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1.
This study investigated the possibility of fingerprinting different organic wastes (cow, pig and horse manure) and the vermicomposts produced by different earthworm species (Eisenia andrei, Eudrilus eugeniae and Lumbricus rubellus) analyzing the profiles of fatty acid methyl esters (FAMEs). We found clear differences between their microbial communities, demonstrating the power and sensitivity of the total FAME analysis. In addition, qualitative and quantitative analyses of specific biomarkers permitted to determine differences between samples and to evaluate the effect of earthworms in the decomposition of organic matter. Fatty acid profiles were largely determined by the different vermicomposting earthworm species. Fatty acid 18:2ω6 increased significantly in horse manure vermicomposted by L. rubellus and in cow manure vermicomposted by the three earthworm species, whereas it decreased significantly in pig manure vermicomposted by L. rubellus and E. eugeniae. Fatty acid 20:4ω6 increased significantly in all vermicomposts obtained with the three earthworm species.  相似文献   

2.
Summary Decomposition of garden refuse was studied in containers with and without the earthworm species Eisenia andrei and Lumbricus rubellus. The reduction of cellulose and hemicellulose was greater where earthworms were present. Respiration was similar regardless of the presence of earthworms, whereas dry matter reduction, on average, was greatest without earthworms. The earthworm biomass decreased during the 58 days of the experiment; E. andrei increased in biomass, whereas L. rubellus died out.  相似文献   

3.
Biofumigation is considered a good alternative to chemical fumigation because it can control crop pathogens and diseases with lower health and environmental risks than chemical fumigants. Glucosinolates are volatile compounds found in most Brassica species, and when hydrolysed, it forms a range of natural toxins including isothiocyanates that act as biofumigants. However, the effect of glucosinolates and their breakdown products on non-target and beneficial soil organisms is not well documented. Three biofumigants, broccoli, mustard and oilseed radish, were evaluated for their effect on earthworms (Eisenia andrei) and the soil microbial community. Sub-lethal endpoints, including growth and reproductive success of the earthworms, were monitored. Genotoxicity of the biofumigants towards earthworms was evaluated by means of the comet assay. Broccoli reduced earthworm reproduction while mustard induced more DNA strand breaks in earthworm cells compared to the control. Soil microbial community function and structure were evaluated by means of community level physiological profiling and phospholipid fatty acid analyses. The effects exerted by the biofumigants on the microbial community were the most pronounced within the first 14 days after application. Carbon substrate utilisation was most affected by the oilseed radish treatment and microbial community structure by the mustard treatment.  相似文献   

4.
The interactive impact of earthworms (Eisenia fetida) and arbuscular mycorrhizal fungi (Rhizophagus intraradices, AM fungi) on the degradation of oxytetracycline (OTC) in soils was studied under greenhouse conditions. Treatments included maize plants inoculated vs. not inoculated with AM fungi and treated with or without earthworms at low (1 mg kg−1 soil DM) or high (100 mg kg−1 soil DM) OTC rates. The root colonization rate, the hyphal density of mycorrhizae, the residual OTC concentration in soils, catalase, dehydrogenase, urease, soil microbial biomass C, Shannon–Wiener index (H) for microbial communities from T-RFLP profiles were measured at harvest. The results indicated that earthworms and AM fungi would individually or interactively enhance OTC decomposition and significantly decreased the residual OTC concentration at both high and low OTC rates. Both earthworms and AM fungi could promote the degradation of OTC by increasing soil microbial biomass C at both high and low OTC rates. The effect of soil enzyme activity and soil microbial diversity on OTC decomposition was different between high and low OTC rates. Hyphomicrobium and Bacillus cereus were dominant bacteria, and Thielavia and Chaetomium were dominant phyla of fungi at all occasions. Earthworm activity stimulated the growth of Hyphomicrobium and Thielavia, while AM fungi may stimulate Bcereus, Thielavia and Chaetomium, resulting in greater OTC decomposition. The interaction between earthworms and AM fungi in affecting the degradation of OTC may be attributed to different mechanisms, depending on soil microbial biomass, function (enzyme activity) and communities (the abundance of Hyphomicrobium, B. cereus, Thielavia and Chaetomium) in the soil.  相似文献   

5.
Earthworms are animals with reciprocal insemination. Eisenia andrei Bouché, 1972 is a simultaneous hermaphroditic earthworm that lives in manure heaps at high densities, with low opportunities of dispersal, thus very close inbreeding is expected. As the negative effects of inbreeding and outbreeding may be severe, we studied whether E. andrei adjusts its breeding effort according to the degree of mate relatedness. To test this, we performed laboratory experiments in which earthworms were mated with their sibs and with non-sibs from the same population and no-sibs from a geographically isolated population. Inbreeding and outbreeding matings caused a strong reduction of cocoon production, especially in genetic lines with high reproductive rates. As far as we know, this is the first study that indicates reproductive adjustment in earthworms according to the genetic divergence of their partners. Optimal outbreeding should be considered a crucial point in the management of breeding populations for applied purposes.  相似文献   

6.
Artificially created soil-like technogenic formations (STFs) of soccer fields are developed under combined action of intense technogenic and natural factors and processes, which cannot but affect the structure and biological activity of their microbial communities and mesofauna. The microflora of the STFs is very similar to the microflora of the background soddy-podzolic soils of Moscow oblast with respect to the composition of the physiological groups of microorganisms. However, they are drastically different in their quantitative characteristics. The numbers of all the trophic groups of microorganisms, except for the microscopic fungi, in the STFs are much higher than those in the zonal soils. An increased biological activity of the STFs is due to regular watering, heating, application of sand and mineral fertilizers, and technogenic turbation processes. The mesofauna of the STFs is represented by several ecological groups of earthworms, including soildwelling (endogeic) earthworms (Aporrectodea caliginosa), epigeic earthworms dwelling at the soil-litter interface (Lumbricus rubellus), and litter-dwelling earthworms (Eisenia foetida).  相似文献   

7.
Earthworms can have a profound effect on a myriad of soil physical, chemical and microbial parameters. To better understand their role in the soil, they are often studied under controlled conditions. However, a persistent problem in such controlled experiments is the ability of earthworms to escape from experimental units with open tops (e.g. for plant growth). Here, we tested whether adhesive hook tape applied to the inside of mesocosms is effective in confining them to their experimental units. A mesocosm study was set up with hook tape treatments (control, one layer, two layers), mesocosm material (polyvinylchloride – PVC, polypropylene – PP) and earthworm species (Lumbricus rubellus (Hoffmeister), Aporrectodea caliginosa (Savigny), Lumbricus terrestris (L.) + Aporrectodea longa (Ude)) as different factors to study the escape of earthworms during 24 h. In the treatments without hook tape, individuals of L. rubellus and A. caliginosa escaped, with highest escape rates (80%) for L. rubellus from the PP mesocosms, and lowest escape rates (20%) for A. caliginosa from the PVC mesocosms. When hook tape was applied, in either one or two layers, no individuals of those species escaped. The two anecic earthworm species, L. terrestris and A. longa did not escape from any mesocosms, irrespective of the presence of hook tape. As not a single earthworm escaped from the hook tape treatments, we conclude that applying hook tape is a simple, inexpensive and effective method to keep earthworms confined to experimental units.  相似文献   

8.
Fusarium wilts are economically important diseases for which there are no effective chemical control measures. Biological control strategies are becoming efficient alternatives for controlling this disease. The suppressiveness to Fusarium oxysporum f. sp. lycopersici race 1 of grape marc compost and cork compost was evaluated in comparison to peat by using a susceptible cultivar of tomato (Lycopersicon esculentum cv. Marmande). Based on community level physiological profiles, different community structures were evident among the plant growth media evaluated. The peat microbial community, growth medium conducive to wilt, used mostly sugars, while those associated with both composts, the very suppressive grape marc and the moderately suppressive cork, used mostly carboxylic acids, amino acids, amines, phenolic compounds and polymers.  相似文献   

9.
10.
Earthworms have been shown to influence plant growth, survival and fecundity. They can therefore affect plant demography in plant communities changing their composition. A long term mesocosm experiment was set-up to test the effects of an endogeic (Aporrectodea caliginosa) and an anecic (Lumbricus terrestris) earthworm species on assemblages of four species of annuals: one grass (Poa annua), two forbs (Veronica persica and Cerastium glomeratum) and one legume (Trifolium dubium). The number of individuals and the biomass of each species were investigated. A. caliginosa and L. terrestris affected the density of T. dubium at each of the three monitored census dates. The other plant species responded to A. caliginosa and L. terrestris at the second and third generations. The presences of A. caliginosa and L. terrestris reduced the total number of plant individuals from the second to the third generation. At harvest (3rd generation), T. dubium and V. persica had more and larger individuals in the presence of A. caliginosa. When both earthworm species were present, T. dubium had few but larger individuals. Our study confirms that earthworms affect plant demography and plant community structure. Our results also show that accurate prediction of long-term effects of earthworms on plant communities cannot be achieved using results on their short-term effects on plant growth. This is due to the poor understanding of the effects of earthworms on plant resource allocation and demography, and also the possibility that earthworms may exert the opposite effect on the short and long-term availability of nutrients.  相似文献   

11.
In North America, many species of European earthworms have been introduced to northern forests. Facilitative or competitive interactions between these earthworm species may result in non-additive effects on native plant and animal species. We investigated the combined versus individual effects of the litter-dwelling earthworm Dendrobaena octaedra Savigny, 1826 and the deep-burrowing species Lumbricus terrestris L., 1758 on microarthropod assemblages from boreal forest soil by conducting a mesocosm experiment. Soil cores from earthworm-free areas of northern Alberta, Canada, were inoculated with D. octaedra alone, L. terrestris alone, both worm species together, or no earthworms. After 4.5 months, microarthropods were extracted from the soil, counted, and identified to higher taxa. Oribatid mites were further identified to family and genus. Abundance of microarthropods was significantly lower in the treatment containing both species than in the no earthworm treatment and the L. terrestris treatment. Oribatida and Prostigmata/Astigmata differed significantly among treatments and were lowest in the treatment containing both earthworm species, followed by the D. octaedra treatment, although post-hoc pairwise comparisons were not significant. Within the Oribatida, composition differed between the control and L. terrestris treatments as compared to the D. octaedra and both-species treatments, with Suctobelbella and Tectocepheus in particular having higher abundances in the control treatment. Effects of the two earthworm species on microarthropods were neither synergistic nor antagonistic. Our results indicate that earthworms can have strong effects on microarthropod assemblages in boreal forest soils. Future research should examine whether these changes have cascading effects on nutrient cycling, microbial communities, or plant growth.  相似文献   

12.
Earthworms,one of the most important macroinvertebrates in terrestrial ecosystems of temperate zones,exert important influences on soil functions.A laboratory microcosm study was conducted to evaluate the influence of the earthworm Eisenia fetida on wheat straw decomposition and nutrient cycling in an agricultural soil in a reclaimed salinity area of the North China Plain.Each microcosm was simulated by thoroughly mixing wheat straw into the soil and incubated for 120 d with earthworms added at 3 different densities as treatments:control with no earthworms,regular density(RD)with two earthworms,and increased density(ID)with six earthworms.The results showed that there was no depletion of carbon and nitrogen pools in the presence of the earthworms.Basal soil respiration rates and metabolic quotient increased with the increase in earthworm density during the initial and middle part of the incubation period.In contrast,concentrations of microbial biomass carbon and microbial biomass quotient decreased in the presence of earthworms.Earthworm activity stimulated the transfer of microbial biomass carbon to dissolved organic carbon and could lead to a smaller,but more metabolically active microbial biomass.Concentrations of inorganic nitrogen and NO3--N increased significantly with the increase in earthworm density at the end of the incubation(P<0.05),resulting in a large pool of inorganic nitrogen available for plant uptake.Cumulative net nitrogen mineralization rates were three times higher in the ID treatment than the RD treatment.  相似文献   

13.
《Soil biology & biochemistry》2001,33(7-8):1123-1130
The aim of this study was to investigate the effects of carbaryl, at different concentrations and exposure times, on the biochemical responses of the earthworm, Eisenia fetida andrei (E. andrei) to: (1) elucidate the mechanisms of action of carbamate compounds; and (2) explore the potential for using these responses as biomarkers to monitor carbamate-contaminated soils or for use in sublethal assays to test chemicals in the laboratory. Thus, earthworms were exposed to increasing concentrations of carbaryl (CA) (12, 25 and 50 mg kg−1 artificial soil) for different periods of time (2, 7 and 14 days) using the standard soil test method. The activities of the following enzymes were measured: catalase (CAT), acetylcholinesterase (AChE), glutathione reductase (GR), glutathione-S-transferase (GST), methoxyresorufin-O-deethylase (MROD) and NADH (NADH Red) and NADPH (NADPH Red) cytochrome reductases activities. Levels of lipid peroxides (LP), peroxidizable lipids (LPI), total glutathione (total GSH) and the percentage of oxidized glutathione (%GSSG) were also determined. Our results showed that cholinesterases are the main target of carbaryl in E. andrei. Carbaryl also inhibited biotransformation enzyme activities but did not induce oxidative stress. Changes were detected in phase I and acetylcholinesterase activities upon exposure to the lowest dose of carbaryl (12 mg kg−1). This demonstrated the sensitivity of these parameters in E. andrei. In addition, discrimination between doses and exposure times was clearer when all the responses were considered rather than a selective choice of biomarkers. This confirms our previous finding that a suite of biochemical responses could be used as a sublethal assay for testing chemicals in the laboratory or for soil contamination surveys.  相似文献   

14.
Many aspects of the reproduction and mating behaviour of earthworms remain poorly understood. In this study, we focused on body size as a possible trait that influences earthworm reproduction and mating processes. Eisenia andrei is a simultaneously hermaphroditic animal with reciprocal insemination and many hermaphrodites are expected to mate not primarily to get their own eggs fertilized, but rather to get the opportunity to fertilize the eggs of their partners. We investigated whether E. andrei has a size-dependent sex allocation, i.e. if larger earthworms are more biased toward female allocation and produce more egg mass and whether E. andrei has a size-related mate choice by studying the relationship between mating delay and cocoon production. To test this, we compared cocoon production between pairs of earthworms of equal and different size. Mature individuals of E. andrei were classified in two size classes (small and large) and we performed a two-factorial experiment with earthworm size and the size of the partner as factors. After copulation, earthworms were isolated and thereafter their mass and the number of cocoons they produced were recorded weekly for 18 weeks. We found no evidence of size-dependent sex allocation and we found no effect of size-assortative mating on cocoon production. With respect to the differences in the time to mate, the mating delay seems to indicate the existence of some kind of mate choice, independent of the earthworm size. Those earthworms that were matched sooner laid many cocoons, but those that waited a long time to mate laid fewer cocoons. This effect was stronger in those individuals paired with large partners, suggesting that some large partners are more desired ‘males’ than others; the reason for this remain as an open question. In general, our results confirm that earthworms are able to discriminate their partners and adjust their breeding effort accordingly.  相似文献   

15.
Soil adsorption and the toxicity of four chloroanilines for earthworms were investigated in two soil types. The toxicity tests were carried out with two earthworm species, Eisenia andrei and Lumbricus rubellus. LC50 values in mg kg?1 dry soil were recalculated towards molar concentrations in pore water using data from soil adsorption experiments. An attempt has been made to develop Quantitative Structure Activity Relationships (QSAR's) using these results and data on five chlorophenols and dichloroaniline in four soils and five chlorobenzenes in two soils published previously (Van Gestel and Ma, 1988, 1990; Van Gestel et al., 1991). Significant QSAR relationships were obtained between 1) adsorption coefficients (log K om ) and the octanol/water partition coefficient (log k ow ), and 2) LC50 values (in itμmol L?1 soil pore water) and log K ow . It can be concluded that both earthworm species tested are equally sensitive to chlorobenzenes and chloroanilines, E. andrei is more sensitive than L. rubellus to chlorophenols.  相似文献   

16.
17.
The hydrolase activity was studied using the fluorescein diacetate (FDA) hydrolysis assay in order to assess the microbial activity in composts and vermicomposts obtained with participation of Eisenia fetida andrei, Aporrectodea caliginosa, and A. rosea earthworms from cattle manure, leaves, and peat. The hydrolase activity (the Michaelis—Menten constant, K m ) was found to be lower in the vermicomposts than in the composts and correlated with a corresponding decrease in the length of fungal hyphae. The determination of the hydrolase activity according to the reaction of FDA hydrolysis may be recommended to control the process of vermicomposting and the quality of vermicomposts. Thus, the process of vermicomposting may be characterized with the use of the functional (hydrolase activity) and structural (microbial biomass, length of fungal hyphae) approaches.  相似文献   

18.
The distribution of earthworms in 18 types of tundra, middle-taiga, alas, and floodplain soils of Yakutia has been studied. The species Eisenia nordenskioldi is typical of Yakutian soils. The area, population density, and seasonal dynamics of earthworms in permafrost-affected soils have been determined. It is shown that earthworms are absent in excessively moist peat-muck permafrost-affected soils, excessively dry soddy soils of alases (thermokarst depressions), and soddy alluvial soils under steppe communities. The best living conditions for earthworms are associated with meadow floodplain, meadow alas, and mucky calcareous soils.  相似文献   

19.
The growth of earthworms in substrates enriched with rock (gneiss and steatite) powder, and the potential of vermicomposting in increasing solubilisation of minerals present in rock powder and in promoting plant growth were evaluated. Cattle manure (400 g), was enriched with 0, 5 and 20% of gneiss or steatite powder. Each pot with this mixture received nine earthworms (Eisenia andrei), at a density of 1000 indiv. m−3. After 60 d, earthworms were collected, counted and weighed (fresh and dry). Maize was cultivated in a greenhouse in pots with an Oxisol that was fertilised with the vermicompost obtained above. Treatments with Oxisol fertilised with gneiss or steatite only and unfertilised soil were used as controls. Shoot length was measured weekly from the soil surface to the tips of the leaves. After 73 d, the plants were harvested, the roots washed from the soil and shoots and roots dried and weighed. Plants fertilised with vermicompost enriched with rock powder were taller and heavier than plants fertilised with non-enriched vermicompost. Plants grown on soil fertilised with rock powder but not with vermicompost were larger than plants grown on unfertilised soil. Vermicompost enriched with steatite powder resulted in a larger effect on plant growth than the mere sum of applying vermicompost of non-enriched manure and steatite alone to the soil. A similar, but non-significant effect was also observed for gneiss. The different effects between gneiss and steatite may be associated with the lower resistance to chemical weathering of steatite minerals compared to gneiss minerals, as well as the former being softer than the latter. The effect of vermicompost on the optimisation of nutrient release from silicate rocks seems to depend on the rock type.  相似文献   

20.
Laboratory experiments were used to study the effect of food quantity and quality on the biomass of earthworms, and the influence of earthworms on plant growth and infiltration of water into soil. Earthworms with the most food gained weight faster than those with little or no supplementary food. The latter also failed to become reproductively mature. Earthworms lost weight on a nitrogenpoor diet, but this was not rectified by supplementing such food with inorganic nitrogen added to the soil 2 weeks before the worms. Ryegrass grown in soil in which earthworms (Allolobophora trapezoides) had been kept grew more slowly than in soil which had no previous worm activity, perhaps indicating that earthworms had converted relatively-available organic N into less available forms.Microscolex dubius gave the fastest infiltration rates of water into soil when clover mulch was present. With Eisenia foetida there was little effect of worm density on infiltration rates; the highest density significantly increased infiltration but only when clover hay had been mixed in the soil. The surface casting behaviour of the two earthworm species varied with the placing of the food offered.  相似文献   

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