Pedological trends and implications for forest productivity in a Holocene soil chronosequence, Calvert Island, British Columbia, Canada.

Chronosequence studies of soil formation and ecosystem development provide important insights into the pathways and rates of change occurring on centennial and millennial time scales. In cool or temperate humid environments, Podzols are the predominant soil type formed under coniferous forests in coarse-textured parent material and have been a major focus of chronosequence studies. This study examined the rate and mechanisms of Podzol development and related forest productivity in a sand dune chronosequence in a hypermaritime climate in coastal British Columbia (BC). The sequence spans 10,760 864 years over eight sites and is the first documented chronosequence in coastal BC to span most of the Holocene Epoch. Soil samples from each genetic horizon were analyzed for bulk density, pH and concentrations of total carbon (C), pyrophosphate- and oxalate-extractable aluminum (Al) and iron (Fe), and total elements. Within ~3,500 years a mature Podzol had formed, with cemented horizons (ortstein and placic) present. Organo-metallic complexation appeared to be the dominant mechanism involved in podzolization . Despite a mild, moist climate conducive to chemical weathering, all soils had similarly low values for the Chemical Index of Alteration, suggesting that congruent dissolution of primary minerals may be occurring. Ecosystem retrogression is apparent in the latter stages of the chronosequence – a phenomenon not previously documented in coastal BC. Further research is needed to examine the interactions of nutrient limitation, soil physical barriers, and other possible drivers of ecosystem retrogression.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author