HR: 1330h
AN: NB33G-16 [Abstracts]
TI: Community Resilience and Resistance in Regulated Rivers.
AU: * Noel, L
EM: laura.noel@unb.ca
AF: Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive,
Fredericton, NB E3B 6E1 Canada
AU: Culp, J M
EM: joseph.culp@ec.gc.ca
AF: Canadian Rivers Institute, Department of Biology, University of New Brunswick, 10 Bailey Drive,
Fredericton, NB E3B 6E1 Canada
AU: Culp, J M
EM: joseph.culp@ec.gc.ca
AF: National Water Research Institute, Environment Canada, 10 Bailey Drive, Fredericton, NB E3B 6E1 Canada
AB:
Across diverse ecosystems, environmental factors such as nutrient loading have been shown to induce changes in state and
reduce ecosystem resilience. Riverine communities are under increasing pressures from nutrient loading and fragmentation and
it is unknown how these pressures will affect community resistance and resilience. This study focuses on determining 1) if
nutrient loading and regulation change the resilience and resistance of rivers to further disturbances (floods); and 2) how
particular community features create resilience and resistance. Along nutrient and algal biomass gradients in regulated and
unregulated reaches of the Saint John River, Canada, community resilience (system capacity to return to its original state
post disturbance) is examined both temporally and spatially. Resistance (ability to resist change) is measured by the
nutrient concentration at which a change in ecological state occurs. State includes both community structure (species
abundance and diversity of benthic algae and invertebrates) and community function (photosynthesis to respiration ratio). To determine how community features create resilience, trophic decoupling and food web connectance are examined along nutrient
and physical disturbance gradients by comparing food webs constructed from stable isotope and biomass information. Because
decreased resilience is linked with state shifts, strategies for sustainable ecosystem management should focus on maintaining resilience.
DE: 1803 Anthropogenic effects
DE: 1871 Surface water quality
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly