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Research
Interests
| Nitrogen
biogeochemistry in temperate forest ecosystems
- Nitrogen cycling is the mostly studied biogeochemical
process in ecology and temperate forest is one of the
most familiar ecosystems to general public and to professional
ecologists, yet we still lack many mechanistic understandings
in this fundamental process in temperate forests and such
lack of understandings limits our abilities to interpret
natural patterns of N cycling, to predict N cycling in
human modified and managed systems, and to prevent a series
of environmental consequences related to N alterations.
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My lab is currently focusing on the mechanisms involved
in N retention in temperate forests. Why some forests
retain atmospheric deposited N while others don't? What
factors affect year to year variations of N export from
a forest ecosystem? Does plant species composition affect
ecosystem N retention and if so, through what kinds
of mechanisms? What are the major forms of N losses?
These questions have fundamental academic interests
as well as practical applications. For example, if N
from atmospheric deposition is mainly retained as soil
organic N, that will create not only a nitrogen sink
but also a carbon sin, consequently a negative feedback
to global climate change. On the other hand, if most
N is lost through denitrification in the form of N2O,
then that contributes positively to global warming.
Or nitrogen can be lost as nitrate to streams, contributing
to local and regional eutrophications.
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View our field sites and Comment on the abstract
of a recently submitted proposal to the NSF-Ecosystem panel.
Other related
Nitrogen reference sources:
National Atmospheric Deposition Program at http://nadp.sws.uiuc.edu
A recent article on acid deposition in the Northeastern USA:
Driscoll 2001
Visit a special AMBIO 2002 issue covering Second International
Nitrogen Conference at http://www.ambio.kva.se/
and the N conference site at http://www.esa.org/n2001/
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Urban
ecology and the alterations of ecosystem processes
- Urbanization is the most dramatic changes human beings
have ever brought to the earth, fundamentally alters
ecosystem structures, functions, species compositions
and interactions. Urbanization is the necessity of civilization,
understand ecological changes accompanying urbanization
is thus essential. I have been involved in studying
both "ecology in the city" (study individual
patches in a city) and "ecology of the city"
(treat the whole city as an ecosystem). Study ecosystem
processes in urban remnant "natural" patches
and human created patches allows us to understand the
human impacts of urbanization, and ecosystem alleviation
of human pollutions. Study city "as a whole"
allows us to understand the constraints on urban development
and the effect of urbanization to neighboring ecosystems
from a landscape perspective.
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A recent article on the long-term studies of urban ecosystems:
Grimm 2000
Visit NSF supported Long Term Ecological Research sites at
Urban Baltimore http://www.ecostudies.org/bes/
and Central-Arizona-Phoenix http://caplter.asu.edu/overview/
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Landscape
configuration and nutrient cycling at a watershed scale
- One of the current directions of my lab is to understand
nutrient cycling in a watershed with mixed land use, and
to address non-point source pollution associated with
various human activities. Many factors, including sizes
of different land use patches, their relative positions,
and different biogeochemical processes in different patches,
affect nutrient retention and output at a watershed level.
My personal interests lay on riparian ecosystem, an area
sits in between terrestrial upland and aquatics with dynamic
biogeochemical processes, large seasonal variations, and
unique species compositions. |
Plant
- Soil interactions and soil microbial ecology
- My interests in microbial ecology are mainly due to
its importance in explaining biogeochemical patterns.
I am particularly interested in microbes responsible for
mycorrhizal symbiosis, nitrification, methane production
and consumption, and lignin decomposition.
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Additional Links
of Interest:
Ecological Society of America http://www.esa.org/
National Science Foundation - Biology http://www.nsf.gov/home/bio/start.htm
National Center for Environmental Researches (NCER) http://es.epa.gov/ncer/
Long Term Ecological Research (LTER) http://www.lternet.edu/
Great Lakes Research Consortium http://www.esf.edu/glrc/
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