Timber Harvest Influences on Hydrology and Water Quality of PNW Forested Wetlands. Possibly the world’s shortest talk, if we base it on known facts. C. Rhett Jackson, Assistant Professor of Hydrology Warnell School of Forest Resources University of Georgia, Athens, GA.
Possibly the world’s shortest talk, if we base it on known facts.
C. Rhett Jackson, Assistant Professor of Hydrology
Warnell School of Forest Resources
University of Georgia, Athens, GA
* All previously observed, to some degree, in studies from the eastern U.S.
A Forested Wetland (or bog), PNW Forested Wetlands
small, semi-isolated, on till
Conceptual: Not to Scale.
Very shady below canopy, low primary productivity in understory and forest floor, seasonal surface saturation.
What critters live here?
Increased solar insolation, local decrease in ET, small water table rise
Shrub and herbaceous vegetation response,
Possible rutting of hydric soils depending on yarding methods,
Possible heavy deposition of logging slash (limbs and tops).
Study conducted in Georgia Coastal Plain depressional wetlands.
Increased solar radiation, decreased ET in GW contributing area, water table rise, possible nitrogen release. Sediment? Fertilizer?
Higher water tables, solar insolation, and nutrient release from uplands spur vegetation conversion. Shrub and herbaceous vegetation response, possible die-off of wetland trees. Sediment inputs are only likely from road surfaces.
Scary scenario: Habitat becomes suitable for bullfrogs - eat native amphibs.
The analogous question for streamflows in forested basins has been difficult to answer.
The hydrologic changes associated with urbanization, known to harm wetlands, are much larger.
Need to frame this question in terms of life histories of key species.
A Related Issue - Warming of Shallow Groundwater effects of timber harvest?
From Jenelle S.D. Black, U.W. MS Thesis, 2001 effects of timber harvest?
Issue: Will clearcutting an area of shallow groundwater flow to a headwater stream cause unacceptable water temperature increases?
This was a big issue in the Dickey River watershed analysis.
Issue is the subject of a groundwater study for the Bull trout group.