The Wog Wog Habitat Fragmentation Experiment

1992 ◽  
Vol 19 (4) ◽  
pp. 316-325 ◽  
Author(s):  
Christopher R. Margules
Keyword(s):  
Experimental Design ◽  
Habitat Fragmentation ◽  
Field Experiments ◽  
Biological Diversity ◽  
Fragment Size ◽  
Experimental Treatment ◽  
Treatment Data ◽  
Drainage Line ◽  
Pre Treatment ◽  
Line Sample

An experiment to study the effects of habitat fragmentation on biological diversity was commenced in an Eucalyptus forest, in February 1985, at Wog Wog in southeastern New South Wales, Australia. The two hypotheses which are being tested are (1) that habitat fragmentation reduces biological diversity, and (2) that the reduction in diversity is fragment-size dependent.The experimental design consists of three fragment-sizes replicated six times. The sizes are 0.25 ha, 0.875 ha, and 3.062 ha, the two larger ones being progressively c. 3.5 times the size of the smaller ones. Four replicates (12 fragments) were retained as Eucalyptus forest when the surrounding land was cleared for a softwood (Pinus radiata) plantation. Two replicates (six fragments) are controls in an adjacent State Forest.The sampling is stratified into slopes, drainage lines, and inner and outer zones, with samples replicated twice in each stratum. Thus, there are two outer slope and two outer drainage-line sample sites, and two inner slope and two inner drainage-line sample sites. This gives 144 permanent sample sites within the Eucalyptus forest.Following the experimental treatment, a further 44 permanent sample sites were established between the fragments. Aranae, Phalangida, Formicidae, Scorpionidae, Diplopoda, Coleoptera, and vascular plants, are the main groups of organisms involved in the experiment. Mosses and liverworts, breeding birds, small ground-mammals, skinks, and bats, are also being monitored.Monitoring commenced in February 1985. The experimental treatment, i.e. forest fragmentation, took place during 1987. Two years after the treatment there were still no experimental results, because of the inherent delays in sorting and identifying the arthropods, and in establishing and managing the very large database involved. However, the analysis of some pre-treatment data is used to assess the experimental design. This analysis demonstrates the importance of adequate replication in ecological field experiments.

scholarly journals Improvement of waste water quality by application of mixed algal inocula

2018 ◽  
Vol 53 (1) ◽  
pp. 77-82
Author(s):  
MA Riaz ◽  
B Ijaz ◽  
A Riaz ◽  
M Amjad
Keyword(s):  
Waste Water ◽  
Experimental Treatment ◽  
Total Coliform ◽  
Post Treatment ◽  
Coliform Bacteria ◽  
Physiochemical Parameters ◽  
Pollutant Concentrations ◽  
Pre Treatment ◽  
Wastewater Samples ◽  
The One

Present study aim to investigate application of microalgae for improvement of physiochemical parameters of waste water and improvement of treatment process through reducing the pollutant concentrations including coliform bacteria through their ability to uptake nutrients. Aquatic cultures were conducted in container with dimensions of 1.5×3sq ft. and wastewater samples 5 Litre samples were collected in plastic cans from Sukhnar drain and algal samples were collected from Bhaini Sigyain Village near Ravi Siphon, Lahore. The one experimental treatment lasted for 10 days to make 50% 5 liter water added concentration and 200g of inocula of algae were grown in wastewater container for experiments to optimize at room temperature as local outdoor cultures conditions for wastewater treatment. Total experiment repeated thrice and completed in 30 days. Results show that treatments improved the physiochemical parameter after week. Turbidity (NTU), total suspended solids (mg/L), total dissolved solids (mg/L), nitrate (mg/L), phosphate (mg/L) decrease (P < 0.05) after treatment. However, pH not significantly decreases (P≥ 0.05) pre-treatment values 6.56±0.05 (mg/L) and post-treatment 6.53± 0.057(mg/L). Maximum total coliform disinfection (P < 0.05) was indicated with 200 g of algae was pre-treatment 1602± 6.8 (MPN) and post treatment 1447±39.5 (MPN) observed.Bangladesh J. Sci. Ind. Res.53(1), 77-82, 2018

scholarly journals Sensor Placement via Optimal Experiment Design in EMI Sensing of Metallic Objects

2016 ◽  
Vol 2016 ◽  
pp. 1-14
Author(s):  
Lin-Ping Song ◽  
Leonard R. Pasion ◽  
Nicolas Lhomme ◽  
Douglas W. Oldenburg
Keyword(s):  
Experimental Design ◽  
Field Experiments ◽  
Information Gain ◽  
Estimation Error ◽  
Sensor Placement ◽  
Model Parameters ◽  
Placement Problem ◽  
Empirical Survey ◽  
Optimal Experiment ◽  
Linearized Model

This work, under the optimal experimental design framework, investigates the sensor placement problem that aims to guide electromagnetic induction (EMI) sensing of multiple objects. We use the linearized model covariance matrix as a measure of estimation error to present a sequential experimental design (SED) technique. The technique recursively minimizes data misfit to update model parameters and maximizes an information gain function for a future survey relative to previous surveys. The fundamental process of the SED seeks to increase weighted sensitivities to targets when placing sensors. The synthetic and field experiments demonstrate that SED can be used to guide the sensing process for an effective interrogation. It also can serve as a theoretic basis to improve empirical survey operation. We further study the sensitivity of the SED to the number of objects within the sensing range. The tests suggest that an appropriately overrepresented model about expected anomalies might be a feasible choice.

scholarly journals Genetic and Biological Diversity of Trichoderma stromaticum, a Mycoparasite of the Cacao Witches'-Broom Pathogen

2006 ◽  
Vol 96 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Jorge T. de Souza ◽  
Alan W. V. Pomella ◽  
John H. Bowers ◽  
Carlos P. Pirovani ◽  
Leandro L. Loguercio ◽  
...  
Keyword(s):  
Field Experiments ◽  
Biological Diversity ◽  
Limiting Factor ◽  
Genetic Groups ◽  
Group I ◽  
Length Polymorphisms ◽  
Different Temperatures ◽  
Broom Disease ◽  
Agar Media ◽  
And Performance

The witches'-broom disease, caused by the basidiomycete Crinipellis perniciosa, is the most limiting factor for cacao cultivation in Brazil. Trichoderma stromaticum is a mycoparasite of the witches'-broom pathogen of cacao that is currently being applied in the field to manage the disease in Bahia State, Brazil. In this work, molecular and traditional methods were used to study the genetic and biological diversity of this mycoparasite. Ninety-one isolates, mostly collected from farms not sprayed with the fungus, were analyzed by amplified fragment length polymorphisms (AFLP), which showed that two genetic groups (I and II) of T. stromaticum occur in Bahia State. This classification of T. stromaticum into two distinct AFLP groups was also in agreement with several other characteristics, including growth on agar media at different temperatures and sporulation on infected stem segments (broom pieces) and rice grains. Group II favors higher temperatures compared with group I. The genetic and biological differences of the isolates, however, were not evident in field experiments, where sporulation was evaluated on the surface of brooms under natural conditions. Our results show that there is considerable genetic and biological diversity within T. stromaticum in Bahia and other cacao-growing regions of South America that are affected by the witches'-broom disease. This diversity could be explored in the development of efficient biological control agents against the disease. Factors that may affect the application and performance of this biocontrol agent in the field, such as sporulation on rice substrate and on the brooms and growth at various temperatures, are discussed.

8. Experimental Research

2017 ◽  
Author(s):  
Sandra Halperin ◽  
Oliver Heath
Keyword(s):  
Experimental Design ◽  
Research Design ◽  
Experimental Research ◽  
External Validity ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Ethical Issues ◽  
Natural Experiments ◽  
The Common ◽  
Internal And External Validity

This chapter explores the principles of experimental research design as well as the issues and problems associated with different aspects of the approach. In particular, it considers the issue of internal and external validity, the common obstacles associated with experimental research, and what can be done to try and avoid or minimize them. The chapter first describes the five steps involved in the classic version of the experimental design before discussing three types of experimental design: laboratory experiments, field experiments, and natural experiments. It also examines the ethical issues that arise from experimental research and concludes by highlighting some of the advantages of experimental research.

scholarly journals Field Experiments and Behavioral Theories: Science and Ethics

2019 ◽  
Vol 53 (1) ◽  
pp. 89-93 ◽  
Author(s):  
Elizabeth Carlson
Keyword(s):  
Field Experiment ◽  
Real World ◽  
Field Experiments ◽  
Experimental Treatment ◽  
Constant Field ◽  
Relevant Factor ◽  
Multiple Factors ◽  
Behavioral Theories ◽  
Political Theories

ABSTRACTThe design of field experiments makes them inappropriate for testing many common political theories. These theories propose that certain factors—for example, income or information—affect how individuals make choices. To test these theories, researchers typically investigate the correlation between the relevant factor and individuals’ choices, holding other factors constant. Field experiments, in contrast, allow multiple factors to vary at once: they create real-world disruption and do not control how actors behave in response. Subjects’ choices will be affected by the experimental treatment as well as by other changes that occur as the larger system reacts. It will be difficult to isolate the effect of any one factor, particularly without a good preexisting model of the system and how it is likely to respond. If a field experiment will not tell us what we need to know, the benefit of the study cannot outweigh harm, and it also will be unethical.

scholarly journals Applying MERLIN for modelling nitrate leaching in a nitrogen saturated Douglas fir forest in the Netherlands after decreased atmospheric nitrogen input

1998 ◽  
Vol 2 (4) ◽  
pp. 431-437
Author(s):  
A. Tietema ◽  
B. A. Emmett ◽  
B. J. Cosby
Keyword(s):  
The Netherlands ◽  
Nitrate Leaching ◽  
Fast Response ◽  
N Deposition ◽  
Atmospheric Nitrogen ◽  
Refractory Organic Matter ◽  
N Input ◽  
Treatment Data ◽  
Pre Treatment ◽  
Manipulation Experiment

Abstract. The MERLIN model was applied on the results of a field-scale manipulation experiment with decreased nitrogen (N) deposition in an N saturated forest ecosystem in the Netherlands. The aim was to investigate the mechanisms that could explain the observed rapid response of nitrate as a result of the decreased N input. Calibrating the model to pre-treatment data revealed that, despite the high atmospheric N input, the trees relied on N mineralised from refractory organic matter (ROM) for their growth. MERLIN could simulate only the fast response of nitrate leaching after decreased input if this ROM mineralisation rate was decreased strongly at the time of the manipulation experiment.

Influence of receptions of the main processing of the soil, fertilizers and means of protection of plants on a contamination, agrophysical properties of the soil and efficiency of barley

10.12737/3832 ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. 139-143
Author(s):  
Спичков ◽  
Sergey Spichkov ◽  
Фомин ◽  
Vladimir Fomin
Keyword(s):  
Field Experiments ◽  
Plant Protection ◽  
Plant Protection Products ◽  
Soil Treatment ◽  
Soil Tillage ◽  
Soil Cultivation ◽  
The Third ◽  
Subsurface Treatment ◽  
Pre Treatment ◽  
Sowing Seed

The field experiments with barley of multiserial Vakula variety were conducted on gray forest soil of Kama region of theRepublic of Tatarstan. This experiment was carried out to identify the responsiveness of barley for fertilizers, methods of the basic soil cultivation and plant protection products. On average over three years of our research, the highest yield of barley (3.95 tons per hectare) was obtained in the flattered soil tillage and carrying out the calculated fertilizernorm in the way, when we used the seed protectant Stinger for pre- treatment of the soil. The yield was a little lower (3.88 tons per hectare), when we used Binoram for pre-sowing seed treatment, Albit was in the third place (3.80 tons per hectare), the fourth - Rizoagrin (3.65 tons per hectare), and the fifth - control (3.42 tons per hectare). The lowest barley yield (2.46 tons per hectare) were obtained on the background when not fertilized subsoiling tillage without the use of plant protection products. The use of seeds for incrustation, treated by Stinger chemical fungicide, increased the yield to 4.0 centner per hectare, compared with the control. When we used moldboard plowing, the yield declined in control to 4.7 centner per hectare and at fertilizered background to 4.9 centner per hectare, and at KSN soil treatment to3-5.3 centner per hectare. In arid 2010 the highest barley harvest was obtained at KSN-3 soil treating, on the second place is subsurface treatment and the third is plowing. Modern energy-saving methods of the basic soil cultivation, treating the calculated norms of fertilizers and use of plant protection products contribute to the production of planned productivity, saving fuel and lubricants, but they are unable to maintain phytosanitary conditions in barley fields within economic threshold. Taking inro account above-mentioned and the current state of agriculture in the steppe of the Volga region, it is necessary to alternate basic soil treatment methods, application of calculated norms of fertilizers and use protectants and biofungicides for pre-sowing treatment, considering fitoekzamination of seeds.

Field Experiments and Natural Experiments

2009 ◽  
Author(s):  
Alan S. Gerber ◽  
Donald P. Green
Keyword(s):  
Experimental Design ◽  
Growth And Development ◽  
Field Experiments ◽  
Observational Research ◽  
Natural Experiments ◽  
Methodological Issues ◽  
Political Methodology ◽  
Field Experimentation ◽  
The Many

This article evaluates the strengths and limitations of field experimentation. It first defines field experimentation and describes the many forms that field experiments take. It also interprets the growth and development of field experimentation. It then discusses why experiments are valuable for causal inference. The assumptions of experimental and nonexperimental inference are distinguished, noting that the value accorded to observational research is often inflated by misleading reporting conventions. The article elaborates on the study of natural experiments and discontinuities as alternatives to both randomized interventions and conventional nonexperimental research. Finally, it outlines a list of methodological issues that arise commonly in connection with experimental design and analysis: the role of covariates, planned vs. unplanned comparisons, and extrapolation. It concludes by dealing with the ways in which field experimentation is reshaping the field of political methodology.

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