**[Topic List:]{.underline}**

1.  Nutrient Laden Surface Runoff from Mature Forest Sierran Watersheds:
    Sources and amounts -- Dr. Wally Miller

2.  Tahoe Science Consortium Science Themes Discussion -- Catherine
    Schoen

**[Topic Summaries:]{.underline}**

**Nutrient Laden Surface Runoff from Mature Forest Sierran Watersheds:
Sources and amounts -- Dr. Wally Miller**

Dr. Wally Miller gave a review of a study of forest runoff documented in
the article titled "Inconspicuous Nutrient Laden Surface Runoff from
Mature Forest Sierran Watersheds" and also presented new information
from forest litter leaching experiments documented in Theresa Loupe's
Masters Thesis titled "Inorganic N and P Concentrations in O-Horizon
Leachate from a Mixed Conifer Sierran Forest". The first study consisted
of installing runoff collection devices mid-slope in forested areas near
Truckee and the South Shore of Lake Tahoe. Over a 20 month period
(December 2001 to July 2003) 141 runoff samples were collected from 12
study plots (8 in Truckee and 4 in South Shore). Concentrations of
NH~4~^+1^, NO~2~^-1^ + NO~3~^-1^, and ortho-P in the runoff were higher
than any previously reported for other natural waters from mature forest
in Tahoe and surrounding ecosystems. Fire suppression in the Tahoe Basin
may play a part in this in the in the higher concentration because it
results in an accumulating layer of forest litter that slows nutrient
cycling and increases the potential for greater nutrient release.

The second study sought to determine if the layer of forest litter,
called the O-Horizon, present in Sierran Forests is an important source
of inorganic N and P in the runoff. Monoliths of O-horizons (10 to 15 cm
thick) were collected from the field and brought back to the lab for
bench scale leachate studies. Three of the monoliths were kept in tact
and three were separated in to Oi (fresh needles) and Oe (decomposing
needles) monoliths. Each monolith was subject to nine leaching cycles
that consisted of an initial and final misting with Reno Tap water and 7
daily snowmelt applications in between, and the volume of water applied
to the monoliths represented 23% of the mean annual precipitation.
Leachate was sampled at multiple points during each leaching cycle, and
all leachate was collected. The Reno tap water, snowmelt, and leachate
were analyzed for NH~4~^+^-N, NO~3~^-^-N, and PO~4~^3-^-P. Water and
nutrient budgets were developed with the leaching experiment data. The
nitrate and ammonium had inverse peaks over the course of the leaching
experiment where first the ammonium concentrations peaked then the
nitrate concentrations peaked, indicating mineralization followed by
nitrification. But the phosphorus came out much quicker in first misting
with much lower concentrations for the rest of the leaching cycles. Due
to abiotic formation of a lignin complex all monoliths reduced ammonium
concentration and the Oi horizon to the greatest degree. All monoliths
released nitrate and phosphates at similar magnitudes, but Oi at the
highest rate. Based on the leachate experiment results, net inorganic
nitrogen discharge is 0.45 kg/ha, and phosphate discharge is 2 kg/ha
from the o-horizon.

The article "Inconspicuous Nutrient Laden Surface Runoff From Mature
Forest Sierran Watersheds" can be found at the following internet
address:
<http://www.springerlink.com/media/5f8rkyguqj0vwvc7tpq0/contributions/g/3/5/0/g3503123v8v532pn.pdf>
Theresa Loupe's Masters Thesis "Inorganic N and P Concentrations in
O-Horizon Leachate from a Mixed Conifer Sierran Forest" will be on file
at the UNR Library within the next six months.

**Tahoe Science Consortium Science Themes Discussion -- Catherine
Schoen**

As a result of a last minute speaker cancellation, the Tahoe Science
Consortium's (TSC's) Science Themes were discussed at the December 7,
2005 LTIMP meeting. Tim Rowe of the USGS gave a brief description of
connection between the TSC's Science Themes and SNPLMA Round 7 research
grants. Because there were numerous research proposals submitted for
Round 6 research funds, the TSC has developed Science Themes that will
be used as criteria for Round 7 research proposals in hopes of defining
a more organized approach to research in the Basin. Utilizing the "Key
Management Questions" as criteria for research proposals was suggested
and rejected due to the number of questions, and to avoid confusion
created from the various versions of the "Key Management Questions"
circulating in our community. In addition to addressing one of the
defined science themes, Round 7 research proposals must also have a
federal agency sponsors to be funded from the \$3.75 million of SNPLMA
funds designated for research. Tim indicated that EPA rules prohibit
individuals from developing the Science Themes and submitting research
proposals for the same. The TSC is seeking input on the developed
themes, but has not received much input to date. The Round 7 SNPLMA
Research proposals are expected to be called for in January or February
of 2006.

LTIMP members brought up a number of concerns related to EIP, erosion
control project implementation, and adaptive management that they felt
could be served by research in the Basin. In addition to wanting to
prioritize the list of science themes, LTIMP members thought it would be
important to develop and apply criteria for prioritizing the EIP list.
The EIP list consists of a large number of projects that have not been
prioritized and are therefore given equal footing for available funding.
Assessing the degree of identified impacts in each EIP project area
would help prioritize the projects for funding and implementation.

LTIMP members were also looking for a greater connection between
proposed science themes and the implementation of erosion control
projects. There is a need for more applied science research that
assesses the effectiveness of commonly used BMP's in erosion control
projects. Similar to researching the impacts to groundwater from
infiltration basins, there are many other common components of erosion
control projects that have not been evaluated in the field or bench
scale, but that continue to be employed in erosion control projects
based on opinion. It would be beneficial to determine the conditions for
effective application of commonly used BMP's, as well as conditions
where they are ineffective or detrimental. LTIMP suggests a theme for
project implementation/effectiveness.

Research of the maintenance needs of erosion control projects and their
components could provide valuable information for future management
decisions. Maintenance is required for some BMP's to sustain
effectiveness (Sediment traps), as well there are maintenance activities
(sweeping) that increase the effectiveness of constructed erosion
control projects. The negative impacts of these maintenance practices
(vactor waste disposal, and sweeper generated dust clouds) should also
be determined and added to the positive benefits, to get a true
understanding of the net benefit. Erosion control project maintenance is
going to be a big issue for management to wrestle with given the growing
burden each implementer assumes (CTC grants require 20 year maintenance)
and the declining sources of funding for maintenance activities.

LTIMP members also recognized that there is little or no opportunity for
Adaptive Management of EIP implementation due to the limited effort to
report accomplishments beyond \$'s spent. While there is currently an
effort to develop accomplishment units, the effort to apply and analyze
them to determine EIP accomplishments and effectiveness will require
substantial effort, that would benefit from a consistent approach and
uniform reporting. It is clear with the impending TMDL that project
effectiveness will need to be measured in terms of load reductions. Will
the accomplishment units being developed provide useful input to
calculating project effectiveness in terms of load reductions, or will
implementers be required to develop and apply two different approaches,
to meet the regulating agencies' needs? How do we determine what has
been accomplished, and the net benefit? How do we analyze those
accomplishments to determine what changes need to be made to improve or
correct what has been done?

In Attendance:

Jay Aldean, HDR\*

Nancy Alvarez, USGS-WRD\*

Kim Carr, EDAW

Scott Carroll, CTC

Robert Erlich, LRWQCB

Steve Hall

Jere Harper, FS-LTBMU

Jon-Paul Harries, TRPA

Zach Hymanson, CTC

Christine Kirick, Wood Rodgers

Theresa Loupe, UNR

Chad Praul, NTCD

Dave Rios, NTCD

Tim Rowe, USGS-WRD

Catherine Schoen, USFS\*

Mark Sedlock, CTC

Chuck Taylor, USDA-NRCS

Chris Twomey, c2me\*

Rita Whitney, TRPA\*

Russ Wigart, CSLT

Next Agenda\*: