RESEARCH OPPORTUNITY AWARD (ROA) PROPOSAL

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1

RESEARCH
OPPORTUNITY AWARD (ROA)
PROPOSAL


The Influence of Geomorphic and Anthropogenic Processes on Decadal
-
Scale Sediment
Yield in the Western Cascades, Oregon: An Updated Compilation of Experimental
Watershed Data at H.J. Andrews Experimental Forest


Stephen B. Taylor, Associate Professor, Earth and Physical Sciences Department, Western
Oregon University, Monmouth, Oregon 97361; taylors@wou.edu


Frederick J. Swanson, Research Geologist, Pacific Northwest Research Station, U.S. Forest
Service, Corvall
is, Oregon 97331; fred.swanson@orst.edu


1.

INTRODUCTION


Mountainous watersheds, less than 100,000 ha, are fundamental landscape elements that form an
important setting for local ecological interactions, forest resource management, human occupation, and
w
ater supply development (Wohl, in press). As components of the global hydrosphere, they encompass a
set of physical and biological variables that interact via complex systems response and interdependent
feedback mechanisms (Schumm, 1977; Swanson and other
s, 1990). Upland watersheds also represent the
foundation
al components for mass
transfer from continent
s to ocean basins, directly contributing 50% of
the sediment that is exported annually (Milliman and Syvitski, 1992). Study of the production, transpor
t,
and storage of sediment in drainage basins is essential for deciphering their evolution and assessing the
relative controls of complex variables (Dietrich and Dunne, 1978; Swanson and others, 1982b). In
addition, geomorphic analysis establishes the fun
damental framework for monitoring the response of

forest ecosystems to extrinsic variables such as climate, land use,

and
natural disturbance

(Swanson,
1980; Swanson and Franklin, 1988; Stallins, 2006). As such, the understanding of hydrogeomorphic
variab
les and ecological process interactions is critical for designing sustainable water resource and
habitat management plans.

The purpose of this pro
posed work

is to extend
existing sediment
-
transport research in small,
mountainous watersheds at H.J. Andre
ws Experimental Forest (HJA), Oregon (Figure
s

1

and 2; attached
at back
).

The Andrews is comprised of 6400 ha (15,810

ac) of forestland located in the
Tsuga
heterophylla

zone of the western Cascades (Franklin and Dyrness, 1988). This region is renowned f
or its
rich forest habitat, productive timberlands and abundant water supply.
These f
orested drainage basins
export sediment by colluvial and alluvial processes in high
-
gradient channel systems. HJA
was
established in 1948 and
is manag
ed by the
Pacific N
orthwest Research Station
(USDA Forest Service)
.
Originally established to study timber harvesting techniques and forestry management practices, the
Andrews has evolve
d into a world
-
class
research facility and forms part of the Long
-
Term Ecological
Resear
ch (LTER) network supported by the National Science Foundation.
Given the
history
of science
at

Andrews, over 50 years of hydrologic and sediment
-
transport data are available for three sets of
c:
\
research
\
andrews_sabbatical
\
andrews_proposal_ver_
10
.doc


2

experimental watersheds ranging in size from 9


101 ha
(Table

1, attached at back)
(Swanson and Jones,
2002). These watersheds form part of a series of p
aired
-
basin
studies that are
used to evaluat
e the long
-
term hydrogeomorphic
effects of vegetative disturbance and recovery in a coniferous forest biome.
While
som
e of the paired
-
bas
in sediment data were analyzed

in the 1980’s

(e.g. Swanson et al., 1982a, 1982b;
Grant and Wolff, 1991), this work is superannuated

and an
up
-
to
-
date

synthesis is needed.
The specific

research objectives
of this proposal
are to: (1) com
pile and update existing sediment yield records from
gaged experimental watersheds at HJA, (2) analyze the sediment records in the context of historic land

use and hydrometerological events, and (3) evaluate the effects of geomorphic and anthropogenic
vari
ables on decadal
-
scale sediment yields in the western Cascades of Oregon.

This robust data set
provides an excellent platform from which t
o posit process
-
response models for

interdependent variables
that control sediment transfer in mount
ainous watersheds
.

The research proposed herein comprises par
t of a cooperative research opportunity

experience for
the first author

(Taylor)
, in
collaboration with personnel from

Andrews Experimental Forest and Oregon
State University. Taylor is a tenured associate pro
fessor of geology at Western Oregon University, a
f
our
-
year, undergraduate
institution in the mid
-
Willamette Valley. The proposed research activities are
designed to provide opportunities for: (1) professional development away from the demands of teaching

duties at a liberal arts college, (2) extension of research
-
based experiences to undergraduates, (3)
community outreach, and (4) scientific contribution to the understanding of upland watershed dynamics in
the Pacific Northwest.


2.

PHYSIOGRAPHIC SETTING
OF ANDREWS EXPERIMENTAL FOREST


2.1. Topography and Climate


Andrews Experimental Forest is physiographically defined by the Lookout Creek watershed which
forms part of the Blue River basin and McKenzie
-
Willamette drainage system of west
-
central Oregon
(F
igure 1). This fifth
-
order watershed (
sensu

Strahler, 1957) drains westward into the Blue River and
occu
pies a total drainage area of 64

km
2
. Lookout Cre
ek lies 25 km west
of the High Cascades
divide
and
is bounded to the north and south by Blue River and

Lookou
t ridges, respectively (Figure 2
). Land
surface elevatio
ns range from 420 m (1350 ft) near

t
he drainage basin outlet to 1630 m (5347 ft) at
Carpenter

Mountain.

Taylor and Hannan (1999) summarized historic climate data for western Oregon. Andrews
E
xperimental Forest straddles Oregon Climate Zones 2 (Willamette Valley) and 4 (Northern Cascades),
with
moist, westerly Pacific air driven landward by
cyclonic and frontal storm systems. Precipitation
patterns are strongly seasonal with 80%

of annual tota
l occurring between October and

March. Average
annual precipitation varies from 230 cm (90 in) to 355 cm (140 in) across the Lookout Creek basin, as

3

governed by foreceful lifting
over elevated topography of the Cascade Range
. Persistent winter snow
cover

occurs at altitudes above 1100 m (Harr, 1981).

HJA mai
ntains 10 ga
ging stations in the Lo
okout Creek watershed
, with an outlet station located
600 m
upstream of the confluence with the Blue River

(Figure 2
)
. Analysis of stream
flow records reveals
that f
looding and high discharges directly correspond to seasonal precipitation patterns. Mean annual
discharge on Lookout Creek is 3.5 m
3
/sec (123 ft
3
/sec
) with average winter and summer season flows on
the order of 5.6 m
3
/sec (197 ft
3
/sec
) and 1.5 m
3
/sec (52
ft
3
/sec
), respectively. In descending order, the
three peak discharges of record (1950
-
2005) occurred in February 1996, 227 m
3
/sec (8000 ft
3
/sec
);
Dec
ember 1964, 189 m
3
/sec (6660 ft
3
/sec
); and Ja
nuary 1972, 118 m
3
/sec (4180 ft
3
/sec
).

Rain
-
on
-
snow
conditi
ons in
winter months are the common cause of catastrophic flooding and slope failure in the
western Cascades (Harr, 1981; Swanson and others, 1998).


2.2. Regional Tectonic Setting


HJA is situated in the Cascadia volcanic arc province with the Juan de Fuc
a Plate subducting
eastward beneath North America

(Figure 1
). This sub
duction zone has
a long history of oblique
convergence, tectonic accretion, arc volcanism, dextral shear, and clockwise rotation (Wells and others,
1984). Long
-
term rates of plate conv
ergence average 3.5 to 4.0 cm/yr (Adams 1984). Lookout Creek,
Blue River and the McKenzie River form headwaters to the Willamette Valley which represents a forearc
basin situated between the accretionary Coast Range

and Cascade volcanic a
rc

(Figure 1)
.
T
he Cascades
are characterized by

intermediate to mafic volcanism dating from late Eocene (40
-
35 Ma) to p
resent. Arc
volcanism is
narrowing and migrati
ng eastward over time, with
geometry of High Cascade volcanoes
controlled by the present
-
day subduction
-
z
one configuration (Priest, 1990).

Structurally,
HJA
is located 5 km west of the Horse Creek fault system (Figure 1). This system of
north
-
trending, en echelon n
ormal faults offsets
down
-
dropped blocks to the east, thus marking the
western boundary of the
High Cascades graben (Pries
t, 1990). This
intra
-
arc graben is 30 km wide and 50
km long, formed in association with regional east
-
west extension, parallel to tectonic strike of the
Cascadia subduction zone. As a result, the High Cascades in central Orego
n forms a distinct structural,
physiographic, and hydrogeologic province associated with arc
-
related Quaternary volcanism (Priest,
1
990; Sherrod and Smith, 2000).
Lookout Creek is geologically positioned at the eastern edge of the
w
estern Cascades provinc
e (Figure 1). The region was

uplifted between 5 and 3.5 Ma, approximately
concomitant with intra
-
arc graben development to the east (Priest, 1990; Smith and others, 1987). Hence,
the mountainous drainage
basins of the w
estern Cascades were largely establ
ished during the Pliocene
and subsequently sculpted by a spectrum of surface processes over the past 3 million years.


2.3. Bedrock Geology



4

Swanson and James (1975), Priest
and others (1988
), and Sherrod and Smith (2000) provided
comprehensive summaries o
f the bedrock geology in the Blue River
-
Lookout Creek region. Lookout
Creek is underlain by an Oligocene to Pliocene sequence of basaltic

(<57% SiO
2
)

to andesitic

(57
-
62%
SiO
2
)
, volcanicl
astics and lava flows (Figure 3
). Strata are gently tilted with dip
s less than 10 degrees to
the east
-
southe
ast, hence
geologic contacts are sub
-
parallel to top
ographic contour
. Bedrock can be
divided into three lithostratigraphic intervals: (1) a lower volcaniclastic sequence that forms part of the
Oligocene
-
M
iocene Lit
tle Butte Formation (early w
estern Cascades volcanism), (2) a middle lava flow
sequence comprising a portion of
the Miocene Sardine Formation (late w
estern Cascades volcanism), and
(3) an upper lava flow sequenc
e erupted during the Pliocene (e
arly Hig
h Cas
cades volcanism) (Figure 3
).
The lower volcaniclastic sequence is hydrothermally altered a
nd outcrops

on lower
-
elevation (< 850 m
)
hillslopes and valley bottoms in the western portion of Lookout Creek
. The middle and upper sequences
are dominated by eros
ionally resistant lava flows that support higher
-
elevation hillslopes and ri
dges (>
850 m
)
to the east
-
southeast
. The southwestern
corner of HJA is intruded by

a dike swarm that cross
-
cuts
older volcaniclastics, and likely served as a feeder system for

ov
erlying lava flows (Figure 3
).


2.4. Surficial Geology


The geomorphology and surficial geology at HJA was described by Swanson and James (1975),
Swanson and others (1982b), and Grant and Swanson (1995).
The present
-
day landscape is the product of
Pliocen
e
-
Quaternary incision associated with

glacial, fluvial, and mass wasting processes. Remnant
glacial features include erosional cirques at higher elevations along ridge lines to the east and south, and
isolated patches of late Wisconsinan till

(Figure 2)
.

Evidence for older glacial deposits occurs at lower
elevations in the Lookout Creek drainage, extending down the valley to 760 m (2500 ft).
Site soils are
weakly developed and formed on bedrock terrain mantled with veneers of colluvial and residual
diami
cton (
“gravelly loams”,
< 3 m thick). Subgroups include Typic Dystrochrepts, Typic
Hamplumbrepts, Ultic Hapludalfs, and Andic Dystrochrepts in decreasing order of abundance (Dyrness
and Hawk, 1972). Given the high rates of erosion in this mountainous lan
dscape, the sediment record
only extends back to middle Pleistocene.

Lookout Creek can be divided into hillslope and valley
-
bottom geomorphic regimes. Style of
surficial process and landform associations are controlled by topographic position, underlying
bedrock
geology, and resistance to erosion. The western portion of the watershed is character
ized by steep side
-
slopes (60
-
70%
) and low
-
order mountain valleys. Co
lluvium is transported
in
hillslope environments via
a combination of diffusive mass wasting

processes (e.g. creep, tree throw, bioturbation) and larger
-
scale
slope failure

(Figure
s

3

and 4
)
. Other mass wasting features include earthflow deposits, rotational
slumps, slid
e scars, and landforms
indicative of debris flow processes (e.g. bedrock
-
sco
ured channel
b
ottoms, slide scars, and gravel

levees). The sediment mass is delivered to higher
-
order tributaries by a

5

spectrum of hydraulic processes that range from streamflow to hyperconcentrated flow to debris flow.
Once in the primary fluvial system
, turbulent channel flow expor
ts sediment out of sub
-
basins

as
dissolved, suspended, and traction load

(Figure 4)
. Each of these processes routes sediment into and out
of storage, depending on energy level of the syste
m (Swanson and others, 1982a). Storm
-
driven slope
failure and debris flow events occur episodically throughout the western Cascad
es
. (
Swanson and
Dyrness, 1975; Swanson and Swanston, 1977
)
. D
ebris flow
s

dramatically alter valley
-
floor morphology
(Benda, 1990) and have a significant influenc
e on aquatic ecosystems in the Pacific Northwest (Gregory
and others, 1989).
During the past 55

years of study at HJA
,
75% of
geomorphically significant
debris
-
flow events occurred
during the two winter storms of record in
1964
-
1965 and
1996 (
Snyder, 2000
).

Another event of note includes a storm in February, 1986 which spawned localized debris flow in select
sub
-
basins.

Grant and Swanson (1995) concluded that bedrock geology exerts a dominant influence on mass
wasting processes and valley morphology at HJ
A. The stratigraphic occurrence of hydrothermall
y altered
volcaniclastic
s overlain by erosion
ally
-
resistant flow rocks
result
s

in over
-
steepened slopes and an
unstable colluvial en
vironment subject to earth flow
,
rotational slump, and debris slide (Figure
s

3

and 4
)
.


2.5. Vegetation and Landuse


The western Cascades Range lies in the
Tsuga heterophylla

Zone of Franklin and Dyrness (1988).
Dominant forest species include
Pseudotsuga menziesii

(Douglas
-
fir),
Tsuga heterophylla

(western
hemlock), and
Thuja p
licata

(western red cedar), with lesser occurrence of
Abies amabilis

(silver fir) at
higher elevations (Vanderbilt and others, 2002). Understory vegetation includes rhododendron, salal,
various fern varieties, and Oregeon grape (Cromack and others, 1979).

T
his vegetative assemblage forms
part of the classic old
-
growth timber stands (400


500 yrs old) that were logged extensively in the Pacific
Northwest during the early and mid
-
1900's. Federal forest lands comprise over 50% of the western
Cascades, 25%
of which is
subject to logging and road construction (Jones and Grant, 1996).
Approximately 30% of HJA land was cut and revegetated with plantation forests
of
varying composition
and age. Prior to anthropogenic activities, the natural disturbance regime
was driven primarily by
climatically
-
controlled wildfire, flooding, and mass wasting (Swanson and others, 1990). Field evidence
suggests that HJA experienced notable fire disturbance in the 1800’s, prior to implementation of forest
management practices.


3. PREVIOUS RESEARCH


Study of
long
-
term watershed behavior has been a central feature of the Andrew Experimental
Forest research program for more than 50 years, most notably in the International Biological Program of
the 1970s and Long
-
Term Ecological Res
earch (LTER) program since 1980.

Hydrologic and geomorphic

6

research at HJA spans a

breadth of topics including
runoff
-
respo
nse analysis
, hyporheic zone studies,
hillslope hydrology, sediment budget analysis, mass transfer mechanisms, woody debris distribu
tion,
landform ana
lysis,
and geomorphic effects

of
extreme meteorological events. Swanson and Jones (2002)
provided a synthesis of recent and past
hydrogeomorphic
work at the HJA
study site.

Small
experimental watersheds

(9
-
101 ha)

at Lookout Creek
form t
he basis for paired
-
basin studies
that focus on various aspects
of geomorphic, hydrologic, and ecological monitoring

(Table 1)
. This

long
-
term
research
has spanned the careers of three g
enerations of scientists and generated a rich body of
literature cove
ring
a wide variety of t
opics related to mountain ecosystems
. The results of this

work
repres
ent an invaluable foundation upon which to frame

regional
forest

management plans.

Long
-
term h
ydrologic and sediment
-
transport data are available for three sets
o
f paired basins,
including

watersheds 1
-
2
-
3

(WS 1
-
2
-
3)
, watersheds 6
-
7
-
8

(WS 6
-
7
-
8)
, and watersheds 9
-
10

(WS9
-
10)
(Figure 2
, Table 1)
. Of the three sets,
WS 1
-
2
-
3 and WS 9
-
10 have

received the most attention in
terms of
sediment budget analyse
s
and
studie
s relating
sediment yield to timber harvest techn
iques

(
e.g.
Frederiksen and Harr, 1979;
Swanson and others, 1982a
, 1982b
;
Grant and Wo
lff, 1991; Grant and
Hayes, 2000
; Swanson and Jones, 2002).


3.1. Experimental Watersheds 1
-
2
-
3


Fredericksen (1970)
, Fre
deriksen and Harr (1979),
and Grant and Wolff (1991) conducted sediment
yield a
nalyses on WS 1
-
2
-
3
. This work was more recently updated by Grant and Hayes (2000), with a
status report summarized in

Swanson and Jones (2002). These cited works cover variab
le time periods of
the sediment discharge record, ranging from
1958 to 1999

(Table 1)
. S
tudies

at WS 1
-
2
-
3

document
significant
sediment
-
yield
increase
s

in the years immediately following timber harvest, with an
exponen
tial decline as forest regeneration
progresses
.

In addition, catastrophic debris flow events have a
considerable effect on sediment yield trajectories recorded at
the
HJA experimental watersheds.

As such,
Grant and Wolff (1991
) concluded that evaluation of harvest effects on long
-
term sedi
ment yield must be
considered in the context of timing in relation to storm
-
induced transport events.


3.2. Experimental Watersheds 9
-
10


The
original focus of the WS 9
-
10 paired basin project

was on variation in

nutrient cycles as related
to

anthropogenic

disturbance (harvest practice),
peak flow discharge,
vegetative regrowth, erosion, and
aquatic biology (Cromack and others, 1979
; Harr and McCorison, 1979). Cromack and others

(1979)
used WS
-
10 to quantify

the
change in sediment yields
resulting from
ti
m
ber harvest

and vegetative
re
growth in the western Cascades.
Their study examined changes in WS
-
10 within the first 3 years
following harvest (1975
-
197
8);

quantifying
storage volume
s

and transport rates of organic matter,

7

nitrogen content, and channe
l bed
load
.
They concluded that
logging

increased
org
anic debris loading in
streams and
net sed
iment y
ield over the period of study
.


Work on
WS
-
10 was extended further by
Swanson and others (1982a
) who
compiled a sediment
budg
et
emphasizing
exchanges between h
illslope and channel storage compartments. They examined
pre
-
harvest organic and
inorganic material transfer covering
the pe
riod
from 1969 to 1974.
In addition, a

short
-
duration analysis of post
-
logging effects in WS
-
10 was provided by Swanson and Fredri
ksen (1
982)
and Swanson and Jones (2002
). These studies

documented increased rates of post
-
harvest

sediment yield
,
peaking in the second year after cutting, with
subsequent
exponential declines
after revegetation
. As with
the WS 1
-
2
-
3 paired basin set, th
e sediment record at WS
-
10 is overprinted with the effects of debris flow
activity spawned during storm event
s in February 1986 and
1996. In contrast, WS
-
9 shows no evidence
of debr
is flow occurrence for
the past several centuries. T
he presence or
absenc
e of debris flow
is likely
controlled by

inter
-
site variation in
geomorphic variables.
Regardless of causal mechanisms,
episodic
debris
-
flow events have
demonstrable
impacts on long
-
term trajectories of post
-
harvest sediment yield

in
the w
estern Cascades

(Figure 5)
(
Grant and Wolff, 1991;
Swanson and Jones, 2002)
.

In sum, the previous sedimentation studies in paired
-
basin

experiments at HJA demonstrate that
complex response mechanisms operate in forested watersheds, with dynamic interplay between harvest
t
reatments, frequency of meteorological events, and intrinsic geologic v
ariables
.


4
.

STATEMENT OF THE PROBLEM


Timber harvesting from coniferous forests represents an anthropogenic disturbance that initiates
secondary ecological succession as vegetative re
covery occurs over time (Cromack and others, 1
979).
This perturbation
results in
hydrogeomophic response via changes in

stream discharge, en
ergy
expenditure, and
sediment yields. Other variables that influence the system include road construction,
loggin
g practice, and post
-
harvest management techniques (e.g. tree planting, slash burning, fertilization).
In terms of forest ecosystem function, routing and storage of sediments have significant influence on
distribution of nutrients and disturbance zones (S
wanson and others, 1982a, 1982b).
Understanding of
the post
-
harvest effects, rate of vegetative recovery, and attendant response in the hydrogeomorphic
system through time is essential for des
ign of habitat management and timber harvest plans

(
Gregory and

others, 1989; FEMAT, 1993;
Reid and Dunne, 1996).


4.1. Need
s Assessment


The long
-
term stream
flow

and sediment records at HJA represent an important data set
from which
to draw inferences about

the relative effects of geomorphic and anthropogenic disturb
ance on watershed
behavior.

While various aspects of this work
were
completed in previous studies
(Table 1)
,
the analyses
are based on
record
s

primarily from the 1970s and 1980s. There is signifi
cant need to update the

8

sediment
yield records and conduct
a comprehensive synt
hesis that includes the full 35
-
year record
,
particularly for the WS 9
-
10 basin set.

This time frame is i
mportant as it includes the February 1996
storm

event, and thus represents an opportunity to further decipher the relative roles o
f anthr
opogenic and
meteorologic

disturbance on mass
transport rates at HJA.
Updated sediment yield records are necessary
to more accurately reflect present
-
day sedimentation patterns
and to map out time
-
averaged response
trajectories during post
-
harvest
vegetative recovery

(Figure 5)
.


4.2. Research Questions


Given the above di
scussion, the critical
questions
considered in this investigation are
summarized
as follows:


(1)

What is the relationship between forest management, geomorphic disturbance, vegetative

recovery
and sediment flux over time?


(2)

What ar
e the
effects of timber harvesting on
hydrogeomor
phic variables
in paired basins

at HJA?


(3)

What are the long term, decadal
-
scale, effects o
f timber harvesting on sediment
-
yield trajectorie
s in
paired basins

at
HJA?

What ar
e the
effects of post
-
ha
rvest revegetation on sediment
-
yield t
rajectories
(
Figure 5)
?


(4)

What ar
e the long term
effects of storm
-
driven geomorphic processes on sediment
-

yield trajecto
ries
in paired watersheds
?

How does the occurrence of episodi
c debris flow events impact the sediment
yield trajectories

(
Figure 5)
?


(5)

Wha
t portions of the sediment
-
yie
ld trajectories
are controlled by

basin
-
scale changes in sediment
suppl
y versus variation in discharge and stream power
?


5
.

PROJECT
GOALS AND
OBJECTI
VES


We propose to
conduct an updated compilation and analysis of sediment yield data in the WS 9
-
10
basin set. The purpose of this project is to
extend the i
nterpretation and
findings from studies of
s
ediment
routing in these basins
since the last public
ations 25 years ago (
e.g.
Cr
omack and others,

19
79
, Swanson
and others,
1982
a
). This

early

work posed hypothes
es about changing rates of sediment flux
in the post
-
log
ging landscape, described sediment storage and transfer

under
for
ested conditions, and pro
vided
frameworks for assessing
the
effect
s of forest disturbance on sediment transport

(Figures 4 and 5)
.
Given
that we now
have a long (>30 yrs)
decadal
-
scale
record o
f post
-
logging sediment yield,
we will
use
the
updated compilations
to test
hypoth
eses
of biotic controls on
sedim
ent transfer

and also document rat
es of
soil loss in

watershed

environments.
The results of this study will be used to predict the effects of future
forest management practices on sediment transport systems in mountainous waters
heds
of the Pacific
Northwest
.


9

Specifically, we propose to compile, analyze, and pub
lish records of
surface erosion (through
1987), dissolved constituents of precipitation and streamflow (cations, silica, and a few others) (to
present), suspended and bedlo
ad sediment (to present), and debris fl
ows (1986, 1996 events).
Retrospective
analyses will give annual measures of temporal variation in sediment discharge over nearly
40 years from a forested
control
watershed

(WS
-
9)

and for 30+ years from a cl
earcut ba
sin (WS
-
10). The
results will be used to
constrain

sediment yield trajectories through time, following timber harvest and

subsequent vegetative recovery.
We will

also
examine
the
influences of climate variability, including 50
-
year
flood events
, and chan
ge in vegetative

cover on
orga
nic and inorganic mass transfer
. The findings
will then be compared

to
other
studies of biogeochemical cycling
at HJA and similar research
sites

throughout the United States.

Project results will contribute to the derivation

of empirical,
process
-
response models that may be used to mitigate effects of forest management practices on surface eros
ion
and sedimentation
.


6
.

METHODOLOGY


The proposed research will employ standard techni
ques for sediment
-
budget analyse
s, following
the protocol outlined by Reid and Dunne (1996).
Watershed sediment budgets are constructed by
quantifying the principal processes responsible for production and transport of surficial material. The
task involves monitoring hillslope and valley
-
bottom tra
nsport processes, with recognition of the linkages
between transfer and storage elements (Dietrich and Dunne, 1978; Trimble, 1983). Essential components
of sediment budgets include quantification of transport processes, storage elements, and time
-
averaged

sediment yields (Dietrich and others, 1982).
The
study
proposed herein
will focus

on

a retrospective
analysis of

sedime
nt yield and time
-
averaged
transfer rates

in WS9 and WS10
. Changes in s
torage
volumes and delineation of specific routing mechanis
ms a
re of secondary consideration
.


S
ediment yield
, erosion

and streamf
low data for WS 9
-
10

are stored
both in
-
house at HJA
and
on
Web
-
based information systems such as ClimDB/Hydro
DB, comprising part of the USDA
Forest Service
information network
(
http://www.fsl.orst.edu/ climhy/
).
The daily suspended sediment yield will be
derived as a product of
streamflow
discharge and suspended sediment concentration. Spot readings of
suspended sediment concentrations wil
l used to extrapolate average annual yield according to regression
models de
veloped
by Grant and Wolff (1991).

D
ata will be analyzed in the context of average
annual
yields, pea
k
-
flow discharge, precipitation patterns
, se
asonal variability and debris flow

occurrence
.


7. FACILITIES AND RESOURCES




8.
PROJECT
TIMELINE



10

For budgeting purposes, the proposed project period is divided into three quarters, approximately
organized according t
o the academic calendar established

by the Oregon State Board of Higher

Education. T
he project periods include: Quarter 1 (
spring 2007
)
, April 1


June 30;
Quarter 2 (
summer
2007
)
, July 1


September 30; and Quarter 3

(
fall 2007
)
, October 1


December 31.

During this period,
the first author (S. Taylor) will be on research
leave from teaching duties at Western Oregon University,
and serving as a visiting research associate to F. Swanson, jointly in residence at HJA and Oregon State
University. A breakdown of the proposed project timeline is as follows:


Quarter 1

04/01/07



06/30/07


Taylor
0.7
0

FTE

Data
collection
, field work

Quarter 2

07/01/07



09/30/
07


Taylor 0.7
0

FTE

Data analysis

Quarter 3

10/01/07


12/31/07


Taylor 0.25 FTE

Manuscript preparation


9.
PROJECT JUSTIFICATION


9
.1. Scientific Merit


Sediment budget tech
niques were originally defined and applied to mountainous watersheds in the
Oregon Coast Range

and w
estern Cascades during the 1970s, including those at HJA (Dietrich and
Dunne, 1978; Swanson and others, 1982
b
; Reid and Dunne, 1996)
. The long
-
term sedimen
tologic and

hydrologic record at HJA
provides an important source of data that spans the careers of multiple
generations of forest scientists. Quantifying and analyzing sediment yield records over such long time
frames allows evaluation of episodic meteor
ologic events, seasons, climate change, and vegetative
change.
The
WS9
-
10 basin set has

been a centerpiece for work on hydrology, biogeochemical cycling,
and soil/sediment routing in native and managed forests.
While several studies have examined the pos
t
-
logging sediment yield histo
ries
at HJA,

an updated synthesis is lacking
. There is signific
ant need to
extend
the
records, map out the
sediment
-
yield trajectories, and establish an updated

framework for long
-
term forest management decisions in the weste
rn Cascades.

The ongoing work on
sediment storage and
transport add
resses soil erosion,
nutrient capital, and disturbance themes that are import
ant parts of the
LTER program.
This
project will make a valuable contribution to the research mission at Andre
ws
Experimental Forest.

Study of small
mountainous
watersheds
at HJA
p
rovides a unique opportunity to

examine causal
relationships between landscape and land
-
use variables. S
caling is such that variability
of independent
geologic, climatic

and tectonic va
riables is minimized, thus allo
wing detailed examination
o
f local
disturbance regimes
.

The results of this study will
be used to advance c
onceptual and quantitative models
of sediment
-
transpor
t dynamics in headwater systems.


9
.2. Application and Releva
nce



11

L
and managers are increasingly conc
erned with erosion
responses to forestry and water resource
practices (Reid and Dunne, 1996).
Regional sediment budget analyses provide important data

from which
to predict future impacts by proposed land
-
surface al
terations.

Given that forest harvest rotation on much
Federal land is on the order of 80
-
100 years (Swanson and Fredriksen, 1982), the 30 to 40 year sed
iment
record at HJA provides an

important data set from which to design
regional
management plans.

Sedi
ment
-
yield models are also a
prime consideration in the assessment of
water management
syst
ems, dams, and reservoirs in the western Cascades. E
xisting management systems

are lar
gely
based
on early records
associated with
clearcutting techniques

in the 197
0s
. Since the initial
logging
treatments

in paired
-
basin studies at HJA
,
net regional
sediment yields have
diminished as forest recovery has
progressed and
harvesting techniques
have shifted towards
selective
-
thinning

techniques
.
Discrepancies
may
arise
when applying sediment
-
re
s
ponse data from th
e 1970’s to present
-
day management

practices
.

Given that many of the water management facilities

o
n f
edera
l lands
are currently

under review for re
-
licensing,
updated erosion
records
are needed
to more accuratel
y reflect pre
sent
-
day sedimentation
patterns and assess environmental impact

to aquatic ecosystems
.


9
.3.
Impact on
Undergraduate Education


T
he proposed research comprises part of a cooperative professional
-
development experience for the
first author whil
e on leave from teaching duties at Western Oregon University (WOU).

WOU

is a four
-
year undergraduate institution that forms an integral part of the Oregon University System
, with a historic
emphasis on teacher preparation
. Taylor is a member of the Earth

and Physical Sciences

Department
.
His content expertise includes environmental geology, fluvial geomorphology, and sedimentology.
The
WOU Earth Science program
provides a liberal arts core education and
offers B.S./B.A. degrees with
minors in Earth Syst
em Science and Geology.
The annual number of
students in the program
ranges from
30 to 50, with 1500 students tracking through the introductory Earth System Science sequence (ES100).
Taylor’s work
directly supports the advancement of geoscience education
, environmental management,
and hazards mitigation in t
he state of Oregon and beyond.
As such, the project offers significant potential
in terms of extending research
-
based experiences to undergraduates.



9
.4. Synergistic Potential


A landmark contribu
tion to the understanding of temperate forest geomorphology was provided by
Hack and Goodlett (1960) in the central Appalachians. Hack and Goodlett’s seminal work formed the
basis for the classic sediment budget and routing studies
conducted
in the conife
rous biome of the Pacific
Northwest (e.g. Dietrich and Dunne, 1978; Swanson and others, 1982b). As part of his dissertation work,
the first author used the Little River basin of Virgin
ia, Hack and Goodlett’s hallowed
study site, as a
bench
mark for compari
son to understand sediment storage bud
gets
in sandstone landscapes of the central

12

Appalachians (Taylor, 1999; Taylor and Kite, 2006). One of the comparator sites in Taylor’s work
included the Fernow Experimental Forest in West Virginia,

part of the Northe
astern Research Station
(U.S. Forest Service). The scientific linkages between the Appalachian work

and proposed HJA study are
numerous
, with the proposed
project representing closure of an ac
ademic feedback loop that has a
publication
lineage dating back

to 1960. Given this historic cross
-
fertilization
, t
he authors view the
present
proposal for work at HJA
as a seed project that will lead to longer
-
term synergistic research.

The
WS9
-
10
study will serve as a

starting point for long
er
-
term collaboration t
hat has high potential for
significant academic return. It is envisioned that the proposed work wil
l serve as a catalyst for

further

comparative
sedim
ent
-
budget studies
, at varying scales and under differing geologic conditions.
Preliminary

ideas for fut
ure work inc
lude comparative studies
with other watersheds in the U.S.,
construction of a si
te
-
wide sediment budget for Lookout Creek
,
regional
evaluation of geologic controls
on valley morphology, and derivation of
generalized
sediment
-
transport models fo
r the western Cascades.


10.

PROJECT DISSEMINATION


Data compilations, analyses, and derivative products resulting from this project will be made
available via web
-
based information technologies managed by the Andrews LTER facility.
Interim

findings will be p
resented at the fall 2007 meeting of the American Geophysical Union, with final
products submitted for publication in relevant, peer
-
reviewed journals. Project results will also be
disseminated at the local institutional level through campus newsletters,
faculty web sites, and class
curricular

materials (e.g. reading as
signments, contextual problem sets
, and class field trips).


11. RESULTS FROM PRIOR NSF SUPPORT


11.1. Taylor (Western Oregon University)



Co
-
PI Taylor has not directly received any NSF sup
port within the last five years.


11.2. Swanson (U.S. Forest Service)



A summary of outcomes from prior NSF support to Swanson is listed is follows:


The following information must be provided:

(a) the NSF award number, amount and period of support;

(b) t
he title of the project;

(c) a summary of the results of the completed work, including, for a research project, any contribution to
the

development of human resources in science and engineering;

(d) publications resulting from the NSF award;


13

Figure 1

14

Figu
re 2

15

Figure 3

16

Figure 4

17

Figure 5

18

Table 1

19

12.
REFERENCES CITED


Adams, 1984
, Active deformation of the Pacific Northwest conti
nental margin: Tectonics, v. 3,

p. 449
-
472.


Benda, L., 1990, The influence of debris flows on channels and valley floors in the Ore
gon Coast

Range, U.S.A.: Earth Surface Processes and Landforms, v. 15, p. 457
-
466.


Cromack, K., Jr.,
S
wanson, F. J., and Grier, C. C., 1979,
A comparison of harvesting methods and their

impact on soils and environment in the Pacific Northwest
:
in

C. T. Y
oungberg, ed., Forest soils and
land use: Proceedings of the

Fifth N
orth American Forest Soils Conference, Fort Collins, CO, p.
449
-
476
.


Dietrich, W.E., and Dunne, T., 1978, Sediment budget for a small catchment in mountainous terrain:

Zeitschrift fur Ge
omorphologie Supplementband, v. 29, p. 191
-
206.


Dietrich, W.E., Dunne, T., Humphrey, N.F., and Reid, L.M., 1982, Construction of sediment budgets for

drainage basins,
in

Swanson, F.J., Janda, R.J., Dunne,

T., and Swanston, D.N., eds.,
Sediment
budgets and

routing in forested dra
inage basins: Portland,
U.S. Forest Service, Pacific Northwest
Forest and Range Experiment Station Genera
l Technical Report PNW
-
141,
p.

5
-
23.


Dyrness, C.T. and Hawk, G., 1972, Internal Report 43: Vegetation and Soils of the Hi
-
15 W
atersheds,

H.J
. Andrews Experimental Forest:
Coniferous Forest Biome, U.S. Analysis of Ecosystems,
University of Washington, Seattle, Washington, USA.


FEMAT (Forest Ecosystem Management Assessment Team), 1993,
Forest ecosystem management: an

ecological, e
conomic, and social assessment, Portland, Oregon: U.S.D.A., Washington, D.C.


Franklin, J.F., and Dyrness, C.T., 1988, Vegetation of Oregon and Washington, second edition:

Oregon State University Press, Corvallis, 216 p.


Fredriksen, R.L., 1970, Erosion a
nd sedimentation following road construction and timber harvest on

unstable soils in three small western Oregon watersheds: U.S. Forest Service Pacific Northwest
Forest and Range Experiment Station Research Paper PNW
-
104, 15 p.


Fredericksen, R.L., and Har
r, R.D., 1979, Soil, vegetation, and watershed management,
in

Heilman, P.E.,

Anderson, H.W., and Baumgartner, D.M., eds., Forest soils of the Douglas
-
fir region: Cooperative
Extension Service Publication, Washington State University, Pullman, WA, p. 231
-
260.


Grant, G.E., and Hayes, S.K., 2000, Geomorphic response to peak flow increases due to forest harvest

activities, western Cascades, Oregon: Eos, v. 81. p. S220.


Grant, G.E., and Swanson, F.J., 1995, Morphology and processes of valley floors in mount
ain streams,

western Cascades, Oregon,
in

Costa, J.E., Miller, A.J., Potter, K.W., and Wilcock, P., eds., Natural
and anthropogenic influences in fluvial geomorphology: The Wolman volume: American
Geophysical Union Geophysical Monography 89, p. 83
-
101.


G
rant, G.E., Swanson, F.J., and Wolman, M.G., 1990, Pattern and origin of stepped
-
bed morpho
logy in

high
-
gradient streams, w
estern Cascades, Oregon: Geological Society of America Bulletin, v. 102,
p. 340
-
352.


Grant, G.E., and Wolff, A.L., 1991, Long
-
term

patterns of sediment transport after timber harvest,


20

western Cascades Mountains, Oregon, USA,
in

Peters, N.E., and Walling, D.E., eds., Sediment and
stream water quality in a changing environment: Trends and explanation: Proceedings of the
Vienna IAHS Sy
mposium, Vienna, Austria, August, 1991, International Association of
Hydrological Sciences Publication 203, p. 31
-
40.


Gregory, S.V., Lamberti, G.A., and Moore, K.M., 1989, Influence of valley floor landforms on stream

ecosystems: U.S. Department of Agricu
lture Forest Service General Technical Report PSW
-

110.


Hack, J.T., and Goodlett, J.C., 1960, Geomorphology and forest ecology of a mountain region in the

central Appalachians: U.S. Geological Survey Professional Paper 347, 66 p.


Harr, R.D., 1981, Some c
haracteristics and consequences of snowmelt during rainfall in western Oregon:

Journal of Hydrology, v. 53, p. 277
-
304.


Harr, R.D., and McCorison, F.M., 1979, Initial effects of clearcut logging on size and timing of peak

flows in a small watershed in wes
tern Oregon: Water Resources Research, v. 15, p. 90
-
94.


Jones, J.A., and Grant, G.E., 199
6, Peak flow responses to clear
cutting and roads in small and large

basins, western Cascades, Oregon: Water Resources Research, v. 32, p. 959
-
974.


Jordan, P., 2006,
The use of sediment budget concepts to assess the impact on watersheds of forestry

operations in the southern interior of British Columbia: v. 79, p. 27
-
44.


Milliman, J.D. and Syvitski, J.P.M., 1992, Geomorphic and tectonic control of sediment discharge
to the

ocean: The importance of small mountain rivers: Journal of Geology, v. 100, p. 525
-
544.


Priest, G.R., 1990, Volcanic and tectonic evolution of the Cascade Volcanic Arc, central Oregon: Journal

of Geophysical Research, v. 95, p. 19,583
-
19,599.


Pri
est, G.R., Black, G.L., Woller, N.M., and Taylor, E.M., 1988,

Geologic map of the McKenzie Bridge

quadrangle, Lane

County, Oregon: Oregon Department of Geology and Mineral

Industries
Geological Map Series GMS
-
48, scale 1:62,500.


Reid, L.M. and Dunne, T.,

1996, Rapid evaluation of sediment budgets: Catena Verlag GMBH,

Reiskirchen, Germany, 164 p.


Schumm, S. A., 1977, The fluvial system: New York, John Wiley &Sons, 338 p.


Sherrod, D.R. and Smith, J.G., 2000, Geologic map of upper Eocene to Holocene volca
nic and related

rocks of the Cascade Range, Oregon: U.S. Geological Survey, Geologic Investigation Series, Map
I
-
2569 (2 map sheets with explanatory text).


Smith, G.A., Snee, L.W., and Taylor, E.M., 1987, Stratigraphic, sedimentologic, and petrologic rec
ord of

late Miocene subsidence of the central Oregon High Cascades: Geology, v. 15, p. 389
-
392.


Snyder, K.U., 2000, Debris flows and flood disturbance in small, mountain watersheds: Unpublished

M.S. Thesis, Oregon State University, Corvallis, Oregon, 53

p.


Stallins, J.A., 2006, Geomorphology and ecology: Unifying themes for complex systems in

biogeomorphology: Geomorphology, v. 77, p. 207
-
216.



21

Strahler, A.N., 1957, Quantitative analysis of watershed geomorphology: American Geophysical

Union Transactio
ns, v. 38, p. 913
-
920.


Swanson, F.J., 1980, Geomorphology and ecosystems,
in

Waring, R.H., ed., Forests: fresh perspectives

from ecosystem analysis: Proceedings of the 40
th

annual biology colloquium, April 27
-
28, 1979,
Oregon State University Press, Corv
allis, OR, p. 259
-
170.


Swanson, F.J., and Dyrness, C.T., 1975, Impact of clearcutting and road construction on soil erosion by

landslides in the western Cascade Range, Oregon: Geology, v. 3, p. 393
-
396.


Swanson, F.J., and Franklin, J.F., 1988, The long
-
t
erm ecological research program: EOS, v. 69, p. 34.


Swanson, F.J., Franklin, J.F., and Sedell, J.R., 1990, Landscape patterns, disturbance, and management in

the Pacific Northwest, USA:
in

Zonneveld, T.S., and Forman, R.T.T., eds. Changing Landscapes:
An

Ecological Perspective: Springer Verlag, New York, p. 191
-
213.


Swanson, F.J., and Fredriksen, R.L., 1982, Sediment routing and budgets: Implications for judging

impacts of forestry practices:,
in

Swanson, F.J., Janda, R.J., Dunne, T., and Swanston, D.N.,

eds.,
Sediment budgets and routing in forested drainage basins: Portland, Oregon, U.S. Forest Service,
Pacific Northwest Forest and Range Experiment Station General Technical Report PNW
-
141, p.
129
-
137.


Swanson, F. J., Fredriksen, R. L., and McCorison, F
. M, 1982a,
Material transfer in a western Oregon

forested watershed,
in

Edmonds, Robert L., ed.
,

Analysis of coniferous forest ecosystems in the
western United S
tates:

US/IBP Synthesis Series 14. Stroudsburg, PA
,
Hutc
hinson Ross Publishing
Company, p.
233
-
266.


Swanson, F.J. and James, M.E., 1975, Geology and geomorphology of the H.J. Andrews Experimental

Forest, western Cascades, Oregon: USDA Forest Service Research Paper PNW
-
188, Portland,
Oregon, 14 p.


Swanson, F.J., Janda, R.J., Dunne, T., and Swanst
on, D.N., eds., 1982b, Sediment budgets and routing in

forested drainage basins: Portland, Oregon, U.S. Forest Service, Pacific Northwest Forest and
Range Experiment Station General Technical Report PNW
-
141, 165 p.


Swanson, F.J., Johnson, S.L., Gregory,
S.V., and Acker, S.A., 1998, Flood disturbance in a forested

mountain landscape: Bioscience, v. 48, no. 9, p. 681
-
689.


Swanson, F.J., and Jones, J.A., 2002, Geomorphology and hydrology of the H.J. Andrews Experimental

Forest, Blue River, Oregon,
in

Moor
e, G., ed., Field guide to geologic processes in Cascadia:
Oregon Department of Geology and Mineral Industries Special Paper 36, p.289
-
314.


Swanson, F.J. and Swanston, D.N., 1977, Complex mass
-
movement terrains in the western Cascade

Range, Oregon: Review
s of Engineering Geology, v. 3, p. 113
-
124.


Taylor, G.H., and Hannan, C., 1999, The climate of Oregon: from rain forest to desert: Oregon State

University Press, Corvallis, 211 p.


Taylor, S.B., 1999, Geomorphic controls on sediment transport efficiency
in the central Appalachians: A

comparative analysis of three watersheds underlain by the Acadian Clastic Wedge: Unpublished
PhD Dissertation, West Virginia University, Morgantown, WV, 463 p.



22

Taylor, S.B., and Kite, J.S., 2006, Comparative geomorphic anal
ysis of surficial deposits at three central

Appalachian watersheds: Implications for controls on sediment
-
transport efficiency:
Geomorphology, v. 78, p. 22
-
43.


Trimble, S.W., 1983, A sediment budget for Coon Creek basin in the Driftless Area, Wisoncin, 1
853
-

1977: American Journal of Science, v. 283, p. 454
-
474.


Vanderbilt, K.L., Lajtha, K., and Swanson, F.J., 2002, Biogeochemistry of unpolluted forested watersheds

in the Oregon Cascades: Temporal patterns of precipitation and stream nitrogen fluxes:
B
iogeochemistry, v. 62, p. 87
-
117.


Wells, R.E., Engebretson, D.C., Snavely, P.D., and Coe, R.S., 1984, Cenozoic plate motions and the

volcano
-
tectonic evolution of western Oregon and Washington: Tectonics, v. 3, p. 275
-
294.


Wohl, E., In Press, Human impac
ts to mountain streams: publication pending in Geomorphology, draft

version available online at www.sciencedir
ect.com.