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1.
艾比湖湿地土壤有机碳垂直分布特征及其影响因子分析   总被引:5,自引:0,他引:5  
为了揭示干旱区湿地土壤有机碳垂直分布特征及其影响因子,对新疆艾比湖湿地不同生境土壤有机碳含量及其影响因子进行了测定和分析.研究结果表明,该区域土壤有机碳含量相对较低(1.08~11.49 g/kg),且各生境土壤有机碳垂直分布的态势不尽相同;不同生境中,有植被覆盖的湿地具有较高的土壤有机碳含量;艾比湖湿地土壤不同层次有机碳含量与容重、pH值呈极显著负相关(p0.01),与全氮呈极显著正相关(p0.01),与盐度呈显著正相关(p0.05).  相似文献   

2.
再生水回灌对土壤理化性质及土壤细菌的影响   总被引:1,自引:0,他引:1  
通过室内土柱模拟实验,采用多种土壤指标测定法和高通量测序手段探究了再生水回灌过程中再生水对土壤理化性质和土壤细菌的影响.结果表明,经再生水淋滤,9个样品土壤腐殖酸(HA)平均含量减少0.59 g·kg~(-1),土壤pH值增加0.08,有机碳(SOC)、重金属铜(Cu~(2+))平均含量分别增加了2.02 g·kg~(-1),0.923 g·kg~(-1).土壤原始样品经高通量测序占优势的菌种有变形菌门(Proteobacteria 27.38%)、放线菌门(Actinobacteria 24.68%)等,淋滤后变形菌门丰度升高至37.27%,放线菌门减少至20.62%,说明再生水淋滤后土壤环境发生较大变化.  相似文献   

3.
农牧交错带地区土地利用方式多变,人为的改变土地利用方式会影响土壤释放CO2的速率.分别对新开垦农田、多年耕种农田、退耕还草草地、多年生草地4种利用类型的土壤温度、土壤有机碳含量、土壤呼吸速率进行监测和研究,结果表明:4种土地利用类型土壤呼吸速率的日变化图像呈单峰性曲线,其中草地平均呼吸速率最大,为0.85g·m-2·d-1.4种土地利用类型土壤温度与土壤呼吸速率呈正相关关系,其中新开垦农田变化明显,K值最高,达到0.045.从整个生长季来看,4种土地利用类型平均呼吸速率表现为新开农田>草地>还草草地>农田,分别为0.97g·m-2·d-1、0.85g·m-2·d-1、0.77g·m-2·d-1和0.56g·m-2·d-1.0-10cm和10-20cm土层土壤有机碳含量大小关系与土壤呼吸速率基本吻合.试验表明不论对草地进行开垦还是对农田进行退耕还草都会增加土壤CO2的释放.  相似文献   

4.
热带雨林次生林碳循环对全球碳平衡具有重要意义,森林土壤有机碳分布特征及影响 因素已成为研究热点。土壤粒径组成与pH值是影响土壤有机碳碳库稳定性的重要物理化学因 子。在海南岛东部的吊罗山、七仙岭以及五指山选取10个热带雨林次生林典型样地,分层采集距地 表0 ~ 10 cm、11 ~ 30 cm、31 ~ 50 cm的土样,利用有机元素分析仪测定土壤有机碳质量分数,采用电 位法测定pH值,使用马尔文激光粒度仪测定土壤粒径。结果表明:在空间上,平均有机碳质量分 数由大到小依次为五指山、七仙岭、吊罗山;在垂直方向上,3个区域表层土壤有机碳质量分数随着 剖面深度的增加而递减,呈表聚性特征;3个区域土壤有机碳质量分数与pH值、粉粒含量无显著相 关性,与黏粒含量呈显著(P < 0.05)或极显著(P < 0.01)正相关,砂粒含量与五指山、吊罗山土壤有 机碳质量分数呈显著负相关(P < 0.05);黏粒含量是海南岛东部热带雨林次生林土壤有机碳质量分 数的主控因子,后续可考虑研究固碳微生物对土壤有机碳分布的影响,进一步探讨热带雨林次生 林土壤有机碳的分布特征与累积规律。  相似文献   

5.
通过对大山村地区实地采集的133个土壤样品检测,分析了该区域森林土、耕作土和茶园土中硒及与其它7种元素含量变化和不同用地类型硒与其它元素的相关性。结果表明,土壤全硒含量平均值为0.502±0.033mg·kg~(-1),属于富硒土壤;土壤铜、锌、铅、镍、铬、汞和砷7种元素含量平均值均小于国家规定的农用地土壤污染风险筛选值,远小于农用地土壤污染风险管控值;土壤有效态硒含量平均值为0.149±0.011mg·kg~(-1),有效度为29.6%,与全硒呈线性正相关关系;茶园土有效态硒与pH值呈极显著正相关(P0.01);耕作土有效态硒与有机质呈极显著正相关(P0.01);森林土全硒、有效态硒与镍、铅呈极显著负相关(P0.01),与锌、砷呈显著正相关(P0.05);耕作土有效态硒,与镍呈显著负相关(P0.05),而与汞呈显著正相关(P0.05);茶园土全硒、有效态硒,与锌、砷呈显著正相关(P0.05)。研究提供了大山村地区土壤环境pH值、有机质、全硒和有效态硒及铜、锌、铅、镍、铬、汞和砷7种元素背景值资料,可为该区土壤风险管控和富硒资源的开发利用提供参考依据。  相似文献   

6.
盐碱芦苇湿地土壤活性有机碳组分垂直分布及相关性分析   总被引:1,自引:0,他引:1  
刘骞  汤洁 《科学技术与工程》2020,20(5):1760-1766
湿地是地球生态环境的重要组成部分,也是碳循环和转化的重要场所,湿地土壤活性碳库与气候变化有着密切联系。盐碱湿地具有独特的土壤性质,以吉林西部松嫩平原盐碱湿地为例,以土壤类型图和土地利用类型图为基础,选取吉林松原查干湖天然盐碱芦苇湿地为研究对象。明晰盐碱湿地土壤活性有机碳组分垂直分布及影响因素分析,为盐碱区脆弱湿地生态环境管理与保护、区域碳库源汇研究及客观评价其在区域气候变化中的作用,以及退化湿地生态恢复提供科学依据。在研究区丰水期进行采样,在地上植被为芦苇的湿地土壤地块设置9个采样区,每个区域设置4个采样点,按照0~10、10~20、20~30、30~40、40~50 cm分层采集土壤样品。分析测定土壤有机碳(soil organic carbon,SOC)、易氧化有机碳(readily oxidized organic carbon,ROOC)、水溶性有机碳(water soluble organic carbon,WSOC)、微生物量碳(microbial biomass carbon,MBC)含量及土壤pH、含水率、容重、孔隙度等,以阐明盐碱芦苇湿地土壤有机碳及其活性组分分布特征及影响因素。结果表明:查干湖盐碱湿地土壤有机碳及活性组分垂直分布规律明显,呈现伴随土层加深而逐渐减少的趋势,且在土壤的各个剖面层土壤有机碳含量与易氧化有机碳、水溶性有机碳、微生物量碳含量间呈显著相关;研究中各土壤活性有机碳占土壤有机碳比例不一,呈现ROOC明显高于WSOC和MBC,[w(ROOC)/w(SOC)]%为87.01±10.63 g/kg、[w(WSOC)/w(SOC)]%为0.58±0.06 g/kg、[w(MBC)/w(SOC)]%为8.19±0.72 g/kg;查干湖盐碱湿地土壤有机碳及活性组分垂直分布受土壤pH、容重、孔隙度影响明显,呈显著相关,土壤含水量相对影响较小。  相似文献   

7.
上海城市绿地土壤有机碳、全氮分布特征   总被引:2,自引:0,他引:2  
选择上海市中心城区公园、道路、街头等样地,研究了城市绿地土壤有机碳、全氮的分布特征及其在不同利用方式下各土壤剖面的含量变化。结果表明:上海城市绿地土壤有机碳、全氮平均含量分别为11.21、1.06 g/kg,其中有机碳含量以0~10 g/kg和10~20 g/kg为主,分别占全部的47.18%、47.18%,全氮含量以0.5~1.0 g/kg和1.0~1.5 g/kg为主,分别占全部的49.56%和39.80%;与上海市郊区农田土壤相比,中心城区绿地土壤有机碳平均含量低5.68g/kg,幅度为33.63%,全氮平均含量低0.89 g/kg,幅度为45.64%;与第2次土壤普查上海数据相比,上海中心城区绿地土壤有机碳含量下降了10.19 g/kg,降幅为47.62%,全氮含量下降了0.18 g/kg,降幅为14.52%。不同利用方式下城市绿地土壤有机碳、全氮含量从大到小顺序为公园、街头、道路,且差异主要与人为养护水平有关;城市绿地土壤有机碳、全氮含量随剖面深度增加呈下降趋势,且表层均显著高于下层(p<0.05)。回归分析表明,城市土壤有机碳、全氮之间满足显著线性关系,符合方程y=0.056 3x+0.430 5。研究结果表明,提高土壤养护水平,降低人为活动影响强度是增加城市绿地土壤有机碳、全氮的重要途径。  相似文献   

8.
为探究广西刁江流域沿岸农田土壤和水稻的汞污染状况,选取广西刁江流域沿岸农田土壤-水稻系统,采用地累积指数(Igeo)法进行土壤汞污染评价,研究该区域稻田土壤及水稻(Oryza sativa L.)植株的汞含量特征及影响因素。结果表明,研究区的耕层土壤汞平均含量为309 ng/g,有97.5%的土壤汞含量超过全国表层土壤汞背景值(87 ng/g),有27.5%的土壤汞含量超过广西表层土壤汞背景值(225 ng/g)。地累积指数评价结果显示,研究区内80%的土壤处于无污染状态,但有个别点位的土壤汞污染较严重,仍需要注意进行环境监管。土壤各形态汞含量均值排序为残渣态>腐殖酸结合态>铁锰结合态>碳酸盐结合态>水溶态>离子交换态>强有机结合态,土壤汞的生物有效性较低。研究区稻米汞平均含量为6.08 ng/g,籽实汞超标率为6%,水稻植株根、叶、茎、壳、籽实汞含量之比约为13.5∶5.2∶1.7∶1.2∶1。稻米对土壤汞的富集系数平均值为0.031,富集能力较弱。相关性分析结果表明,土壤汞含量与稻米汞含量、土壤有机碳(Soil Organic Carbon,SOC)、pH值均无显著相关关系,稻米汞含量与SOC呈显著负相关关系。  相似文献   

9.
为了解山东省聊城市城区水岸带土壤中Hg,As含量特征和污染状况,于2015年3月至4月采集了35个水岸带土壤样品,采用王水消解-原子荧光光度计法测定了土壤中Hg,As的含量,并对水岸带土壤Hg,As的污染状况进行了评价.结果表明:聊城市城区水岸带土壤pH值的范围为8.62~9.96,呈碱性;有机质的平均质量分数为32.57 g·kg~(-1);Hg和As的质量分数平均值分别为0.139 mg·kg~(-1)和9.56 mg·kg~(-1),各点位As含量均符合国家土壤环境质量一级标准,Hg的超标率为45.7%.As与土壤有机质呈显著正相关(p0.05).以山东省土壤元素背景值为评价标准,水岸带土壤As总体表现为轻度污染和轻微生态风险,Hg表现为重度污染和较高生态危险.  相似文献   

10.
为了解不同林龄马尾松Pinus massoniana人工林土壤碳储量的动态变化,选取广西横县镇龙林场不同林龄(幼龄林、中龄林、成熟林、过熟林)的马尾松人工林为研究对象,对林地土壤有机碳含量及土壤碳储量的变化特征进行研究,并探讨其影响因素。研究表明,随着林龄递增,各土层土壤有机碳含量及土壤碳储量总体表现为增加趋势,且不同林龄的同一土层之间均差异显著。不同林龄0—60 cm土层土壤有机碳含量表现为过熟林(16.82±0.23)g/kg > 成熟林(13.47±0.14)g/kg > 中龄林(10.91±0.38)g/kg > 幼龄林(10.74±0.14)g/kg,且差异显著(P<0.05)。不同林龄0—60 cm土层土壤碳储量表现为过熟林(104.92±18.08)t/hm2>成熟林(100.52±1.18)t/hm2 > 中龄林(80.25±5.34)t/hm2 > 幼龄林(80.23±4.54)t/hm2,且差异显著(P<0.05)。各林龄土壤有机碳含量、土壤碳储量主要集中在0—20 cm土层,并随土层深度的增加而递减,表现为土壤碳表聚现象,表层(0—20 cm)土壤碳储量所占比例均明显高于其他土层,表明不同林龄主要影响马尾松人工林土壤表层的碳含量;不同林龄土壤有机碳含量、土壤碳储量与乔木、灌木层Shannon-Wiener指数、物种丰富度、凋落物层现存量、总孔隙度、土壤含水量、土壤pH值均无显著相关关系(P>0.05),与根系生物量呈极显著正相关关系(P<0.01),与土壤容重呈极显著负相关关系(P<0.01);群落总生物量、地上部分生物量均与表层(0-20 cm)土壤有机碳含量和土壤碳储量呈极显著正相关关系(P<0.01),与20-40,40-60 cm土层土壤有机碳含量呈显著正相关关系(P<0.05),而与后两个土层的土壤碳储量均无显著相关。该结果为研究土壤碳储量动态变化提供科学依据,有利于实现尾松人工林多目标可持续经营。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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