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1.
Surindra Suthar 《The Environmentalist》2009,29(1):78-84
Epigeic earthworms (Oligochaeta) have been appeared as key organisms to convert organic waste resources into value-added products,
i.e., vermicompost and worm biomass. The assessment of reproduction potential of composting earthworm may be beneficial for
large-scale earthworm production. Although, the waste minimizing potential of Perionyx excavatus and Perionyx sansibaricus is well proved, but little information is available about their fecundity rate. In this study, the efforts have been made
to explore the growth and reproduction biology of P. excavatus and P. sansibaricus, using cattle waste solid as culture substrate, under laboratory conditions. Earthworms were weighed weekly and number of
cocoons produced per week assessed. Biomass productions, fecundity, maturation, natality all were significantly different
between P. excavatus and P. sansibaricus. The highest mean individual biomass was 767.7 ± 18.4 mg and 612.6 ± 20.6 mg, respectively in P. sansibaricus and P. excavatus. However, the highest cocoon numbers occurred in P. excavatus (492.3 ± 13.6), significantly higher than P. sansibaricus (269.6 ± 17.1). Fecundity was slightly different in both species: 1.38 ± 0.77 cocoons adult worm−1 week−1 (P. excavatus) and 1.58 ± 0.74 cocoons adult worm−1 week−1 (P. sansibaricus). The hatchling success rate (%) was highest in P. excavatus. Overall natality (juveniles adult−1 week−1) was highest in P. sansibaricus (1.52) than P. excavatus (1.26), which suggests that P. sansibaricus may be a better candidate for rapid propagation of earthworms in cattle waste solid. 相似文献
2.
The vermicomposting ability of Lampito mauritii (Kinberg) and Perionyx ceylanensis Michaelsen was evaluated by using three different types of organic substrates such as leaf litter of Polyalthia longifolia, Pennisetum typhoides cobs (pearl millet) and a weed, Rottboellia exaltata (whole plant except the roots) in combination with cowdung (1:1). Vermicomposting studies (120 days) conducted to optimize
the number of worms required for efficient conversion based on the reduction of C/N ratio, percentage decomposition of organic
substrates, total number and biomass of earthworms recovered from the vermibed substrates clearly showed that vermibeds with
4 kg of organic materials can hold about 60–80 L. mauritii and about 90–120 P. ceylanensis for efficient decomposition. The percentage decomposition of each organic substrate treated with different numbers of L. mauritii (20, 40, 60, 80 and 100 earthworms) and P. ceylanensis (30, 60, 90, 120 and 150) showed significant difference (P < 0.001) between numbers of worms introduced per vermibed but the difference between substrates was not significant within the treatments.
Vermicomposting resulted in significant increase in electrical conductivity (28.54–49.82%), total nitrogen (43.96–90.83%),
total phosphorus (27.42–68.10%) and total potassium (27.42–113.18%), whereas decrease in organic carbon (35.05–49.74%), C/N
ratio (55.48–73.18%) and C/P ratio (50.46–66.90%) in different vermibeds introduced with L. mauritii and P. ceylanensis. Both the earthworm species can be used for vermicomposting different organic substrates; however, duration of vermicomposting
with P. ceylanensis is not as much of L. mauritii. The use of L. mauritii for vermicomposting of other substrates has been well established by other workers also but standardization of P. ceylanensis, a locally available species, for vermicomposting of different organic substrates is a new finding and the species could be
useful for vermiconversion of organic substrates under local conditions. 相似文献
3.
The biological removal of phosphates was carried as a part of treatment strategy. Vetiveria zizanioides (L.) Nash belonging to the family Poaceae was used for biological removal of biostimulants. Vetiver reportedly has mycorrhizal
association; besides having potential for removal of PO4
−3 also showed allelopathic affect on the microorganisms present in the water. In fact after a period of 96 h old roots of this
plant have been found to have killing effects on the E. coli, Enterobacter spp. Pseudomonas spp. belonging to the family Enterobacteriaceae. The paper is opening a new face of study. 相似文献
4.
Kirk W. Davies Jonathan D. Bates Dustin D. Johnson Aleta M. Nafus 《Environmental management》2009,44(1):84-92
Mowing is commonly implemented to Artemisia tridentata ssp. wyomingensis (Beetle & A. Young) S.L. Welsh (Wyoming big sagebrush) plant communities to improve wildlife habitat, increase forage production
for livestock, and create fuel breaks for fire suppression. However, information detailing the influence of mowing on winter
habitat for wildlife is lacking. This information is crucial because many wildlife species depended on A. tridentata spp. wyomingensis plant communities for winter habitat and consume significant quantities of Artemisia during this time. Furthermore, information is generally limited describing the recovery of A. tridentata spp. wyomingensis to mowing and the impacts of mowing on stand structure. Stand characteristics and Artemisia leaf tissue crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) concentrations were measured
in midwinter on 0-, 2-, 4-, and 6-year-old fall-applied mechanical (mowed at 20 cm height) treatments and compared to adjacent
untreated (control) areas. Mowing compared to the control decreased Artemisia cover, density, canopy volume, canopy elliptical area, and height (P < 0.05), but all characteristics were recovering (P < 0.05). Mowing A. tridentata spp. wyomingensis plant communities slightly increases the nutritional quality of Artemisia leaves (P < 0.05), but it simultaneously results in up to 20 years of decrease in Artemisia structural characteristics. Because of the large reduction in A. tridentata spp. wyomingensis for potentially 20 years following mowing, mowing should not be applied in Artemisia facultative and obligate wildlife winter habitat. Considering the decline in A. tridentata spp. wyomingensis-dominated landscapes, we caution against mowing these communities. 相似文献
5.
Eichhornia crassipes was tested for its ability to bioconcentrate 8 toxic metals (Ag, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) commonly found in wastewater
from industries. Young plants of equal size were grown hydroponically and amended with 0, 0.1, 0.3, 0.5, 1.0, 3.0, and 5.0
mM of each heavy metal individually for 21 days. The test plant had the lowest and the highest tolerance indices for Hg and
Zn, respectively. A significant (P ≤ .05) reduction in biomass production was observed in metal treated plants compared with the control. All strace elements
accumulated to higher concentrations in roots than in shoots. Trace element concentrations in tissues and the bioconcentration
factors (BCF) were proportional to the initial concentration of individual metal in the growth medium and the duration of
exposure. From a phytoremediation perspective, E. crassipes is a promising plant species for remediation of natural water bodies and/or wastewater polluted with low levels of Zn, Cr,
Cu, Cd, Pb, Ag and Ni. 相似文献
6.
Nsikak U. Benson Joseph P. Essien Godwin A. Ebong Akan B. Williams 《The Environmentalist》2008,28(3):275-282
The levels of total petroleum hydrocarbons in two commonly consumed benthopelagic shellfishes, Macura reptantia and Procambarus clarkii, harvested from benthic sediment of Qua Iboe Estuary were determined using a gas chromatography with flame-ionization detector.
Seventy-two (72) samples each of benthic sediment and the shellfishes were collected monthly between June 2003 and February
2004 covering the peak periods of the wet and dry seasons. Concentrations of hydrocarbons were highly variable and ranged
between 5.00 and 232.00 μg/g dry weight of benthic sediment, 3.05 and 11.30 μg/g dry weight of M. reptantia, 1.62 and 9.00 μg/g dry weight of P. clarkii. Pearson’s correlation analysis of total hydrocarbon concentrations in subtidal sediments with levels in the fauna species
yielded positive significant (P < 0.05) correlations in M. reptantia (r = 0.737) and P. clarkii (r = 0.924). This is indicative of a long term and chronic accumulation of hydrocarbons in the estuarine ecosystem, reflecting
the potential for exposure of the resident biota and the risk to human health. 相似文献
7.
Clementina O. Adenipekun Olusola J. Oyetunji Luqman S. Kassim 《The Environmentalist》2008,28(4):446-450
The effect of spent engine oil on the height, leaf number, leaf area, stem girth, chlorophyll, and moisture contents of Corchorus olitorius grown on 0, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, and 3.0% (v/w oil/soil) oil-contaminated soil was investigated. The engine
oil at all concentrations delayed the germination of C. olitorius by 2 days (compared to control) and there was a general significant reduction in all the growth parameters in plants grown
on contaminated soil compared to control plants. The highest leaf area of 26.8 cm2 was found in the control plant and least was found in the 0.6% soil (0.11 cm2) after 3 weeks while no values were recorded on the 0.8–3.0% engine-oil-contaminated soil after 5 weeks of experiment. The
highest chlorophyll content was also found in the control plant (11.5 mg/l). This showed that spent engine oil has an adverse
effect on the growth of C. olitorius plant. 相似文献
8.
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
9.
Crab samples, both male and female specie, were purchased from fishermen at the Ojo Rivers, Lagos, Nigeria. The samples separated
into abdomen, muscle tissue, and thorax were oven dried at 80°C for 3 days. The dried samples were then pulverized in a clean
acid-washed mortar and pestle. Approximately 1.00 g each of the pulverized samples was weighed and Zn, Cr, Pb, and Cd were
determined in the solution of the aqua regia digested samples by means of AAS (Buck Scientific 210 GVP model). The results
obtained showed Zn metal to be consistently higher in all the female parts compared to the male with values of 12.92 ± 3.65 μg/g
to 16.03 ± 1.08 μg/g and 9.33 ± 1.77 μg/g to 15.75 ± 1.02 μg/g, respectively. Mean values of 0.39 ± 0.09 μg/g and 0.22 ± 0.02 μg/g
cadmium were found in the abdomen and tissue of the male crab as against 0.35 ± 0.07 μg/g and 0.17 ± 0.07 μg/g in the female
crab. The tissues of both species have comparable value of chromium. Lead was below the detection limit of 0.05 μg/g in the
tissues of male crab but the female tissue contained 0.83 ± 0.13 μg/g and in other parts identified, lead was consistently
higher than the 2.00 μg/g permissible level of WHO in foods. A simple pair t-test did not demonstrate any significant difference in the distribution of metals between the male and female crabs. The
coefficient of variation (CV) calculated for each metal with respect to the studied parts showed Pb to be widely distributed
(56.23–89.54%) while Cr did not vary widely (4.17–8.20%). 相似文献
10.
Responses of lagoon crab, Callinectes amnicola were explored as useful biological markers of heavy metal pollution. The toxicity level of the metals based on the 96-h LC50
values showed that copper with LC50 value of 0.018 mM was found to be two times more toxic than Lead (0.041 mM) against the
lagoon crab, C. amnicola. The exposure of the lagoon crab to sublethal concentrations (1/100th and 1/10th of 96-h LC50 values) of Cu and Pb compound,
respectively, resulted in the bioaccumulation of the test metals to varying degrees in the selected organs that were dependent
on the type of metal and concentration of metal compound in the test media. The degree of metal (Cu and Pb) accumulation was
generally in the following order: gills > muscle > heptopancrease. Exposure of the crabs to sublethal concentrations of the
metals also caused pathological changes such as the disruption of the gill filaments and degeneration of glandular cells with
multifocal areas of calcification in the hepatopancreas. A reduction in the weight of the exposed animals over a 14-day period
of observation was also recorded. The significance of these results and the usefulness of the biological endpoints in monitoring
programmes aimed at establishing the total environmental level of heavy metals in aquatic ecosystems were discussed. 相似文献
11.
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
12.
Physico-chemical characteristics of the feed and optimum worm density are important parameters for the efficient working of
a vermicomposting system. Overcrowding of worms can affect the efficiency of a vermicomposting system even if all other parameters
have been optimized. This article reports the effect of stocking density and feed quality on the growth and fecundity of Eisenia fetida under laboratory conditions. The feed mixtures contained cow dung and textile mill wastewater sludge in different ratios.
Three feed mixtures and five stocking rates (1, 2, 4, 8, and 12) were tested for 12 weeks. The results showed that E. fetida growth rate was faster at higher stocking densities; however, biomass gain per worm was faster at lower stocking densities.
Sexual maturity was attained earlier at higher stocking densities. Growth rate was highest in 100% cow dung at all the stocking
densities when compared to textile mill wastewater sludge containing feed mixtures. A worm population of 27–53 worms per kg
of feed was found to be the most favorable stocking density. 相似文献
13.
Olanike O. Aladenola Ayodele E. Ajayi Ayorinde A. Olufayo Babatunde Ajayi 《The Environmentalist》2008,28(2):123-127
The performance of a mixture of a forest bye product and cement for the production of storage structure for harvested rainwater
was assessed. Three mix ratios of Cement: Gmelina arborea sawdust 3.0:1.0 (specimen A), 2.5:1.0 (specimen B) and 2.0:1.0 (specimen C) were considered. Engineering properties and dimensional
stability of the different mix-ratios were monitored from prototypes cylindrical pots and test billet specimens. Possible
change in quality of stored rainwater, with time was monitored in all the three cases. Water quality parameters monitored
include pH, hardness, total suspended solids, alkalinity, acidity and total dissolved CO2. The tensile stress obtained were 110, 104, and 95 N/mm2, while the compressive strength were 5,000, 3,000, and 2,000 kN for specimens A, B and C respectively. Accelerated aging
test showed that sample A were more resistant to deformation, while specimen C were more susceptible to change in structure
over time. Similarly, the values of tensile and compressive strength after accelerated aging test increased in the order of
specimen A > B > C. Except in specimen C where significant differences in alkalinity and acidity were observed, there were
no significant differences in quality of the water stored in the pots after 2 months of storage. The results indicate the
suitability of the Gmelina arborea waste as an alternative in constructing water storage structures in rural communities. 相似文献
14.
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
15.
Heavy metals in the aquatic environment have, to date, come essentially from naturally occurring geochemical resources. However,
this has been enhanced by anthropogenic activities such as crude oil exploration and exploitation activities, resulting in
pollution in the Taylor Creek aquatic ecosystem. The catfish species Bagrus bayad and other environmental segments were collected from five selected sites along Taylor Creek, southern Nigeria, and total
metal concentration determined. The concentration levels of the metals in B. bayad were higher than the values reported in the literature for fresh fish and may lead to a higher risk of harmful effects. The
bivariate regression models relating metals in B. bayad and metals in the surface waters were significant (R
2 ≥ 0.9002). The log (bio-concentration factor; BCF) values of Cr and Zn in B. bayad were the highest, whereas the lowest was found for Ni. The ecological distribution of the log (BCF) values was, for all the
heavy metals, moderately stable over the creek. All log-transformed bio-magnification factors (BMF) in the creek were positive,
which indicates that the metal concentration was greater in B. bayad than in suspended particulate matter (SPM). The absolute log (BMF) values of heavy metals can, therefore, be ranked in order
of decreasing magnitude: Cr (3.26) > Zn (2.99) > Cd (2.93) > Fe (2.76) > Pb (2.66) > Mn (2.36) > Ni (2.24). This sequence
indicates that toxic metals such as Cd, Cr and Pb are undergoing significant bio-reduction from SPM to B. bayad. The degree of correlation between the metals was different in B. bayad, which suggests that the sources of the metals polluting Taylor Creek were diverse. 相似文献
16.
The theoretical concept, “asset specificity,” is applied to real data in the context of Danish nature conservation network
planning in order to produce illustrative examples of an economic measure of the network’s vulnerability to exogenous shocks
to the species composition. Three different measures of asset specificity are quantified from the shadow value of eliminating
a key species from the individual grid cells. This represents a novel approach and a different interpretation of the term,
as it is conventionally used as a qualitative indicator in the transaction cost economics literature. Apart from supplementing
existing cost measures with an indicator of risk associated with investments in protected areas, this study demonstrates how
the estimation and interpretation of various asset specificity measures for geographical areas may qualify policy makers’
choice of policy instrument in conservation planning. This differs from the more intuitive approach of basing policy instrument
choice solely on the rarity of the species in a given area. 相似文献
17.
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
18.
This paper communicates the effect of bioremediation on the performance of Okro plant (Abelmoshus esculentus) in a typical Niger Delta soil that has received 5% crude oil pollution level. Biodegrading bacteria such as Pseudomonas
fluorescen, Acinetobacteria iwofii, Bacillus
subtilus, Arthrobacter
globiformis that was isolated from previously polluted soils was introduced into the samples. The treatment combinations are as follows
(A) = control without crude oil; B = soil + crude oil, (C) = soil + crude oil + microbes, (D) = soil + crude oil + microbes,
(E) = soil + crude oil + microbes + fertilizer (F) soil + microbes and (G) = soil + fertilizer. The treatment (E) gave the
highest number of leaves, % crop emergence, plant biomass, microbial population and degradation of petroleum hydrocarbon compared
to any of the treatments that had received crude oil. This suggested that fertilizer application does not only stimulate microbial
growth but it provides the plant with more available nutrients required for plant growth. 相似文献
19.
S. O. Asagba G. E. Eriyamremu J. O. T. Emudainohwo I. Okoro 《The Environmentalist》2010,30(3):260-266
The activities of some oxidative enzymes (aldehyde oxidase, AO, EC 1.2.3.1; xanthine oxidase, XO, EC 1.17.3.2; sulphite oxidase,
SO, EC 1.8.3.1; and monoamine oxidase, MO, EC 1.4.3.4) were investigated in the liver, gill, kidney, brain and muscle of a
variety of African catfish (Clarias gariepinus) after 7 and 21 days of exposure to 0.1, 0.2 and 0.4 ppm cadmium (Cd) in ambient water. MO, SO and AO activities were significantly
(p < 0.05) decreased in a dose-dependent manner in the liver, kidney and gill in the 7-day Cd-exposed fish when compared to
control. Conversely, brain MO, AO and SO activities were significantly (p < 0.05) elevated in a dose-dependent manner in the same fishes relative to control. As in the 7-day Cd-exposed fish, the
activities of MO, AO and SO were significantly (p < 0.05) decreased in a dose-dependent manner in the gill, kidney and liver of catfish exposed for 21 days. Same is true for
XO in these organs after both duration of exposure, except in the liver where no significant change was observed relative
to control. The inhibition of these oxidative enzymes in the liver, gill and kidney of catfish may interfere with their biotransformation
function, and ultimately the survival of the fish may be compromised. 相似文献
20.
VIRGINIA GALLEGOS PÉRULA RAFAEL M. NAVARRO CERRILLO PILAR FERNÁNDEZ REBOLLOo GEMADEL VALLE MURILLO 《Environmental management》2003,31(1):0086-0099
The objective of this study was to examine postfire regeneration of tree, shrub, and dwarf shrub species, in relation to levels
of damage in four planted pine forests (Pinus pinea, Pinus pinaster) in Andalusia. A prefire vegetation map was used for detailing species composition, vertical structure, and density and another
for detailing the extent and intensity of fire damage. Between 3 and 7 years after the fires, an inventory was made of the
vegetation in each area, using the step-point method. The information thus obtained was used to determine the amount of cover
in the dwarf/shrub and tree layers, the frequency of species in each of the layers, floristic richness, and diversity (Shannon
index). The botanical composition of the dwarf and shrub layer was analyzed using TWINSPAN. Variables were poorly correlated
with level of fire damage, which suggests that the forests in this study followed the autosuccession model. Because of the
artificial origin or seminatural condition, regeneration of the dominant tree species is poor, and it seems unlikely that
forests will recover to their prefire state. Therefore action is recommended to restore these ecosystems. 相似文献