Fall River/Matlock/Molalla Progress March 31, 2011
Report to NCASI: 2010 progress and current plans
page 1 of 4
March 31, 2011
Rob Harrison, Paul Footen, University of Washington
Scott Holub, Weyerhaeuser Company
Tom Terry, Weyerhaeuser Company (retired), now at USFS Olympia lab
Tim Harrington, Connie Harrington, Warren Devine, USFS, Olympia lab
Summary: Funding to the University of Washington from NCASI is currently
supporting research and outreach efforts for the Fall River, Matlock and Molalla longterm soil productivity studies (LTSPs), particularly facilitating direct comparisons of
results at the three sites. The major accomplishments and publications during 2010 and
continuing into 2011 include:
1) Publishing of a special issue (Issue 1 in 2011) of the Journal Forest Science entitled
"Deep Soils". Rob Harrison, Tom Fox and Dan Richter were editors. The cover of
this issue shows a profile of a Boistfort series soil from the Fall River LTSP with C
and N distribution with depth (Figure 1). Two of the eight articles in the special issue
include detailed information from the Fall River, Matlock and Molalla LTSPs,
including "Initial Response of Soil Carbon and Nitrogen to Harvest Intensity and
Competing Vegetation Control in Douglas-Fir (Pseudotsuga menziesii) Plantations of
the Pacific Northwest" by Robert A. Slesak, Stephen H. Schoenholtz, Timothy B.
Harrington, and Nathan A. Meehan (Slesak et al. 2011), and Deep Soil Horizons:
Contribution and Importance to Soil Carbon Pools and in Assessing WholeEcosystem Response to Management and Global Change by Robert B. Harrison, Paul
W. Footen, and Brian D. Strahm (Harrison et al. 2011).
Copies of the entire publication are available at:
http://soilslab.cfr.washington.edu/publications/DeepSoilsForestScience2011.pdf
2) Completion and publication of Chapter 6 "Maintaining Adequate Nutrient Supply -Principles, Decision-Support Tools, and Best Management Practices" by Robert B.
Harrison, Douglas A. Maguire and Deborah Page-Dumroese, in Sam D. Angima and
Thomas A. Terry (eds) Best Management Practices for Maintaining Soil Productivity
in the Douglas-fir Region. Oregon State University extension manuscript EM9023,
April 2011.
Copies of the entire manuscript are available at:
http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/20678/em9023.pdf
3) Completion of 5-year aboveground biomass equations and estimates at Matlock and
Molalla, and submission of a journal article manuscript to Canadian Journal of Forest
Research entitled "Predicting 5-year vegetation control effects on aboveground
biomass and nitrogen distribution of planted Douglas-fir on three sites", by W.D.
Devine, T.B. Harrington, T.A. Terry, R.B. Harrison, R.A. Slesak, D.H. Peter, C.A.
Harrington, C.J. Shilling, S.H. Schoenholtz.
Fall River/Matlock/Molalla Progress March 31, 2011
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4) Production of a manuscript, which is still being written, comparing nitrogen leaching
rates and total amounts of N lost by leaching, after harvesting at the highly-productive
Fall River (Boistfort series soil) LTSP to the lower productivity, coarse-textured
Matlock LTSP (Grove series soil). We already have several publications on N
leaching losses at Fall River, and work on comparisons of Matlock and Molalla, but
the quantitative (total loss) comparisons of these two sites will make that work much
more powerful and important. An anticipated date for submission of the manuscript is
late April or early May 2011.
5) Measurements of current tree diameters and heights at the Fall River LTSP are being
completed, and 26 trees have been sampled for detailed analysis to provide final
estimates of biomass in the bole-only harvest with and without competing vegetation
control. Field and lab work is currently being completed and we expect to prepare a
manuscript on methodology that will be submitted to a forestry journal by June.
6) Though no detailed plans have been made yet, after we have the field and lab work on
the Fall River stand biomass completed to the point of writing the manuscript, we
plan to resample Fall River soil to determine carbon and nutrient contents. There are
few estimates of the impacts of harvesting on soil carbon in Douglas-fir plantations of
the Pacific Northwest, and all suffer from serious problems of methodology, either by
quantifying soil C retrospectively and comparing to a stand at a different stage of
development, by sampling of only the forest floor or shallow soil horizons (typically
to 20cm), or other complications (Borchers and Perry 1992; Cromack et al. 1999;
Griffiths and Swanson 2001; Klopatek 2002; Kraemer and Hermann 1979; Prietzel et
al. 2004). In fact, Slesak et al. (2011), in their work on soil C change 2 years after
harvesting, found overall increases in soil C, and the largest changes in deeper parts
of the soil profile. Increases in the 30-60 cm zone added 11.1 Mg C ha-1 at the
Matlock LTSP. The largest changes in the Matlock LTSP were also below 30 cm.
Harrison et al. (2011) similarly found it would be impossible to determine ecosystem
C changes in a variety of ecosystems and treatments without sampling soil deeper
than 20 cm.
At Fall River LTSP, we built the carbon pools for the entire second-growth stand
before the site was harvested (Ares et al. 2005), sampled to 80 cm mineral soil depth
across all sites, and if we resample using similar methods as we used to characterize
the soil initially, this should give us the best estimate of the impact of various harvest
methods on soil carbon (i.e. bole-only, total-tree and total-tree+ with vegetation
control and bole-only harvest without vegetation control) available to-date for a
period of 11 years since harvesting. We will probably change the methodology
slightly to sample at fixed depth, but this will still give a comparable value. We
would also hope to take similar, longer-term resampling at Matlock and Molalla
LTSPs.
6) Additional plans for extending Fall River LTSP: Currently we are participating
with Weyerhaeuser Company and Oregon State University on a proposal that would
produce one or possibly two additional Fall River-type LTSP's in the region. The
Fall River/Matlock/Molalla Progress March 31, 2011
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proposal, developed with Idaho State University, received high initial reviews and
may be funded. We can't offer detail on this except to state that we will continue to
pursue additional funding sources to enhance our ability to assess the impacts of
forest management on long-term soils productivity. The Fall River LTSP gives us the
best model study in the region for doing this.
Literature Cited
Ares, A., T.A. Terry, K. B. Piatek, R.B. Harrison, R.E. Miller, B. Flaming, C. Licata, B.
Strahm, C.A. Harrington, R. Meade, H. W. Anderson, L.C. Brodie, and J.M. Kraft.
2007. The Fall River long term site productivity study in coastal Washington: site
characteristics, experimental design, and biomass, carbon and nitrogen stores before
and after harvest. U.S. Department of Agriculture Forest Service Gen. Tech. Report
PNW-GTR-691, Portland, OR, 85 p.
Available at: http://soilslab.cfr.washington.edu/publications/Ares-et-al-2007-GTR691.pdf
Borchers, J.G., Perry, D.A., 1992. The influence of soil texture and aggregation on
carbon and nitrogen dynamics in Southwest Oregon Forests and clearcuts. Canadian
Journal of Forest Research 22:298–305.
Cromack, K., Miller, R.E., Helgerson, O.T., Smith, R.B., Anderson, H.W., 1999. Soil
carbon and nutrients in a coastal Oregon douglas-fir plantation with red alder. Soil
Science Society of America Journal 63:232–239.
Griffiths, R.P., Swanson, A.K., 2001. Forest soil characteristics in a chronosequence of
harvested Douglas-fir forests. Canadian Journal of Forest Research 31:1871–1879.
Harrison, R.B., P.W. Footen and B.D. Strahm. 2011. Deep soil horizons: Contribution
and importance to soil C pools and in assessing whole-ecosystem response to
management and global change. Forest Science 57:67-76.
Available at: http://soilslab.cfr.washington.edu/publications/Harrison-etal-2011.pdf
Klopatek, J.M., 2002. Belowground carbon pools and processes in different age stands of
Douglas-fir. Tree Physiology 22:197–204.
Kraemer, J.F., Hermann, R.K., 1979. Broadcast burning: 25-yr effects on forest soil in the
western flanks of the Cascade Mountains. Forest Science 25:427–439.
Prietzel, J., Wagoner, G.L., Harrison, R.B., 2004. Long-term effects of repeated urea
fertilization in Douglas-fir stands on forest floor nitrogen pools and nitrogen
mineralization. Forest Ecology and Management 193:413–426.
Available at: http://soilslab.cfr.washington.edu/publications/Prietzel-etal-2004.pdf
Slesak, R.A., S.H. Schoenholtz, T.B. Harrington and N.A. Meehan. 2011. Initial
Response of Soil Carbon and Nitrogen to Harvest Intensity and Competing
Fall River/Matlock/Molalla Progress March 31, 2011
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Vegetation Control in Douglas-Fir (Pseudotsuga menziesii) Plantations of the Pacific
Northwest. Forest Science 57:26-35.
Available at: http://soilslab.cfr.washington.edu/publications/Slesak-etal-2011.pdf