Effects of spraying the herbicides 2,4-D and 2,4,5-T on a population of the tortoise Testudo hermanni in southern Greece

A population of the tortoise Testudo hermanni near Olympia in southern Greece was studied by mark-recapture from 1975 to 1984. Part of the site was sprayed with the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) each year from 1980, producing symptoms of poisoning (swollen eyes, fluid discharge from the nose and immobility) in tortoises. Survival rates of tortoises 10 cm or larger were significantly lower in the affected areas, with extra mortality of about 34% year-1, against an annual survival rate of 0.85-0.90 in unaffected areas. Changing population structures showed that juveniles were even more strongly affected, with the proportion of juveniles in samples decreased by half. The population in the sprayed area declined to near zero by 1984, due to mortality rather than to emigration, since more movements were recorded into than out of the affected area. There was no difference in body mass condition between sprayed and unsprayed areas, showing that effects were acute; mortality was not due to starvation from loss of food plants. The scale and pattern of mortality was similar to that from a severe scrub fire; spraying is potentially more catastrophic since often repeated at shorter intervals than burning. Possible physiological mechanisms of death are discussed. The susceptibility of tortoises to 2,4-D and 2,4,5-T (or to associated dioxin impurities) presents a warning for conservation of these late-maturing animals.     

The effects of oil spill chemicals on carbon translocation rates in Phaseolus vulgaris L

Phaseolus vulgaris L. cv. Black Valentine when sprayed with Corexit dispersants shows a rapid inhibition of photosynthesis. The plant retains the ability to translocate fixed carbon, and this involves mobilising previously fixed carbon in the sprayed leaf or the repartitioning of carbon from unsprayed regions of the plant towards the growing sink regions. The ability to maintain carbon translocation while photosynthesis is declining maximises the regrowth potential of the plant.     

Persistence characteristics of operationally sprayed fenitrothion in nearby unsprayed areas of a conifer forest ecosystem in New Brunswick

Abstract

Persistence characteristics of operationally sprayed fenitrothion were investigated in various substrates sampled from neighbouring unsprayed areas in New Brunswick. Air, water, sediment, aquatic plants, fish, balsam fir [Abies balsamea (L.) Mill] foliage, forest soil and litter samples were collected from random sampling locations selected within 200 m from the operational spray blocks. The same substrates were resampled from the same plots and from the same locations about a year later just prior to the commencement of the operational spraying. Control samples were collected from an unsprayed site, near Sault Ste. Marie, Ontario. All samples were analysed for fenitrothion, by gas‐liquid chromatography. Except the fish samples all the substrates collected during the time of operational spraying contained low but detectable levels of fenitrothion. When collected a year later prior to the operational spray program, only balsam fir showed any detectable levels (detection limit, 0.01 ppm) of the chemical. All other samples showed no fenitrothion residues (detection limit for air, 10 ng/m³; for water, 0.01 ppb; and for other samples, 0.01 ppm). The findings confirmed that fenitrothion does not persist for an extended period of time in the aquatic substrates. The conifer foliage, however, showed persistent residues at a level of about 0.55 ppm even after the winter months, although there was no indication of accumulation of the chemical as a result of repeated exposure. The study demonstrated that the conifer needles acted as a micro sink for the chemical which showed a tendency to persist in the leaf tissues for a considerable length of time.     

Response of grassland ecosystem to air pollutants: I-Experimental concept and site of the Braunschweig grassland investigation program

Temporal changes in spatial distribution and population density of linyphiid spiders were studied in relation to physical factors and deltamethrin spraying in the field. The results of the study have been used to set the conditions necessary when plot size is reduced in field trials. The results showed independence of observations at 7 m from an unsprayed reservoir, with respect to migration, in the week following pesticide application. Soil moisture had a positive effect on trapping success, without having apparent effect on trapping success, without having was found for deltamethrin spraying on wet and dry soil. Shifts in the spatial distribution of spider activity showed a close correlation with crop microclimatic conditions. The effect of trapping on population density was shown to be limited. The results suggest that small plots surrounded by a border of 7 m are appropriate for assessing short term pesticide effects on adult linyphiid spiders in winter wheat.     

Field and laboratory simulations of storm water pulses: behavioural avoidance by marine epifauna

Epifaunal communities associated with macroalgae were exposed to storm water pulses using a custom made irrigation system. Treatments included Millipore freshwater, freshwater spiked with trace metals and seawater controls to allow for the relative importance of freshwater inundation, trace metals and increased flow to be determined. Experimental pulses created conditions similar to those that occur following real storm water events. Brief storm water pulses reduced the abundance of amphipods and gastropods. Freshwater was the causative agent as there were no additional effects of trace metals on the assemblages. Laboratory assays indicated that neither direct nor latent mortality was likely following experimental pulses and that epifauna readily avoid storm water. Indirect effects upon epifauna through salinity-induced changes to algal habitats were not found in field recolonisation experiments. Results demonstrate the importance of examining the effects of pulsed contaminants under realistic exposure conditions and the need to consider ecologically relevant endpoints.     

Soil dehydrogenase, phosphomonoesterase and arginine deaminase activities in an insecticide treated groundnut (Arachis hypogaea L.) field

Chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2 pyridyl phosphorothioate) 20 EC and Quinalphos (O,O-diethyl O-quinoxalin-2-yl phosphorothioate) 25 EC, were applied in groundnut (Arachis hypogaea L.) field as seed treatment at 25 ml/kg and soil treatment at 4 l/ha in 1998 and 1999. The residues of these insecticides were monitored during the entire crop season and their effect on the soil enzymes dehydrogenase, phosphomonoesterase and arginine deaminase were studied. Ninety nine percent of chlorpyrifos residues were dissipated within 60 days from seed treated soil and 98% dissipation was observed in soil treated field for the same days. Its half lives in seed treated soil were 8 days and 7 days and in soil treated field were 9.2 days in and 7.5 days in 1998 and 1999 respectively. Dissipation of quinalphos in comparison to chlorpyrifos was slow both in seed treated and soil treated field. Eighty seven percentage to 92% dissipation of quinalphos residues were observed from seed treated soil and 98% residues were dissipated from soil treated field within 75 days. Its half lives in seed treated soil were 20 days and 18 days and in soil treated field, its half lives were 13 days and 17 days 1998 and 1999 respectively. Inhibition in dehydrogenase activity followed by recovery was observed both in seed and soil treatments with chlorpyrifos. An inhibition of 17.2% was estimated after 60 days of seed treatment in comparison to control. Dehydrogenase activity was significantly reduced to 63% after 15 days of quinalphos seed treatment in comparison to control in 1998. Similar trends were observed in 1999. A significant inhibition in dehydrogenase activity was observed after soil treatment both in 1998 and 1999. Phosphomonoesterase activities were significantly inhibited upto 25.2% as compared to the control, on the 15th day of chlorpyrifos seed treatment in 1998 and similarly, after one day of treatment in 1999. Quinalphos inhibited the phosphomonoesterase activity till the end of the experimental period in the soil treated fields, whereas recovered within 30-60 days of treatment in the seed treated fields. Arginine deaminase activity was significantly stimulated within one day after chlorpyrifos seed and soil treatments in both years. The activity was almost threefold higher on the 30th and the 15th day of soil treatment in 1998 and 1999, respectively. A temporary inhibition of arginine deaminase activity was observed after quinalphos treatment. It was observed that in most of cases insecticides have temporary inhibitory effect on soil enzymes. However, inhibition was smaller in seed treated soil than in direct soil treatment.     

Response types in Collembola towards copper in the microenvironment

Laboratory studies were carried out to cast light on differences in density responses among collembolan species to copper (Cu)-polluted environments. In a recolonisation experiment, mesofauna originating from a copper (Cupolluted arable field were allowed to colonise defaunated Cu-contaminated and uncontaminated soil cores for 3 months. The abundances of Pseudosinella alba and gamasid mites were higher in the uncontaminated soil, whereas the majority of other collembolans tended to be more abundant in the Cu-enriched soil. Behavioural experiments were conducted to test the ability of single Collembola species to distinguish between filter paper and food soaked in water, Cu, and calcium (Ca) solutions. Onychiurus armatus avoided both Cu and Ca, whereas Folsomia quadrioculata and Folsomia manolachei showed a significant preference for Cu. Isotomurus palustris was not able to distinguish between Cu and water. The results are compared and discussed with regard to other studies on the occurrence and behaviour of Collembola in Cu-contaminated environments. We suggest that microsite selection according to preference or avoidance of high salinity of pore water may partly explain the community structure of Collembola in Cu-polluted soils which are characterised by an increase of euedaphic species. More studies have to be carried out to generalise this concept and to explore to what extent reduced predation by gamasid mites contribute to the success of certain Collembola in Cu-contaminated sites.     

Identification of realistic worst case aquatic macroinvertebrate species for prospective risk assessment using the trait concept

Purpose  

Approaches in environmental risk assessment for pesticides are becoming more and more realistic. Thereby, risk assessment has to be protective in a way that no long-lasting (adverse) effects on populations will occur in the environment. Since this imperative includes species generally showing high population vulnerability due to their life history traits, prospective risk assessment should be based on realistic worst cases. Based on life history traits, the purpose of the current study was to verify whether a worst case combination of low potential for intrinsic recovery and low ability for recolonisation can be found in the field.     

Comparison of Statistical Designs and Experimental Protocols Used to Evaluate Rain Acidity Effects on Field-Grown Soybeans

Published results of four field experiments testing effects of acidic precipitation in field-grown soybeans have led to contradictory conclusions. This paper examines the experimental procedures and protocols of the four experiments which could have contributed to differences in both the reported crop yields and the interpretations or conclusions drawn from the experiments.

The most important difference among the experiments is in their statistical designs. Two of the field layouts used only one plot per treatment, providing replication only for plants, rows or sectors within plots, but not among plots. By using real data from a highly replicated experiment it is shown that with such deficient statistical designs treatment effects cannot be separated from other microenvironmental variables peculiar to a specific plot location.

The other two experiments were highly replicated. They were designed to detect differences of approximately 10% among treatment means. Type 1 error, a, was predetermined, and replication was sufficient to keep type 2 error low. This design was made possible because a preliminary experiment was available to estimate the expected components of variance. Despite differences in the procedures and protocols among the four experiments, it is primarily the quality of the experimental design which has determined their validity and relative utility for crop loss assessment.     

Constitutional tolerance to heavy metals of a fiber crop, ramie (Boehmeria nivea), and its potential usage

It is observed that ramie (Boehmeria nivea), an economic fiber crop, can establish and colonize metal-contaminated sites in China. Metal tolerance and accumulation by ramie originating from 13 metal-contaminated and 4 “clean” sites in China were compared under field and hydroponic conditions. All selected populations and germplasms displayed good growth performance under diverse metal-contaminated habitats; while growth responses, metal accumulation and tolerance were similar among the 8 populations and 2 germplasms when exposed to solutions containing elevated As, Cd, Pb, or Zn in the laboratory. These revealed that ramie possesses a certain degree of constitutional metal tolerance. To our knowledge, this is the first report of constitutional metal tolerance possessed by a fiber crop. Ramie can be considered as a good candidate for both fiber production and phytoremediation of sites contaminated by multi-metals, as it accumulates relative low metal concentrations, but possesses both high biomass and high economic value.     

Assessing the nature of the combined effects of copper and zinc on estuarine infaunal communities

Elevated levels of copper and zinc in sediment have been shown to adversely affect estuarine infauna. We investigated the additivity of the combined effects of copper and zinc on infaunal recolonisation through a manipulative field experiment in Orewa estuary, New Zealand, using defaunated sediment discs treated with these metals. The nature of their combined effects varied among infaunal taxa and the particular variables being examined. Additive effects were detected for species richness, for the mean log abundances of the polychaetes Prionospio sp. and Scoloplos cylindrifer and for the multivariate response of the community as a whole. Antagonistic effects were detected for the mean log abundances of total infauna and the polychaete Heteromastus sp. Characterising the potentially interactive nature of the combined effects of multiple heavy metals is essential in order to build predictive models of future environmental impacts of metal accumulation in estuarine sediments.     

Compatibility analysis of material and energy recovery in a regional solid waste management system

The rising prices of raw materials and concerns about energy conservation have resulted in an increasing interest in the simultaneous recovery of materials and energy from waste streams. Compatibility exists for several economic, environmental, and managerial reasons. Installing an on-site or off-site presorting facility before an incinerator could be a feasible alternative to achieve both goals if household recycling programs cannot succeed in local communities. However, the regional impacts of presorting solid waste on a waste-to-energy facility remain unclear because of the inherent complexity of solid waste compositions and properties over different areas. This paper applies a system-based approach to assess the impact of installing a refuse-derived fuel (RDF) process before an incinerator. Such an RDF process, consisting of standard unit operations of shredding, magnetic separation, trommel screening, and air classification, might be useful for integrating the recycling and presorting efforts for a large-scale municipal incinerator from a regional sense. An optimization modeling analysis is performed to characterize such integration potential so that the optimal size of the RDF process and associated shipping patterns for flow control can be foreseen. It aims at exploring how the waste inflows with different rates of generation, physical and chemical compositions, and heating values collected from differing administrative districts can be processed by either a centralized presorting facility or an incinerator to meet both the energy recovery and throughput requirements. A case study conducted in Taipei County, which is one of the most densely populated metropolitan areas in Taiwan, further confirms the application potential of such a cost-benefit analysis.     

Effects of herbicide spray drift on selected species of nature conservation interest: the effects of plant age and surrounding vegetation structure

There has been increasing awareness of the possible impact of herbicide drift on vegetation in nature reserves and field-margin habitats adjacent to treated areas. However, relatively little is known about the impact of such drift on species typical of these habitats. To investigate this problem a series of bioassay experiments simulating spray drift were carried out with five native plant species of different age placed at different distances up to 4 downwind from a sprayer under standardized conditions. These experiments used three herbicides--glyphosate, MCPA and mecoprop--in three types of surrounding vegetation structure--short, medium-height and tall grassland. Many plants showed symptoms of damage after spraying but showed no significant growth reduction at the end of the season even underneath the sprayer. Where a reduction in yield was found, it occurred close to the sprayer. In general, young plants were more often affected than old ones. Yield promotion occurred for some species between 2 and 4 m downwind of the sprayer (curvilinear response) with unknown ecological consequences. The structure of the surrounding vegetation influenced the response for some species, which indicates that deposition patterns can be complex, and thus there may be difficulty in predicting effects in semi-natural communities from simple deposition models.     

Isolation, identification and characterization of Bacillus amyloliquefaciens BZ-6, a bacterial isolate for enhancing oil recovery from oily sludge

Over 100 biosurfactant-producing microorganisms were isolated from oily sludge and petroleum-contaminated soil from Shengli oil field in north China. Sixteen of the bacterial isolates produced biosurfactants and reduced the surface tension of the growth medium from 71 to <30 mN m⁻¹ after 72 h of growth. These bacteria were used to treat oily sludge and the recovery efficiencies of oil from oily sludge were determined. The oil recovery efficiencies of different isolates ranged from 39% to 88%. Bacterial isolate BZ-6 was found to be the most efficient strain and the three phases (oil, water and sediment) were separated automatically after the sludge was treated with the culture medium of BZ-6. Based on morphological, physiological characteristics and molecular identification, isolate BZ-6 was identified as Bacillus amyloliquefaciens. The biosurfactant produced by isolate BZ-6 was purified and analyzed by high performance liquid chromatography-electrospray ionization tandem mass spectrometry. There were four ion peaks representing four different fengycin A homologues.     

Declining coastal piscivore populations in the Baltic Sea: Where and when do sticklebacks matter?

Intraguild predation interactions make fish communities prone to exhibit alternative stable states with either piscivore or prey fish dominance. In the Baltic Sea, local declines of coastal piscivores like perch (Perca fluviatilis) have been observed to coincide with high densities of sticklebacks (Gasterosteus aculeatus). Mechanisms behind this shift between piscivore and stickleback dominance were studied both experimentally and in field. Results showed that predation by sticklebacks has a strong negative effect on perch larvae survival, but this effect rapidly decreases with increasing perch size, likely due to gape limitations and digestion constraints in sticklebacks. Large spatial and temporal variations in patterns of stickleback migration into perch spawning sites were observed. Whether or not high density of sticklebacks will cause declines in coastal piscivore populations is suggested to depend on the availability of spawning sites in which sticklebacks do not migrate into or arrive late in the reproduction season of coastal piscivores.     

Estimation of emission fluxes from a horizontal flux budget method, exemplified with determination of pesticide volatilization

The paper describes an experimental set-up designed to measure the volatilization of different pesticides after application under full-scale field conditions. The pesticides were sprayed around the circumference of a circle and measurements of meteorology and air concentrations of pesticides were taken in the centre of the circle. The paper describes how the dimensions like the radius of the circle and height of the mast in the experimental set-up are found from theoretical considerations. A method to increase the confidence of the flux calculations is described. It utilizes that several substances were applied simultaneously and that a certain parameter in the fitted concentration profiles depends on turbulence only and thus have the same value for all substances. The design was used during two campaigns, conducted on the same location, one during fall on bare soil and one in spring on a barley crop.     

Distribution patterns of lead accumulation in roadside soils: a case study from Erzurum, Turkey

Surface soils along roadsides or near to industrial areas may contain high concentrations of lead that adversely affect plant production. Lead contamination of roadside soils is generally attributed to the exhaust emissions of automobiles operating with leaded gasoline. The objectives of this study were to determine the relationships between lead accumulation in soils and the distance from the road edge, predominant wind direction and soil depth, and to define vertical and horizontal distribution patterns of lead accumulation within the study area. The lead content of soil decreased rapidly with the distance from the road, and the relationship was described by a power function. The contamination was more dependent on the predominant wind direction. Our results indicated that lead that had accumulated within the top few centimetres of soil had been mixed throughout the ploughing layer in cultivated lands. Soils within 40 m of the motorway had at least 2 to 6 times higher amounts of lead than the background level.     

Residues and half-lives of pyrethrins on field-grown pepper and tomato

The dried flower heads of Tanacetum cinerariifolium Trev. (Family: Compositae) contain insecticidal compounds collectively called "pyrethrins." Pyrethrins are the subject of intense interest for use in crop protection because their toxicological properties permit control of certain insect species at application rates as low as 5-10 g AI acre(-1). Seedlings of sweet pepper, Capsicum annuum L. cv. Bell Boy Hybrid and tomato, Lycopersicon esculentum Mill. cv. Mountain Spring F1 Hybrid were planted and sprayed with a Multi-Purpose Insecticide formulation that contains 0.2% pyrethrins, 1.0% piperonyl butoxide (PBO), 88% diatomaceous earth, and 10.8% inert ingredients. The formulation was sprayed on pepper and tomato foliage when tomato fruits became red ripe and pepper became mature green at the rate of 6 lbs of formulated product per acre (5.4 and 27.2 g AI of pyrethrins and PBO, respectively). Following spraying, pepper and tomato leaves and fruits were collected at different time intervals for residue analysis using a high performance liquid chromatograph (HPLC) equipped with a UV detector. Residues of pyrethrins and PBO were generally higher on the leaves than fruits. Initial deposits (1 h following spraying) of pyrethrins were significantly higher on pepper than tomato fruits. Half-life (T1/2) values on pepper and tomato fruits did not exceed 2 h. Where concern exists over synthetic pesticide residues on treated crops and in the environment, pyrethrins are suitable alternatives that can be used to reduce the risk of exposure to synthetic pesticide residues.     

Agricultural capacity and conservation in high biodiversity forest ecosystems

Agricultural development is a leading cause of habitat destruction that increasingly threatens global biodiversity. To help understand the likelihood and implications of agricultural expansion in areas of high conservation importance, this article examines agricultural suitability in forested portions of biodiversity hotspots and tropical wilderness areas, regions with especially rich concentrations of species found nowhere else. The study employs geographic information system technology to examine suitability for six crop categories in selected conservation localities worldwide: those portions of regions containing high biodiversity, protected areas (e.g. national parks) within these regions, and 10-km bands around the protected areas that are dominated by forest. Analyses reveal low suitability for most crop categories under both commercial and subsistence scenarios, with a few exceptions. In most cases, adequate planning can enable the coexistence of agriculture and biodiversity without compromising either.