How will
climate change affect
Southern California's ecosystems?
UCI PI: Mike Goulden lab
Co-PI: Katie Suding lab (UCI EEBiol)
This is a new project that is starting in the next year.
Our goal is to better understand how Southern California's ecosystsm
will respond to environmental change.
Link to full proposal
Proposal Abstract: Physiological, demographic, competitive and
biogeochemical controls on the response of California’s ecosystems to
environmental change
Michael L. Goulden, Department of Earth System Science, UCI,
mgoulden@uci.edu
Katharine N.
Suding, Department of Ecology and Evolutionary Biology, UCI
We
propose research to better understand the impact of environmental
change on
Southern California’s ecosystems. An ecosystem’s response to
environmental
change is determined by several mechanisms, including shifts in plant
physiology, plant demography, plant competition and community
composition, and
biogeochemistry and nutrient cycling. Our goal is to understand how
each of
these mechanisms contributes to an ecosystem’s overall response to
environmental change.
Researchers have used various
approaches to investigate the ecological effects of environmental
change,
including manipulations, interannual observations, and gradient studies. Each of these approaches provides a key
piece of the puzzle, but no single approach provides a complete picture
of
ecosystem response. We will use a hybrid experimental design that
simultaneously incorporates manipulations and interannual and gradient
observations to better understand the effects of changing water balance
on
California’s ecosystems. We will work along a 150-km climate transect
that
traverses the San Joaquin Hills and the Santa Ana, San Jacinto, and San
Bernardino Mountains. We will establish two types of sites: Natural
Gradient
Sites in grassland, coastal sage, chaparral, evergreen hardwood
forest,
pine forest, pinyon pine woodland, and creosote bush desert, where we
will
measure ANPP, litterfall, LAI, community composition, nitrogen
mineralization,
plant water status, and the fluxes of CO2, energy, and water
vapor,
and Experimental Sites in grassland, coastal sage, pine
forest, pinyon
woodland, where we will manipulate the environment.
We will use observations of the effects
of
interannual climate variation within the individual Natural Gradient
Sites to
understand the short-term effects of climate variability on ecosystem
physiology and ecosystem function. We will use comparisons across the
Natural
Gradient Sites to determine the long-term effects of climate on
community
composition and ecosystem function. We will manipulate water input at
the
Experimental Sites to understand how a change in moisture balance
affects NPP,
plant community composition, nutrient cycling, and plant water use. We
will
manipulate fire, nitrogen availability, and propagule input at two of
the
Experimental sites (coastal sage and grassland) to further understand
how
multiple environmental changes interact to control ecosystem response.
Our
research will focus on high value ecosystems in a
region where climate change is expected to have a major impact. Four considerations underscore the
importance and relevance of this research. (1) Southern California
provides an
excellent natural laboratory for understanding how climate controls
ecosystem
function. (2) Southern California’s location at the edge of the mean
winter
storm track and exposure to climate variability associated with the
ENSO and
PDO increase to the likelihood of pronounced future climate change. (3) Southern
California’s semiarid climate and
steep climate and vegetation gradients increase the likelihood that a
change in
climate will have a major impact on California’s ecosystems. (4) The
tight link
between climate, ecosystem function and natural disasters in Southern
California increases the likelihood that climate change will result in
large
socioeconomic impacts.