[Bgsa] Meeting with John Sabo, this week's Colloquium speaker

[Mauricio Torres]

Hello,

this week's Colloquium speaker is John Sabo from Arizona State University,
currently on sabbatical at NCEAS. His research is mainly focused on
freshwater ecology and ecological modelling. His recent papers have explored
the effect of disturbance on community ecology. Please let me know if you
are interested in meeting with him on Thursday, we still have some openings.
If interested please send me your hours of availability.

Thanks!

Mauricio

PD. See below a summary of his Thursday's talk, his bio, and links to his
research.

*Title*: Floods, droughts and the scaling of food chain length with drainage
area in rivers


*Summary: *

Floods, droughts and other extreme hydrologic events play key roles in
coupling human and natural systems.  Floods can cause tremendous damage and
mortality and cripple local economies.  By contrast, floods are critical to
freshwater fisheries, some of which supply the majority of the protein to
people in developing nations.   Prolonged droughts and human dewatering of
rivers for municipal, industrial and agricultural uses pit farmers against
fisherman for limiting water resources forcing us to ask tough questions
like: "Which rivers (and their fisheries) are we willing to let run dry in
order to put produce on the table?"  Or, "How will fish, and the food webs
that support them, respond to prolonged or intensified extreme events?"
Food chain length (FCL) is a fundamental component of food web structure,
and large fish--often at the top of aquatic food chains--are the pièce de
résistance across the world. In this talk I will describe the results from
my recent work documenting how floods and droughts impact FCL in river
ecosystems of North America.  Studies in a variety of ecosystems suggest
that FCL is determined by energy supply, environmental stability, and/or
ecosystem size.  However, the nature of the relationship between
environmental stability and FCL, and the mechanism linking ecosystem size to
FCL, remain unclear. In rivers FCL increases with drainage area and
decreases with hydrologic variability (floods) and intermittency (severe
drought). Both floods and droughts appear to shorten river food chains but
do so in different ways.  Droughts eliminate top predators whereas floods
take out the middle men in food webs forcing top predators to forage lower
on the food chain.  Hence, the effects of droughts are more severe and
appear to be more long lasting. The dewatering of rivers nationwide and
globally is having measureable effects on fisheries in freshwater and in
coastal ecosystems.  These effects will intensify in California until we
adopt a 7-state, regional water conservation plan aimed at reducing surface
and groundwater withdrawals by 16-34% before the next population doubling in
the region.


*Short Bio:  *

Dr. Sabo is an aquatic ecologist interested in using insights from the
fields of hydrology and geomorphology to understand the ecology of rivers.
He has worked on rivers in coastal Washington, California and most recently
the Colorado River and its tributaries.  Dr. Sabo is broadly interested in
articulating regional scale solutions to problems in freshwater
sustainability.  Dr. Sabo received a Masters degree in Fisheries from the
University of Washington and a Ph.D.  in Ecology from UC Berkeley.  He spent
1 year as an NRC postdoc at the National Marine Fisheries Service developing
and refining risk assessment methods for endangered species.   He joined the
faculty at Arizona State University in 2001, where he is an Associate
Professor in the School of Life Sciences.  Dr. Sabo’s research in Arizona
focuses on the role of water (as a resource and source of disturbance) in
determining community structure in stream and riparian ecosystems.  This
work is funded by the National Science Foundation, the US Geological Survey
and the US Department of Defense.  Currently, Dr. Sabo is a visiting
professor in Ecology, Evolution and Marine Biology at UCSB.


*Links:*

http://www.public.asu.edu/~jlsabo/

http://www.sciencemag.org/content/330/6006/965.abstract



Mauricio

=================================
Mauricio Torres-Mejia
PhD Candidate
Department of Biology
University of California, Riverside, CA, 92521
USA
http://student.ucr.edu/~rtorr006/
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