HR: 1340h
AN: B23A-0924    [Abstracts]
TI: Homogeneous biogeochemical functions in terrestrial ecosystems of the heterogeneous coastal temperate forest ecosystem
AU: * D'Amore, D
EM: ddamore@fs.fed.us
AF: USDA Forest Service Pacific Northwest Research Station, 2770 Sherwood Lane, Suite2A, Juneau, AK 99801,
AU: Fellman, J
EM: jfellman@fs.fed.us
AF: University of Alaska, Fairbanks, PO Box 757500, Fairbanks, AK 99775,
AU: Edwards, R
EM: rtedwards@fs.fed.us
AF: USDA Forest Service Pacific Northwest Research Station, 2770 Sherwood Lane, Suite2A, Juneau, AK 99801,
AU: Hood, E
EM: eran.hood@uas.alaska.edu
AF: University of Alaska, Southeast, 11120 Glacier Hwy., Juneau, AK 99801,
AU: Berkowitz, J
EM: jberkowitz@fs.fed.us
AF: USDA Forest Service Pacific Northwest Research Station, 2770 Sherwood Lane, Suite2A, Juneau, AK 99801,
AB: The coastal temperate rainforest ecosystem of southeast Alaska has a complex landscape morphology at both large and small scales. The drastic topographic variation of this mountainous post-glacial landscape combined with frequent storms has developed a mosaic of forests and wetlands. At the stand level, lateral variation in topography, caused by frequent disturbances, such as windthrow and tree mortality, has produced hummocks and hollows. This complex terrestrial system has posed a challenge to terrestrial ecologists and soil scientists who have attempted to map ecosystem types and determine biogeochemical functions within these terrestrial ecosystems. Initial hydropedological research in the region has revealed patterns associated with hydric soil formation along soil toposequences. We have used a hydropedological approach to determine common hydrologic and biogeochemical functions in several specific ecosystem types associated with the soil toposequence including uplands, forested wetlands and bogs. The terrestrial communities in southeast Alaska are influenced by hydrology, soil type, and geomorphology, which we term "Hydropedomorphic" to describe the communities and their associated biogeochemical functions. We have combined observations of soil hydrology, measurements of carbon, nitrogen and phosphorus concentrations in soil solution and tributary streams along with novel measurement techniques of dissolved organic matter components using PARAFAC analysis to establish homogeneous patterns among these diverse hydropedomorphic units. Distinct vertical gradients in soil saturation and redox potential lead to specific biogeochemical transformations among the hydropedomorphic units. The hydropedomorphic units contribute dissolved organic material to tributaries that varies in quality and quantity seasonally. The identification of DOM export associated with specific mappable landscape attributes provides a template for estimating watershed and regional cycles of carbon, nitrogen, and phosphorus dynamics for assessments of ecosystem development and climate change.
DE: 0428 Carbon cycling (4806)
DE: 0497 Wetlands (1890)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting