环型湿地土壤养分的空间分布规律   总被引:18,自引:0,他引:18       下载免费PDF全文
刘吉平  吕宪国  杨青  郗敏 《土壤学报》2006,43(2):247-255
以三江平原环型湿地作为研究对象,对其环带状植被区湿地土壤的有机碳、全氮、全磷和全钾的空间分布规律进行了初步研究。结果表明,环型湿地土壤有机碳、全氮、全磷和全钾具有明显的空间水平分异规律,有机质、全氮、全磷的含量由环型湿地中心向边缘逐渐减少,全钾的含量和碳氮比逐渐增加。土壤有机碳、全氮、全磷和全钾在垂直方向上具有明显的分层和富聚现象,自上而下,有机质的含量逐渐降低;全氮含量除漂筏苔草群落外,其他各群落土壤全氮含量呈先增加后减少的分布;大部分植物群落全磷含量呈先减后增的“V”型分布;全钾含量呈表层和底层较高、中间层较低的“中空”状分布。通过相关分析表明,环型湿地土壤有机碳与全氮具有相似的空间分布规律,全钾与有机碳、全氮具有相异的空间分布规律,而全磷具有自己独特的空间分布规律。环型湿地土壤的有机碳、全氮、全磷和全钾的空间分布主要受植物体元素含量、生物过程和水文地貌过程影响,它通过过程影响湿地的功能。研究环型湿地的有机碳、全氮、全磷和全钾的空间分布规律不仅有助于完善湿地土壤形成和发育的理论,探明湿地的生态过程和功能,而且为合理利用和保护湿地提供科学依据。  相似文献   

13.
Morphological features, physicochemical properties, and specific characteristics of the organic matter of cryozems (Cryosols) under postpyrogenic larch forests affected by fires 2, 6, 22, 55, and 116 years ago are considered. The morphological changes in the soils affected by fires are manifested by the burning of the upper organic horizons with preservation of pyrogenic features in the soils for more than a century after the fire. In the first years (2 and 6 years) after the fire, the acidity of the organic horizons and their base saturation become lower. The postpyrogenic soils are characterized by the smaller contribution of the organic horizons to the total pools of soil organic carbon. In the studied cryozems, the organic carbon content is correlated with the contents of oxalate-extractable iron and aluminum. A decrease in the content of water-soluble organic compounds in the soils is observed after the fires; gradually, their content increases upon restoration of the ground cover.  相似文献   

14.
A-horizons of 48 Haplic Phaeozems and Kastanozems in plain sites of the Semiarid Argentinian Pampas under three contrasting management systems (virgin bushland, permanent pasture and continuous agriculture) were studied. Morphological characteristics, organic carbon and total nitrogen levels and E4:E6 ratios were determined on the assumption that both quantity and quality of organic matter should be related to soil texture of parent materials in this region since other soil forming factors are uniform. The more intensive land use produced an averaged decrease of 7 cm in A-horizon thickness and degradation of soil structure, but little changes in color and properties of boundaries to AC horizons. In virgin soils organic carbon and nitrogen contents correlate with silt + clay fractions (r = 0,92 and 0,99, respectively), while E4:E6-ratios are related to clay contents (r = ?0.69*) confirming the strong influence of soil texture. Agricultural-management and pasture use of soils lead to dispersion of these correlations probably because of differential influence of varying intensities of land use within each management system. Soils under continuous agriculture show lower organic carbon contents than virgin soils only at clay + silt > 40%. Eragrostis curvula-pastures seems to be more effective in restoring organic matter and nitrogen levels in sandy but not in loamy soils with respect to virgin soils. This may be due to a better efficiency of E. curvula-roots in coarse than in fine textured soils to produce humificable residues than the autochthonous grass species.  相似文献   

15.
The loss of total and organic phosphorus and the transformations of inorganic phosphorus fractions were investigated in a chrono-toposequence of strongly weathered and leached soils formed from granite. Over 80% of the total phosphorus originally present was lost from the system during the period of soil development studied. Non-occluded and occluded phosphorus showed a regular, and residual phosphorus an irregular, overall decline in absolute profile quantity with increasing soil development (i.e. increasing weathering and leaching). The proportion of non-occluded phosphorus in the profile declined asymptotically whereas residual phosphorus increased conversely to non-occluded phosphorus and ranged from 58% to 72% of total inorganic phosphorus in the most strongly developed profiles. Proportions of occluded phosphorus increased with increasing soil development. The relative rates of decline of the inorganic phosphorus fractions and forms were shown to be in the order: acid-extractable CaP > non-occluded P > occluded P > residual P.The final profile in the sequence is considered to represent a terminal steady-state system in which small losses of phosphorus from the system are balanced by gains of phosphorus from the atmosphere.The nature and extent of the vegetation on the sequence profiles was linked with declining acid-extractable CaP and non-occluded phosphorus contents. The tendency towards a heath-type vegetation on the later profiles of the sequence leads to a decline in many properties associated with the organic cycle, including total soil nitrogen, oxidisable carbon, and cation-exchange capacity. Declines in profile weights of several other soil properties were also observed. These included total soil calcium, magnesium, potassium, aluminium, iron, and profile clay content. In many cases the observed declines followed an asymptotic path. The declines were attributed to the completion of weathering of stones and gravels in the later profiles of the sequence whereupon no fresh minerals enter the pedogenetic process.  相似文献   

16.
17.
刘玲  崔俊芳  杨红薇  唐家良 《土壤》2023,55(5):991-1000
有机肥和秸秆等有机物料添加是调控土壤肥力的重要手段,可促进农田土壤有机碳的数量和质量发生变化。研究选取盐亭紫色土农业生态试验站长期(16a)6种不同施肥处理试验小区,探究两种形式的外源有机物料(猪粪堆肥和秸秆还田)添加对土壤有机碳及总氮、总磷、硝态氮和速效磷养分含量的影响,并基于固态13C核磁共振波谱技术(13C-NMR)分析其对土壤有机碳化学组分的影响。研究发现,添加有机物料可显著增加0~30 cm土壤有机碳和各养分含量;猪粪堆肥施用对土壤总磷、速效磷和硝态氮含量的影响大于秸秆还田。结果还表明两种有机物料添加改变了耕层土壤有机碳化学组成及其稳定性,有机物料添加增加了0~10 cm表层土壤有机碳中烷氧基碳和羧基碳的比例,降低了烷基碳的比例,同时降低了10~20 cm土层羧基碳比例,增加了烷基碳比例。本研究可为区域旱耕地有机碳库稳定性及其碳汇功能评估提供科学依据。  相似文献   

18.
The distribution of zinc, manganese, copper, cobalt, and nickel in Andosols was investigated. Sixty nine soil samples were collected from different horizons of an Andosols profile in Miyakonojo Basin in south Kyushu, Japan, The total contents of heavy metals were determined by digestion and four extraction solutions, 1 M NH4Ac (ammonium acetate) pH 4.5, 0.1 M HCl, 0.01 M EDTA (ethylenediaminetetraacetic acid) pH 6.5, and 0.005 M DTPA (diethylenetri-aminepentaacetic acid) pH 7.3 were used to determine the contents of available Zn, Mn, Cu, Co, and Ni in Andosols in relation to the organic carbon content. The results of the extraction analysis showed that by the use of 0.1 M H Cl high value of extracted heavy metals in the upper layers of the humus horizons were obtained while EDTA extraction yielded a large amount of the above mentioned metals in the high humus horizons. The extractable heavy metals contents were high and these metals closely related to the organic carbon content mostly in the humus horizons in the profile. Where, biocycling process may play an important role in the concentration of heavy metals. Based on the study, it was found that the total content of Zn increased towards the C horizons or pumice layers in the soil profile. Such a trend was also found in the case of the Mn content. While the Cu content in the humus horizons was much higher in the upper part of each humus horizon. According to this study the distribution of heavy metals, Cu (organic matter complexes) in the Andosols profile was more stable than that of Zn (organic matter complexes) in soils. It was shown that Zn in the surface humus horizon was enriched but that some amount was leached under buried conditions. The same phenomenon was also observed in the distribution of Mn in the profile. The movement of Co and Ni in the soil profile was limited, as evidenced by the sharp reduction in the concentrations of these two metals in buried soils.

Hence, it is concluded that the distribution of Zn, Mn, Cu, Co, and Ni was considerably higher in the humus horizons of the Andosols profiles.  相似文献   

19.
荒漠草原人工柠条林重建的土壤养分效应   总被引:3,自引:2,他引:3  
采用时空互代方法,构建了由天然草地和7,12,27a柠条林组成的序列,对其下土壤有机质、全氮、碱解氮、有效磷进行了研究。结果表明:(1)0—200cm土壤剖面上的有机质含量由草地、幼龄林、中龄林、老龄林依次增加,有机质含量增加的显著程度随着林龄的增加在更深土层上体现。(2)全氮含量由草地到幼龄林阶段显著增加,由幼龄林到中龄林再到老龄林依次减少。幼龄林、中龄林、老龄林之间全氮含量减少的最大幅度随林龄增加向土壤深层移动。碱解氮与全氮具有一致的规律。(3)整个土壤剖面上有效磷含量依次为:老龄林<幼龄林<中龄林<草地。(4)3个不同林龄的柠条林的有机质、全氮、有效磷在柠条行内和行间的空间差异均不显著。柠条行内与行间的有机质和全氮相关程度很高,有效磷相关性不显著。  相似文献   

20.
武夷山不同海拔典型森林土壤有机碳和全氮储量分布特征   总被引:1,自引:1,他引:0  
熊小玲    任寅榜    吕茂奎    李晓杰    聂阳意    谢锦升   《水土保持研究》2022,29(4):83-88
为探究武夷山森林土壤碳氮储量的分布特征,以武夷山国家公园不同海拔高度(600,1 000,1 400 m)的典型森林土壤为研究对象,研究土壤有机碳和全氮含量及储量随海拔高度的变化规律,分析了影响土壤有机碳和全氮储量变化的因子。结果表明:随着海拔的升高,土壤有机碳和全氮的含量在0—5 cm土层和5—10 cm土层变化规律不同,5—10 cm土层的土壤碳氮含量随海拔变化趋势更为明显,而0—5 cm土层的土壤碳氮含量表现为1 000 m海拔较高; 海拔1 000 m的土壤C/N明显高于海拔1 400 m和600 m; 在土壤有机碳和全氮储量方面,1 400 m明显高于1 000 m和600 m,且高海拔区域土壤碳氮储量的变化幅度显著大于低海拔区域,两土层间差异不显著; 相关分析和RDA分析表明细根C/N和土壤温度是影响土壤有机碳和全氮储量的主导因子。综上所述,土壤有机碳和全氮的分布随海拔升高并非线性增长,受到气候、植被特征及土壤状况的综合影响,高海拔地区土壤碳氮储量对气候变化的响应更为敏感。  相似文献   

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