A study of the soils and leachates of two ecologically different forest sites was started in September, 1968 with an object of evaluating soil factors as to site differentiation. Tension lysimeters with silicon carbide powder, as a contact material, were used to collect water passing through the soils of the two sites at a soil water tension of less than 0.10 bar. As the study was performed on sloping topography, tension lysimeters were required to measure both the down slope pathway and the vertical percolation of the soil water. The leachates from the master horizons of the two soils were collected weekly. The anion and cation content of the leachates was determined along with electrical conductivity, pH and total volume of water. The two soils, Whatcom series and Blaney series, were sampled according to their morphological characteristics. The samples were analyzed for selected physical, chemical and mineralogical properties. The properties selected were such that soil characterization was accomplished and information was provided for leachate interpretations. A greater volume of water passed through the Whatcom soil (permanent seepage site) than through the Blaney soil (mesic site). This was reflected in the genetic and morphologic characteristics of the two soils. The largest quantity of leachate was collected immediately above the compacted material under the solum. The cation concentrations of the leachates from these zones were similar in both the Whatcom and Blaney soils. Higher cation concentrations were observed in the leachates from the spodic horizons. Sodium was the cation of highest concentration in all the leachates and calcium, magnesium and potassium occurred in decreasing order. Seasonal trends seemed to appear to be present in both the anion and cation concentrations. The principal causes of these trends appeared to be the quantity and rate of water passing through the soil and soil temperature, although the latter was not measured directly it was inferred from the seasonal patterns. Soil water relations and associated soil properties appeared to be the main reasons for better tree growth on the Whatcom soil. The exchangeable calcium and magnesium content of the Whatcom soil may also have an influence. Field evaluation of forest sites may be accomplished using soil morphological characteristics as these are reflections of the important soil properties desirable for Douglas-fir growth. / Land and Food Systems, Faculty of / Graduate

Previous attempts to classify nutrient regimes of forest soil have been qualitative evaluations utilizing vegetation and/or physiographic site characteristics, morphological soil properties, and parent material. The major objective of this study was to describe and classify the soil nutrient regimes (SNR) of some Pseudotsuga menziesii ecosystems on southern Vancouver Island, British Columbia. The order of increasing variability for forest floor properties was pH(H₂0) <TC <TN <TS <TP <exMg <exCa <exK <exMn <minN. The order of increasing variability for mineral soil properties was pH(H₂0)=pH(CaC1₂) <TN <TC <exP = exMg <S0₄ <minN = exK <exCa <exMn. Consistent trends in soil property variability along gradients of soil moisture or nutrient availability or between parent material lithologies were not apparent. Multivariate analysis of understory vegetation and indicator plant analysis suggested a major trend in variation corresponding to a complex environmental gradient related to increased availability of soil moisture and nutrients. The arrangement of study plots along the gradient showed groupings which corresponded to both the calculated soil water deficit and inferred soil nutrient regime. One multivariate axis accounted for most of the variation of soil properties between study plots. The mineral soil and forest floor plus mineral soil quantities of minN, TN, exCa and exMg significantly increased along the nutrient gradient. Ordinations of mineral soil and forest floor plus mineral soil properties arranged most plots according to the moisture-nutrient gradient. Discriminant analysis of the soil properties selected linear combinations of properties which separated sites, parent material lithologies, soil moisture regime classes and SNR classes. Cluster analysis confirmed that minN and exMg of the forest floor plus mineral soil best separated SNR classes. Multivariate summaries of variation in understory vegetation and foliar nutrients were highly correlated to the soil properties which best separated SNR classes. The increasing quantities of these nutrients corresponded to increases in site index for the study sites. It was concluded that significant differences in N, Ca, and Mg availability existed between SNR classes for the study sites. These differences in nutrient availability corresponded to changes in understory vegetation, foliar nutrient status and site index for the study sites. Using forest floor plus mineral soil quantities of minN and exMg, a multivariate classification of the four SNR classes recognized in this study was proposed. / Forestry, Faculty of / Graduate

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Thesis (doctoral)--Swedish University of Agricultural Sciences, 2006. / Thesis documentation sheet inserted. Appendix reprints four manuscripts co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains x, 282 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 1999. / Typescript (photocopy). Includes bibliographical references (leaves 117-121). Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2003. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains viii, 52 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 47-52).

No description available.