共查询到20条相似文献,搜索用时 46 毫秒
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Ibrahim Yakubu 《The Environmentalist》2008,28(4):376-378
In order to prevent ‘an impending neem failure’, from the incidence of the twin problems of the neem scale insect infestations
and neem dieback, six authenticated provenances (Allahabad, Karnataka, Jodphur, Madinipur, Mukkambu and Annur), from the natural
range of the species in India, were collected and appraised for survival in a degraded land in Kano, Nigeria. Established
in a completely randomised block design with four replications, the trial was conducted with a view to restrengthening and/or
replacing the already weakened Local Land Race of the species in the study area. There was a statistically significant difference
in the survival of the seven provenances. The established differences are between Allahabad 83% (6.40 SEM), Mukkambu 83% (6.40 SEM),
Annur 76% (4.90 SEM), Jodphur 63% (15.09 SEM) and Madinipur 56% (6.73 SEM), on the one hand, and Karnataka 17% (1.91SEM) and
the Local Land Race, with 13% (0.13 SEM), on the other hand. The research recommends Allahabad and Mukkambu 83% (6.40 SEM)
based on this outstanding performance. 相似文献
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膦基聚羧酸与其他水处理剂的协同效应研究 总被引:5,自引:1,他引:5
利用水处理剂复配体系之间的协同效应,可以提高现有水处理剂的使用效率。对次膦酸基聚丙烯酸(PCA)分别与HEDP和PAA复配后的阻垢及缓蚀性能试验结果表明,将60%的PcA与40%的HEDP、以及将80%的PCA与20%的HEDP分别复配后,在阻碳酸钙与阻硫酸钙垢作用方面均具有协同效应,将PCA与PAA复配后,在阻碳酸钙与硫酸钙垢作用方面不存在协同效应。任意质量分数的PCA与HEDP复配后均具有缓蚀协同效应,PCA与PAA复配后不存在缓蚀协同效应。 相似文献
5.
We have made an attempt to understand the significance of physiographic factors viz., altitude, aspect, slope and soil characteristics
in determining the structure, composition, growth behavior and distribution of Himalayan Silver Fir (Abies pindrow Spach.) through a comparative analysis of two temperate forests. The occurrence of highest density (370 and 225 ind/ha),
importance value index (213.10 and 190.60) and total basal cover (TBC; 95.72 and 51.15 m2/ha) values along with the availability of higher organic carbon (6.53 and 4.47%), nitrogen (N; 0.73 and 0.44%) and potassium
(K; 621 and 319 ppm) contents in the soils just beneath the hilltops (2,650–2,800 and 2,550–2,650 m asl), on steeper slopes
(45°–50° and 42°–45°) and North-East aspects have revealed better growth of A. pindrow on both the sites. Stem density positively correlated with TBC (0.771), Shannon–Wiener diversity index (H′; 0.879), OC (0.601),
N (0.758) and K (0.752), whereas TBC has shown significant positive relationship with H′ (0.894), K (0.793) and N (0.716).
Similarly, H′ has also shown significant positive correlation with slope (0.721), K (0.855) and N (0.791). Interestingly,
positive correlation of altitude with stem density (0.557) and of slope with TBC (0.608) was noticed in the distribution of
A. pindrow individuals. 相似文献
6.
Marcela Rojas Felipe Quintero Witold F. Krajewski 《Journal of the American Water Resources Association》2020,56(4):568-585
This paper explores the performance of the analysis‐and‐assimilation configuration of the National Water Model (NWM) v1.0 in Iowa. The NWM assimilates streamflow observations from the United States Geological Survey (USGS), which increases the performance but also limits the available data for model evaluation. In this study, Iowa Flood Center Bridge Sensors (IFCBS) data provided an independent nonassimilated dataset for evaluation analyses. The authors compared NWM outputs for the period between May 2016 and April 2017, with two datasets: USGS streamflow and velocity observations; Stage and streamflow data from IFCBS. The distribution of Spearman rank correlation (rs), Nash–Sutcliffe efficiency (E), and Kling–Gupta efficiency (KGE) provided quantification of model performance. We found the performance was linked with the spatial scale of the basins. Analysis at USGS gauges showed the strongest performance in large (>10,000 km2) basins (rs = 0.9, E = 0.9, KGE = 0.8), with some decrease at small (<1,000 km2) basins (rs = 0.6, E = ?0.25, KGE = ?0.2). Analysis with independent IFCBS observations was used to report performance at large basins (rs = 0.6, KGE = 0.1) and small basins (rs = 0.2, KGE = ?0.4). Data assimilation improves simulations at downstream basins. We found differences in the characterization of the model and observed data flow velocity distributions. The authors recommend checking the connection of USGS gauges and NHDPlus reaches for selected locations where performance is weak. 相似文献
7.
M. Tayyeb Javed W. Nimmo Asif Mahmood Naseem Irfan 《Journal of environmental management》2009,90(11):3429-3435
An experimental investigation was performed to study the effect of oxygenated liquid additives, H2O2, C2H5OH, C2H4(OH)2 and C3H5(OH)3 on NOx removal from flue gases by the selective non-catalytic reduction (SNCR) process using urea as a reducing agent. Experiments were performed with a 150 kW pilot scale reactor in which a simulated flue gas was generated by the combustion of methane operating with 6% excess oxygen in flue gases. The desired levels of initial NOx (500 ppm) were achieved by doping the fuel gas with ammonia. Experiments were performed throughout the temperature range of interest, i.e. from 800 to 1200 °C for the investigation of the effects of the process additives on the performance of aqueous urea DeNOx. With H2O2 addition a downward shift of 150 °C in the peak reduction temperature from 1130 to 980 °C was observed during the experimentation, however, the peak reduction efficiency was reduced from 81 to 63% when no additive was used. The gradual addition of C2H5OH up to a molar ratio of 2.0 further impairs the peak NOx reduction efficiency by reducing it to 50% but this is accompanied by a downward shift of 180 °C in the peak reduction temperature. Further exploration using C2H4(OH)2 suggested that a 50% reduction could be attained for all the temperatures higher than 940 °C. The use of C3H5(OH)3 as a secondary additive has a significant effect on the peak reduction efficiency that decreased to 40% the reductions were achievable at a much lower temperature of 800 °C showing a downward shift of 330 °C. 相似文献
8.
Comparative studies on plant species richness, endemism, floristic composition, and structure between protected and unprotected
forests are few in the Eastern Arc Mountains, one of the most biodiverse ecosystems in Africa. This study from one mountain
range, the East Usambaras, examines floristic and structural tree data from 41–0.5 ha plots in four types of Eastern Arc forest:
active agroforests, recently abandoned agroforests, mature secondary forest, and natural forest. Active agroforests had significantly
lower tree species richness, endemic species richness, and stand density compared to natural and mature secondary forest.
Recently abandoned agroforests contained a higher tree species richness, density, and tree height than active agroforests.
Active and abandoned agroforests were dominated by an invasive tree, Maesopsis eminii. This tree species makes up a large percentage of the stems in active agroforests (26%), recently abandoned agroforests (32%),
and in the canopy of mature secondary forests ∼ 30 years post logging (30%). Through time the increasing dominance of this
non-native tree in active agroforests is a concern when considering the role of agroforests in a landscape scale conservation
strategy. 相似文献
9.
Thu Nguyen Marcus Hilliard Gary T. Rochelle 《International Journal of Greenhouse Gas Control》2010,4(5):707-715
Amine volatility is a key screening criterion for amines to be used in CO2 capture. Excessive volatility may result in significant economic losses and environmental impact. It also dictates the capital cost of the water wash. This paper reports measured amine volatility in 7 m MEA (monoethanolamine), 8 m PZ (piperazine), 7 m MDEA (n-methyldiethanolamine)/2 m PZ (piperazine), 12 m EDA (ethylenediamine), and 5 m AMP (2-amino-2-methyl-1-propanol) at 40–60 °C with lean and rich loadings giving CO2 partial pressures of 0.5 and 5 kPa at 40 °C. The amine concentrations were chosen to maximize CO2 capture capacity at acceptable viscosity. At the lean loading condition (where volatility is of greatest interest), the amines are ranked in order of increasing volatility: 7 m MDEA/2 m PZ (6/2 ppm), 8 m PZ (8 ppm), 12 m EDA (9 ppm), 7 m MEA (31 ppm), and 5 m AMP (112 ppm). The apparent amine partial molar excess enthalpies in these systems were estimated to range from ~10 to 87 kJ/mol of amine. 相似文献
10.
Inter-seasonal studies on the trace metal load of surface water, sediment and Tympanotonus fuscatus var. radula of Iko River were conducted between 2003 and 2004. The impact of anthropogenic activities especially industrial effluent,
petroleum related wastes, gas flare and episodic oil spills on the ecosystem are remarkable. Trace metals analyzed included
cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), nickel (Ni), vanadium (V) and zinc (Zn). Sediment
particle size analysis revealed that they were characteristically psammitic and were predominantly of medium to fine grained
sand (>73%), less of silt (<15%) and clay (<10%). These results correlated with low levels of trace elements such as Pb (0.03 ± 0.02 mg kg−1), Cr (0.22 ± 0.12 mg kg−1), Cd (0.05 ± 0.03 mg kg−1), Cu (0.04 ± 0.02 mg kg−1) and Mn (0.23 ± 0.22 mg kg−1) in the sediment samples. This observation is consistent with the scarcity of clayey materials known to be good scavengers
for metallic and organic contaminants. Sediments indicated enhanced concentration of Fe, Ni and V, while other metal levels
were relatively low. The concentrations of all the metals except Pb in surface water were within the permissible levels, suggesting
that the petroleum contaminants had minimal effect on the state of pollution by trace metals in Iko River. Notably, the pollutant
concentrations in the sediments were markedly higher than the corresponding concentrations in surface water and T. fuscatus tissues, and decreased with distance from point sources of pollution. 相似文献
11.
Eduardo González María González-Sanchis Álvaro Cabezas Francisco A. Comín Etienne Muller 《Environmental management》2010,45(4):669-681
The structure of the floodplain forests of the Middle Ebro River (NE Spain) was examined at patch and landscape scales along
a three-step chronosequence defined according to the extent of flow regulation-induced hydrogeomorphic changes, with the ultimate
purpose of producing baseline information to guide through management and restoration plans. At patch scale, a total of 6,891
stems within 39 plots were registered for species, diameter and health status. The stem density, size class distribution,
canopy dieback and mortality were further compared by means of non-parametric tests. At landscape scale, the temporal evolution
of the area occupied by forest stands of different ages in the floodplain along the chronosequence was evaluated using four
sets of aerial photographs dated in 1927, 1957, 1981 and 2003. The within-patch structure of pioneer forests (<25–30 years old) was characterized by dense and healthy populations of pioneer species (Populus nigra, Salix alba and Tamarix spp.), but the area occupied by these forest types has progressively decreased (up to 37%) since the intensification of river
regulation (ca. 1957). In contrast, non-pioneer forests (>25–30 years old) were characterized by declining and sparse P. nigra–S. alba–Tamarix spp. stands, where late-seral species such as Ulmus minor and Fraxinus angustifolia were frequent, but only as small-size stems. At landscape scale, these type of senescent forests have doubled their surface
after river regulation was intensified. Populus alba only appeared in the oldest plots recorded (colonized before 1957), suggesting sexual regeneration failure during the last
five decades, but usually as healthy and dense stands. Based on these findings, measures principally aimed at recovering some
hydrogeomorphic dynamism are recommended to guarantee the self-sustainability of the floodplain forest ecosystem. 相似文献
12.
Fresh whole plants of Pistia stratiotes were exposed to varying doses of crude oil (0–100 ppm) for 28 days at normal temperature of 30 ± 2°C. Samples were taken
weekly during this period for determination of changes in leaf area, root length, number of leaves, and number of sprouts.
The cross-section of one terminal end of the major roots and cellular distribution of the meristematic region were also examined.
The results show that crude oil was toxic to the plant at all concentrations in all investigated parameters for as low as
10 ppm. Association was also observed between crude oil toxicity and certain metals inherent in the crude oil such as manganese
and lead. Cell shape disruptions, changes in mitotic indices, and the distortion of cellular anatomy and structure at the
apical region also characterized the presence of crude oil in the environment of P. stratiotes. P. stratiotes may not be a good bio-accumulator of crude oil but may be used for the detection of pollution. 相似文献
13.
Erna Dadasyan Gayane Ayrapetyan Naira Baghdasaryan Yerazik Mikayelyan Sinerik Ayrapetyan 《The Environmentalist》2012,32(2):166-174
It was shown that the 4 Hz 30 dB mechanical vibration (MV) of physiological solution (PS) had modulation effect on snail heart
contractility. However, the nature of metabolic pathway of MV-treated PS-induced effect is not clear yet. It was suggested
that the MV-induced modulation of water molecules dissociation leads to the variation of reactive oxygen species’ level in
cell bathing medium, which could serve as a messenger for switching on the metabolic pathway(s) responsible for modulation
of muscle contractility. The aim of present work was to check this hypothesis and to elucidate the metabolic pathway through
which the effect of MV-treated PS on heart contractility was realized. For this purpose, the effect of MV on heat fusion periods
(HFP) and H2O2 content in PS, as well as on heart contractility, 45Ca2+ efflux, intracellular levels of cGMP and cAMP, muscle hydration, and ouabain binding were studied. It was shown that MV treatment
of PS increased the HFP-(21.33 ± 4%) and decreased the H2O2 content-(5 ± 0.9%). The intracardiac perfusion by MV-treated PS increased the amplitudes of heart contractility, which was
accompanied by the increasing of 45Ca2+ efflux (252.4 ± 16%), elevation of cGMP’s level (42.05 ± 7%), decreasing of cAMP’s level (82.67 ± 7%), increasing of the
tissue hydration (18.64 ± 3%), and increasing of the number of ouabain binding sides (25 ± 4%). It was suggested that MV-induced
increasing of heart muscle contraction amplitudes is due to the decreases of H2O2 content in the medium, which leads to the elevation of heart muscle contractility in result of activation of cGMP-dependent
Na+/Ca2+ exchange in forward regime. 相似文献
14.
The present study investigated the photocatalytic activity of an S-doped TiO2 photocatalyst with regards to dimethyl sulfide degradation under visible-light irradiation, along with its deactivation and reactivation. The dimethyl sulfide conversion was between 85% and 93% for the lowest relative humidity range (10–20%) and close to 100% for the two higher relative humidity ranges (45–55% and 80–90%). The conversion was also close to 100% for the two lowest input concentrations (0.039 and 0.195 ppm), while it was between 91% and 96% at 3.9 ppm and between 85% and 90% at 7.9 ppm. In contrast to the input concentration dependences on conversion, the calculated degradation rates increased as input concentrations increased. The dimethyl sulfide conversion at low concentrations (≤0.39 ppm), which are associated with non-occupational inn occurring. However, catalyst deactivations were observed during the photocatalytic process whdoor air quality issues, was up to nearly 100% for long time periods (at least 603 h), without any significant catalyst deactivatioen higher concentrations (3.9 and 7.8 ppm) were used. The photocatalyst, reactivated by using two types of air (dried and humidified) under visible-light irradiation, did not regain all of its initial activities. Sulfate groups were qualitatively identified as the reaction products on the photocatalyst surface. In addition, gaseous byproducts, quantitatively determined, included dimethyl disulfide, methanol, and SO2. It is noteworthy that the peak concentration of dimethyl disulfide (0.79 ppm = 790 ppb), generated over the photocatalytic process with the highest dimethyl sulfide input concentration, exceeded the odor threshold value of 0.1–3.6 ppb for dimethyl disulfide. 相似文献
15.
Thrassyvoulos Manios Michalis S. Fountoulakis Anastasios D. Karathanasis 《Environmental management》2009,43(5):908-920
Two free water surface (FWS) and two subsurface flow (SSF) pilot-size wetlands were constructed for the evaluation of their
performance in treating highway runoff (HRO) in the heart of the Mediterranean region, the island of Crete, at the southernmost
point of Greece. Detailed recordings of the resources involved during the construction allowed a thorough calculation of the
cost of the systems and the requirements in materials, man-hours, and equipment. The two identical FWS systems had a surface
area of 33 m2 each, while the two identical SSF covered 32 m2 each. One FWS and one SSF, named FWS12 and SSF12, respectively, were designed with a hydraulic retention time (HRT) of 12 h,
with each one capable of treating a maximum HRO of 12.6 m3/day. The other couple, named FWS24 and SSF24, respectively, was designed with an HRT of 24 h, with each receiving a maximum
HRO of 6.3 m3/days. An influent storage tank was required to hold the runoff during the common storm events and control the flow rate (and
the hydraulic retention time) into the wetlands. This construction represented 25% of the total construction cost, while 5%
was spent on the influent automated (and sun-powered) control and distribution system, from the storage tank to the wetlands.
The respective total cost allocated to the two SSF systems (€14,676) was approximately 10% higher than that of the FWS (€13,596),
mainly due to the three different-sized gravel layers used in the SSF substrate compared to the topsoil used in the FWS, which
tripled the cost and placement time. The Total Annual Economic Cost (TAEC) was €1799/year and €1847/year for the FWS and SSF
pair, respectively. TAEC was also used to compare the economic efficiency of the systems per cubic meter of HRO treated and
kilograms of COD and TSS removed from the wetlands during their first operational year. Based on these estimations, FWS12
recorded the lowest TAECCOD and TAECTSS values (€89.09/kg and €43.69/kg, respectively) compared to the other three systems, presenting a more economically favorable
option. 相似文献
16.
Jutamas Kaewsuk Worachat Thorasampan Monthon Thanuttamavong Gyu Tae Seo 《Journal of environmental management》2010,91(5):1161-1168
This experimental study was conducted to evaluate a membrane sequencing batch reactor (MSBR) with mixed culture photosynthetic bacteria for dairy wastewater treatment. The study was undertaken in two steps: laboratory and pilot scale experiments. In the first step, kinetics analysis of the MSBR was carried out in a laboratory scale experiment with influent COD concentration of 2500 mg/L. The pilot scale experiment was conducted to investigate the performance of the MSBR and checked the suitability of the kinetics for an engineering design. The kinetic coefficients Ks, k, kd, Y and μm were found to be 174-mg-COD/L, 7.42/d, 0.1383/d, 0.2281/d and 1.69/d, respectively. There were some deviations of COD removal efficiency between the design value and the actual value. From the kinetics estimation, COD effluent from the design was 27 mg/L while the average actual COD effluent from the experiment was 149 mg/L. Due to the different light source condition, the factors relating to light energy (i.e. Lf and IR%) must be incorporated into engineering design and performance prediction with these kinetic coefficients of the photosynthetic MSBR. 相似文献
17.
A study was carried out in Nawa tehsil of Nagaur district to assess the prevalence of dental fluorosis and its crippling effect
due to ingestion and prolonged exposure of fluoride over a long period of time. During the survey of the study area, high
concentration of fluoride (14.62 ppm) has been recorded. The presence of fluoride in quantities in excess of limits is a serious
matter of concern from a public health point of view. Due to higher fluoride level in groundwater, several cases of dental
fluorosis have appeared at alarming rate in the study area. The children’s teeth are damaged and are characterized by black
and brown stains as well as cracking and pitting of the teeth have been observed. In the study area, 93.12% population suffered
from dental fluorosis, and it was more prevalent in men (94.90%) than in women (90.00%). Dental fluorosis was also examined
according to different grades. Out of the total 72 afflicted, in the 4–16-year age group, 41.46% were suffering from Grade
I, Grade II was more prevalent in 33.85% of the 17–28-year age group and similarly Grade II was more prevalent in 39.13% of
the 29–40-year age group. In the age group of above 40 years, grade III and grade IV were more prevalent. Thus, in the higher
age group, the prevalence and severity of fluorosis is almost certainly due to longer exposure to fluoride. The major risk
factor consistently identified for dental fluorosis was the consumption of fluoridated drinks and fluoride supplements. Ingestion
of calcium, vitamin D and vitamin C is effective in protection from fluoride toxicity to certain extent. 相似文献
18.
Md. Abul Kalam Azad Md. Nozrul Islam Ashraful Alam Hasan Mahmud M. A. Islam M. Rezaul Karim Matiar Rahman 《The Environmentalist》2009,29(4):436-440
A pot-culture experiment was conducted in open-field conditions with highly cultivated locally transplanted (T) aman rice
(Oryza sativa L.) named BR-22 in arsenic (As)-amended soil (0, 1.0, 5.0, 10.0, 20.0, 30.0, 40.0 and 50.0 mg kg−1 As) of Bangladesh to see the effect of As on the growth, yield and metal uptake of rice. Arsenic was applied to soil in the
form of sodium arsenate (Na2HAsO4). Arsenic affected the plant height, tiller and panicle numbers, grain and straw yield of T-aman rice significantly (P ≤ 0.05). The grain As uptake of T-aman rice was found to increase with increase of As in soil and a high grain As uptake
was observed in the treatments of 30–50 mg kg−1 As-containing soil. These levels exceed the food hygiene concentration limit of 1.0 mg kg−1 As. However, the straw As uptake varied significantly (P ≤ 0.05) from a low concentration of As in soil (5 mg kg−1) and the highest uptake was noticed in 20 mg kg−1 As treatment. 相似文献
19.
Rita JC Gama-Rodrigues EF Gama-Rodrigues AC Polidoro JC Machado RC Baligar VC 《Environmental management》2011,48(1):134-141
Agroforestry systems (AFSs) have an important role in capturing above and below ground soil carbon and play a dominant role
in mitigation of atmospheric CO2. Attempts has been made here to identify soil organic matter fractions in the cacao-AFSs that have different susceptibility
to microbial decomposition and further represent the basis of understanding soil C dynamics. The objective of this study was
to characterize the organic matter density fractions and soil size fractions in soils of two types of cacao agroforestry systems
and to compare with an adjacent natural forest in Bahia, Brazil. The land-use systems studied were: (1) a 30-year-old stand
of natural forest with cacao (cacao cabruca), (2) a 30-year-old stand of cacao with Erythrina glauca as shade trees (cacao + erythrina), and (3) an adjacent natural forest without cacao. Soil samples were collected from 0-10 cm
depth layer in reddish-yellow Oxisols. Soil samples was separated by wet sieving into five fraction-size classes (>2000 μm,
1000–2000 μm, 250–1000 μm, 53–250 μm, and <53 μm). C and N accumulated in to the light (free- and intra-aggregate density
fractions) and heavy fractions of whole soil and soil size fraction were determined. Soil size fraction obtained in cacao
AFS soils consisted mainly (65 %) of mega-aggregates (>2000 μm) mixed with macroaggregates (32–34%), and microaggregates (1–1.3%).
Soil organic carbon (SOC) and total N content increased with increasing soil size fraction in all land-use systems. Organic
C-to-total N ratio was higher in the macroaggregate than in the microaggregate. In general, in natural forest and cacao cabruca
the contribution of C and N in the light and heavy fractions was similar. However, in cacao + erythrina the heavy fraction
was the most common and contributed 67% of C and 63% of N. Finding of this study shows that the majority of C and N in all
three systems studied are found in macroaggregates, particularly in the 250–1000 μm size aggregate class. The heavy fraction
was the most common organic matter fraction in these soils. Thus, in mature cacao AFS on highly weathered soils the main mechanisms
of C stabilization could be the physical protection within macroaggregate structures thereby minimizing the impact of conversion
of forest to cacao AFS. 相似文献
20.
Diversity of Soil Nematodes in Areas Polluted with Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAHs) in Lanzhou,China 总被引:1,自引:0,他引:1
This study investigated the soil nematode community structure along the Yellow River in the Lanzhou area of China, and analyzed
the impact of heavy metals (Cd, Pb, Cr, Cu, and Zn) and polycyclic aromatic hydrocarbons (PAHs) on the nematode community.
Soil samples from five locations (named A–E), which were chosen for soil analysis, showed significant differences in their
heavy metal content (p < 0.01), as well as in the variety of nematodes (up to 41 genera) and families (up to 20) that were present. The different
samples also differed significantly in the total PAH content (p < 0.05), as well as the six types of PAH present. Sites A–C showed the most severe contamination with heavy metals and PAHs;
these sites had the lowest abundance of fungivores and omnivore/predators, but the proportion of bacteriovores was the highest
(p < 0.05). Site E, in contrast, showed only minor pollution with heavy metals and PAHs, and it contained the highest abundance
of plant parasites (p < 0.05). Several nematode ecological indicators were found to correlate with concentration of soil pollutants at all the
sites tested: the maturity index (MI, in addition to plant parasites), plant parasite index (PPI), ΣMI (including all the
soil nematodes), Shannon-Wiener diversity index (H′′), and Wasilewska index (WI). Disturbance to the soil environment was more severe when MI, ΣMI, and H′ values were lower. The results of the study show that the abundance and structure of the soil nematode communities in the
sampling locations were strongly influenced by levels of heavy metals and PAHs in the soil. They also show that the diversity
index H′ and the maturity index can be valuable tools for assessing the impact of pollutants on nematodes. 相似文献