Oscillation of Three Phosphorus Forms and Suspended Solids Content from 1999 to 2007 in a Spanish Agroforestry Catchment under Atlantic Climate

Phosphorus (P) transfers may accelerate water eutrophication to waters. Increasing awareness of the role of diffuse P sources motivates land managers in different regions of Europe to undertake conservation programs that place emphasis not only on soil conservation but also on water quality and eutrophication risk. Fertilizer applications and wastes are the main sources of dissolved P in Galicia and in the Atlantic regions of Spain. The aim of this study was to assess the temporal changes in concentration of total P (TP), sedimentary P (SP), and total dissolved P (TDP) and suspended solids at the outlet of an agroforestry catchment located in northwestern Spain. The study datasets range from January 1999 to December 2007, with 992 water samples collected. The water-collection strategy was a stratified point sampling involving more frequent collections when flow was high. Phosphorus contents were assessed by inductively coupled plasma (ICP)–mass spectroscopy (MS), and suspended solids were measured by filtration. The content ranges of the different studied P forms and suspended solids were as follows: TDP between 1 and 672 mg L^?1, SP between 1 and 1064 mg L^?1, TP between 1 and 1111 mg L^?1, and suspended solids between 1 and 1044 mg L^?1. A few events of intense precipitation with peaks of TP greater than 200 mg L^?1 and in some cases even more than 1000 mg L^?1 were responsible for most of the P losses in the catchment studied. TP and SP, TP and suspended solids, and SP and suspended solids showed highly significant correlations during the entire study period, evidencing the erosive origin of P in this catchment.     

Solid-Solution Metal Partitioning for the Upper Mero River Basin (NW Spain)

This study determines the seasonal variability of metal partition coefficients [aluminium (Al), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn)] and analyses the importance of suspended sediments (SS), dissolved organic carbon (DOC) concentrations, pH, and discharge (Q) on the seasonal variability of metal partition coefficients (K_Ds) in the headwaters of the Mero River catchment, which drains an agroforestry area in northwestern Spain. Metal partition coefficients were used as an approach to relate dissolved and particulate fractions. Water samples were collected over 3 years (2005–2008) at the catchment outlet. The mean metal dissolved concentrations were: Fe (43.5 μg L^?1) > Al (23.3 μg L^?1) > Zn (1.8 μg L^?1) > Mn (1.2 μg L^?1) > Cu (0.3 μg L^?1). Partition coefficients followed the order Mn > Al > Fe > Zn > Cu, and their values exhibited low variability. Al, Cu, and Zn partition coefficients presented the greatest values in summer, except during 2007–2008, when the greatest K_Ds value was observed in autumn, whereas the K_Ds of Fe showed the greatest values in winter. The K_D of Mn has no seasonality. For Al, Cu, and Zn, the seasonal SS concentrations were closely related to Kd. For Fe, Kd was more closely related to DOC concentration than to SS concentration.     

冻融次数和含水量对棕壤总有机碳和可溶性有机碳的影响

以东北地区棕壤为供试土样,采用人工控温,室内培养的方法,使土样经受不同冻融处理,研究了冻融次数和含水量对棕壤有机碳的影响。研究结果表明,冻融次数和含水量对棕壤总有机碳的影响不显著,冻融次数对可溶性有机碳的影响达到显著水平,随着冻融次数的增加土壤可溶性有机碳含量呈先降低后升高的趋势,在试验设计范围内表现为冻融降低了棕壤可溶性有机碳的含量,可溶性有机碳占总有机碳的比例随冻融作用的变化趋势与可溶性有机碳基本一致。土壤可溶性有机碳对冻融处理的反映较为敏感,可以作为反映不同冻融处理对土壤有机质影响的一个较好的指标。     

Effects of Land Management on Different Forms of Soil Carbon in Olive Groves in Mediterranean Areas

This study analyses soil organic carbon (SOC) and hot‐water extractable carbon, both measures of soil quality, under different land management—(i) conventional tillage (CT); (ii) CT plus the addition of oil mill waste alperujo (A); (iii) CT plus the addition of oil mill waste olive leaves (L); (iv) no tillage with chipped pruned branches (NT₁); and (v) no tillage with chipped pruned branches and weeds (NT₂)—in a typical Mediterranean agricultural area: the olive groves of Andalusia, southern Spain. SOC values in CT, A, NT₁ and NT₂ decreased with depth, but in NT₂, the surface horizon (0–5 cm) had higher values than the other treatments, 47% more than the average values in the other three soils. In L, SOC also decreased with depth, although there was an increase of 88·5% from the first (0–10 cm) to the second horizon (10–16 cm). Total SOC stock values were very similar under A (101·9 Mg ha⁻¹), CT (101·7 Mg ha⁻¹), NT₁ (105·8 Mg ha⁻¹) and NT₂ (111·3 Mg ha⁻¹, if we consider the same depth of the others). However, SOC under L was significantly higher (p < 0·05) at 250·2 Mg ha⁻¹. Hot‐water extractable carbon decreased with depth in A, CT and NT₁. NT₂ and L followed the same pattern as the other management types but with a higher value in the surface horizon (2·3 and 4·9 mg g⁻¹, respectively). Overall, our results indicate that application of oil mill waste olive leaves under CT (L) is a good management practice to improve SOC and reduce waste. Copyright © 2014 John Wiley & Sons, Ltd.     

黄土丘陵区土壤有机碳含量对侵蚀坡面表层土壤含水量时空变化的影响

表层土壤含水量能敏感反映降雨、气温、侵蚀等环境要素的变化,明确表层土壤含水量时空变化特征可为农业生产及土壤环境效应评价等提供参考。以黄土丘陵区不同有机碳水平的侵蚀坡面为对象,连续监测了2016年11月至2018年3月0-5 cm土壤含水量的动态变化,结合降水资料,分析了不同土壤有机碳水平下侵蚀坡面沉积区、侵蚀区及对照区表层土壤含水量的变化特征。结果表明:(1)表层土壤含水量不同季节变化差异显著,夏季变幅最大,单日最大变幅可达14.3%,春、秋、冬季的单日最大变幅<8.0%。换言之,夏季是土壤水分变化的敏感期。(2)土壤有机碳水平、坡面部位、土壤温度对表层水分变异的影响程度因季节而异。(3)土壤侵蚀加剧了坡面表层土壤含水量变异,变异程度表现为沉积区>侵蚀区>对照(未侵蚀)区;侵蚀前后侵蚀区表层土壤含水量变化量与沉积区变化量的差值随有机碳水平升高从0.85%增加至9.81%。(4)侵蚀坡面表层土壤含水量的时空异质性随有机碳水平升高呈非线性变化趋势。     

沉积物中微生物量与有机碳形态的相关性研究

以富营养化类型不同的乌梁素海和岱海为对象,根据水域面积及生态类型进行采样及分析测试,开展了湖泊沉积物中微生物量与有机碳形态的相关性研究,对比分析了2个湖泊沉积物微生物量的分布特征及其差异性,初步探讨了2个湖泊沉积物微生物量与含水率、pH及有机碳各形态间的相关性。结果表明,乌梁素海表层沉积物中微生物量介于5.59×10^8～32.46×10^8个·g^-1dw,平均16.36×10^8个·g^-1dw;岱海表层沉积物微生物量介于4.76×10^8～43.66×10^8个·g^-1dw,平均25.04×10^8个·g^-1dw;乌梁素海微生物量的高值区位于湖区东南部,岱海微生物量的高值区位于湖心区;2个湖泊沉积物柱芯中的微生物量均随深度增加而减少,沉积物微生物量与含水率、总氮和活性有机碳呈显著相关性。     

Spatial and Temporal Ozone Pattern Concentrations in a NW Region of Spain

Measurements of ozone were carried out at two different sites in the area surrounding a thermal power plant located in the Northwest of Spain during 1993–1995. The concentration of O₃ in the ambient air varied from 6 to 257 μg m^-3 exhibiting a wide temporal, seasonal and spatial variation. On a few occasions 1-hr ozone concentration was more than 180 μg m^-3, which represents the maximum 1-hr limit of ozone in ambient air as prescribed by the European Commission.     

不同森林植被下土壤水溶性有机碳研究

在我国亚热带采集了常绿阔叶林、马尾松林、杉木林和毛竹林土壤,分析了土壤总有机碳和水溶性有机碳含量。结果表明:土壤总有机碳含量常绿阔叶林和毛竹林显著高于杉木林和马尾松林。土壤水溶性有机碳含量毛竹林显著高于杉木林,极显著高于马尾松林,阔叶林和杉木林也显著高于马尾松林。水溶性有机碳占总有机碳比率以杉木林最高,达1 26%(25℃)和1 82%(100℃),马尾松林最低,仅0 78%(25℃)和1 30%(100℃)。马尾松林、杉木林和毛竹林土壤水溶性有机碳与土壤总有机碳含量间的相关性均达显著水平,相关系数分别为0 5106 (100℃提取),0 4739 (25℃提取)和0 4752 (25℃提取)。     

宁夏引黄灌区不同类型土壤重组有机碳特征分析

[目的]探究宁夏引黄灌区土壤总有机碳与重组有机碳的特征及相互关系,为研究宁夏引黄灌区固碳效应及碳库稳定性提供科学依据。[方法]以宁夏引黄灌区为研究对象,通过实地采样与分析,测定不同土壤类型总有机碳与重组有机碳含量。[结果]土壤类型是影响宁夏引黄灌区土壤有机碳变化的主要因素,经灌溉耕作后,灌溉土壤总有机碳及重组有机碳含量较对照土壤均有所增加,平均增加量分别为2.27和2.02g/kg,增加量随土层深度增加而减小,增加幅度因土壤类型存在差异;重组有机碳与总有机碳存在显著相关关系(p0.001)。[结论]重组有机碳是总有机碳的重要部分,它与总有机碳之间的相关性随着土层深度的增加而增强,说明灌溉耕作活动及灌溉时间对土壤有机碳具有一定的影响。研究重组有机碳能更好地了解灌区土壤碳库稳定性。     

围封对流动沙丘表层土壤有机碳、全氮和活性有机碳的影响

以流动沙丘为对照,研究不同围封年限(14年和26年)下科尔沁退化沙质草地表层(0-15cm)土壤有机碳、全氮及活性有机碳的变化。结果表明:流动沙丘围封显著提高了土壤有机碳(SOC)、全氮(TN)、轻组有机碳(LFOC)和微生物量碳(MBC)含量,14年和26年围封样地SOC、TN、LFOC和MBC含量均随围封年限的增加而增加,且0-5cm层增幅高于5-15cm层。14年和26年围封样地土壤碳氮比显著高于流动沙丘,但2个围封样地之间差异不显著。流动沙丘围封也显著增加了表层SOC、TN、LFOC和MBC储量,0-15cm土层SOC、TN、LFOC和MBC储量均表现为26年围封地>14年围封地>流动沙丘。相关分析表明,LFOC、MBC均与SOC存在极显著正相关关系,说明LFOC和MBC均可作为衡量土壤有机碳变化的敏感指标。     

不同干扰程度下黄河三角洲植被群落有机碳分布特征

为研究不同干扰程度下滨海湿地有机碳分布特征,选择黄河三角洲干扰程度较小的一千二管理站和黄河口管理站及干扰程度较大的东营港和五号桩4个研究区,对不同植被群落下的土壤有机碳含量、密度及单位面积储量进行研究。结果表明:植被生长初期(5月)一千二管理站、东营港、五号桩和黄河口管理站土壤有机碳含量、有机碳密度以及单位面积有机碳储量分别为3.504,3.433,3.698,3.815g/kg、4.84,4.58,5.02,5.56kg/m2和4 237.00,3 807.42,4 272.77,4 917.63t/km2。植被生长旺期(8月份)一千二管理站、东营港、五号桩和黄河口管理站土壤有机碳含量、有机碳密度以及单位面积有机碳储量分别为3.90,3.63,3.45,3.62g/kg、5.32,4.83,4.46,5.25kg/m2和4 588.02,4 010.10,3 614.95,4 623.12t/km2。人为活动干扰较大的五号桩和东营港地区,有机碳含量、有机碳密度以及单位面积有机碳储量较小;光滩有机碳含量比有植被生长的湿地低;互花米草湿地有机碳含量和有机碳密度在植被生长初期高于其他湿地类型,但这种优势在生长旺期不显著,与黄河口管理站和一千二管理站芦苇湿地单位面积有机碳储量相比较,互花米草湿地单位面积有机碳储量要低。由此可见,人为干扰对滨海湿地有机碳含量、密度及储量产生较大的影响,保护湿地完整性对于减少碳排放、维护滨海湿地的碳汇功能具有重要的作用。     

祁连山排露沟流域土壤有机碳空间变异性研究

为研究小流域尺度下土壤有机碳的变异规律,运用地统计学方法对研究区0—10,10—20,20—40 cm土壤有机碳含量的空间变异性进行了研究。结果表明:流域内不同土层有机碳含量属于中等强度变异,具有强烈的空间自相关性;土壤有机碳含量在0,135°方向上空间变异程度明显,空间分布的各向异性显著;克里格插值结果显示流域内阴坡土壤有机碳含量明显高于阳坡,高海拔区域土壤有机碳含量高于低海拔区域;不同土层间,土壤有机碳含量均表现为青海云杉灌丛草地,表明不同植被类型对土壤有机碳含量和分布有着重要影响。土壤有机碳含量的空间变异性特征,与土壤性质、地形因子等结构性因素有关,为研究祁连山小流域土壤信息差异性的测量和描述提供科学依据。     

长期施肥对黑土水溶性碳含量和碳矿化的影响

以农业部哈尔滨黑土生态环境重点野外科学观测试验站长期定位试验为平台,研究了长期施肥对黑土水溶性碳（WSOC）和矿化碳的影响。结果表明,施肥对土壤WSOC的含量有很大影响,比较而言,单施化肥对WSOC含量无明显影响,而施加有机肥可使黑土WSOC含量增加。土壤对水溶性有机碳的吸附量与平衡前水溶性有机碳的浓度显著相关。有机肥与无机肥料配施可以提高土壤矿化碳含量。     

淮南矿区煤矸石风化物特性及有机碳分布特征

以淮南矿区潘一矿煤矸石山为研究对象,通过对煤矸石风化物的理化特性、电镜扫描(SEM)、能谱(EDS)和总有机碳(TOC)含量分析,初步研究了煤矸石风化物有机碳分布和释放规律,以及煤矸石山堆积淋溶作用对周边土壤溶解性有机碳(DOC)含量的影响。结果表明,从山顶、山腰到山脚煤矸石风化物中的总有机碳(TOC)含量依次减小,随着采样深度的增加总有机碳(TOC)含量逐渐变大。煤矸石风化物中总有机碳含量与煤矸石风化物粒径大小呈正相关,与煤矸石风化物的风化程度成负相关。不同粒径煤矸石风化物淋滤液中溶解性有机碳(DOC)的含量随着淋溶时间增大而减小,在96h淋滤液中溶解性有机碳含量趋于稳定,且值较为接近。距离山脚2~100m内,随着采样距离的增加土壤中溶解性有机碳含量(DOC)呈减少趋势。在距离煤矸石山80~100m处土壤溶解性有机碳含量接近正常农田土壤含量。     

基于不同林分类型下土壤碳氮储量垂直分布

以辽东大伙房水库周边防护林典型林分针阔混交林(落叶松-油松-刺槐混交林)、油松林、落叶松林、刺槐林为研究对象,对其土壤养分含量进行测定,研究了不同林分土壤剖面上有机碳、全氮、有机碳储量的分布规律。结果表明:随着土层深度的增大,4种林分的土壤有机碳、全氮含量均逐渐降低;4种林分土壤剖面有机碳含量大小顺序为落叶松林(24.16g/kg)刺槐林(23.07g/kg)针阔混交林(16.06g/kg)油松林(15.76g/kg);全氮含量大小顺序为刺槐林(5.23g/kg)落叶松林(4.57g/kg)油松林(3.45g/kg)针阔混交林(2.42g/kg);C/N平均值大小顺序为落叶松林(7.36)针阔混交林(6.51)油松林(4.67)刺槐林(4.57);4个林分0-40cm土层的有机碳储量大小为落叶松林(112.94t/hm~2)刺槐林(107.40t/hm~2)针阔混交林(105.42t/hm~2)油松林(89.89t/hm~2);4种林分土壤pH无明显差别,各土层土壤pH随土层深度增加而增大;4种林分土壤容重由高到低顺序依次为针阔混交林(1.73g/cm~3)油松(1.65g/cm~3)落叶松(1.64g/cm~3)刺槐(1.56g/cm~3)。4个林分土壤有机碳含量与土壤全氮含量互相间均存在极显著正相关关系,土壤有机碳、全氮含量与C/N之间则没有明显相关关系;在针阔混交林中,土壤容重、土壤全氮含量和土壤pH与土壤有机碳之间存在线性数量关系,而其他纯林则没有这种关系。     

Phosphorus and Suspended Sediment Loads in Base-Flow and Runoff Events: A Case Study of a Small Stream in NW Spain

This study focuses on the role of runoff events in influencing concentrations and export of suspended sediments and phosphorus in a headwater stream draining an agroforestry catchment in northwestern Spain. Large differences exist between suspended sediment and phosphorus (P) concentrations measured during base-flow conditions and runoff events, with a higher delivery during runoff events. Suspended sediment and phosphorus exports were 29.44 and 0.08 kg ha^?1 y^?1 respectively, with more than 50% delivered during runoff events (12% of the year). The relative contributions of phosphorus forms to the total annual export were 75% and 25% as particulate and dissolved phosphorus, respectively. Soil erosion is the main source of suspended sediment and phosphorus in the stream.     

免耕对华北地区潮土碳库特征的影响

以实施7年的中国科学院禹城综合试验站冬小麦-夏玉米轮作免耕长期定位试验场为对象,系统研究免耕条件下土壤总碳(TC)、有机碳(SOC)、无机碳(SIC)的变化,为进一步评价免耕措施对华北地区潮土碳库的影响提供数据支持。研究设置免耕秸秆覆盖(NTRC)、免耕施用有机肥(NTRR)、常规耕作(CT)3种处理,分析表层(0-20cm)及深层(20-60cm)土壤TC、SOC及SIC的变化特征和影响因素。主要结果为:NTRC和NTRR能够增加0-20cm土层TC含量及储量,但降低20-60cm土层TC含量及储量,0-60cm总碳储量表现为NTRC>CT>NTRR;与CT相比,NTRC能够显著增加0-20cm而降低20-60cm土层SOC含量及储量,NTRR增加了0-5cm土层SOC含量及储量,在5-60cm则呈降低趋势,0-60cm土层SOC储量表现为CT>NTRC>NTRR;NTRC增加了0-60cm土层SIC储量,而NTRR则影响较小。TC与SOC呈显著正相关(P<0.05),而与SIC呈显著负相关(P<0.05),说明总碳的变化趋势与SOC一致,与SIC相反。     

外源有机碳对黑土有机碳及颗粒有机碳的影响

为了阐释外源有机碳在土壤有机碳运转中的作用机制,以黑土为供试材料,进行了5年的室外培养试验,并结合室内全土及颗粒组分单独矿化培养试验,研究了不同外源有机碳对黑土有机碳(SOC)、颗粒有机碳(POC)含量及其矿化特征的影响。试验包括单施化肥、牛粪配施化肥、鸡粪配施化肥、秸秆配施化肥和树叶配施化肥5个处理。结果表明:(1)单施化肥黑土SOC的损失主要来源于POC的损失,外源有机碳有利于SOC和POC的累积,与对照相比,禽畜粪便处理的SOC和POC平均增加幅度分别为16.6%和27.8%,植物残体处理的SOC和POC平均增加幅度分别为27.0%和46.4%;(2)一级动力学方程能较好地描述SOC和POC的矿化动态(R~20.9),且POC比SOC易矿化,POC的60d累积矿化量是SOC的3倍以上;(3)禽畜粪便处理和植物残体处理的POC平均矿化率分别为31.5%和29.8%,禽畜粪便处理的POC更易矿化;(4)外源有机碳有效降低了黑土有机碳的矿化,尤其是牛粪,其SOC矿化率为1.9%,比对照低了3.4%,其POC矿化率为24.8%,比对照低17.4%;(5)外源有机碳在黑土中的碳累积能力表现为树叶秸秆牛粪鸡粪。     

UV-B辐射增强对土壤有机碳稳定性的影响

以母质相同、有机碳含量不同的2个水稻土为研究材料,通过室内模拟光照,探讨紫外辐射(UV-B,280~315nm)对土壤总碳(TC)、可溶性有机碳(DOC)和复合酚(AEP)含量的影响以及土层厚度不同(0.95,1.89,2.84mm)对UV-B辐射的响应特征。结果表明:与黑暗处理相比,培养96h后,无论是在有机碳含量低的土壤(A土)还是在有机碳含量高的土壤(B土)中,UV-B辐射均显著降低了土壤TC的含量,却增加了土壤DOC的含量,在试验结束时,土壤A和B的TC含量分别降低了3.11%和6.18%,而土壤DOC含量分别增加了16.05%和9.89%。在UV-B辐射96h后,与1.89,2.84mm土层相比,土层厚度为0.95mm时土壤TC、DOC和AEP含量变化幅度最大,A和B两个土壤中TC含量分别降低了19.11%和14.35%,DOC和AEP含量分别增加了18.66%和18.92%与23.52%和22.70%,而UV-B辐射对厚度为1.89mm和2.84mm的土层TC、DOC和AEP含量并无显著影响。研究结果表明UV-B辐射对土壤碳库稳定性有一定的影响,在农业生产中为了保护碳库稳定性,应该尽量减少地表裸露。     

秸秆覆盖对冬小麦农田土壤有机碳及其组分的影响

通过对黄土高原旱塬区冬小麦地4种覆盖方式下(无覆盖对照处理(CK)、全生育期9 000kg/hm~2秸秆覆盖(M1)、全生育期4 500kg/hm~2秸秆覆盖(M2)和夏闲期9 000kg/hm~2秸秆覆盖(SM))土壤的田间定位试验和室内分析,探讨不同秸秆覆方式对冬小麦地土壤有机碳及其组分含量以及各组分之间相关性的影响。结果表明:(1)较CK(无覆盖对照)处理,M1(全生育期9 000kg/hm~2)、M2(全生育期4 500kg/hm~2)和SM(夏闲期9 000kg/hm~2)处理,均显著增加0—10cm和10—20cm土层的土壤有机碳、微生物量碳、潜在矿化碳和颗粒有机碳含量(p0.05),而20—40cm土层差异不明显,其中M1(全生育期9 000kg/hm~2)处理效果最佳,SM(夏闲期9 000kg/hm~2)处理作用相对较弱。(2)不同覆盖方式影响土壤微生物量碳、潜在矿化碳和颗粒有机碳在总有机碳中的分配比例,土壤微生物量碳、潜在矿化碳和颗粒有机碳的相对含量变化范围分别为1.96%~3.31%,2.83%~3.78%,18.13%~37.25%。(3)各覆盖方式下土壤有机碳及其组分含量都随着土层的逐渐深入而下降,且土层越深,变化越趋于缓慢。(4)不同覆盖方式下的土壤有机碳及其组分含量两两之间均达到了极显著正相关关系(p0.01),颗粒有机碳、微生物量碳和潜在矿化碳与土壤有机碳的相关系数依次为:0.847,0.700,0.614,可见微生物量碳、潜在矿化碳、颗粒有机碳含量在一定程度上决定于土壤有机碳的贮存量。综上所述,秸秆覆盖对土壤有机碳及其组分含量具有增加效应,全生育期9 000kg/hm~2秸秆覆盖方式实际运用价值较高。颗粒有机碳和微生物量碳的动态变化更能反映土壤有机碳的早期变化,是土壤肥力变化更加敏感的指标。