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1.
重金属污染对水稻土微生物及酶活性影响研究进展 总被引：2，自引：0，他引：2
水稻土受到重金属污染不仅影响水稻的产量品质，而且对水稻土微生物及酶活性的影响不容忽视。本文系统综述了水稻土重金属污染的来源，重金属污染对水稻土微生物生物量、种群数量、群落结构以及土壤酶活性的影响，并针对重金属污染对水稻土微生态效应研究的不足提出了未来应该研究的重点和方向，指出：①加强水稻-重金属-微生物三者相互作用、相互影响方面的研究；②在研究重金属污染与水稻土土壤微生物生态特征的关系的基础上，加强对重金属、土壤理化性状和水稻等因素进行综合并定量化分析，将是明确重金属对土壤微生物生态特性的影响及相关机理的关键；③应用分子生物学方法以及系统生物学方法，促进重金属污染胁迫下水稻土微生物活性及功能的演变规律及响应适应过程；④加强基于长期定位实验的研究，在较长的时间尺度和较大的空间尺度上认识水稻土生态系统在重金属胁迫下的演变规律和机制；⑤重金属污染对水稻土酶活性的研究应重点从机理方面入手，注重结合土壤酶的动力学参数和热力学参数，深化土壤酶与复合污染的作用机理，进一步揭示复合污染致毒途径及其机理，同时借助分子手段，探索重金属污染水稻土中更多未发现的酶的特性，寻找更加敏感、更能普遍推广的重金属污染土壤的综合性指标，以期为重金属污染水稻土的风险评价和生物修复提供科学依据。 相似文献
2.
土壤微生物对土壤重金属污染反应敏感,是探讨矿区土壤重金属污染生态效应的有效指标之一。通过野外调查与采样和室内分析,研究了藏中矿区重金属污染对土壤蔗糖酶、脲酶、脱氢酶和酸性磷酸酶活性、微生物生物量C（MBC）、N（MBN）和P（MBP）、土壤基础呼吸、代谢商（qCO2）及可矿化N的影响。研究表明,矿区土壤重金属Cu、Zn、Pb、Cd全量和有效含量均高于对照土壤;随着矿区土壤重金属含量增加,土壤酶活性、微生物量C、N和P、可矿化N均逐渐降低,土壤基础呼吸和qCO2则逐渐升高;土壤重金属与土壤蔗糖酶活性、脲酶活性、脱氢酶活性、酸性磷酸酶活性、MBC、MBN、土壤基础呼吸、qCO2及可矿化N具有显著的线性相关;脱氢酶活性对土壤重金属污染最为敏感,表明脱氢酶活性可作为藏中矿区土壤环境质量变化的有效指标。 相似文献
3.
Microbial Biomass and Tolerance of Microbial Community on an Aged Heavy Metal Polluted Floodplain in Japan 总被引：1，自引：0，他引：1
Takafumi Kamitani Hirosuke Oba Nobuhiro Kaneko 《Water, air, and soil pollution》2006,172(1-4):185-200
The objective of the present study was to increase understanding of the effects of heavy metal pollution and soil properties on microorganisms in relation to the biomass and microbial functional community. Soil samples were collected from aged polluted and reference sites on a floodplain. The soil Cu, Zn and Pb total concentrations were much higher at the polluted sites (average 231.6–309.9 mg kg?1, 195.7–233.0 mg kg?1, and 72.4–86.0 mg kg?1, respectively) than at the reference site (average 33.3–44.0 mg kg?1, 76.7–98.0 mg kg?1, and 30.8–41.6 mg kg?1, respectively), while the available heavy metal concentrations in CaCl2 extraction were similar in all sites. Small seasonal variations in the size of microbial biomass were observed. Ambient soil properties (e.g. total C, N, pH, moisture content, and CEC) affected the soil microbial biomass more than the heavy metal pollution. However, the aged pollution tended to impact on the composition of the microbial community. PICT (pollution-induced community tolerance) test using BIOLOG Ecoplates showed enhanced tolerance of the microbial community to Cu stress in the polluted site. In non polluted but low nutrient, low pH and low moisture soil, the microbial biomass was lower and the microbial community was more vulnerable to Cu stress. In spite of the low heavy metal availability due to ageing, the BIOLOG technique provided sensitive detection of microbial community level changes in PICT analysis. 相似文献
4.
采集南方几种重金属污染下的水稻土,通过室内培养的方法研究土壤CO2排放的动态变化以及微生物学指标的差异。结果表明,在60d的培养期内,前7d土壤呼吸速率较高,占了整个排放量的30．89％～64．37％,并且这一阶段重金属对土壤呼吸速率的影响最大。重金属对土壤微生物生物量的影响表现出增加、抑制与无显著性差异的结果,而重金属对微生物熵及微生物代谢熵（qCO2）的影响却是极显著的,同时表现出增加与降低的不同结果。这说明土壤呼吸以及不同的微生物学指标,在长期的复合重金属污染条件下,其表现并不一致,微生物熵与代谢熵用于基本性质差异较大的土壤时,对重金属的响应更为灵敏。此外,土壤重金属的累积还能提高土壤中有机碳的含量。 相似文献
5.
Decomposition occurs in the aboveground and ground litter and soils of tropical rain forests, but little is known about the protozoa that stimulate bacterial activity and turnover. I examined litter and ground soils, epiphytic bryophyte soils on tree trunks and branches, and adventitious roots of lianas attached to tree trunks, within 2 m above ground in the Luquillo Experimental Forest, within the Caribbean National Forest, Puerto Rico. Amoebae numbered 69,000–170,000, ciliates 1000–25,000, and testate amoebae 58,000–190,000 g−1 dry wt. of litter, but were reduced by 0.25–0.5 of these abundances in the underlying soils. In the aboveground soils, amoebae numbered 64,000–145,000, ciliates 1000–8000, and testate amoebae 84,000–367,000 g−1 dry wt. of soil. Eighty species of ciliates and 104 species of testate amoebae were found. About 50% of the individuals in ciliate and 33% in testate amoebae populations were small r-selected species, illustrating that functional differences between species determine community composition. Although protozoan numbers are best described as “protozoan potential” because many individuals may be dormant, the high moisture content of tropical rain forest litter and soils suggest almost continually connected soil water films (necessary for protozoan transport), and together with the large numbers and biodiversity of protozoa, suggest that a major proportion of these protozoa contribute to the bacterial decomposition channel of organic matter. 相似文献
6.
在室内培养条件下,应用4因素5水平二次正交回归旋转组合设计方案,对重金属复合污染红壤的微生物活性及群落功能多样性进行了研究。结果表明,在Cu、Zn、Pb、Cd复合污染生境中重金属的微生物毒性效应发挥主要由Cd、Cu两元素决定,其生物毒性顺序表现为:Cd>Cu>Zn>Ph,红砂泥中表现较为突出。与单一镉、单一铅污染处理相比,重金属复合污染对供试红壤微生物生物活性及其群落功能多样性的影响并非仅仅表现出简单的加和作用,同时还存在协同作用和拮抗作用。典型相关分析显示,红壤微生物活性与重金属含量之间关系密切,第一对典型变量的相关系数r达0.885 8、0.932 8,均达极显著水平(p<0.001), 说明重金属复合污染与红壤微生物间存在较为稳定的数量反馈机制,红壤总体微生物活性指标能较好地反映供试红壤重金属复合污染状况,可作为重金属污染红壤环境质量评价及量化分类的有效指标。 相似文献
7.
Valentyna Krashevska Michael Bonkowski Mark Maraun Liliane Ruess Ellen Kandeler Stefan Scheu 《Soil biology & biochemistry》2008,40(9):2427
We investigated microbial biomass, fungal biomass and microbial community structure at three altitudes (1000, 2000 and 3000 m) and in two soil layers [L/F layer (Layer I) and underlying H/Ah layer (Layer II)] of tropical mountain rain forests in southern Ecuador. Basal respiration, microbial biomass and concentration of ergosterol generally declined from Layer I to Layer II and peaked at 2000 m. Compared to temperate forest ecosystems microbial biomass and ergosterol concentrations were generally low. Patterns in phospholipid fatty acids indicated that the composition of microbial communities markedly changed from Layer I to Layer II. These differences between layers decreased with increasing altitude. The concentration of the arbuscular mycorrhizal fungal marker PLFA 16:1ω5c decreased with altitude in Layer I but increased in Layer II. The fungal-to-bacterial ratio increased with altitude and was higher in Layer I than in Layer II. Presumably, low microbial biomass in soils of tropical forest ecosystems is due to high temperature associated with high respiration but also low litter quality, with the latter declining with altitude. These conclusions are supported by the fact that at higher altitude the microbial community changed from a bacterial-dominated to a fungal-dominated system. CCA showed that microbial biomass correlated closely with density of a number of putatively bacterial feeding testate amoeba species including Corythion dubium Taranek, 1871, Euglypha cristata Leidy, 1879, Trigonopyxis arcula Penard, 1912, Tracheleuglypha dentata Deflandre, 1928 and Trinema lineare Penard, 1890. Ergosterol concentrations, but not the PLFA 18:2ω6c, strongly correlated with the putatively fungal feeding species Phryganella acropodia (Hertwig, Lesser, 1874) Hopkinson, 1909. Generally, parallel to microbial biomass and ergosterol concentrations the density of testate amoebae peaked at 2000 m. However, compared to microbial parameters changes in testate amoebae communities between two layers were less pronounced. The data suggest that density and community structure of testate amoebae are driven by the availability of food resources (bacteria and fungi) which at high altitude decrease with increasing moisture and decreasing pH. 相似文献
8.
《European Journal of Soil Biology》2002,38(3-4):297-300
In the north of France, a century of industrial metallurgic activities produced significant heavy metal soil pollution. In the north of France zinc smelter waste created a gradient of zinc concentration from 171 to 19 000 ppm in 35 m. The aim of this study was to evaluate the effects of soil pollution on the composition, density and diversity of macrofauna communities. The results showed that heavy metals reduce the overall density of earthworms and other macrofauna populations. The composition of the macrofauna community changed with the degree of pollution. There was no simple relationship between soil zinc content and species richness. In polluted areas, the number of species could be lower, equal or higher than in unpolluted zones. Increase of species richness in some polluted zones was due to the settlement of tolerant arthropod taxa. Coleoptera and some Arachnida were possibly favoured by the litter accumulation resulting from the reduced population densities of earthworms and other decomposers. 相似文献
9.
Stuart S. Bamforth 《Pedobiologia》2010,53(6):361-367
Decomposition occurs in the surface litter and soil to support temperate rainforests, but little is known about the protozoa that stimulate bacterial activity and turnover. I examined surface litter and top soils, fallen logs, and epiphytes within 2 m from the soil surface in Olympic National Park, USA, of the Pacific Northwest Temperate Coniferous Rain Forest. Ciliates in surface litter numbered 180-580 g−1 dry weight, but were reduced by 20-60% in the underlying soils. Testate amoebae numbered 18,000-77,000 g−1 dry weight in both litter and soil although they were often more abundant in underlying soils. Rotting logs, essential for tree regeneration, supported similar numbers of ciliates, but twice the numbers of testate amoebae. In three epiphytic soils, ciliates numbered 350-550, and testate amoebae 35,000-195,000 g−1 dry weight of soil. In these soils, 26 species of gymnamoebae, 64 species of ciliates, and 113 species of testate amoebae were found. About 65% of the individuals in ciliate and 45% in testate amoebae populations were small, r-selected taxa. Rain forest soil protozoa have distinct testate amoebae populations, and are characterized by enormous biodiversity, the dominance of acrostome species, the proliferation of Euglypha and Nebela species, and the appearance of aquatic taxa. Ecological succession of ciliates and testate amoebae follows an additive (non-replacement) pattern according to a neutral model. The large numbers of persistent r-selected species respond to ecosystem disturbances by mobilizing quickly to resume the bacterivory necessary to help restore the recovering above-ground plant community. 相似文献
10.
Danny R. Jackson William J. Selvidge Beverly S. Ausmus 《Water, air, and soil pollution》1978,10(1):13-18
Effects of heavy metals on forest nutrient cycling processes were investigated using intact forest microcosms. Baghouse dust from a primary Pb smelter in southeastern Missouri was applied on the microcosms to approximate one annual deposition of metals at 0.4 km from the smelter. Contaminated litter from a forest adjacent to the smelter was also placed on the microcosms. Total dosage of Pb, Cd, Zn, and Cu was 11.0, 0.128, 0.748, and 0.161 mg cm?2, respectively. Sustained increases in leaching rates of Ca and NO3-N were found in microcosms amended with heavy metals. After 20 mo, extractable Ca, NH3-N, NO3-N and dissolved organic carbon (DOC) were significantly lower in treated soil to a depth of 5 cm. In addition, extractable NH3-N, NO3-N and DOC were significantly lowered to a depth of 10 cm. Results from this experiment indicate that forest microcosms can be used for determining the effect of heavy metals on forest ecosystems. 相似文献
11.
温室不同管理模式对土壤微生物生物量碳和原生动物丰度的影响 总被引：2，自引：0，他引：2
为了解温室环境下不同的农业管理模式对土壤微生物生物量碳和原生动物的影响,以中国农业大学曲周日光温室长期定位试验为研究对象,于2012年8—12月进行了5次取样,测定了有机、无公害和常规管理模式下的土壤真菌、细菌生物量碳和原生动物丰度。结果表明:温室环境土壤以细菌分解途径占优势;原生动物中鞭毛虫占绝对优势。管理模式对土壤真菌生物量碳、细菌生物量碳、微生物生物量总碳、原生动物各类群(鞭毛虫、纤毛虫和肉足虫)丰度及总数均有显著影响,但对真菌/细菌比率、鞭毛虫和肉足虫的相对丰度没有显著影响。细菌、真菌和微生物生物量碳在不同管理模式间总体呈现相同的规律,即有机模式无公害模式常规模式;对于原生动物,不同类群呈现出复杂的动态变化规律,总体上有机模式下原生动物数量高于无公害和常规模式的。管理模式对微生物生物量碳和原生动物的影响主要体现在生物量上,而对功能群结构的影响较小。 相似文献
12.
长期重金属胁迫下的土壤微生物特征: 沈阳张士污灌区的案例研究 总被引：2，自引：0，他引：2
Soil samples were collected from Zhangshi Wastewater Irrigation Area in the suburb of Shenyang City, China, an area with a 30-year irrigation history with heavy metal-containing wastewater. The chemical properties and microbial characteristics of the soils were examined to evaluate the present situation of heavy metal pollution and to assess the soil microbial characteristics under long-term heavy metal stress. In light of the National Environmental Quality Standards of China, the soil in the test area was heavily polluted by Cd and to a lesser degree by Zn and Cu, even though wastewater irrigation ceased in 1993. Soil metabolic quotient （qCO2） had a significant positive correlation, while soil microbial quotient （qM） had a negative correlation with content of soil heavy metals. Soil microbial biomass carbon （MBC） had significantly negative correlation with Cd, but soil substrate~induced respiration （SIR）, dehydrogenase activity （DHA）, cellulase activity, and culturable microbial populations had no persistent correlations with soil heavy metal content. Soil nutrients, except for phosphorous, showed positive effects on soil microbial characteristics, which to a certain degree obscured the adverse effects of soil heavy metals. Soil Cd contributed more to the soil microbial characteristics, but qM and qCO2 were more sensitive and showed persistent responses to heavy metals stress. It could be concluded that qM and qCO2 can be used as bioindicators of heavy metal pollution in soils. 相似文献
13.
Sebastian Loeppmann Mikhail Semenov Evgenia Blagodatskaya Yakov Kuzyakov 《植物养料与土壤学杂志》2016,179(1):39-47
The rhizosphere reflects a sphere of high substrate input by means of rhizodeposits. Active microorganisms and extracellular enzymes are known to be responsible for substrate utilization in soil, especially in rooted soil. We tested for microbial‐ and enzyme activities in arable soil, in order to investigate the effects of continuous input of easily available organics (e.g., root‐exudates) to the microbial community. In a field experiment with maize, rooted and root‐free soil were analyzed and rhizosphere processes were linked to microbial activity indicators such as specific microbial growth rates and kinetics of six hydrolytic extracellular enzymes: β‐glucosidase, β‐cellobiohydrolase, β‐xylosidase, acid phosphatase, leucine‐ and tyrosine‐aminopeptidase. Higher potential activities of leucine‐aminopeptidase (2‐fold) for rooted vs. root‐free soil suggested increased costs of enzyme production, which retarded the specific microbial growth rates. Total microbial biomass determined by the substrate‐induced respiration technique and dsDNA extraction method was 23% and 42% higher in the rooted surface‐layer (0–10 cm) compared to the root‐free soil, respectively. For the rooted soil, potential enzyme activities of β‐glucosidase were reduced by 23% and acid phosphatase by 25%, and increased by 300% for β‐cellobiohydrolase at 10–20 cm depth compared to the surface‐layer. The actively growing microbial biomass increased by the 17‐fold in rooted soil in the 10–20 cm layer compared to the upper 10 cm. Despite the specific microbial growth rates showing no changes in the presence of roots, these rates decreased by 42% at 10–20 cm depth compared to the surface‐layer. This suggests the dominance in abundances of highly active but slower growing microbes with depth, reflecting also their slower turnover. Shifts in microbial growth strategy, upregulation of enzyme production and increased microbial respiration indicate strong root effects in maize planted soil. 相似文献
14.
H.-S. Helmisaari J. Derome H. Fritze T. Nieminen K. Palmgren M. Salemaa I. Vanha-Majamaa 《Water, air, and soil pollution》1995,85(3):1727-1732
Distribution and fluxes of copper within Pinus sylvestris stands were studied during 1992–1994 along a heavy-metal pollution gradient in south-western Finland. The stands are situated at distances of 0.5, 4 and 8 km from a copper-nickel smelter that started operating in 1945 at Harjavalta. According to the results, copper concentrations in the soil, in the understorey vegetation and in the trees increased steeply towards the smelter. Almost 50 years' accumulation of heavy metals in the soil has caused direct toxic effects to soil microbes, thus decreasing decomposition and nutrient mineralisation. During the past few years, sulphur and heavy metal emissions from the copper and nickel smelter have been radically decreased. However, the heavy metals which have been accumulating in the soil for decades continue to affect the vegetation for a long time through soil processes. Consequently, long-term accumulation in the soil has to be taken into account when determining the critical loads of forest ecosystems for heavy metals. 相似文献
15.
Heterotrophic protists (e.g. testate amoebae) play an important part in primary succession because these unicellular organisms occur immediately at newly exposed land surfaces in high abundances and biomasses, facilitating the establishment of plants and animals. We investigated testate amoebae from soils of different age and successional stage, which revealed remarkably high abundances and biomasses even at very dry sites. Emphasis was set on two inland dune microchronosequences of different plant successional stages (bare sand, Corynephorus canescens and Polytrichum piliferum as early stages; Festuca ovina and Pinus sylvestris as late stages). The number of testate amoebae species increased clearly with the successional stage of the vegetation cover, but no consistent replacement or extinction of taxa was observed. The newcomers obviously did not reduce the density of the residents, although the community pattern (abundances, biomasses, dominances) was significantly altered. Organism-free substrate of different quality exposed to the air or adjacent soil was colonised quickly and in high abundance by testate amoebae, but no temporal replacement of species occurred. Cluster analysis of species inventory and abundances of numerous types of soil of different age highlight a classification of amoebal communities towards regional influences rather than local successional stages of vegetation. These data corroborate the fact that belowground communities operate differently from plant communitites in that they are characterised by additive invasion and not by interspecific competition. This is typical for a neutral community model. 相似文献
16.
Humus forms and metal pollution in soil 总被引：1，自引：0，他引：1
Smelters in northern France are a serious source of soil pollution by heavy metals. We have studied a poplar plantation downwind of an active zinc smelter. Three humus profiles were sampled at increasing distance from the smelter, and the thickness of topsoil horizons was measured along a transect. We analysed the vertical distribution of humus components and plant debris to assess the impact of heavy metal pollution on the humus forms and on soil faunal activity. We compared horizons within a profile, humus profiles between them, and traced the recent history of the site. Near the smelter, poplar trees are stunted or dead and the humus form is a mor, with a well‐developed holorganic OM horizon. Here faunal activity is inhibited, so there is little faecal deposition and humification of plant litter. At the distant site poplar grows well and faunal activity is intense, so there are skeletonized leaves and many organo–mineral earthworm and millipede faecal pellets. The humus form is a mull, with a well‐developed hemorganic A horizon. The passage from mor to mull along the transect was abrupt, mor turning to mull at 250 m from the smelter, though there was a progressive decrease in heavy metal deposition. This indicates that there was a threshold (estimated to be 20 000 mg Zn kg?1) in the resilience of the soil foodweb. 相似文献
17.
Large accumulation of heavy metals in organic layers of forest soils may adversely affect the structure and diversity of microbial communities. The objective of this study was to assess the influence of different soil chemical properties on structure and diversity of microbial communities in soils polluted with different levels of heavy metals. The soil samples were taken at ten sites located in the vicinity of the cities of Legnica and Olkusz, differently polluted with Cu, Zn and Pb. The samples were measured for pH and the contents of organic C (Corg), total N (Nt), total S (St) and total Zn, Cu and Pb. The measured gross microbial properties included microbial biomass (Cmic) and soil respiration (RESP). The structure of soil microbial communities was assessed using phospholipid fatty acid (PLFA) analysis and the structure of soil bacterial communities using pyrosequencing of 16S rRNA genes. To assess diversity of the bacterial communities the Chao1 index was calculated based on the pyrosequencing data. For Cmic and RESP the most important factors were Nt and Corg, respectively. The structure and diversity of soil microbial communities revealed by PLFA profiles and pyrosequencing depended mainly on soil pH. The effect of high heavy metal contents on soil microbial properties was weaker compared with other soil properties. High concentrations of heavy metals negatively affected RESP and the Chao1 diversity index. The heavy metal pollution altered the structure of microbial communities measured with PLFA analysis, but the effect of heavy metal pollution was not observed for the structure of soil bacteria measured by pyrosequencing. The obtained results indicate that the use of soil microbial properties to study heavy metal effects may be difficult due to confounding influences of other environmental factors. In large-scale studies local variability of soil properties may obscure the effect of heavy metals. 相似文献
18.
Identifying the patterns of soil microbial responses to increasing nitrogen (N) availability are important since microbial processes are related to the potential nutrient transformations. The effects of the addition of N to the soil microbial community of the Gurbantunggut Desert, China, are described in this paper. The study was conducted over a two-year period with trials commencing at the beginning of each growing season. Soil enzyme activity, microbial biomass and microbial community level physiological profile (CLPP) were determined at 0–5 cm and 5–10 cm soil depths. Nitrogen was added to the soil at five rates plus a control, i.e. 0, 0.5, 1, 3, 6 and 24 g N m−2 y−1. We hypothesized that soil enzyme activities and microbial biomass N (MBN) would firstly increase and then decrease, and CLPP would be altered with increasing N addition, due to the deleterious effects of higher N addition upon microbial activity. Because of the relatively higher organic matter in the upper depth of soil layers, we further hypothesized that the responses of microbial activities in the 0–5 cm depth would be more marked than at 5–10 cm. In partial support of our hypothesis, soil enzyme activities, microbial biomass and nutrient concentrations responded to N addition with the most significant changes occurring in the 0–5 cm soil depth. Addition of N resulted in an increase in MBN and a decrease in urease activity. Invertase and alkaline phosphatase (AlP) activities increased at low doses of N addition and showed a decrease at higher doses. There was no evidence of change in oxidative enzyme activity at low N treatments but activity decreased at high N additions. However, the CLPP was not affected by N addition. The results of this study suggest that N supplementation in this desert soil may affect C transformation, increase availability of N and P, and immobilize N in the microbial biomass. Responses of the enzyme activity to N supplementation occurred within the context of an apparently stable or unresponsive microbial community structure. 相似文献
19.
Siti Khodijah Chaerun Nurmi P. D. Pangesti Koki Toyota William B. Whitman 《Water, air, and soil pollution》2011,217(1-4):491-502
Characteristics, such as microbial biomass, basal respiration, and functional diversity of the microbial communities, were investigated in paddy soils located in Bandung, West Java Province, Indonesia, that have been heavily polluted by industrial effluents for 31 years. Paddy soil samples (10?C20 cm) were taken from two sites: polluted soils and unpolluted soils (as control sites). The polluted soils contained higher salinity, higher sodicity, higher nutrient contents, and elevated levels of heavy metals (Cr, Mn, Ni, Cu, and Zn) than unpolluted soils. Soil physicochemical properties, such as maximum water holding capacity, exchangeable sodium percentage, sodium adsorption ratio, and swelling factor, in polluted soils were much greater than those in unpolluted soils (P?<?0.05). Changes in the physical and chemical soil properties were reflected by changes in the microbial communities and their activities. BIOLOG analysis indicated that the functional diversity of the microbial community of polluted soils increased and differed from that of unpolluted soils. Likewise, the average rate of color development (average well color development), microbial biomass (measured as DNA concentration), and the soil CO2 respiration were higher in polluted soils. These results indicate that major changes in the chemical and physical properties of paddy soils following the application of industrial wastewater effluents have had lasting impacts on the microbial communities of these soils. Thus, the increased activity, biomass, and functional diversity of the microbial communities in polluted soils with elevated salinity, sodicity, and heavy metal contents may be a key factor in enhancing the bioremediation process of these heavily polluted paddy soils. 相似文献
20.
铁路交通对铁路旁土壤重金属污染的影响——以陇海铁路郑州—圃田段为例 总被引：4，自引：0，他引：4
以陇海铁路郑州-圃田段为例,在野外调查、采样和实验室分析的基础上,探讨了铁路交通对周围土壤N i、Pb、Cr、Zn、Cu和Cd六种重金属含量与分布的影响。结果表明,铁路南侧农田土壤六种重金属元素都出现不同程度的富集,最大含量均分布在距铁路路基30m的范围内,随着距离的增加,各重金属元素含量表现出不同的下降趋势。土壤各重金属污染程度的次序为:Zn>Pb>Cd>Cu>Cr>N i。土壤Pb和Zn污染最为严重,近路基处为重度污染,随着距路基距离的增加,由中度污染逐渐变为轻度污染。土壤N i和Cr虽不构成污染,但仍具有明显的铁路影响特征。在距路基10 m范围内为土壤重金属重度污染带,10~100 m范围内为中度污染带,100~500 m范围内为轻度污染带。 相似文献