Biogeomorphology

Several future projects are planned in collaboration with ecosystem scientists, earth scientists and engineers in a newly funded (as of August 2002) NSF Science and Technology Center, the National Center for Earth Surface Dynamics (NCED), based at the St. Anthony Falls Hydraulics Laboratory, St. Paul, Minneapolis.   The Angelo Coast Range Reserve will be a primary experimental field laboratory for these collaborations.

Physiology to food webs in river networks.  What is the influence of landscape (drainage network) position on the distribution and abundance, performance, and food web interactions of key organisms?  To what degree are network distributions explained by the physiology and natural history of a particular species, and to what degree do population and community level phenomena play controlling roles? 

Scaling in river-watershed ecosystems.  How do controls over processes like stream metabolism or material fluxes and retention vary as we increase spatio-temporal scales?  Where and why in scale transitions do scale dependent regime changes occur, and where do phenomena appear to be 'scale free'? 

Energy sources and interaction strength in food webs.  What are the spatial dimensions of interactions and fluxes affecting food webs?  What is the relationship between spatial energy sources and the strength of local species interactions?

Feedbacks from biota to landscapes.  How do organisms influence earth surface processes and landscape evolution?

Food Webs in acid mine drainage

This collaboration builds on previous research by Jill Banfield (an NCED co-PI) and her Berkeley group on adaptations and biogeochemical impacts of extremophile microbes in acid mine drainage, with pH (<1) and temperatures of 50°C  ( AMD Home website).  Other collaborators include Phil Hugenholz, Wayne Getz, Jeff Boore (DOE Joint Genome Institute) and Jo Handelsman (U. Wisconsin, Madison).

Species impacts on ecosystems near steady state. What are the roles and impacts on ecosystem productivity (H2SO4 production) of various members of acid mine drainage communities at 'steady state'?  Can we predict their importance from genomics?

Recovery from disturbance.   What are the impacts of disturbance and the mechanisms of succession in acid mine drainage communities?  How do earlier colonizing (or re-activating) organisms affect later arrivals, the environment and community structure during succession?

Tributary effects on cross-habitat exchange of energy, nutrients, and contaminants

This collaboration with Bill Rainey and Gilbert Cabana (Université du Québec à Trois-Rivières) examines cross-habitat effects at confluences of less productive tributaries with more productive mainstem channels.  In the Truckee, South Fork Eel, and Upper Sacramento Rivers, we are investigating how tributary and mainstem food webs interact, and the specific effects of juxtaposition of contrasting habitats, and movements of consumers and resources across their boundaries.

What is the influence of tributaries on cross-habitat ecological exchanges between rivers and watersheds, or between mainstem and tributary channels or riparian zones? 

Floodplain restoration in the Cosumnes River

As part of the Cosumnes Research Group lead by Jeff Mount and Jim Quinn at U.C. Davis, we plan to investigate the influence of floodplain inundation and floodplain vegetation structure on emergent insects & aerial insectivores and floodplain soils. The Cosumnes Reserve is partially owned by The Nature Conservancy, an active participant in this project. For more information on the reserve itself see www.cosumnes.org.

Emergent insects. Led by bat biologist Bill Rainey our group will investigate how the inundation regime (the residence time of water and seasonal timing of spillover and reconfinement) and the structure of seasonally inundated stands of trees, forbs, grasses influence abundances and activity of emerging aquatic insects, and the ability of insectivores to track them.  We will collaborate with meteorologists and turbulence experts at UCD and NCED to measure impacts of vegetation and wind speed on air turbulence patterns that advect and concentrate insects.  These structures and processes may also alter insectivore (bat, bird,  spider, adult odonate) activity and their ability to track prey.

Floodplain soils. We have long known that river inundation restores the fertility of agricultural floodplain lands, but how?  Postdoc Sandra Clinton will examine the processes that vector products of the aquatic food web into soils after reconfinement.  The consequences for soils of different ecosystem states during inundation will be investigated.

Riparian restoration in the Middle Sacramento River

The Nature Conservancy, under leadership of TNC ecologist Greg Golet, is replacing senescent orchards with native riparian trees  and shrubs as part of restoring communities and natural processes along the Middle Sacramento River (website).  In collaboration with scientists at Stillwater Sciences, Inc. (a Berkeley-based environmental consulting company), we are looking at three response variables which may help the TNC measure the state and direction of change in and around these restored ecosystems.

Bat diversity and activity/abundance in contrasting terrestrial (riparian forest remnants,  different age restorations and orchards) and aquatic sites (river main  stem and backwater).

Landscape distribution of stable nitrogen and carbon isotopes, which can indicate land use effects (e.g., nitrogen loading  from livestock) and the linkages of ecosystems over various spatial scales.

Distribution,abundance, diversity, and carbon sources of benthic and drifting aquatic insects in mainstem and tributary channels important for salmonid rearing.

Seasonal Elevational activity-abundance of bats and insect prey in Yosemite National Park

This study is led by Dr. Elizabeth (Dixie) Pierson, in collaboration with Bill Rainey, Chris Corben, Les Chow (USGS), and Mary Power with support from  the Yosemite Fund via the National Park Service.  Its motivating question emerged from  previous investigations of seasonal distributions of bats in Yosemite.

How are bat activity/abundances and species diversity  at different elevations related to the local seasonal availability of insects?  We are conducting monthly surveys of bats within four 2000' wide bands of elevation, in a variety of habitat types (wet meadows, rivers, creeks, forests). Concomitant sampling of  insect emergence, and activity-density of flying insects in light traps, give relative indices of prey availability, which  are influenced by seasonal changes in surface water and temperature along  the elevation gradient.