Influences of chronic contamination of oil field exploitation on soil nematode communities at the Yellow River Delta of China

Oil production related activities have led to many environmental problems. Around 80% of the total output of crude oil is generated from terrestrial oilfields in the world. However, the impact of oil exploitation procedures on soil animal communities has not been fully understood. This study investigated the responses of soil nematode communities to the oil exploitation activities in the Yellow River Delta of China. By setting 10 oilfield sites and 5 relatively uncontaminated sites (controls), we found that the content of soil total petroleum hydrocarbons (TPH) was significantly higher at oilfield sites than at controls. With a longer oil exploitation history, the content of soil TPH increased. Soil nematode community structure at oilfield sites was largely different from that at controls. Soil nematodes were significantly less abundant but more diverse at oilfield sites than at controls. The proportions of fungal feeders were significantly lower at oilfield sites than at controls, attaining only half of those at controls. The nematode trophic diversity and genus number negatively correlated with the duration of petroleum exploitation history. This study elucidated the difference in soil nematode communities caused by oilfield exploitation and indicated that the nematode diversity was most obviously influenced by the soil TPH content and the oil exploitation history.     

黄河三角洲土壤运行多样性初步调查研究

1995－1996年对黄河三角洲9个代表性样区,进行了土壤运动定性,定量调查,并对古代,近代,现代黄河三角洲3个代表性样区开展了土壤动物周年调查,研究了土壤动物的种类组成,分布和节季变化,以及土壤动物多样性,调查研究结果,黄河三角洲共鉴定出土壤运动38种,土壤运动种类组成和数量分布因三个三角洲成土年龄不同而存在差异,土壤运动多样性以夏季为丰富,黄河三角洲土壤运动多样性]与均匀度表现为正相关关系,与单纯度呈负相关趋势。     

Response of soil nematode communities to long-term application of inorganic fertilizers in the black soil of Northeast China

The effects of inorganic fertilizers on soil nematode communities were studied in a long-term fertilization experimental field in the Black Soil Region of Northeast China, where no fertilizer (CK), N fertilizer (N), combined application of N and P (NP), combined application of N and K (NK), and combined application of N, P and K (NPK) were compared. The results showed that the total nematode abundance was not affected significantly by inorganic fertilizers in the long-term field experiment. The numbers of bacterivores increased significantly in the NP treatment compared to the CK treatment, and those of fungivores and plant-parasites were inhibited in the NPK treatment. The similarity between CK and NPK treatment and the nematode diversity were higher than in other treatments. The stability of the soil ecosystem was disturbed by the inorganic fertilizers, as indicated by the change in MI values under different treatments. The response of soil nematodes mainly depended on the types of inorganic fertilizers applied.     

Response of soil nematode communities to long-term application of inorganic fertilizers in the black soil of Northeast China

The effects of inorganic fertilizers on soil nematode communities were studied in a long-term fertilization experimental field in the Black Soil Region of Northeast China,where no fertilizer (CK),N fertilizer (N),combined application of N and P (NP),combined application of N and K (NK),and combined application of N,P and K (NPK) were compared.The results showed that the total nematode abundance was not affected significantly by inorganic fertilizers in the long-term field experiment.The numbers of bacterivores increased significantly in the NP treatment compared to the CK treatment,and those of fungivores and plant-parasites were inhibited in the NPK treatment.The similarity between CK and NPK treatment and the nematode diversity were higher than in other treatments.The stability of the soil ecosystem was disturbed by the inorganic fertilizers,as indicated by the change in MI values under different treatments.The response of soil nematodes mainly depended on the types of inorganic fertilizers applied.     

黄河三角洲草地退化的研究

黄河三角洲位于东经118°7′—119°10′,北纬36°56′—38°12′;东自山东省小清河口,西至徒骇河口,以利津县宁海为顶点向渤海湾呈扇形分布。自50年代以来,随着国营及地方农场的建立以及人口的不断增长,这一地区的草地资源得到了广泛的开发利用。但是,由于一些单位只顾盲目地开垦草地和过度放牧、割草,30多年来整个黄河三角洲盐碱化、退化草地达6.67×10~4ha多,约占当地草地总面积的40%。本文研究了该地区草地退化的现状并就退化程度与累计开发时间的关系初步进行了数     

黄河改道以来黄河三角洲演变过程及其驱动机制

基于1976—2009年的23期遥感影像,并结合1976—2008年利津站水沙数据以及黄河流域年均降水量数据,定量分析黄河入海水沙特征以及黄河三角洲演变过程及其驱动机制.结果表明:1976—2008年间,黄河入海年径流量和年输沙量呈现出年际变化大和丰枯水(沙)年交替的特征,但总体均呈下降趋势;清水沟流路河口三角洲岸线和面积变化总体呈淤积增长趋势,三角洲的发育过程大致分1976—1985年、1986—1995年和1996—2009年3个阶段,3个阶段的增长速率逐阶段递减;黄河三角洲岸线和面积与利津站累积输沙量之间均呈显著的指数函数关系;黄河流域降水量的年际波动与利津站入海输沙量年际波动基本同步,并具有相关性,说明黄河流域降水量的年际波动是引起入海径流量和输沙量波动的重要原因.     

Response of reed community to the environment gradient water depth in the Yellow River Delta, China

We investigated and monitored a reed community in the fields.Data on the bio-ecologieal characteristics and β-diversity of reed communities in different environmental gradients (mainly based on water depth) of the Yellow River Delta were collected through multianalysis,extremum analysis and β-diversity index analysis.In accordance with the square sum of deviations (Ward)cluster analysis,10 sampling plots were divided into six types with the dominant plants in different plots varying according to the change in environmental gradients.The dominant plants in these plots varied from aquatic plants to xerophytes and salt tolerant plants as water depth decreased.The average height and diameter of the reeds at breast level were significantly correlated with the average water depth.The fitness curves of average density and coverage with average water depth were nonlinear.When the average water depth was 0.3 m,the average density and coverage of reeds reached the apex value,while the height and diameter of the reeds at breast level increased with the water depth.There were obvious changes to the environmental gradient in the Yellow River Delta.The transitional communities were also found to exist in the Yellow River Delta by β-diversity analysis.Vicarious species appeared with the change in water depth.The occurrence of substitute species is determined by the function of common species between adjacent belts.The different functions of common species led to differences in community structure and function and differences in dominant plants.The result reflects the variations of species present in different habitats and directly reflects environmental heterogeneity.The values of//-diversity indices of adjacent plots were higher than those of nonadjacent plots.There are transition zones between the xerophytes and aquatic plants in the Yellow River Delta.In an aquatic environment,the similarity of reed community is higher than that of xeromorphic plants.The β-diversity index can reflect plant succession trends caused by the change in environmental gradients in the Yellow River Delta.The β-diversity index reveals plant responses to changes in environmental gradient and is helpful in observing changes in patterns of species diversity in relation to environmental gradient change and evolving trends in the future,which in turn plays a prominent role when environmental water requirements of wetland are discussed.     

Dioxin-like Polychlorinated Biphenyls Contamination and Distribution in Soils from the Modern Yellow River Delta,China

The concentrations of 12 dioxin-like Polychlorinated Biphenyls (dl-PCBs) were determined from 37 soil samples collected from the modern Yellow River Delta (China) in March 2006. The PCB concentrations were determined by dual capillary GC-ECD. The total dl-PCBs concentrations were in the range of 108.7 to 2153 ng/kg with an average of 800.5 ng/kg. The toxic equivalency (TEQ) in this area varies from 2.3 × 10^{? 5} to 9.5 × 10^{? 5} ng-TEQ/kg, so the delta is slightly polluted by PCBs. PCB118, the main congener, accounted for 46.7% of the total dl-PCB. More than 60% dl-PCBs were penta-PCBs. The spatial distribution of the dl-PCBs is discussed in detail. The distribution of the PCBs suggests that water runoff is the main source of the total contaminant burden in the delta, and that atmospheric precipitation plays an important role.     

A management-oriented valuation method to determine ecological water requirement for wetlands in the Yellow River Delta of China

A wide range of human impacts have resulted in changes to wetland water regimes throughout the natural reserve of the Yellow River Delta. Specific local impacts which affect wetland water regimes include hydrological alterations associated with urban and agricultural development. Increasingly, management decisions must be made regarding the amount and timing of water required to maintain the ecosystem's diversity and its ecological characteristics. In this paper, based on the practice in the natural reserve and the important request of Ramsar for the “wise use” of wetlands in which ecological characteristics need to be reserved, a set of management objectives for the wetland natural reserve is proposed. The objectives include protecting the ecosystem and the waterfowl resources in the new wetland, renewing biodiversity and maintaining the function of the ecosystem. By means of a correlation analysis between the wetland biota and water regime, the ecological water requirement for the wetlands is proposed and classified into three classes, i.e., minimum, moderate and perfect water requirement, corresponding to the basic, moderate and perfect management objective, respectively. The results show that the minimum, moderate and perfect water requirements, respectively, are 37.94×10⁸, 49.47×10⁸ and 64.57×10⁸ m³ per year if the water required for sediment flushing is not considered in the wetland natural reserve. If the water required for sediment flushing is included, the amount will be 187.94×10⁸, 199.47×10⁸ and 214.57×10⁸ m³ per year, respectively, which cover 47%, 50% and 54% of the available ecological water quantities observed in the lower Yellow River during the 1950s.     

Response of reed community to the environment gradient-water depth in the Yellow River Delta, China

We investigated and monitored a reed community in the fields. Data on the bio-ecological characteristics and β-diversity of reed communities in different environmental gradients (mainly based on water depth) of the Yellow River Delta were collected through multianalysis, extremum analysis and β-diversity index analysis. In accordance with the square sum of deviations (Ward) cluster analysis, 10 sampling plots were divided into six types with the dominant plants in different plots varying according to the change in environmental gradients. The dominant plants in these plots varied from aquatic plants to xerophytes and salt tolerant plants as water depth decreased. The average height and diameter of the reeds at breast level were significantly correlated with the average water depth. The fitness curves of average density and coverage with average water depth were nonlinear. When the average water depth was 0.3 m, the average density and coverage of reeds reached the apex value, while the height and diameter of the reeds at breast level increased with the water depth. There were obvious changes to the environmental gradient in the Yellow River Delta. The transitional communities were also found to exist in the Yellow River Delta by β-diversity analysis. Vicarious species appeared with the change in water depth. The occurrence of substitute species is determined by the function of common species between adjacent belts. The different functions of common species led to differences in community structure and function and differences in dominant plants. The result reflects the variations of species present in different habitats and directly reflects environmental heterogeneity. The values of β-diversity indices of adjacent plots were higher than those of nonadjacent plots. There are transition zones between the xerophytes and aquatic plants in the Yellow River Delta. In an aquatic environment, the similarity of reed community is higher than that of xeromorphic plants. The β-diversity index can reflect plant succession trends caused by the change in environmental gradients in the Yellow River Delta. The β-diversity index reveals plant responses to changes in environmental gradient and is helpful in observing changes in patterns of species diversity in relation to environmental gradient change and evolving trends in the future, which in turn plays a prominent role when environmental water requirements of wetland are discussed. __________ Translated from Acta Ecologica Sinica, 2006, 26(5): 1533–1541 [译自: 生态学报]     

Effect of slow-release urea on soil nematode community structure in a Chinese soybean field

The effect of slow-release urea on soil nematode community structure was investigated in a soybean field in northeast China. Three treatments, no urea (CK), conventional urea (U) and slow-release urea (SRU), were arranged in a completely random design. The results show that the abundance of total nematodes was significantly higher in SRU than in CK and U. Significant differences in the abundance of bacterivores with colonizer-persister (cp) values 2–3, fungivores with cp 2 and herbivores with cp 3 were found among different treatments. Forty-one genera were identified, of which Acrobeloides, Aphelenchus and Heterodera were dominant. Soil nematode guilds and genera exhibited different responses to slow-release urea. The most trophic groups and genera had greater abundances in SRU than in CK and U. Slow-release urea had a positive effect on soil nematode community structure.     

Geochemical speciation and ecological risk assessment of heavy metals in surface soils collected from the Yellow River Delta National Nature Reserve,China

In this study, a comprehensive assessment of soil heavy metal (HMs) pollution in the Yellow River Delta National Nature Reserve (YRDNNR) was conducted. Spatial distributions, chemical fractions, and sources of eight HMs (Cu, Zn, Pb, Cr, Cd, Fe, Mn, and Ni) in 46 soil samples in the studied region were analyzed. In addition, the potential risks of the HMs were evaluated. The results showed that the mean concentrations of Cu, Zn, Pb, Cr, Cd, Fe, Mn, and Ni were 19.4, 65.2, 38.4, 55.9, 0.078, 41546.5, 510.3, and 27.5 mg kg^?1, respectively. It indicates that the concentrations of most HMs, with exception of Pb and Fe, in samples were similar to the background value of soil in China. Principal component analysis results showed that the HMs originated mainly from natural sources, but Pb pollution in the studied area was significantly caused by anthropogenic activities. In addition, Ecological risk assessment statistical analysis indicates that the HM contamination level in YRDNNR ranged from low to moderately polluted, however, the environmental risk due to Mn and Pb contamination was high.     

Arbuscular mycorrhizal status of wild plants in saline-alkaline soils of the Yellow River Delta

A survey was made of the arbuscular mycorrhizal (AM) status of five dominant wild plants Tamarix chinensis, Phragmites communis, Suaeda glauca, Aeluropus littoralis var. sinensis and Cirsium setosum in saline-alkaline soils of the Yellow River Delta that show low plant diversity. All of the species were colonized and showed typical AM structures (arbuscules, vesicles). The colonization percentage ranged from 0.2% to 9.5%, where C. setosum was the highest. The species richness of AMF at the different sites ranged from 2.00 to 2.40 per 50 ml soil, with an average of 2.16. Species diversity ranged from 1.99 to 2.22 per 50 ml soil, with an average of 2.13. Spore density ranged from 3 to 30 per 50 ml soil, with an average of 12. Glomus was the dominant genus, with a frequency and relative abundance of 88.1% and 68.4%, respectively. G. caledonium, with a frequency and relative abundance of 15.0% and 4.6%, respectively, was the dominant species. Differences were also observed in the distribution of AMF in different soil layers. Although there were still AM fungal spores in the layer 40 cm below the surface, most spores were found at a depth of 0–40 cm.     

黄河三角洲芦苇种群高度和地上净生产量生长季动态

黄河三角洲位于山东省东北部。本地区自然植被的主要类型是盐生草甸,其中广泛分布在低平洼地、黄河故道以及池塘河渠的芦苇(Phragmites communis)种群是该地区重要的农业资源之一。通过在生长季中对这一种群的定位研究,初步揭示了种群高度和地上净生产量动态的基本规律。一、自然环境概况黄河三角洲在中国植被区划上属暖温带落     

黄河三角洲莱州湾柽柳低效次生林质效等级评价

以黄河三角洲莱州湾柽柳次生灌木生态林为对象,选取林分生长和土壤理化性状等24项指标,采用综合因子法研究柽柳林低效的主要影响因子和低效林划分的主要参数.结果表明:柽柳树木生长指标与反映土壤质量状况的主要指标相关性不明显,仅依据树木的生长状况不能反映柽柳林的低效程度,需采用树木生长和土壤改良指标来综合判断.土壤含盐量、林龄、土壤含水量、单株地上茎和叶生物量及地径是反映低效柽柳林分质效高低的主要指示因子,其次为土壤容重、孔隙度及土壤养分特征.莱州湾柽柳低效林可划分为生长潜力型、轻度低质型、中度低效型、中度低质低效型和重度低质低效型5大类型.依据聚类分析的类平均值探讨了其林分特征、低效原因及经营改造方法.     

Distribution and Contamination Risk Assessment of Dissolved Trace Metals in Surface Waters in the Yellow River Delta

This study investigated the dissolved trace metal contamination levels of Zn, Sr, B, Al, Ba, Fe, Mn, Li, V, Be, Cd, Cr, Cu, Mo, Ni, Se, and Pb in 23 surface waters of the Yellow River Delta (YRD) in China. Coefficients of variation with 66–260% reflected large spatial variations of concentrations of metals. Compared to drinking water guidelines established by the World Health Organization and the U.S. Environmental Protection Agency, the primary trace metal pollution components (Al, B, V, and Zn) were above drinking water standard levels by 82.6%, 47.8%, 52.2%, and 52.2%, respectively. Preliminary risk assessments were determined via the Hazard Quotient (HQ) to evaluate the human health risk of these metals. HQ_ingestion of V indicated potential deleterious health effects for residents. Hierarchical cluster results revealed that clusters 1, 2, and 3 were primarily affected by pollution from industrial and domestic activities, natural and agriculture activities, and oil fields, respectively. Principal component analysis results indicated Fe, Mn, Al, and Ba were controlled by natural sources, whereas anthropogenic activities led to high pollution levels of Al, B, V, Zn, and Sr.     

沿黄地区盐碱地种植水稻土壤理化性质的比较

土壤盐碱化是一个世界性的问题,中国盐渍土面积为3. 47×105 km2(不包括滨海滩涂) [1]. 陕西省沿黄地区分布有大面积盐碱地,该地区土地利用率极低. 盐碱地治理通常采用水利工程、化学改良和生物改良等措施[2-4] ,植物改良技术因具有费用少、见效快以及在改善大面积盐碱土的同时能获得经济效益等优点而受到广泛关注. 已有的在盐碱地区种植水稻(Oryza sativa Linn.)的研究集中在不同改良剂对盐碱地的改良效果及对水稻产量的影响,盐分胁迫对水稻生长的影响以及作物收获还田后对盐碱地的改良等方面[5-7]. Hussain等[8]研究了水稻在盐碱地的耐盐机制;罗新正等[9]认为,连续多年采用种稻模式进行单纯性洗排盐碱可明显降低松嫩平原盐碱地表层土壤的含盐量.     

大气污染对珠江三角洲森林及土壤影响的初步研究

于1998年4月至1999年3月采用定点测定和面上调查相结合的方法,开展大气污对珠江三角洲森林生长及其土壤酸碱性和肥力特性的影响研究。初步结果表明大气污染引起珠江三角洲地区发生大面积、高频率的酸雨,主要的污染物有SO     

大气污染对珠江三角洲森林及土壤影响的初步研究

于1998年4月至1999年3月采用定点测定和面上调查相结合的方法,开展大气污染对珠江三角洲森林生长及其土壤酸碱性的肥力特性的影响研究。初步结果表明：大气污染引起珠江三角洲的地区发生大面积、高频率的酸雨,主要的污染物有SO、NOx、悬浮颗粒物等;随着污染程度的增大,森林土壤pH值降低,SO4^2-和AI^3 质量浓度增大;马尾松、湿地松叶片叶绿素含量降低,生长衰退甚至死亡;但不同树种对大气污染敏感程度不同,种植马占相思比马尾松更能增加林地对酸雨缓冲力和提高土壤肥力。