Bait-lamina Test Research Articles

Organic textile dye improves the visual assessment of the bait-lamina test

Rapid ecosystem assessments are needed for large-scale ecotoxicological studies and coordinated distributed experiments. Bait-lamina stripes are commonly used as a standardized method to assess decomposer activity, but it is often difficult to distinguish bait substrate from soil. In the present study our aim was to identify a dyeing method that improves the precision of visual assessment of decomposition rates, while having negligible side effects. We compared five different dyes (food dye, Easter Grass, organic textile dye, ink, and wall paint) with control substrate in microcosms containing either acidic or alkaline soil with two introduced Collembola species (Folsomia candida and Sinellacoeca). Organic textile dye showed the highest precision of visual assessment, and had no detectable side effects on decomposition rates, soil microbial activity (biomass and respiration), or Collembola densities. We recommend using organic textile dye to improve the bait-lamina test due to the high precision and the ease of preparation.

Toxicity of three biocides to springtails and earthworms in a soil multi-species (SMS) test system

Effects of three biocides, esfenvalerate, picoxystrobin and triclosan, were studied in a Soil-Multi-Species (SMS) test system with four springtail- and one earthworm species exposed for eight weeks. All biocides affected springtail population growth negatively, and species- and chemical specific differences had clear impacts on their dominance structure. We suggest that differences in vulnerability may be influenced by activity related to species-specific vertical distribution in the soil. The responses of the springtail Folsomia fimetaria differed strongly from previous results from a single-species experiment with the same biocides. Survival of juvenile earthworms was more sensitive to biocide exposure than weight gain, and earthworm performance was significantly correlated with springtail abundance. Feeding activity of soil organisms measured with the bait lamina test system was a sensitive criterion for esfenvalerate and picoxystrobin exposure, but not for triclosan. The results suggest that interspecific interactions such as resource- and interference competition may influence the toxicity of biocides. SMS test systems may hence be a suitable method for investigating direct and indirect effects in combination under standardized laboratory conditions.

Utility of bioassays (lettuce, red clover, red fescue, Microtox, MetSTICK, Hyalella, bait lamina) in ecological risk screening of acid metal (Zn) contaminated soil

The objective of this study was to assess selected bioassays and ecological screening tools for their suitability in a weight of evidence risk screening process of acidic metal contaminated soil. Intact soil cores were used for the tests, which minimizes changes in pH and metal bioavailability that may result from homogenization and drying of the soil. Soil cores were spiked with ZnCl2 or CaCl2. Leachate collected from the soil cores was used to account for the exposure pathways through pore water and groundwater. Tests assessed included MetSTICK in soil cores and Microtox in soil leachate, lettuce (Lactuca sativa), red fescue (Festuca rubra) and red clover (Trifolium pratense) in the soil cores and lettuce and red clover in soil leachate, Hyallella azteca in soil leachate, and an ecological soil function test using Bait Lamina in soil cores. Microtox, H. azteca, lettuce and red fescue showed higher sensitivity to low pH than to Zn concentrations and are therefore not recommended as tests on intact acidic soil cores and soil leachate. The Bait Lamina test appeared sensitive to pH levels below 3.7 but should be investigated further as a screening tool in less acidic soils. Among the bioassays, the MetSTICK and the T. pratense bioassays in soil cores were the most sensitive to Zn, with the lowest nominal NOEC of 200 and 400mg Zn/kg d.w., respectively. These bioassays were also tolerant of low pH, which make them suitable for assessing hazards of metal contaminated acid soils.

Soil fauna feeding activity in temperate grassland soils increases with legume and grass species richness

Edaphic fauna contributes to important ecosystem functions in grassland soils such as decomposition and nutrient mineralization. Since this functional role is likely to be altered by global change and associated shifts in plant communities, a thorough understanding of large scale drivers on below-ground processes independent of regional differences in soil type or climate is essential. We investigated the relationship between abiotic (soil properties, management practices) and biotic (plant functional group composition, vegetation characteristics, soil fauna abundance) predictors and feeding activity of soil fauna after accounting for sample year and study region. Our study was carried out over a period of two consecutive years in 92 agricultural grasslands in three regions of Germany, spanning a latitudinal gradient of more than 500 km. A structural equation model suggests that feeding activity of soil fauna as measured by the bait-lamina test was positively related to legume and grass species richness in both years. Most probably, a diverse vegetation promotes feeding activity of soil fauna via alterations of both microclimate and resource availability. Feeding activity of soil fauna also increased with earthworm biomass via a pathway over Collembola abundance. The effect of earthworms on the feeding activity in soil may be attributed to their important role as ecosystem engineers. As no additional effects of agricultural management such as fertilization, livestock density or number of cuts on bait consumption were observed, our results suggest that the positive effect of legume and grass species richness on the feeding activity in soil fauna is a general one that will not be overruled by regional differences in management or environmental conditions. We thus suggest that agri-environment schemes aiming at the protection of belowground activity and associated ecosystem functions in temperate grasslands may generally focus on maintaining plant diversity, especially with regard to the potential effects of climate change on future vegetation structure.

Evaluation of the joint effect of glyphosate and dimethoate using a small-scale terrestrial ecosystem

In the present work a small-scale terrestrial ecosystem (STEM) containing a soil collected from an agricultural field in Central Portugal was used to evaluate the effects of the combination of the herbicide glyphosate and the insecticide dimethoate. Earthworms ( Eisenia andrei), isopods ( Porcellionides pruinosus), turnip seeds ( Brassica rapa), and bait-lamina strips were placed in the STEM. The results showed that the application of the recommended field dose of both pesticides did not cause any effect on the weight variation of earthworms and growth of the plants. The application of the herbicide, even at 5 and 10 times the field dose, increased feeding activity in soil (bait-lamina test), although the application of dimethoate led to a decrease in feeding activity in all concentrations tested. The binary mixtures performed showed that according to the Independent Action model, synergism (higher effect than expected from the single exposures) was observed in both the shoot length and fresh weight of B. rapa at 5 times the field dose, but antagonism was observed at 10 times the field dose. Regarding the germination success, synergism was observed at the field dose, but antagonism was detected at 5 times and 10 times the field dose. There was a decrease on the earthworm's weight in all concentrations tested, although no statistical differences were observed in any of the treatments made. Regarding depth distribution of E. andrei, worms were found in the upper layer more than it was predicted for all concentrations. In the mixtures with the field and 5 times the field dose there was a decrease in the feeding activity (bait-lamina consumption) by the soil fauna. From the four biomarkers assessed on the isopods (Catalase, Acetylcholinesterase, Glutathione- S-transferase, and Lipid peroxidation), only a significant decrease in the Acetylcholinesterase activity upon dimethoate and the binary mixtures exposures performed with the field dose was observed and on Lipid peroxidation at the field doses of single and binary exposures.

Soil faunal activity as measured by the bait-lamina test in monocultures of 14 tree species in the Siemianice common-garden experiment, Poland

In 1970–1971, 53 tree monoculture study plots were established (20 m × 20 m) in Siemianice (SW Poland) by clearcutting of an 81-year-old pine forest. The following 14 tree species were planted there with 3 or 6 replicates: Abies alba, Acer pseudoplatanus, Acer platanoides, Betula pendula, Carpinus betulus, Fagus sylvatica, Larix decidua, Picea abies, Pinus sylvestris, Quercus robur, Tilia cordata, Pinus nigra, Quercus rubra and Pseudotsuga menziesii. During 34 years of monitoring the soil chemistry, ground floral composition and litter decomposition rates differed strongly between some tree species. The aim of this study was to determine whether tree species also influenced soil faunal activity. In June and October 2006, 50 bait-laminas were distributed in the center of each study plot and exposed for 42 and 33 days, respectively. The soil faunal activity levels in plots of the same tree species were similar but differed between monocultures, being particularly high in monocultures of L. decidua and P. abies. These differences cannot be directly attributed to the soil chemical characteristics. Soil faunal activity was significantly higher in summer than in autumn, although soil moisture was lower in summer (12% at the beginning and 4% at the end of the period) than in autumn (10% and 12%, respectively). The main factor affecting seasonal differences in soil faunal activity seems to be soil temperature, which was significantly higher in summer (mean 19.3 °C) than in autumn (mean 10.1 °C). Faunal activity differed also along the soil profile, with maximum at 0–4 cm depth.

Biomarkers for the assessment of chlorpyrifos effects on earthworms and on soil functional parameters

The objective of this work was to evaluate the effects of chlorpyrifos on earthworms and on soil functional parameters. An integrated laboratory-field study was performed in a wheat field in Argentina, sprayed with chlorpyrifos at two recommended application rates (240 or 960 g ha-1 style='vertical-align:baseline'> a.i.). Laboratory tests included neutral red retention time, comet assay (single cell gel electrophoresis), and avoidance behavior, each using the earthworm Eisenia andrei exposed in soil collected 1 or 14 days after pesticide application, and the bait-lamina test. Field tests assessed organic matter breakdown using the litterbag and bait-lamina assays. Earthworm populations in the field were assessed using formalin application and hand-sorting. The neutral red retention time and comet assays were sensitive biomarkers to the effects of chlorpyrifos on the earthworm E. andrei; however, the earthworm avoidance test was not sufficiently robust to assess these effects. Feeding activity of soil biota, assessed by the bait lamina test, was significantly inhibited by chlorpyrifos after 97 days, but recovered by the 118th day of the test. Litterbag test showed no significant differences in comparison to controls. Earthworm abundance in the field was too low to adequately test the sensitivity of this assessment endpoint.

The effects of organic and conventional management practices on feeding activity of soil organisms in vineyards

This study investigated whether the activity of soil organisms in a vineyard soil in the Western Cape, South Africa, was affected differently by different management practices. The influences of organic and conventional treatments were compared in two vineyard blocks, one previously organically and the other conventionally managed. In each block, experimental plots received either full chemical weed control or ‘organic’ treatment, as recommended by the Organic Standards of the British Soil Association. Pest and disease control practices followed in the conventionally treated vineyard block included the use of various pesticides. The bait-lamina test was used to assess feeding activity of soil organisms. The feeding activity in the previously organically managed block, subsequently receiving conventional surface chemical treatment, decreased over time as the soil moisture content decreased. A comparison of feeding activity and moisture content on the previously organically managed block after both types of treatments, indicated that the activity was substantially higher in the organically treated plots compared to the conventionally treated ones, while the soil moisture contents were very similar. This indicated that the organic treatment favoured soil biological activity directly or indirectly. The treatment contributed to the preservation of more favourable moisture conditions for soil biological activity. A microcosm study to determine feeding activity of fauna in soil from both vineyard blocks, each subjected to both a conventional and organic treatment under controlled conditions in the laboratory, showed a statistically significantly (P < 0.05) higher feeding activity in the soil that was organically treated and provided further indications that organic management practices, as used here, may result in higher soil faunal feeding activity over the short term compared to conventional practices.

The effects of organic and conventional management practices on feeding activity of soil organisms in vineyards

This study investigated whether the activity of soil organisms in a vineyard soil in the Western Cape, South Africa, was affected differently by different management practices. The influences of organic and conventional treatments were compared in two vineyard blocks, one previously organically and the other conventionally managed. In each block, experimental plots received either full chemical weed control or ‘organic’ treatment, as recommended by the Organic Standards of the British Soil Association. Pest and disease control practices followed in the conventionally treated vineyard block included the use of various pesticides. The bait-lamina test was used to assess feeding activity of soil organisms. The feeding activity in the previously organically managed block, subsequently receiving conventional surface chemical treatment, decreased over time as the soil moisture content decreased. A comparison of feeding activity and moisture content on the previously organically managed block after both types of treatments, indicated that the activity was substantially higher in the organically treated plots compared to the conventionally treated ones, while the soil moisture contents were very similar. This indicated that the organic treatment favoured soil biological activity directly or indirectly. The treatment contributed to the preservation of more favourable moisture conditions for soil biological activity. A microcosm study to determine feeding activity of fauna in soil from both vineyard blocks, each subjected to both a conventional and organic treatment under controlled conditions in the laboratory, showed a statistically significantly (P < 0.05) higher feeding activity in the soil that was organically treated and provided further indications that organic management practices, as used here, may result in higher soil faunal feeding activity over the short term compared to conventional practices.

Effects of soil temperature and moisture on the feeding activity of soil animals as determined by the bait-lamina test

The aim of the study was to determine the effect of soil temperature and moisture on the feeding activity of soil fauna. To measure this activity, we conducted two short-term (14 days) experiments using the bait-lamina method. In experiment 1, the enchytraeid Cognettia sphagnetorum was added to defaunated mor humus. The experiment included incubations at four temperatures (−4, 5, 14, and 24 °C) and three moisture regimes (220, 260, and 300% of dry weight). No feeding activity was detected at −4 °C, but at other temperatures the bait-laminae were perforated, and the number of baits consumed increased with time. Because of variable animal survival and because of the rather low bait consumption, the effect of temperature and moisture on the feeding activity was unclear. In experiment 2, intact soil cores were either pre-treated at −21 °C or were not treated until being placed at −4, 5, 14 and 24 °C and two moisture regimes. The pre-treatment at −21 °C killed all meso- and macrofauna except collembolans and mites. Despite high densities of collembolans and moderate densities of mites at 24 °C in the pre-treated cores, there was no bait perforation. In the non-frozen cores, there was no feeding activity at −4 °C, but the activity increased with temperature up to 24 °C. The study showed that the bait-laminae were perforated by the activity of soil-living animals. Bait perforation seemed to be dependent on animals like enchytraeids and lumbricids and to a lesser degree collembolans and mites. The feeding activity measured by the bait-laminae increased with temperature, whereas the effect of soil moisture was less evident.

Evaluation of the “bait-lamina test” to assess soil microfauna feeding activity in mixed grassland

The soil fauna plays an important role in regulating nutrient cycling through predation and comminution of organic residues. The bait-lamina test was proposed as a practical mean to assess soil faunal feeding activity. The test consists of vertically inserting 16-hole-bearing plastic strips filled with a plant material preparation into the soil. We assessed the value of the bait-lamina test in the mixed grassland ecoregion of Canada, using 5-year-old seeded grass field plots. There were five treatments of grass communities, i.e. monocultures of (1) Russian wild rye, (2) switchgrass, (3) green needlegrass, or (4) western wheatgrass, and (5) a grass mixture of western wheatgrass + green needlegrass + switchgrass + little blue stem, which were distributed in four complete blocks, and six bait mix treatments, i.e. bait made with ground tissue of (1) Russian wild rye, (2) switchgrass, (3) green needlegrass, (4) western wheatgrass, (5) alfalfa, or with (6) wheat bran, which were randomized in each plot. Bait-lamina strips were used in groups of five strips inserted in the soil; they were equally spaced across the inter-row. The analysis revealed a marginally significant effect ( P = 0.065) of plant community on soil faunal feeding activity with more activity in mixed grass species compared to green needlegrass plots. Bait flavour had no significant effect ( P = 0.22) on feeding. More ( P < 0.0005) feeding activity was detected close to the soil surface (0–5 mm deep) than at 20 mm below the surface and at deeper depths. Feeding activity was relatively low over the 65-day period of the test (13 June to 17 August 2005), with 8.3% and 2.0% of the lamina (holes filled) showing signs of feeding in the 0–5 and 5–15 mm soil layer. We conclude that the bait-lamina test is appropriate to assess the activity of surface litter processing fauna in mixed grassland, but it is not a good indicator of the decomposition occurring in the soil matrix, where most litter is produced. We recommend the use of a large number of replicated bait-lamina strips and a whole growing season incubation period in soils of the semiarid prairie ecoregion where the surface litter layer is thin and faunal saprobes are relatively scarce.

Feeding Rate of Soil Animals in Different Ecosystems in Pati, Indonesia

The feeding activity of soil animals was measured by using bait lamina test in three main ecosystems, i.e. the teak forest, home garden and rainfed paddy field. Two additional ecosystems in rainfed paddy field, i.e. the old (permanently established bund around paddy fields) and new bunds were examined as well. Three blocks of bait-lamina sticks (each block consisting of 16 individual sticks) were exposed at each location. The bait lamina were retrieved from the soil after two days and visually assessed. Each hole is designated as “fed” (perforated) or “non-fed” hole. The feeding rate is measured as the absolute number of “fed” holes. Soil animals in the old bunds showed the highest feeding activity (55.20%), followed by home garden (39.10%), rainfed paddy field (16.50%), teak forest (15.60%), and new bund (7.80%). The frequency of animals attack to the bait strips also indicated the similar pattern as their feeding activity, i.e. high in the old bunds (0.90), followed by home garden (0.70), teak forest (0.40), new bunds (0.40) and rainfed paddy field (0.30), respectively.

Metal Effects on Soil Invertebrate Feeding: Measurements Using the Bait Lamina Method

Heightened concerns regarding the protection of terrestrial ecosystems at a national level has increased the need to develop a suite of indicators capable of assessing the quality, integrity and fertility of soils. Of the assays currently available, tests that measure aspects of soil function and associated parameters are among the most promising, since these integrate effects on soil quality at the highest level of organisation. In this study we describe results of the deployment of an indicator of soil functional integrity (the bait lamina test) that is designed to measure the feeding activity of soil invertebrates. Bait lamina was used at six grassland sites located along a transect from a smelter at Avonmouth (South-West England) used in the EU funded BIOPRINT II project. Results indicated highest bait removal (feeding) at sites furthest from the factory, intermediate feeding activity at intervening sites and extremely low activities at the two sites closest to the smelter. The strong decline in activity for the group of sites closest to the smelter corresponded with increasing metal concentrations suggesting a clear impact of metals on detritivorous invertebrate feeding. Comparisons of the results of the bait lamina study to previous invertebrate survey work suggested that the differences in observed bait removal can be attributed to direct effects of metals on the abundance and biodiversity of key decomposer groups such as earthworms, isopods, molluscs, myriapods, springtails and mites.

Stratification and dynamics of bait-lamina perforation in three forest soils along a north–south gradient in Russia

The bait-lamina test was developed for estimating soil biotic activity in arable and contaminated soils. To investigate the utility of the test in unpolluted soils under various climatic and soil conditions, three plots along a north–south gradient in the European part of Russia were chosen. They are: (i) a pine forest at the White Sea coast on poorly developed podzolic soils (Karelia Region); (ii) a spruce forest near Borovsk (Kaluga Region) on podzolic soils; and (iii) oak-beech forest near Novorossiysk, on the Black Sea coast with brown soils (Krasnodar Region). Forty bait-laminas were used at each plot and checked at various times of exposure. Parallel sampling to investigate soil macrofaunal diversity was carried out. Litter and small stone mass, water-holding capacity (WHC), loss on ignition (LOI) and pH were determined in every soil sample in the laboratory. Differences in bait-lamina perforation over time were observed and it was concluded that a 10-day exposure is appropriate under most conditions. Great differences in bait-lamina perforation were found between soil types. An optimal combination of climatic factors (Borovsk plot) reflected by Budyko’s drought index corresponded with the highest feeding activity (65% of pierced apertures), although the abundance of soil macrofauna was only 287 individuals m −2. The Novorossiysk plot had higher densities of soil invertebrates (1380 individuals m −2), but they showed a lower trophic activity (27%), comparable to that of the White Sea cost plot (14%). The depth distribution of bait-lamina perforation varied from plot to plot, but maximal activity was always observed at a depth 0–4 cm from the soil surface, which was supported by a proposed index of average depth of tropic activity. Vertical distribution of bait-lamina perforation depended mostly on soil profile structure and climatic conditions.

Suitability of wheat straw decomposition, cotton strip degradation and bait-lamina feeding tests to determine soil invertebrate activity

The activities of earthworms, springtails and mites in the decomposition of different substrates were examined by applying three different test methods: wheat straw degradation, the cotton-strip assay and the bait-lamina test. The main aim was to determine the potential of these three methods to describe the (direct and indirect) contribution of soil invertebrates to decomposition processes in soil. Animals were introduced at different densities to mesocosms consisting of intact soil cores taken from grassland. Wheat straw mass loss, determined after 27 days, and cotton tensile strength loss, measured after 14 days, did not significantly differ for the different densities of earthworms, springtails and mites. These findings indicate that cellulose degradation and wheat straw decomposition are more dependent on microbial activity, rather than on the abundance and activity of soil invertebrates. Soil microbial activity, measured as dehydrogenase activity at the end of the 75-day incubation period, did not show any correlation with animal density. Bait-lamina consumption rate was highest for the mesocosms containing earthworms, and increased with increasing earthworm density. Bait-lamina consumption in the mesocosms inoculated with springtails or mites only was not significantly different from that in the controls without animals. In the case of the mites this might at least partly be explained by the low densities used in this experiment. It may be concluded that whilst the bait-lamina test gives the best reflection of the biological activity of soil animals, in particular earthworms, wheat straw and cotton strip decomposition rates are more indicative of microbial activity in the soil.

Spatial Distribution of Animals and Variation in Their Trophic Activity Measured Using the Bait-Lamina Test in Sod-Podzolic Soil under a Spruce Forest

The mode of spatial distribution of soil animals and their trophic activity was studied in the sod-podzolic soil under a spruce forest. At the “test point” level, no apparent relationship between the distribution of soil animals and physicochemical characteristics of the soil was observed. The patterns of distribution of detritophages and the trophic activity (measured using the bait-lamina test) were similar. The perforation of laminae in the bait-lamina test resulted from the trophic activity of both micro- and mesofauna.

The use of acute and chronic bioassays to determine the ecological risk and bioremediation efficiency of oil-polluted soils.

To compare the effectiveness of acute and chronic bioassays for the ecological risk assessment of polluted soils, soil samples from a site with an historical mineral oil contamination (< 50-3,300 mg oil/kg dry soil) at the Petroleum Harbour in Amsterdam, The Netherlands, were screened for ecological effects using acute and chronic bioassays. A two-step 0.001 M Ca(NO3)2 extraction at a final solution-to-soil ratio of 1:1 was used to prepare extracts for the acute bioassays. Acute bioassays (< or = 5 d) applied to the 0.001 M Ca(NO3)2 extracts from the polluted and reference soils included growth tests with bacteria (Bacillus sp.), algae (Raphidocelis subcapitata), and plants (Lactuca sativa), immobility tests with nematodes (Plectus acuminatus), springtails (Folsomia candida), and cladocerans (Daphnia magna), and the Microtox test (Vibrio fischeri). Chronic bioassays (four weeks) performed on the same soil samples included tests with L. sativa, F. candida, and earthworms (Eisenia fetida) and the bait-lamina test (substrate consumption). The acute bioassays on Microtox showed a response that corresponded with the level of oil pollution. All other acute bioassays did not show such a consistent response, probably because pollutant levels were too low to cause acute effects. All chronic bioassays showed sublethal responses according to the contaminant levels (oil and in some soils also metals). This shows that chronic bioassays on soil samples are more sensitive in assessing the toxicity of mineral oil contamination in soil than acute bioassays on soil extracts. A pilot scale bioremediation study on soils taken from the two most polluted sites and a control site showed a rapid decline of oil concentrations to reach a stable level within eight weeks. Acute bioassays applied to the soils, using Microtox, algae, and D. magna, and chronic bioassays, using plants, Collembola, earthworms, and bait-lamina consumption, in all cases showed a rapid reduction of toxicity, which could be attributed to the degradation of light oil fractions.

Decomposition rates and feeding activities of soil fauna in deciduous forest soils in relation to soil chemical parameters following liming and fertilization

This study investigated the influence of liming and P/K fertilization on the feeding activities of soil fauna and leaf litter decomposition rates in deciduous forest soils. The parameters examined were correlated to soil chemical characteristics. In 1994, we established a field experiment with six plots in an oak-beech forest and added different amounts of dolomite, partly combined with P/K fertilization. Two years thereafter a bait-lamina test was used to examine the feeding activity of soil fauna and a minicontainer test to study beech-leaf decomposition. In 1996, the feeding activity in the Ah horizon was lower in the plots left untreated in 1994 than in the plots which had been fertilized in 1994. The highest feeding activity was found in the treatment with 6 t dolomite ha–1 plus P/K. In all plots, the feeding activity decreased with increasing soil depth. The decomposition rates varied from 0.49% to 0.78% week–1 in the period April–October 1996. In 1996, the plots treated with 6 t dolomite ha–1 had the highest decomposition rates and differed significantly from those treated with 9 t or 15 t dolomite ha–1. No significant differences were found between the untreated plots and those treated with 9 t or 15 t dolomite ha–1. These results were confirmed by those obtained in 1997. The C/N ratio of litter also decreased, mostly in the treatment with 6 t dolomite ha–1. Feeding activities in the Ah horizon correlated positively with pH and concentrations of mobile Ca, Mg, K, and negatively with concentrations of mobile Al and heavy metals. We concluded that an increased supply of mobile nutrients and a decrease in mobile Al and heavy metals in these forest soils, as well as a balanced ratio between macro- and micronutrients, led to increased biological activity.

The bait-lamina test

A general introduction of the bait-lamina test has been made in this article. This article has an introductional character for other articles dealing with the bait-lamina test method and gives the experimental data. The test was first introduced by Törne in 1990 to measure the biological activity of soil. It enables the monitoring of biotic (microbial and zootic) processes in the soil within a short period of time, and detailed investigations. The test system is based on visual assessment of feeding on small portions of thin laminated bait substrate exposed to edaphic processes. The test system has found its application mainly in Germany but in the meanwhile also in Portugal, Switzerland and in the Netherlands in laboratories of soil ecology and soil ecotoxicology. At present there are only few publications in the international literature, but the interest in this method is growing. During the past years two workshops on the subject have been organized in Germany to summarize experiences with and to evaluate the test system and optimize the standard procedure.

A comparison of feeding activity of collembolan and enchytraeid in laboratory studies using the bait-lamina test

The bait-lamina test is an easy and fast method to investigate the `feeding activity' of soil organisms, a quantity reflecting complex decomposition processes. This study aims to provide detailed information about exactly which taxa may feed on bait lamina. Laboratory experiments were conducted with species of Collembola ( Folsomia candida, Onychiurus fimatus) and enchytraeids ( Enchytraeus minutus, Enchytraeus lacteus) and a suspension of microorganisms. We compared defaunated arable soil (gleyic luvisol) and artificial soil as well as two different bait substrates: nettle powder ( Urtica dioica) and wheat bran. Glass tubes ( n=16) of 50 ml capacity were filled with one of the soil substrates, to which were added one bait lamina and either 100 springtails or 75 enchytraeids. Both bait types were accepted by the test animals, but with a strong preference for nettle powder. The feeding activity of all investigated organisms was higher in defaunated arable soil than in artificial soil. The enchytraeids and F. candida had the highest feeding activity.