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1.
森林转换对土壤活性有机碳组分的影响 总被引:1,自引:0,他引:1
为了研究林型转换对土壤活性有机碳组分的影响,在安徽皖南地区蔡家桥林场选取了马尾松次生林、湿地松人工林以及杉木人工林3种森林类型,分别采集了0—10,10—30,30—50 cm的土壤,测定了土壤有机碳(SOC)、颗粒有机碳(POC)、易氧化有机碳(EOC)、微生物生物量碳(MBC)、可溶性有机碳(DOC)以及土壤理化指标,分析了林型转换后土壤活性有机碳组分变化特征及其与土壤理化因子间的相关关系。结果表明:(1)马尾松次生林转换成湿地松人工林和杉木人工林后主要对0—10 cm土壤活性有机碳组分产生影响,其中土壤SOC,POC,EOC含量均在林型转换后出现下降,DOC含量上升,而MBC在林型转换前后无显著差异。(2)林型转换后各土层POC/SOC均出现下降,DOC和EOC占SOC比例总体呈升高趋势,MBC/SOC则未表现出明显规律。(3)土壤有机碳与活性碳组分以及TN,EC,NH+4-N,NO-3-N均呈极显著正相关,各活性碳组分之间也存在极显著正相关关系(p<0.01)。综上,马尾松次生林转换成... 相似文献
2.
小兴安岭森林沼泽湿地土地利用变化对土壤活性碳组分的影响 总被引:4,自引:1,他引:3
[目的]以小兴安岭森林沼泽为研究对象,研究湿地经过人类活动开垦为农田,和排水造林,以及弃耕地的土壤活性碳组分,为深入了解土壤活性碳组分动态变化及其可能影响全球变暖的机制研究提供科学依据。[方法]选择小兴安岭森林沼泽湿地4种土地利用方式(天然沼泽、排水湿地、弃耕地、农田)为研究对象,在野外调查和室内分析的基础上,对比分析土壤有机碳(SOC)、溶解性有机碳(DOC)、微生物碳(MBC)、易氧化碳(EOC)、轻组有机碳(LFOC)、颗粒有机碳(POC)的含量变化和比例关系,并用相关分析法分析土壤有机碳各活性组分之间的关系。[结果]不同土地利用方式土壤有机碳含量随土层深度增加而降低,总体上,在土壤剖面上,天然沼泽的SOC含量大于其他土地利用方式,其他3种土地利用方式之间差异不显著(p0.05)。不同土地利用方式下土壤活性碳组分(DOC,MBC,EOC,POC,LFOC)含量在垂直分布上均呈现出随土壤深度的增加而降低的趋势,土壤活性碳组分含量顺序总体上呈:天然沼泽排水湿地弃耕地农田。4种土地利用类型土壤DOC占SOC的比例,在垂直剖面上,无明显规律变化。土壤SOC含量与DOC,MBC,EOC,POC,LFOC之间的相关性均达到显著水平(p0.05)。土壤DOC和MBC之间呈显著性正相关(p0.05),LFOC和POC之间呈极显著性正相关(p0.05),EOC与其他活性碳组分相关性均不显著(p0.05)。[结论]土地利用变化会对小兴安岭森林沼泽土壤活性碳组分产生影响,应该合理开发小兴安岭森林沼泽湿地。 相似文献
3.
为了研究山东省不同植被类型森林土壤有机碳及其组分分布特征,选取山东省黑松林、柏木林、针阔混交林3种植被类型下的森林土壤为研究对象,比较分析不同土层(0-20cm、20-40cm)的土壤有机碳(SOC)、可溶性有机碳(DOC)、易氧化有机碳(EOC)和颗粒有机碳(POC)的含量变化。结果表明:(1)0-40cm土层黑松林、柏木林和针阔混交林的SOC含量变化依次为4.35-15.04 g·kg-1、5.72-34.87 g·kg-1和3.71-10.72 g·kg-1,各土层中柏木林的SOC含量最高;(2)土壤有机碳及其组分在不同植被类型下存在一定差异,SOC和POC含量表现为柏木林>针阔混交林、黑松林,DOC含量在上、下土层间表现为柏木林>针阔混交林>黑松林,EOC含量表现为针阔混交林>柏木林、黑松林;(3)除黑松林的DOC和EOC外,其余各植被类型的SOC、EOC、EOC、POC含量均表现为随着土层深度的增加而减少;(4)SOC与POC存在极显著正相关关系(P<0.01),其余各碳组分之间关系不显著,冗余分析表明土壤碳组分受土壤理化因子影响较大,全氮对土壤碳组分的影响极显著(P<0.01),速效钾、全钾和pH对土壤碳组分的影响显著(P<0.05)。黑松林、柏木林、针阔混交林土壤的有机碳及其活性组分之间存在差异性,总体上柏木林的有机碳含量最高,说明SOC及其组分受到植被类型和土层深度的影响。 相似文献
4.
为明确秸秆配施膨润土对旱作农田0~40 cm土层土壤有机碳(SOC)、活性有机碳组分及其分配比例和碳库管理指数的影响,于2019—2021年在内蒙古清水河县一间房试验基地连续3年进行田间定位试验。分别设置不施膨润土和秸秆(CK)、单施秸秆(T1)、单施膨润土(T2)和秸秆配施膨润土(T3)4个处理。结果表明:土壤SOC及活性碳组分在年际间表现为先降低后升高[除颗粒有机碳(POC)含量]的变化趋势,不同土层间表现为10~20 cm > 0~10 cm > 20~40 cm;各处理均提高了0~40 cm土层土壤有机碳及其活性组分含量,秸秆配施膨润土效果优于单施。与CK相比,在0~40 cm土层,T3处理土壤SOC、可溶性有机碳(DOC)、易氧化有机碳(LOC)和POC 3年平均提高了7.16%~9.63%、12.35%~18.05%、15.55%~41.97%和100.73%~127.90%,同时提高了不同土层DOC/SOC、LOC/SOC和POC/SOC以及土壤碳库管理指数;土壤SOC及各组分之间均呈显著正相关关系,以LOC相关系数最大,表明LOC可较好地反映出SOC的变化情况。可见,在旱作区采取秸秆配施膨润土措施能够显著提高土壤SOC及其活性组分含量以及碳库管理指数,对土壤肥力提升、质量改善具有重要意义。 相似文献
5.
东北三省典型春玉米种植区土壤剖面碳库变化特征 总被引:1,自引:0,他引:1
6.
长期免耕旱作对冬小麦生长季土壤剖面有机碳含量的影响 总被引:1,自引:0,他引:1
依托21a长期免耕秸秆还田定位试验,探究长期免耕加秸秆还田的田间管理方式对冬小麦生长季0−60cm土层内土壤有机碳(SOC)和土壤活性有机碳(MBC、POC、DOC)的影响。试验共设长期免耕秸秆还田(NT)与常规耕作(CT)两种耕作模式,分析0−60cm土层内土壤总有机碳(SOC)、土壤微生物量碳(MBC)、土壤颗粒有机碳(POC)、土壤可溶性碳(DOC)含量的变化。结果表明,在0−20cm土层,NT处理SOC含量显著高于CT处理,其中0−5cm和5−10cm土层平均SOC含量分别增加了81.2 %和52.9 %,冬小麦不同生育期内土壤SOC含量变化不显著;在0−30cm土层内,与CT处理相比,NT显著改变了土壤MBC、POC及DOC在播种前、越冬前、拔节期、开花期和成熟期5个生育阶段的分布情况,且显著提高了5个生育阶段内土壤活性有机碳的含量(P<0.05),其中0−5cm土层内,土壤MBC、POC及DOC含量在各个时期相较于CT处理分别增长60.8%~161.4%、71.8%~141.1%和21.9%~104.4%。0−60cm土层内,两种耕作方式下的SOC、MBC、POC、DOC均随着土壤深度的增大呈下降趋势。说明长期免耕可提高耕作层土壤有机碳含量和小麦生长季活性有机碳的水平,这为旱地土壤有机碳的高效固存提供了理论依据。 相似文献
7.
岩溶区不同土地利用方式对土壤有机碳及其组分的影响 总被引:6,自引:2,他引:4
选择重庆市中梁山岩溶槽谷中5种土地利用方式(弃耕地、草地、菜地、橘园地和林地)为研究对象,在野外调查和室内分析的基础上,采用方差分析法对比分析了土壤总有机碳、溶解性有机碳、易氧化性碳、轻组有机碳、颗粒有机碳及矿物结合态有机碳的含量变化,并用相关分析法分析了土壤有机碳各组分之间的关系。结果表明:不同土地利用方式土壤总有机碳(TOC)含量随土层深度增加而降低,上下层土壤TOC含量在2.69~13.88g/kg之间,不同植被覆盖类型、耕作方式和施肥是影响土壤TOC分布的重要因素。不同土地利用方式下有机碳各组分(DOC、EOC、LFOC、POC和MOC)含量在垂直分布上均呈现出随土壤深度的增加而降低的趋势,但不同土地利用方式之间的差异较大,主要与植被类型、施肥管理、耕作方式以及人为干扰有关。弃耕地含量均比较低,林地和草地受人为干扰较少含量较高,菜地土壤受施肥和翻耕影响,上下层土壤含量差异不大,橘园地上下层土壤5种有机碳组分含量差异均是最大的。弃耕地受之前耕作影响,弃耕时间短,有机质输入量少,POC/MOC值相对较低,菜地受施肥和翻耕影响上下层土壤POC/MOC值相对比较稳定,草地、橘园地和林地0—20cm土壤POC/MOC值均高于20—40cm,下层土壤有机碳比较稳定。0—20cm和20—40cm土壤有机碳及组分之间存在相关关系,0—20cm土壤TOC与LFOC和MOC之间呈显著正相关,LFOC与POC之间也呈现显著正相关;20—40cm土层,土壤TOC与EOC、LFOC和MOC之间呈显著正相关性,MOC与TOC以及EOC和LFOC均呈现正相关性,LFOC与POC之间关系由表土层的显著正相关转变为极显著正相关。下层土壤比上层土壤有机碳稳定性强,尤其是土壤TOC、LFOC和MOC能够敏感地反映土壤碳库的变化,可以作为土壤有机碳稳定性的敏感性指标。 相似文献
8.
果园土壤有机碳及呼吸速率对豆科和禾本科草类的差异反应 总被引:2,自引:1,他引:1
在行间长期(连续6年)种植豆科植物毛苕子和禾本科植物黑麦草的苹果园,调查土壤不同深度的有机碳组分和表层土壤呼吸速率日变化。结果表明:间作2种植物后,行间土壤0—20,20—40cm土层总有机碳(TOC)、轻质有机碳(LFOC)、可溶性有机碳(DOC)、颗粒有机碳(POC)、易氧化有机碳(ROC)和微生物生物量碳(MBC)含量均显著提高;在40—60cm土层,仅DOC含量明显提高;0—20cm土层的TOC和全部有机碳组分及20—40cm土层的TOC、DOC、POC和ROC的含量在种植毛苕子后均明显高于种植黑麦草。TOC与LFOC、TOC与POC、DOC与LFOC、DOC与MBC、DOC与ROC、MBC与ROC、ROC与POC、LFOC与ROC之间均呈显著正相关,土壤呼吸速率与LFOC、DOC、MBC和ROC之间也呈显著正相关。种植2种草类均显著提高土壤呼吸速率,并使呼吸速率日变化峰型更突出,其中毛苕子的作用效果比黑麦草更显著。 相似文献
9.
闽江口湿地土壤有机碳及其活性组分沿水文梯度分布特征 总被引:1,自引:0,他引:1
《水土保持学报》2014,(6)
为了解河口潮汐沼泽湿地土壤有机碳(SOC)及其活性组分沿水文梯度分布特征,以闽江口鳝鱼滩短叶茳芏(Cyperus malaccensis Lam.var.brevifolius Bocklr)湿地土壤为研究对象,测定并分析高、中和低3个不同水淹频率土壤SOC及其活性组分,包括微生物生物量碳(MBC)、可溶性有机碳(DOC)和易氧化态碳(EOC)含量的变化情况。结果表明:不同水淹频率0-20cm土层SOC含量差异明显(P0.05),表现为低水淹频率中水淹频率高水淹频率;土壤有机碳活性组分沿水文梯度分布特征与SOC分布特征相似,并且与SOC均呈极显著正相关(r0.48,n=45),其中EOC和SOC相关关系最好(r=0.88,n=45),说明SOC一定程度上决定了有机碳活性组分的含量,有机碳活性组分也可以反映SOC含量的变化情况;研究区内MBC/SOC、DOC/SOC和EOC/SOC范围分别为0.14%~0.88%,0.1%~0.47%和25.54%~45.02%,MBC/SOC和DOC/SOC随着水淹频率增大而增大,而EOC/SOC则相反,预示着随水淹频率的增加,MBC和DOC周转速率加快,而EOC稳定性增强;此外,SOC及其活性组分还一定程度受到土壤理化性质的影响,均与含水量呈显著或极显著正相关(r0.35,n=45),与容重呈极显著负相关(r-0.39,n=45);土壤pH与SOC和EOC呈极显著负相关(r-0.51,n=45),而电导率(EC)与MBC和DOC呈极显著正相关(r0.46,n=45)。 相似文献
10.
长期施用有机肥对稻麦轮作体系土壤有机碳氮组分的影响 总被引:5,自引:1,他引:4
11.
Howard B. Ross 《Water, air, and soil pollution》1987,36(3-4):349-363
Trace metals (Cd, Cu, Fe, Mn, Pb, and Zn) concentrations in atmospheric precipitation have been routinely monitored in Sweden since the autumn of 1983. Concentrations are highest in southern Sweden and decrease northward. It is postulated that the long range transport of anthropogenic pollutants from the rest of Europe is the major source of Cd, Pb, and Zn in precipitation. Evidence for this hypothesis is that enrichment factors indicate anthropogenic origin, and Swedish atmospheric emissions of Zn and Cd are 2 to 3 times smaller than deposition fluxes. Also, Cd, Pb, and Zn concentrations are correlated in both space and time and are also well correlated with exSO4 +, a substance known to be of anthropogenic origin transported long distances. 相似文献
12.
Water, Air, & Soil Pollution - Epiphytic lichens were sampled in a Dutch national monitoring survey, which was carried out twice within 5 yr. The samples were analyzed by neutron activation... 相似文献
13.
中国华北地区近40年物候春季变化 总被引:17,自引:4,他引:17
根据华北地区7个观测站物候资料,分析了华北地区1963-1996年及北京1963-2005年物候春季的变化特征及其与气温的关系。结果表明:华北地区的物候春季有明显提早来临的趋势,而造成这一变化的主要因素是本地区近40 a来冬春季气温的明显上升。其中1963-1996年间华北地区1-3月及4月的平均气温分别上升了2.3℃与1.7℃,物候春季起止日期分别提前了9d和4d,因而使得春季长度也延长了5d;北京1963-2003年间1-3月及4月的平均气温分别上升了3.5℃与2.6℃,物候春季的起止日期分别提前了11d和10d,但春季长度没有明显变化。 相似文献
14.
Sediment denitrification in waterways in a rice-paddy-dominated watershed in eastern China 总被引:1,自引:0,他引:1
Xiaobo Li Yongqiu Xia Yuefei Li Todd M. Kana Sonoko D. Kimura Masanori Saito Xiaoyuan Yan 《Journal of Soils and Sediments》2013,13(4):783-792
Purpose
Rice-paddy-dominated watersheds in eastern China are intensively cultivated, and lands with two crops receive as much as 550–600 kg?ha–1?year–1 of nitrogen (N), mainly through the addition of N-based fertilizers. However, stream N concentrations have been found to be relatively low. Waterways in the watersheds are assumed to be effective “sinks” for N, minimizing its downstream movement. We directly measured net sediment denitrification rates in three types of waterways (ponds, streams/rivers, and a reservoir) and determined the key factors that control net sediment denitrification. Such information is essential for evaluating the impact of the agricultural N cycle on the quality of surface water.Materials and methods
The pond–stream–reservoir continuum was sampled every 2 months at nine sites in an agricultural watershed between November 2010 and December 2011. Net sediment N2 fluxes/net sediment denitrification rates were determined by membrane inlet mass spectrometry and the N2/Ar technique. A suite of parameters known to influence denitrification were also measured.Results and discussion
Net denitrification rates ranged between 28.2?±?18.2 and 674.3?±?314.5 μmol N2–N?m–2?h–1 for the streams, 23.7?±?23.9 and 121.2?±?38.7 μmol N2–N?m–2?h–1 for the ponds, and 41.8?±?17.7 and 239.3?±?49.8 μmol N2–N?m–2?h–1 for the reservoir. The mean net denitrification rate of the stream sites (173.2?±?248.4 μmol N2–N?m–2?h–1) was significantly higher (p?<?0.001) than that of the pond sites (48.3?±?44.5 μmol N2–N?m–2?h–1), and the three types of waterways all had significantly higher (p?<?0.01) mean net denitrification rates in summer than in other seasons. Linear regression and linear mixed effect model analysis showed that nitrate (NO3 ?–N) concentration in surface water was the primary controlling factor for net sediment denitrification, followed by water temperature. Using monitoring data on NO3 ?–N concentrations and temperature of the surface water of waterways and an established linear mixed effect model, total N removed through net sediment denitrification in the pond–stream–reservoir continuum was estimated at 46.8?±?24.0 t?year–1 from July 2007 to June 2009, which was comparable with earlier estimates based on the mass balance method (34.3?±?12.7 t?year–1), and accounted for 83.4 % of the total aquatic N. However, the total aquatic N was only 4.4 % of the total N input to the watershed, and thus most of the surplus N in the watershed was likely to be either denitrified or stored in soil.Conclusions
High doses of N in a rice-paddy-dominated watershed did not lead to high stream N concentrations due to limited input of N into waterways and the high efficiency of waterways in removing N through denitrification. 相似文献15.
天津半干旱地区不同种植年限菜田土壤微生物变化特征的研究 总被引:13,自引:1,他引:12
对天津周边半干旱地区不同种植年限的菜田土壤微生物状况调查研究表明 ,该地区土壤微生物以细菌为主 ,夏季微生物总量大大高于冬季 ;随着种菜年限的增加 ,耕层和亚耕层微生物总量都有增加趋势 ,其中细菌和放线菌增加明显 ,真菌有下降趋势 ;真菌类群分析表明 ,少数纤维素分解菌 ,如青霉 (Penicillium)、木霉 (Trichoderma)等为优势菌 ,而糖和木质素分解菌仅占少数。用尖孢镰刀霉 (Fusariumuoxysporum)、大肠杆菌 (Escherichia coli)接种不同种菜年限土壤 ,检测土壤拮抗菌状况发现 ,拮抗菌仅在种植年限长的老菜田的放线菌中发现。表明北方半干旱地区菜田土壤细菌为优势菌 ,主要存在于土壤微孔隙中 ;而适于生活在土壤疏松大孔隙中的真菌数量极少。应注意土壤结构的改良 ,为丰富土壤微生物提供良好的生态环境 相似文献
16.
天津半干旱地区不同种植年限菜田土壤微生物变化特征的研究 总被引:3,自引:0,他引:3
对天津周边半干旱地区不同种植年限的菜田土壤微生物状况调查研究表明 ,该地区土壤微生物以细菌为主 ,夏季微生物总量大大高于冬季 ;随着种菜年限的增加 ,耕层和亚耕层微生物总量都有增加趋势 ,其中细菌和放线菌增加明显 ,真菌有下降趋势 ;真菌类群分析表明 ,少数纤维素分解菌 ,如青霉 (Penicillium)、木霉 (Trichoderma)等为优势菌 ,而糖和木质素分解菌仅占少数。用尖孢镰刀霉 (Fusariumuoxysporum)、大肠杆菌 (Escherichia coli)接种不同种菜年限土壤 ,检测土壤拮抗菌状况发现 ,拮抗菌仅在种植年限长的老菜田的放线菌中发现。表明北方半干旱地区菜田土壤细菌为优势菌 ,主要存在于土壤微孔隙中 ;而适于生活在土壤疏松大孔隙中的真菌数量极少。应注意土壤结构的改良 ,为丰富土壤微生物提供良好的生态环境 相似文献
17.
Phytoremediation is an emerging technology based on the use of green plants to remove, contain, inactivate or destroy harmful
environmental pollutants. Recent developments in Europe and the USA show that the approach is somewhat different on both sides
of the Atlantic. In Europe, phytoremediation has more basically been research driven and, based on the outcomes, applications
have been envisaged. By contrast, the approach in the USA is more application and experience driven. In spite of a growing
track record of commercial success, more demonstration projects are needed to prove that phytoremediation is effective in
order to rigorously measure its underlying economics, and to expand its applications. More fundamental research is also required
to better understand the complex interactions between pollutants, soil, plant roots and micro-organisms at the rhizosphere
level, to increase the bioavailability of pollutants, to fully exploit the metabolic diversity of plants and, thus, to successfully
implement this new green technology. 相似文献
18.
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20.
Shu Wang 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(7):583-589
Proteolytic bacterial communities, which mineralize organic nitrogen, play a key role in agricultural systems. In this study, alkaline metalloprotease (apr) gene fragments from proteolytic bacteria were investigated in bulk and rhizosphere paddy soil from four fields under organic management (for 2, 3, 5, and 9 years), and from one field under conventional management (for 2 years). We analyzed the abundance and structure of the proteolytic bacterial communities using real-time quantitative PCR and denaturing gradient gel electrophoresis. Our results showed that the abundance of proteolytic bacteria ranged from 1.57?×?108 to 8.02?×?108?copies/g of soil. In addition, the abundance of the proteolytic bacteria in the paddy soils under organic management was significantly higher than those in the paddy soil under conventional management. Moreover, the gene copy numbers in the rhizosphere soils were significantly higher than those in the bulk soils. The abundance of proteolytic bacteria tended to increase with the duration of organic management, with the highest abundance being found in the soil that had been under organic management for 5 years. However, the proteolytic bacteria communities in the paddy soils were not significantly affected by management practices. Phylogeny analysis showed that all gel bands obtained represented genes from Pseudomonas. Additionally, correlation analysis and canonical correspondence analysis showed that C/N, C, and N were important factors that influenced the abundance and community structure of the proteolytic bacteria. These results suggest that proteolytic bacteria are indicators in organic management systems, depolymerize organic N and hence maintain soil sustainability.Abbreviations: CM: conventional management; OM: organic management; DGGE: denaturing gradient gel electrophoresis; qPCR: real-time quantitative PCR detecting system; COFCC: China organic food certification center; CCA: canonical correspondence analysis 相似文献