SUMMARY The principles of colour perception are outlined and applied to the problems of soil colour measurement using ‘Munsell Soil Color Charts’. As care is needed in using these charts to make an accurate assessment of soil colour, recommendations for the correct methods for soil colour measurement are outlined. The three soil colour characteristics of Munsell Hue, Value and Chroma are commonly used in multivariate analyses as orthogonal, equi‐dimensional, linear variables that describe perceived colour space. Such an approach may be inappropriate because the angular separation of Hue and an approximately 2.5:1 scaling relationship between Value and Chroma should be accounted for in any model of perceived colour space. An appropriate and simple polar transformation of Munsell colour data is compared with some other coordinate systems for representing colour space, including the CIELAB system. This polar transformation is recommended for processing colour data in multivariate analyses.

The objectives of this study were to examine the effects of two contaminated site soils on seedling emergence and growth, compare the responses of different endpoints and species sensitivity, and develop appropriate statistical methods for the analysis of concentration‐response curves. Plants were exposed to field‐collected soils contaminated with amines or condensate. We reparameterized three nonlinear models (logistic, logistic with hormesis, and exponential) to determine any inhibiting concentration for a specified percent effect and confidence interval using regression analysis. Weighting procedures were applied, when necessary, to accommodate heteroscedasticity. This nonlinear regression approach was very satisfactory when used with data sets, each with 11 treatments, and produced an accurate, easily interpreted, and quantitative description of the data, which also provided qualitative information. The IC50s ranged from 2 to 96% contamination for condensate‐contaminated soil and from 3 to 38% contamination for amine‐contaminated soil. The responses were specific to species, endpoint, and soil. Mass measurements were generally more sensitive and precise than length measurements. Definitive tests were more sensitive than acute tests for endpoints other than emergence.

Abstract-The objectives of this study were to examine the effects of two contaminated site soils on seedling emergence and growth, compare the responses of different endpoints and species sensitivity, and develop appropriate statistical methods for the analysis of concentration-response curves. Plants were exposed to field-collected soils contaminated with amines or condensate. We reparameterized three nonlinear models (logistic, logistic with hormesis, and exponential) to determine any inhibiting concentration for a specified percent effect and confidence interval using regression analysis. Weighting procedures were applied, when necessary, to accommodate heteroscedasticity. This nonlinear regression approach was very satisfactory when used with data sets, each with 11 treatments, and produced an accurate, easily interpreted, and quantitative description of the data, which also provided qualitative information. The IC50s ranged from 2 to 96% contamination for condensate-contaminated soil and from 3 to 38% contamination for amine-contaminated soil. The responses were specific to species, endpoint, and soil. Mass measurements were generally more sensitive and precise than length measurements. Definitive tests were more sensitive than acute tests for endpoints other than emergence.

This ecological study of the Myall Lakes, a lagoon system on the New South Wales central coast, presents the physical setting and characteristics of the Lakes' catchments and relates these characteristics to the hydrochemical features of surface and subsurface waters. In turn these hydrochemical features have been related to the aquatic communities.It is suggested that the predominance of forest vegetation and stable soils in the Lakes' catchment has assisted in retaining these lakes in a generally undisturbed state.Fluctuations of salinity, turbidity and ionic concentrations in the lower part of the system are controlled by natural inputs of rainfall, run-off and tidal flushings. However, Boolambayte Lake and particularly Myall Lake, the upper part of the system, appear to be isolated from these influences. The aquatic communities reflect these hydrochemical differences.The lack of flushing of waters in this upper part of the system, in Dirty Creek and to a lesser extent in the Myall River immediately upstream of the Broadwater, makes these areas particularly susceptible to pollution and eutrophication associated with increased development.

The techniques of cluster analysis and principal component analysis (PCA) were applied to soils data from two Pleistocene alluvial terraces on the Nepean River, N.S.W., the Clarendon and Cranebrook Formations, to address issues raised in the literature regarding their stratigraphic relationships. A total of 160 profiles were sampled at four fixed depths to 1 8 m. Profiles were located in four 1000 by 400 m sample areas, two on each terrace. Soil samples were analysed for colour, pH, and 2.8 M HCl extractable Fe2+, Mn2+, Na2+, K+, Ca2+ and Mg2+. Data were analysed by using whole profiles as the soil entities. One branch of the dendrogram resulting from the cluster analysis contained soil profiles exclusively from sample areas on the Cranebrook Formation, whilst the other branch contained profiles exclusively from sample areas on the Clarendon Formation. Soils typical of the Lowlands Formation, Londonderry Clay and minor subdivisions within the terraces could be distinguished on the dendrogram. Similar subdivisions could also be observed on a PCA scattergram. The Clarendon and Cranebrook Formations are complex units which contain minor terrace features. Each has a distinctly different suite of soils which is consistent with their continued designation as separate stratigraphic units. The Lowlands Formation can be separated from the Cranebrook Formation upstream of Castlereagh and the Clarendon Formation should have its southern boundary to the Londonderry Clay moved north towards Richmond and its stratigraphy redefined.