不同形态氮富集对青菱湖沉积物磷释放的影响          下载免费PDF全文

李慧  杨柳  徐方  周易勇  汪维军  陈文 《水生态学杂志》2021,42(1):108-115

为了揭示无机氮和有机氮对沉积物磷释放的贡献,在武汉市青菱湖草型湖区和藻型湖区分别采集沉积物,进行添加不同形态不同浓度氮(0.5、2.5 g酪蛋白,0.02、0.2 g氯化铵)的培养实验。结果显示,培养结束时,草、藻型湖区沉积物加2.5 g酪蛋白的处理组上覆水中溶解反应性磷(SRP)浓度分别为对照组的64.88倍和5.61倍,而加氯化铵处理组与对照组上覆水中SRP浓度无显著差异;加氯化铵处理组上覆水溶解氧(DO)浓度分别为各自对照组的80%左右,而加酪蛋白处理组上覆水DO浓度分别为各自对照组的10%和4%;整个培养过程中,草、藻型湖区沉积物均为加2.5 g酪蛋白处理组的沉积物碱性磷酸酶活性(APA)稍高于其他处理组相应值,但无显著性差异;草、藻型湖区沉积物加2.5 g酪蛋白处理组磷平衡浓度(EPC0)分别为对照组的2.08倍和1.77倍;而加氯化铵处理组和加0.5 g酪蛋白处理组沉积物EPC0与对照组相应值无显著差异。研究表明,有机氮的富集会增加沉积物磷的释放,而无机氮对沉积物磷释放的贡献不大;有机氮对沉积物磷释放的影响是由形成厌氧的状态、胞外磷酸酶的分泌、改变沉积物磷吸附行为等多种因素综合作用的结果。  相似文献   

中国季风区土壤137Cs背景值研究   总被引：2，自引：0，他引：2  

张明礼  杨浩  王小雷  王轶虹  徐从安  杨九东  戎静 《核农学报》2009,23(4):669-675

 通过测定山东沂蒙山区、江苏苏南丘陵区以及云南滇池流域背景点样品中土壤137Cs活度,探讨了土壤剖面中137Cs的分布状况,发现不同地区不同质地的土壤137Cs 的分布深度有所不同。非耕地137Cs活度呈指数型分布,且与分布深度表现出很强的相关关系;耕地中137Cs活度呈深度分异上的均一性。确定了这几个地区137Cs的背景值分别为1 737.1、1847.2和918.0 Bq/m2。地区土壤137Cs背景值的确定使得 137Cs示踪技术研究土壤侵蚀退化状况、侵蚀和沉积的空间分布成为可能,为土壤资源的可持续利用、土壤侵蚀的经济损益评估及水土保持措施评价等提供有力的技术支持。  相似文献   

调水工程水价计算研究     

鄢碧鹏  刘超 《灌溉排水学报》2005,24(4):69-72

根据跨流域调水工程的特点,分析了容量水价和计量水价的构成和影响因素,明确了容量水价主要由国家投资政策决定,是国家调控调水水价的基本手段,计量水价由供水的资源成本、工程成本和环境成本组成,是调水工程市场化运作的核心问题,全面清晰地表述了调水水价的概念。在此基础上,提出了容量水价和计量水价的计算方法,讨论了有调蓄湖泊情况下的供水成本计算和调水风险问题,为确定调水工程水价奠定了基础。  相似文献   

盘龙江口滇池沉积物重金属的分布及污染评价   总被引：12，自引：2，他引：10       下载免费PDF全文

李仁英  杨浩  陈捷  余天应  金峰 《土壤》2006,38(2):186-191

对盘龙江口滇池沉积物重金属的分布进行了研究并对其污染状况进行了评价。结果表明:Cd、Cr、Cu和Zn在表层沉积物中的含量较高(Pb在中层的含量较高),且随采样深度的增加含量递减,这几种元素的含量顺序基本为Zn>Cu>Cr=Pb>Cd。表层沉积物中各元素之间的相关性较差,中层和底层的相关性较好。表层沉积物重金属与颗粒的相关性较差。除底层沉积物中的重金属与有机质达到显著或极显著相关外,表层和中层的相关性都较差。所研究重金属(除Pb外)随与河口距离的增加,含量降低。利用地积累指数对该河口重金属的污染进行评价,发现重金属污染都在中等程度以上,其污染程度顺序为:Cd>Zn>Cu=Pb>Cr,表明盘龙江入滇池口区的沉积物已受到严重污染。  相似文献   

Genetic persistence of an initially introduced brown trout (Salmo trutta L.) population despite restocking of foreign conspecifics     

Jens Thaulow  Reidar Borgstrøm  Manfred Heun 《Ecology of Freshwater Fish》2014,23(4):485-497

The persistence of the initial genetic structure despite later stocking with foreign conspecifics is influenced by several factors, leading to different levels of introgression. Stream spawning has been assumed to be the prevailing recruitment strategy of brown trout (Salmo trutta L.). However, in lakes with limited stream spawning habitat, but still with high natural recruitment, lake spawning has been proposed. Using fourteen microsatellites, we assessed the genetic structure in a small allopatric brown trout population in the Lake Skavatn, located on the Hardangervidda mountain plateau, Norway. A total of 265 brown trout were obtained from the lake itself, the outlet stream, two tributaries, a littoral sample from a presumed lake spawning site, a suggested stocking source, and a lake sample from 1967, representing the initial lake population. The six Skavatn samples were best represented by three genetic components, showing a shift from the initial population, but with no genetic signal from the suggested stocking source. The littoral sample had the largest similarity to the initial lake population, possibly indicating the importance of lake spawning in a system where streams offer unpredictable spawning and rearing conditions. Due to large annual variations in recruitment contributions from the different spawning and rearing locations, the genetic structure of the lake population probably vary over time.  相似文献   

Genetic Diversity of Gazella subgutturosa Based on Mitochondrial DNA D-Loop Sequence in Xinjiang Ebinur Lake     

TAJIGUL Turap  EZIZJAN Nabi  NING Li-qun  MAHMUT Halik 《中国畜牧兽医》2016,43(5):1316-1322

To investigate the genetic diversity and genetic data of Gazella subgutturosa from Xinjiang Ebinur lake National Wetland Nature Reserves, the Ebinur lake goose antelope 35 feces samples were analyzed.Using noninvasive DNA technology, the mitochondrial DNA D-Loop 878 bp fragment was successfully amplified.Sequences results for GenBank database BLAST comparison and Clustal W and DNASP software analysis.The results showed that the sequences of the above fragments were successfully amplified, total 55 polymorphic loci were detected, which were not found insert and deficiency.This study found 15 variable sites, including 14 transversion sites and 1 top transposition.The average A, T, C and G contents in D-Loop were 28.03%, 31.57%, 24.84% and 15.56%, respectively.The contents of A+T (59.6%) were higher than G+C (40.4%).In addition, a total of 16 mtDNA haploid type were detected, haploid type polymorphism (h) was 0.886 ±0.037, nucleotide diversity degree (π) was 0.037±0.01528.The results showed that Ebinur lake Gazelle subgutturosa maintained high variation in mitochondrial D-Loop sequences.  相似文献   

太湖地区水稻地方品种品质性状多样性研究进展     

敖雁  吴启  薛萍  朱志强  陆豪杰 《中国稻米》2016,(5):27-30

太湖地区种稻历史悠久,积累了丰富的水稻地方品种资源,水稻地方品种的遗传多样性研究可为优质资源的保护利用以及选育新品种提供一些参考。本文从遗传多样性的概念、研究方法、太湖地区水稻地方品种品质性状多样性研究进展等方面进行了综述,总结了太湖流域水稻地方品种资源的相关利用价值。  相似文献   

基于Landsat影像的博斯腾湖水质参数反演模型研究     

周荣攀  徐长春 《湖北农业科学》2016,(10):2507-2513

以内陆博斯腾湖为研究区,通过实测数据和遥感数据,分析了单波段数据、归一化数据、波段组合数据与溶解性总固体、矿化度之间的相关性,建立并筛选获得了最优模型,以期为博斯腾湖溶解性总固体和矿化度两个指标的大面积遥感反演提供理论依据。结果表明,对溶解性总固体与矿化度浓度进行反演,单波段最优分别为B3与B2,最佳模型皆为指数模型;归一化处理后最优波段为B3与B2,最佳模型分别为二次模型与指数模型;波段组合最优为B2×B3与B2-B7,最佳模型为指数模型与指数、线性模型。通过模型的验证与比较,研究发现,归一化法对于溶解性总固体浓度的反演能达到较好的效果,而波段组合法能较好的反演矿化度浓度。  相似文献   

不同退耕年限下菜子湖湿地土壤酶活性变化   总被引：2，自引：1，他引：2  

包先明  程新锋  纪磊  郑真  孔令柱  张平究 《土壤》2016,48(4):692-697

选取菜子湖区不同退耕年限(3、7、9、11、21 a)湿地为研究对象,以仍耕作油菜地和原始湿地为参照,分析了退耕还湖后湿地土壤过氧化氢酶、蔗糖酶、磷酸酶和脲酶活性特征,探讨了退耕还湖后湿地土壤酶活性变化规律。结果表明:相对于仍耕作油菜地,退耕后湿地土壤过氧化氢酶活性表层与亚表层均表现为退耕3~7 a降低,退耕9~21 a升高趋势;表层土壤蔗糖酶活性呈现退耕3 a升高?退耕7 a降低?退耕9~11 a升高?退耕21 a降低的趋势,而亚表层土壤退耕3年急剧升高,而后呈降低的趋势;表层土壤磷酸酶活性则呈现退耕3~11 a逐渐升高,而后逐渐降低的趋势,而亚表层土壤则表现为退耕3~7 a降低?退耕9~11 a升高?退耕21 a降低的趋势;退耕后湿地表层土壤脲酶活性表现为退耕3 a降低,退耕7~9 a升高,退耕11~21 a降低趋势,亚表层则呈现退耕3 a升高,而后逐渐降低的趋势;退耕21 a湿地土壤4种酶活性均与原始湿地仍存在显著性差异。退耕后水文条件的改变和植被的恢复致使土壤酶来源、酶促反应底物与产物和土壤环境因子变化,进而影响退耕后湿地土壤酶活性变化。  相似文献   

Properties of humic substances from the baltic sea and lake ermistu mud     

Monika?übner  Maili?Treuman  Anu?Viitak  Margus?LoppEmail author 《Journal of Soils and Sediments》2004,4(1):24-29

Scope and Goal  Humic substances (HSs) are the product of microbial degradation, chemical polymerisation and oxidation of organic matter. HSs can be divided into different fractions: humic acid (HA), hymatomelanic acid (HMA), fulvic acid (FA) and humin. HSs play a fundamental role in accumulation and exchange processes of chemical compounds (metals and organic pollutants) in the environment. HSs can form soluble complexes that migrate long distances or precipitate, carrying bound cations with them. The migration/precipitation abilities depend on the metal ion, the ion charge, the degree of ionisation of the organic molecule, the ionic strength of the media, and the location of the metal ion. Objective  Estonia is rich in the Baltic Sea and lake sediments. Historically, mud has been used in human treatment as a curative mud. High-molecular HSs are an important part of curative mud and they have a strong effect on its properties. The curative mud which is used in human therapy may not be polluted with different organic and inorganic contaminants. The aim of this work is to characterise and compare HSs isolated from the Baltic Sea mud (Haapsalu Bay) and from the sediments of Lake Ermistu (Estonia). Results and Conclusions  We determined the yield of basic extraction of different HSs components from mud in the course of separation. We found that acid pre-treatment of mud increased the amount of extracted HSs more in the sea mud than in the lake mud. These results show that HSs are bound to the inorganic/organic structure of mud and are released during prolonged treatment with an acid. We performed elemental analysis of the different fractions of HS extracts. HMA fractions had the highest carbon content and the lowest nitrogen content. HMA contains more polysaccharides than amino acid residues. These subunits may cause a better solubility of HMA in water as compared to HA. Acid pre-treatment of the natural sea and the lake mud diminished the content of carbon in most of the HS fractions. The content of nitrogen in the sea and in lake FA diminished by about two times. We determined the metal content in the mud and its HS fractions. We found that the concentration of heavy metals Pb and Cr is lower than <0.08 mg/kg. As expected, the total metal concentration is considerably lower in the lake than in the sea mud. Acid pre-treatment of mud shows that the sea HA forms more stable Fe and Mg complexes, while the sea HMA contains more stable Zn and Cu complexes. The lake HSs result in more stable Mg complexes with HA and HMA fractions. Sea FA binds Cu and Mg better, but lake FA is more effective in binding Zn. To compare the amount of metals extracted from HA, HMA, FA (with that, remains in HS fractions), the metal concentration in the alkaline full extract of the sea mud was determined. Alkaline treatment removed 0.8% Mg, 7.9% Cu, 5.2% Zn and 3.8% Fe together with HSs from the sea mud, the rest remained in humin and in the mineral part of the mud. The following work-up was additionally carried out for most of the metals. So, we found that there was only 1.7% of Fe, 2.1 % of Mg, 23.2% of Zn and 45.2% of Cu left in HA, HMA and the FA fraction (as a sum) from the total amount of those metals in HSs. This means that Cu is the metal most strongly bound to HSs. On the bases of HS separation data we found that the order of stability of the metal-humate complexes is Cu>Zn>Mg>Fe. The ultraviolet spectra of HA, HMA and FA revealed that HMA had the biggest molar absorption and calculated aromaticity. Recommendations and Outlook. The characteristics of HSs, isolated from the Baltic Sea and Lake Ermistu mud reveal the difference of HSs from the sea and the lake mud. Also, different properties of HS fractions are observed. Metals are concentrated variously in different HS fractions. In all cases the content of Pb and Cr was low, meaning that the mud preparations are nontoxic in respect to these metals. The order of stability of metal-humate complexes is Cu>Zn>Mg>Fe. The order of affinity of metals to HS fractions obtained have to be extended to other metals of environmental interest. The ability of HSs to bind metals may make them a candidate for natural, environmentally safe substances to concentrate hazardous metals and to remove them from natural water reservoirs.  相似文献