Research
Improving
prediction of climate change impacts on wetland-rich landscapes:
Testing model mechanisms with flux-data assimilation at multiple
sites.
Funding Source: Department of Energy, National
Institute for Climate Change Research
Dates: September 1, 2007 to February 28, 2011.
UB Principal Investigator: D. Scott Mackay
Project Principal Investigator: Ankur Desai (U.
Wisconsin)
Prediction
of climate change impacts on terrestrial carbon fluxes is highly
uncertain. Upland ecosystem models, even when constrained with
flux tower data, fail to explain interannual variability in CO2
fluxes in the upper Midwest. One possible reason is lack of model
mechanisms for wetland biogeochemistry and hydrology, where fluxes
would be expected to vary with changes in depth to saturation.
Wetlands are expected to be highly sensitive to climate change.
We propose to develop a wetland-landscape model and assimilate
long-term multiple flux tower observations to simulate wetland
and upland mechanisms simultaneously, with evaluation against
unassimilated flux observations. Model evaluation is typically
limited to single sites and extrapolation of these results across
larger regions is questionable. This research will improve understanding
of carbon-rich forest-wetland landscape response to climatic change.
Collaborative research: Restricted plasticity of canopy
stomatal conductance: Conceptual basis for simplified models of
canopy transpiration.
Funding Source: National Science Foundation,
Directorate for Geosciences, Hydrological Sciences Division
Dates: April 1, 2004 to March 31, 2008.
Project Director: D. Scott Mackay
Co-Investigators: Brent E. Ewers (U. Wyoming),
Eric L. Kruger (U. Wisconsin)
Project Web
site
Measuring
and modeling the source, transport and bioavailability of phosphorus
in agricultural watersheds
Funding Source: Environmental Protection Agency
STAR Grant, Nutrient Science for Improved Watershed Management
Dates: November 1, 2002 to November 15, 2006
UB Principal Investigator: D. Scott Mackay
Project Principal Investigator: Richard C. Lathrop
(Wisconsin DNR)
Project
web site
We will measure
and model the sources, transport, and fate of bioavailable phosphorus
(BAP) in the mostly agricultural 604-km2 watershed of Lake Mendota
near Madison, Wisconsin. This well-known eutrophic lake is impacted
by phosphorus (P) loading from agricultural sources, including
row crops, dairy operations, and land applications of manure and
commercial fertilizers. The research will compliment an on-going
nonpollution abatement program targeted at reducing P inputs to
the lake through improved management of these agricultural sources.
Our multidisciplinary team provides the expertise in social science,
outreach, environmental modeling, environmental chemistry, hydrology
and sediment transport, environmental engineering, and limnology
– all of which are needed to accomplish our “systems”
goals. Our focus is on the scale-dependent processes that link
agricultural P sources to watershed export of BAP. Our plan involves
six major objectives: 1) Quantification of the effects of manure
management on runoff BAP; 2) Measurement of the amounts, spatial
patterns, and transport of sediment and BAP in channels and streams
acting as routes for transport through the watershed; 3) Quantification
of the in-stream processes governing the fate and transport of
sediment P; 4) Evaluation and improvement of modeling tools (APEX,
SWAT) for assessing P transport over a wide range of spatial scales;
5) Determination of the relation of BAP losses to the scale of
animal operations; and 6) Integrated outreach with stakeholders,
agency partners and other researchers through farmer-feedback
procedures, agency assessments and model refinement. Knowledge
gained will be crucial for effective state and national TMDL development
and implementation.
Chequamegon Ecosystem-Atmosphere Study (ChEAS)
Funding Source: NSF, Research Collaboration Network
Dates: January 1, 2002 to December 31, 2008
Principal Investigator: Kenneth J. Davis (Penn.
State)
Steering Committee: D. Scott Mackay is one of
7 members
ChEAS is a
NSF-funded interdisciplinary research collaboration network project
aimed at understanding land-atmosphere exchange of cabon, water,
and energy at one of the tallest AmeriFlux towers, located near
Park Falls, Wisconsin. The lead institution for the project is
Penn. State University; Dr. Mackay is one of 6 members of the
ChEAS steering committee.
Link to ChEAS
Terrestrial Regional Ecosystem Exchange Simulator (TREES)
We are developing
this object-oriented land surface process model, which provides
the flexibility to examine model complexity requirements, for
application to flux towers, watersheds, and remote sensing regional
scale projects. Data handling is through a data dictionary, which
supports rapid definition of frames for the input of data, maintenance
of state and flux variables, and output of model results. The
flexibility afforded by objects is exploited for rapidly developing
simulation models that are tailored to specific analytical requirements.
Early TREES development began with a version of RHESSys developed
as part of Mackay's PhD dissertation. Subsequently, TREES has
departed from the RHESSys approach in that it relies on a pure
object-oriented approach.
Adaptive Parameter Restriction and Selection (APReS)
We are developing
a general framework for the analysis of uncertainty in simulation
models. Our approach is motivated by methods such as GLUE and
Parato Optimality. The premise of APReS is that parameter uncertainty
and even model structure uncertainty are interpretable in terms
of fuzzy sets. A nonmonotonic reasoning approach is supported
to allow for the evaluation of simulations based on multiple criteria
in different combinations and priorities. APReS has been applied
to simulation of streamflow in forested watersheds, transpiration
at hillslope to watershed scales, and to transpiration at individual
tree and whole-stand scales. It is currently being used as one
of numerous analytical tools for projects funded by NSF and EPA.
Past
Research
Long-term
water flux changes from converting old-growth pine forests to
hardwood forests in northern Wisconsin. NASA, Land Surface
Hydrology Program, NAG5-8554, 1999-2003, Mackay (PI).
Highlights
and milestones of the Land Surface Hydrology Project were:
1. A comprehensive
database of vegetation, water fluxes, micrometeorology, remote
sensing, soil moisture, tower flux, and process-based models were
used in the first successful scaling-up exercise at the WLEF tower
(Mackay et al., 2002; Ahl et al., 2004b).
2. An essential bridge was developed between leaf and tower flux
measurements with measurements of leaf water potential and transpiration
among seven key species in the WLEF tower footprint (Ewers et
al., 2002; Ewers et al., 2004).
3. Accurate simulations of transpiration models and parameterization
for the heterogeneous forests around WLEF (Mackay et al., 2003a,b;
Samanta and Mackay, 2003).
4. We developed a parameterization scheme to use MODIS land surface
temperature to estimates canopy stomatal conductance for simulation
transpiration and photosynthesis (Mackay et al., 2003c; Mackay
et al., 2004).
Other Past Projects
