矿业可持续发展与无废开采

矿山开采排出废水、废气、废矸石等废弃物对环境造成污染，对生态产生破坏，对经济造成损失。为使矿业持续发展，维护经济效益、社会效益和环境效益的统一，必须采取有效措施，实行矿山无废开采。使矿产资源开发和矿区发展走可持续发展的健康之路。     

Genetic Effects of Habitat Fragmentation on Common Species of Swiss Fen Meadows

Abstract:  The area of Caricion davallianae alliance in Switzerland has been considerably reduced and fragmented during the last 150 years. We assessed the genetic variability, inbreeding level, and among-population differentiation of two common habitat-specific plant species, Carex davalliana SM. and Succisa pratensis Moench, in 18 Caricion davallianae fen meadows subjected to fragmentation. We used a spatial field design of fen systems (six systems total), each consisting of one large habitat island and two small habitat islands. We used allozyme electrophoresis to derive standard genetic parameters ( A, P, H_O, H_E, F_IS, F_ST ). In Carex we identified a consistently lower A in isolated habitat islands; furthermore, H_E was lower in small habitat islands than in large habitat islands. In Succisa we identified a lower H_O in small habitat islands than in larger ones. Small habitat islands were marginally significantly differentiated (  F_ST ) from large islands for Succisa . For both species, no effects were evident for F_IS ; therefore, we argue that genetic drift rather than inbreeding is the main cause of the observed differences. The genetic structure of Carex and Succisa in small habitat islands differed from that in large habitat islands, but differences were small. It appears that the observed differences in genetic variability among fen meadows correspond to observed differences in fitness and demographic traits. We show that habitat fragmentation affects not only the rare species in an ecosystem but also reduces the survival probabilities of common species. One of the main goals of conservation should be to mitigate fragmentation of natural habitats in order to increase population sizes and connectivity.     

Uptake,elimination and biochemical effects of azadirachtin and tebufenozide in algae

Abstract

Effects of azadirachtin (isomer A, AZ‐A) and tebufenozide (TF) on freshwater algae were investigated using indoor aquatic microcosms. AZ‐A and TF were dosed at different concentrations to 10‐L microcosms. Chlorophyll and protein contents of the algae, and the concentrations of the insecticides in water and algae were monitored at intervals of time up to 20 d. Chlorophyll and protein contents in algae were inhibited at treatment levels of 3.0 and 4.5 μg AZ‐A/mL, whereas at 1.5 μg/mL, the chemical stimulated the chlorophyll production. The partition of AZ‐A between water and algae was reversible, and the bioconcentration factor (BCF) was low. In contrast, TF dosed at 0.25 to 0.75 μg/mL stimulated algal growth, probably due to its utilization of carbonaceous and nitrogenous intermediates and other breakdown products of TF as nutrients. The BCF was high and the organism functioned as a sink for the chemical. Extension of the laboratory findings to complex outdoor systems are discussed.     

Persistence of fensulfothion in a sandy‐loam soil and uptake by rutabagas,carrots and radishes using microplots

Abstract

Field microplots were treated with 141 and 282 ppm fensulfothion and 37.1 and 74.2 ppm fensulfothion sulfone. These concentrations are equivalent to field treatment rates of 8.48 and 16.96 kg Al/ha, fensulfothion, and 2.23 and 4.47 kg Al/ha, fensulfothion sulfone, respectively, for banded application (10 cm wide, rows 80 cm apart). The half‐lives in a sandy loam soil were 30–39 and 14–23 days, respectively. Fensulfothion sulfone and sulfide were the main derivatives found in fensulfothion treated soil.

The maximum levels of these derivatives were 21.22 and 22.95 ppm, respectively for the 8.48 kg/ha treatment and 33.90 and 42.45 ppm, respectively, for the higher treatment, which occurred between 30–60 days.

Carrots appeared to take up more fensulfothion from soil than rutabagas or radishes. The residue levels at harvest decreased in the order carrot peel > pulp > rutabagas root > peel > pulp. Residue levels of fensulfothion and sulfone in radishes were similar to those found in rutabagas. The ratio sulfoxide/sulfone in rutabagas ranged from 0.4–1.5 and in carrots from 1.7–7.6. This phenomenon is thought to be due to oxidative enzyme systems present in rutabagas. Dimethyl phosphorothioic acid, but not dimethyl phosphoric acid was detected (max. 1.33 ppm) in some rutabagas samples but not in carrots.     

Degradation of the insecticide fensulfothion by a mixed culture of soil microorganisms

Abstract

Fensulfothion was incubated in nutrient media with a mixed culture of soil microorganisms obtained from sandy loam. The half life of fensulfothion in both inoculated samples and sterile controls was about 16 wk. There was some conversion to fensulfothion sulfone (16% at 6 wk) in inoculated samples, but not in the controls. Traces of fensulfothion sulfide were found in both inoculated samples (<3%) and controls (<2%) . When 1% ethanol was added to the inoculated nutrient mixture the fensulfothion disappeared rapidly (t_½>～1_½> wk) with 32% conversion at 20 wk to fensulfothion sulfide.     

MACROINVERTEBRATE COMMUNITY STRUCTURE AS A PREDICTOR OF WATER DURATION IN WISCONSIN WETLANDS1

ABSTRACT: Fifty‐four Wisconsin wetlands were surveyed in spring 1996 to determine relationships between macroinvertebrate community structure and a suite of 11 environmental attributes. Canonical correspondence analysis (CCA) showed that, after alkalinity, hydroperiod was the next most significant environmental factor influencing macroinvertebrate community structure within the wetlands sampled. CCA and direct gradient biplots were used to identify indicator taxa characteristic of the spring macroinvertebrate communities in persistent and ephemeral wetlands, and taxa characteristic of semi‐terrestrial habitats adjacent to wetlands. Two models were developed to permit the prediction of a wetland's hydroperiod class. One model assigns a range of probabilities that a wetland has a hydroperiod longer or shorter than eight months based on the occurrence or abundance of fairy shrimp, mayflies, scuds, mosquitoes, and phantom midges. A second model predicts that a wetland's hydroperiod is longer or shorter than five months based on the joint occurrences of seven persistent indicator taxa. Data used in both models were derived from a rapid bioassessment of three shoreline D‐frame net sweeps. The use of a coarse level taxonomic identification (primarily order and family) allows the approach to be performed in the field or laboratory. The macroinvertebrate models allow a manager to estimate a wetland's hydroperiod when long term water duration records do not exist. This ability is important to water resource managers because hydroperiod classification (i.e., water permanency) is one criterion used in differentiating wetlands from lakes in Wisconsin and because Wisconsin's legal system affords lakes substantially greater protection than wetlands.     

灭幼脲Ⅲ号杀虫剂在大白菜和土壤中持久性及残留的研究

本文报道灭幼脲Ⅲ号杀虫剂在大白菜和土壤中的残留试验结果.经在南北两地连续两年的田间试验表明,灭幼脲Ⅲ号属非持久性农药,在作物和土壤中都较快地消失,在大白菜上的半衰期为3.8—14.0d,在土壤中为8.8—27.0d.用25％灭幼脲Ⅲ号胶悬剂稀释2500倍,每亩每次按常规用药10g或加倍药量20g(有效成分)施药,喷施2或3次,距最后一次施药三周时,灭幼脲Ⅲ号杀虫剂在大白菜的最大残留量为2.67ppm,在土壤中为13.81ppm.建议该农药在大白菜上的最高允许残留量(MRL)为3ppm,安全间隔期为21d.     

Persistence of hexaconazole,a triazole fungicide in soils

Abstract

Persistence of hexaconazole (2‐(2,4‐dichlorophenyl)‐l‐(lH‐l,2,5‐triazol‐l‐yl) hexan‐2‐ol) was studied in alluvial, red and black soils under flooded and nonflooded conditions. This fungicide was more persistent in all soils under flooded conditions than under nonflooded conditions and at 27°C than at 35°C. Degradation of hexaconazole in sterilized and nonsterilized soils proceeded at identical rates indicating a minor role of micro‐organisms in its degradation. The soil persistence of hexaconazole was not affected by the addition of wheat straw both under flooded and nonflooded conditions.     

Influence of foliar morphology and crown geometry on insecticide deposition and dissipation following an aerial spray over a mixed forest

Abstract

Deposition and dissipation of aerially sprayed phosphamidon insecticide over a mixed forest consisting of different species of coniferous and deciduous trees were studied. The data showed that the chemical deposited more and dissipated slower from deciduous foliage than from conifer needles. Differences in deposits and persistence were also found within each of the two foliar types. Leaf shape and orientation, crown geometry and foliar morphology appear to have played a role. No correlation was found between initial deposit levels and cuticular wax content of different foliar species. A controlled laboratory study showed that surface area/mass ratio played a more important role on initial deposits than pubescence/serrations present on foliar surfaces.     

Sorption and degradation of neonicotinoid insecticides in tropical soils

ABSTRACT

Neonicotinoids are the most widely applied class of insecticides in cocoa farming in Ghana. Despite the intensive application of these insecticides, knowledge of their fate in the Ghanaian and sub-Saharan African environment remains low. This study examined the behavior of neonicotinoids in soils from cocoa plantations in Ghana by estimating their sorption and degradation using established kinetic models and isotherms. Studies of sorption were conducted using the batch equilibrium method on imidacloprid, thiamethoxam, clothianidin, acetamiprid and thiacloprid, while degradation of imidacloprid, thiamethoxam and their respective deuterated counterparts was studied using models proposed by the European forum for coordination of pesticide fate and their use (FOCUS). Analytes were extracted using the quick, easy, cheap, effective, rugged and safe (QuEChERS) procedure and quantified by liquid chromatography-tandem mass spectrometry (LC–MS/MS). Average recoveries were high (≥ 85%) for all analytes. The findings from the study suggest that neonicotinoid insecticides may be persistent in the soils studied based on estimated half-lives > 150 days. The study also revealed generally low-sorption coefficients for neonicotinoids in soils, largely influenced by soil organic carbon.