Project Summary
Intellectual Merit: This proposal will examine
how biological and physical processes interact to
control carbon uptake, storage and release in Arctic tundra ecosystems
and how the self-organizing
nature of these interactions varies across multiple spatial and
temporal scales. Approximately 25%
of the worldís soil organic carbon reservoir is stored
at high northern latitudes in permafrost and
seasonally-thawed soils in the Arctic, a region that is currently
undergoing unprecedented warming
and drying, as well as dramatic changes in human land use. Understanding
how changes in annual
and inter-annual ecosystem productivity interact and potentially
offset the balance and stability of the
Arctic soil carbon reservoir is of utmost importance to global
climate change science. If there is a net
loss of soil carbon to the atmosphere in the form of greenhouse
gases (namely CO2 and CH4),
greenhouse warming could be enhanced. This non-linear, potentially
positive feedback response
could very quickly cause Arctic terrestrial ecosystems to function
in a manner not known to us from
the late Holocene and with globally significant implications.
The proposed activities benefit from a foundation and wealth of
international and national carbon
cycle research undertaken in northern Alaska and other Arctic
regions over the past three decades.
We will initiate a comprehensive study involving an integrated
framework of multi-scale aircraft and
satellite remote sensing, micrometeorological and CO2 and CH4
flux measurements and hydro-
ecological process model simulations over a 350km North-South
transect spanning the dominant
Arctic topographic and land cover units of northern Alaska. The
study region encompasses many
long-term measurement sites that have been in place for 5 to 10
years. We will expand these
observations to include an extensive soil moisture manipulation
involving a 60 hectare tundra
flooding/draining experiment near Barrow Alaska on the Arctic
Coastal Plain. The objective of this
study is to quantify linkages between soil moisture and carbon
uptake, storage and release over
multiple spatial (microbial to landscape) and temporal (minutes
to decades) scales. Only by
increasing the spatial extent of our experimental manipulations
and the duration of our observational
time series can we better understand and predict the effect of
scale on the complex coupling within
Arctic ecosystems; namely, how small scale processes participate
as components of higher scale
phenomenon and how higher scale phenomenon constrain the former
lower scale processes. This
knowledge will improve our understanding of the current behavior
and potential response of arctic
tundra to global change, resulting in better predictions of feedbacks
to climate and the global carbon
cycle.
Broader Impacts: National and international science will benefit
substantially from this project,
as will local residents, who are primarily Native Iñupiat
Eskimo. The landscape manipulation site
will be available to other interested scientists, providing a
regional resource for multi- and
interdisciplinary studies of Arctic change. The project will foster
a new collaborative,
multidisciplinary team of experts comprised of new and experienced
arctic and non-arctic
researchers, and students with direct links to NSF, DOE, and NASA
projects including Ameriflux,
SpecNet, ITEX, SEARCH, CEON and with additional planning, ORION.
Northern Alaska residents
will benefit from the symbiotic ties between community, local
students, educators, and project
investigators. The projectís formal and informal educational
outreach will build on the already highly
successful NSF-funded GK-12 PISCES educational activities at Barrow,
Atqasuk and other rural
villages, the Toolik Lake LTER Schoolyard project and NSFís
REU program. Building on past
development, near real-time data from field instrumentation will
be included in classroom and
mobile displays at the Iñupiat Heritage Center and the
Ukpeagvik Iñupiat Corporation Science
Center.
Research findings also will be made available to policymakers
and land managers to promote
sustainable and minimal impact development in northern Alaska,
where cumulative impacts threaten
large areas of tundra. Through activities such as IPCC, ICIA and
state and local briefings, the research described here will benefit
from the BEOís planned developments (new Global Change
Facility, Education Center, wireless backbone, boardwalks, power,
etc.) and will benefit the BEO by
initiating the installation of many of these improvements. The
baseline data from this project and the
initiation of a long-term manipulation will benefit future research
on the BEO and broader pan-Arctic
region.
Major Objectives
1. Assess the potential effects of widespread drying due to climate
change on arctic tundra carbon budgets. We will quantify carbon
budgets in our experiments by measuring the flux of CO2 and CH4
across the land-atmosphere boundary.
2. Quantify linkages between drivers of change (e.g., thermokarst
and lake basin drainage and flooding) and soil wetness, plant
function, vegetation community composition and productivity, local
disturbance, and soil respiration and methogenesis.
3. Quantify spatial patterns and seasonality of surface soil wetness
for the arctic tundra at multiple scales using ground-based measurements,
airborne and satellite-based active and passive microwave remote
sensing.
4. Combine ground-based measurements, ecological model simulations,
airborne, and satellite-based remote sensing estimates of above-ground
net photosynthesis and NPP with microwave-based remote sensing
estimates of surface temperature and wetness (the major drivers
of soil respiration) for quantifying plot to regional patterns
and seasonality of net carbon exchange (NEE).
5. Develop an integrated, holistic, conceptual model of the interactions
and feedbacks of physical and biological processes in arctic systems
to assess the implications of change to the Arctic and Earth systems.
6. Advertise widely the experimental layout of the large-scale
hydrological manipulation, instrumental infrastructure, aerial
and satellite research platforms, and the potential for multidisciplinary
and international research partnerships to use the manipulation.
7. Utilize and expand current and planned educational and outreach
programs to apply approaches, activities, project expertise, and
results to the National Science Foundation's (NSF's) GK-12 PISCES
Project operating in Barrow, other North Slope areas, Southern
California, and Mexico. Include near-real-time, computer-based
data and Web camera displays at the Iñupiat Heritage Museum
and Barrow Environmental Observatory-affiliated (BEO) outreach
venues, paying special attention to local community relevance.
Disseminate project information through local community meetings,
radio interviews, and displays; professional outreach in refereed
journal publications and national and international meetings;
and contributions to national and international syntheses, summaries,
and policy recommendations. Prepare a special issue for Global
Change Biology summarizing and disseminating results of the
project. Archive data according to the National Science Foundation
Office of Polar Programs data archiving policy and make data freely
available to the public and interested researchers. Contribute
results to ongoing national and international research programs.
