Adaptation of wastewater surface flow wetland formulae for application in constructed stormwater wetlands

Over the past 30 years, the use of constructed wetlands for wastewater treatment has been a topic of significant research culminating in a good data base from which simplistic equations have been derived to aid in the design of these facilities to meet long term water quality treatment performance criteria. Over the past decade, the use of treatment wetlands has extended to stormwater and combined sewer overflow (CSO) management applications. Designing constructed wetlands for stormwater and CSO applications have unique challenges stemming from the highly stochastic nature of the hydraulic and pollutant loading on a stormwater wetland compared with wastewater treatment systems. This paper explores the possibility of adapting the simplistic models for wastewater wetlands for interim use in developing design guidelines for stormwater wetland systems. A procedure that takes into account the unsteady intermittent nature of stormwater inflows to these wetlands has been incorporated into one of these simplistic models and a case study presented to demonstrate the application of the procedure.     

Factors related to diversity of decomposer fungi in tropical forests

Recent studies suggest that host-preferences are common among certain groups of tropical fungal decomposers but rare in others, and sometimes occur where we least expect them. Host preferences among microfungi and ascomycetes that decompose leaf litter are common but usually involve differences in relative frequencies more than presence/absence, so their diversity may be loosely correlated with species richness of host trees. Strong host-specificity appears to be rare among wood decomposer fungi, whereas characteristics of their substrata and habitat are very important for this group. Anthropogenic disturbance predisposed a tropical forest to subsequent hurricane damage, and the resulting direct and indirect effects on host diversity and habitat heterogeneity were reflected in the decomposer fungal community more than sixty years after the original disturbance. While species richness of dictyostelid slime molds and functional diversity of their bacterial prey increased with disturbance, the more diverse microfungi and ascomycetes were apparently negatively affected by disturbance.     

Abdominal pigmentation in Drosophila melanogaster females from natural Indian populations

Females of Drosophila melanogaster collected from five geographically distant populations in India were analysed for the intensity of pigmentation in the 5th, 6th and 7th segments of the abdomen. In all three segments, this intensity was found to vary among individuals of any given population, and, furthermore, different populations differ with respect to this phenotypic trait. Statistical analysis revealed significant intra- and interpopulational variation. A clinical pattern was detected: females from populations closer to the equator tended to have lighter cuticle, in which case differences between the three segments could not be detected and all three segments responded both independently and jointly to latitudinal variation, as indicated by a statistically significant positive correlation between latitude and pigmentation score. This is the first report on abdominal pigmentation analysis in natural populations of D. melanogaster that provides evidence that phenotypic flexibility reflects temperature differences, as a result of which abdominal pigmentation shows geographic differentiation.     

The good,the bad and the ugly: science,aesthetics and environmental assessment

The question is raised, whether there are peculiarly scientific values which can be applied in environmental assessment. The use of the expression scientific interest is traced from its 19th century origins to modern British statutes. It is argued that attempts to replace expert judgements by objective scientific criteria (e.g., indices of biodiversity) can never be completely successful. In particular, interest is an aesthetic atribute particularly valued by scientists but incapable of precise measurement. While science provides the best framework for informed judgements on conservation issues, the judgements of scientists are inevitably distinct from their experimental results. Judgements rest on ethical and aesthetic values such as importance and interest, which are essential constituents of the scientific sub-culture, but which are not uniquely scientific.     

我国自然保护区的生态旅游开发

我国自然保护区的生态旅游开发袁兴中,刘红,高天刚（山东曲阜师范大学２７３１６５）ＤｅｖｅｌｏｐｍｅｎｔｏｆＥｃｏｔｏｕｒｉｓｍｉｎＮａｔｕｒａｌＲｅｓｅｒｖｅｓｏｆＣｈｉｎａ￥ＹｕａｎＸｉｎｇｚｈｏｎｇ;ＬｉｕＨｏｎｇ;ＧａｏＴｉａｎｇａｎｇ（Ｑｕｆ...     

Azadirachtin: I-interaction with the development of red cotton bugs

Azadirachtin, a material isolated from Azadirachta indica A. Juss, was applied to various stages of red cotton bugs (Dysdercus koenigii F.). The phytochemical evoked various specific and nonspecific effects during the course of development. Prolonged development, wing deformities unplasticisation of wing lobes, development of wingless adults and larval mortality were the characteristic features.

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Azadirachtine d'Azadirachta indica I: Interaction avec de développement de Dysdercus koenigii

Résumé L'azadirachtine, isolat de Azadirachta indica A. Juss a été utilisée (par traitement du substrat ou par dépôt sur l'insecte) sur un hétérométabole, Dysdercus koenigii F. Cette substance phytochimique provoque divers effets, spécifiques ou non, pendant le développement.Les modifications caractéristiques sont: un développement prolongé, de déformations alaires, une absence de plastification des bourgeons alaires, une production d'adultes sans ailes et une mortalité nymphale.De tels résultats suggèrent des études complémentaires pour mettre en évidence une hormone d'éclosion chez D. koenigii avec laquelle interférerait l'azadirachtine.

     

Medfly eradication in California:

The impact of malathion-bait sprays (directed against medfly, Ceratitis capitata [Wiedemann]) on an endemic gall midge (Rhopalomyia californica Felt) and its parasitoids was investigated during 1982–83 in the south San Francisco Bay area of northern California. In a heavily sprayed area (Woodside), a population explosion of the midge was detected following 24 applications of malathion bait. The midge population reached levels ca. 90x greater than those observed in an adjacent unsprayed area (Jasper Ridge). In a moderately sprayed area (Portola Valley), the midge population increased as much as 5x that observed in the adjacent unsprayed area (Jasper Ridge), following 12 applications of malathion bait. In laboratory tests, the malathion bait was toxic to both the midge and its parasitoids. The major parasitoids were Torymus koebelei (Huber), Zatropis capitis Burks, Platygaster californica (Ashmead) and Mesopolobus sp. Population increases of the midge following malathion-bait sprays were attributed to destruction of parasitoids and other natural enemies of the midge. If the environmental impact of malathion-bait sprays is related to the number of applications (as suggested in this study), then it would be worthwhile to determine the appropriate bait-spray strategy for a given situation, so as to minimize adverse effects on nontarget species, yet insure suppression or eradication of medfly.

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Résumé L'impact des pièges tratiés au malathion (destinés à Ceratitis capitata Wiedem) sur Rhopalomyia californica Felt et ses parasitoïdes a été examiné en 1982–1983 dans le sud de la zone de la baie de San Francisco en Californie. Dans une zone fortement traitée (Woodside), une explosion de population a été décelée après 24 traitements. La population de R. californica a atteint des niveaux 90 fois supérieurs à ceux observés dans une zone contiguë non traitée (Jasper Ridge). Dans une zone modérément traitée (Portola Valley), avec 12 traitement, la population de R. californica a atteint jusqu'a 5 fois celle de Jasper Ridge. Au laboratoire, le piège à malathion a été toxique tant pour R. californica que pour ses parasitoïdes, dont les principaux étaient: Torymus koebelei (Huber), Zatropis capitis Burks, Platygaster californica(Ashmead) et Mesopolobus sp. L'accroissement de la population de C. capitata après traitement a été attribué à la destruction de parasitoïdes et d'autres ennemis naturels. Si l'effet su l'environnement du traitement est lié au nombre d'interventions (comme le suggère cette étude), alors cela vaudrait la peine de définir une stratégie de traitement appropriée à une situation donnée, de façon à minimiser les effets négatifs sur des espèces non visées, tout en assurant la suppression ou l'éradication de C. capitata.

     

Nitrogen fixation efficiency,natural15N abundance,and morphology of mesquite (Prosopis glandulosa) root nodules

Summary The relative nitrogen fixation efficiencies (RE 1-[H₂ evolved÷C₂H₂ reduced]·100) of four mesquite (Prosopis glandulosa var.torreyana) rhizobia (Strains WR 1001, WR 1002, L5, L9) and a cowpea rhizobia (Strain 176A32) on mesquite were evaluated in a glasshouse experiment. Plant yield, shoot N accumulation, and the natural¹⁵N abundance (¹⁵N) of nodule tissue were determined. Strain WR 1002 failed to nodulate mesquite and strain L5 produced ineffective nodules. Among the three effective strains (WR 1001, L9, 176A32) the cowpea strain (176A32) and strain L9 had significantly higher RE than strain WR 1001. Differences in RE, however, were not accompanied by significantly higher plant yield and shoot N accumulation. The difference in¹⁵N abundance between foliar tissue and nodules (nodules minus leaves) was 0.47 ¹⁵N for the ineffective L5 nodules, while for the effective WR 1001, L9, and 176A32 nodules, respectively, this difference was 8.35, 7.81, and 8.35 ¹⁵N. This indicates a similar relationship between N₂-fixing effectiveness and natural¹⁵N enrichment of nodules that was previously observed in soybeans (Glycine max, L. Merr.). Strains WR 1001 and L9 produced elongate, indeterminate nodules typical for mesquite. The ineffective L5 nodules had few infected cells and an abundance of cortical amyloplasts. Mesquite nodules produced by the cowpea strain were spherical and were somewhat more similar in internal morphology to determinate nodules typical of cowpea than indeterminate nodules normally associated with mesquite.     

COMPARISON OF ATTACHED DIATOM COMMUNITIES ON NATURAL AND ARTIFICIAL SUBSTRATES1

A study of attached diatom communities on artificial and natural substrates was conducted in Wheelwright Pond, New Hampshire, during 1975. There were differences in the species composition growing on artificial glass slides and natural substrates. The slides favored the accumulation of Achnanthes minutissima Kütz. and decreased the relative abundance of Eunotia incisa W. Sm. ex. Greg. and Cocconeis placentula v. euglypta (Ehr.) Cleve. Large growths of planktonic species were also noted on the slides. Compositional differences between slides positioned at 15–30 cm (upper) and 1 m (lower) from the surface of the water were minimal. A similar community composition of periphytic diatoms was found on five aquatic macrophytes.     

Seasonal changes in adventitious root formation in hypocotyl cuttings of Pinus sylvestris: Influence of Photoperiod during stock plant growth and of indolebutyric acid treatment of cuttings

Seedlings of Pinus sylvestris were grown for 6 weeks under natural light conditions in a temperature controlled environment room. Cuttings from these plants were rooted in tap water or in indolebutyric acid (IBA) solutions for 60 days at an irradiance of 16 W m^-2. Experiments were performed at 3-week intervals during two growth seasons. — Seasonal changes in root formation were found in control cuttings as well as in IBA treated cuttings. The number of roots and the percentage of cuttings that rooted were high during early spring and autumn. During the summer period hardly any roots were formed. Stimulation of root formation by IBA occurred manily during spring and autumn when cuttings already possessed the ability to form roots. — The influence of photoperiod during stock plant growth was also investigated. Shorter photoperiod resulted in an increase in the number of roots and rooting percentage. The period during summer where rooting was inhibited under natural light conditions was considerably shortened when stock plants were grown at a photoperiod of only 4 h. The results demonstrate the importance of the growing conditions for stock plants for subsequent root formation. The results are discussed with special reference to the role of irradiance.