2009 LTER All Scientists Meeting - Altered moisture regimes

Niwot Ridge LTER Program: Alpine Ecosystems as Early Warning Systems

Mark Williams — Tue, 01 Sep 2009 17:42:43 +0000

Poster Number:

377

Presenter/Primary Author:

Mark Williams

Co-Authors:

Tim Seastedt

Co-Authors:

Diane McKnight

Co-Authors:

Alan Townsend

Co-Authors:

Bill Bowman

Co-Authors:

Steve Schmidt

Co-Authors:

Peter Blanken

The Niwot Ridge (NWT) LTER site was one of the five original LTER sites established in 1980. The LTER program is based at the University of Colorado-Boulder and is administered through the Institute of Arctic and Alpine Research (INSTAAR) and in cooperation with the Mountain Research Station, with special use permits from the US Forest Service.

Grazing alters grassland sensitivity to more extreme precipitation regimes in tallgrass prairie

Sally Koerner — Tue, 01 Sep 2009 16:52:50 +0000

Poster Number:

376

Presenter/Primary Author:

Sally Koerner

Co-Authors:

Scott Collins

Co-Authors:

Alan Knapp

Co-Authors:

John Blair

Co-Authors:

Melinda Smith

Little information exists on how climate variation may interact with trophic controls on annual net primary production (ANPP), and even less is known about how these interactions will affect community structure. Understanding how communities respond to climate variation and grazing will be crucial for managing grasslands with abundant large herbivores. We conducted a simulated grazing experiment in the Rainfall Manipulation Plots (RaMPs) at Konza Prairie Biological Station, Kansas.

Interactive Effects of Plant Species Diversity and Climate on Seedling Establishment in Grassland

Peter Wragg — Tue, 01 Sep 2009 01:38:45 +0000

Poster Number:

365

Presenter/Primary Author:

Peter Wragg

Co-Authors:

David Tilman

How will anticipated changes in climate interact with grassland plant community composition and diversity to affect the performance of seedlings? We ask this question for two reasons. 1) If plant species are to track spatial shifts in the locations of suitable climatic conditions, plant species must invade communities by means of seedling establishment; more diverse plant communities have been shown to be less invasible, but it is not known how warming will interact with diversity to affect invasion.

Effect of rainfall pulses on soil CO2 fluxes and ecophysiology of Bouteloua eriopoda in a northern Chihuahuan Desert Grassland: a synthesis of research to date

Michell Thomey — Mon, 31 Aug 2009 20:02:20 +0000

Poster Number:

345

Presenter/Primary Author:

Michell Thomey

Co-Authors:

Scott Collins

Co-Authors:

Rodrigo Vargas

Co-Authors:

Jennifer Johnson

Co-Authors:

Renee Brown

Co-Authors:

Don Natvig

Co-Authors:

Michael Friggens

Background/Questions/Methods

Student Poster:

Yes

Hydraulic contributions to differential survival during drought in a piñon-juniper woodland

Jen Plaut — Mon, 31 Aug 2009 19:38:59 +0000

Poster Number:

342

Presenter/Primary Author:

Jen Plaut

Co-Authors:

Enrico A. Yepez

Co-Authors:

Judson Hill

Co-Authors:

Rob Pangle

Co-Authors:

Jennifer Johnson

Co-Authors:

Nate G. McDowell

Co-Authors:

William T. Pockman

Drought-related tree mortality occurs worldwide, including recent episodes in piñon-juniper woodlands of the American west. Although the physiological mechanisms of mortality are poorly understood, carbon starvation may occur in trees that limit transpiration (E) to avoid hydraulic failure.

Student Poster:

Yes

Carbon cycling above treeline: eddy covariance results from high-elevation alpine tundra at Niwot Ridge, Colorado.

John Knowles — Mon, 31 Aug 2009 18:44:49 +0000

Poster Number:

333

Presenter/Primary Author:

John Knowles

Co-Authors:

Peter D. Blanken

Co-Authors:

Mark W. Williams

Ecosystems in topographically complex (mountainous) terrain are responsible for a majority of land-atmosphere CO2 exchange (net ecosystem exchange; NEE) across the western United States due to high inputs of winter precipitation as snowfall. NEE in these regions has been historically difficult to quantify using the eddy covariance (EC) method, however, due to complexities in surface terrain that lead to irregularities in streamline air flow, particularly advective fluxes during periods of low turbulent mixing.

Student Poster:

Yes

A Parcel-level Dasymetric Approach to Mapping Changes in the Distribution of Urban Flooding Risks, Baltimore, Maryland (1950-2000)

Kirstin Dow — Fri, 28 Aug 2009 23:00:12 +0000

Poster Number:

307

Presenter/Primary Author:

Kirstin Dow

Co-Authors:

J. Morgan Grove

Co-Authors:

Sierra Murdoch

Co-Authors:

Jarlath O'Neill-Dunn

Co-Authors:

Chris Boone

Co-Authors:

Geoff Buckley

Environmental justice research seeks to understand the patterns and processes shaping the distribution of environmental burdens and amenities across society. While environmental justice research in the US has generally focused on toxics, urban design, hazard management, and segregation have reshaped patterns of risk associated with environmental processes, such as flooding, and the social patterns of exposure to those risks. In Baltimore, flood risks have been a major impetus behind the engineering of the hydrologic systems of the city.

Development of a hydrological budget for Shark River Slough, Everglades National Park

Amartya Saha — Fri, 21 Aug 2009 14:35:13 +0000

Poster Number:

256

Presenter/Primary Author:

Amartya Saha

A monthly and annual water budget has been created for the entire Shark River Slough (SRS) within the Everglades National Park (ENP) over 2002-2008. Inputs considered are surface water inflows (S12s and S333 canal structures) and rainfall, while outputs consist of discharge to the Gulf of Mexico (Lostman, Shark, Broad, Harney and North rivers) and evapotranspiration (ET).

Meristem density constrains productivity responses to changes in water availability in the Chihuahuan Desert

Lara Reichmann — Tue, 18 Aug 2009 21:34:00 +0000

Poster Number:

229

Presenter/Primary Author:

Lara Reichmann

Co-Authors:

Osvaldo E. Sala

Co-Authors:

Laureano Gherardi

Co-Authors:

Debra P. Peters

In arid ecosystems, current year precipitation explains a low proportion of the annual aboveground net primary production (ANPP). There is evidence that precipitation that occurred in previous years is responsible for the observed difference between actual and expected ANPP, a concept called legacy. Here, we study the mechanisms that generate these legacies, thus we will able to better understand the controls of the global carbon cycle, and to forecast changes in ANPP with a changing climate.

Student Poster:

Yes

Long-term Streamflow Trends from Old Growth Catchments in the Western Cascades

Kathleen Moore — Mon, 17 Aug 2009 21:55:59 +0000

Poster Number:

219

Presenter/Primary Author:

Kathleen Moore

Co-Authors:

Julia Jones - Principal Advisor

Climate warming in western North America is expected to result in reduced snowpack, earlier melt, and increased evapotranspiration. Consequently a shift toward a greater proportion of streamflow earlier in the water year with diminished spring and summer streamflows is anticipated. However, few datasets exist of streamflow with associated climate and vegetation records adequate to interpret changes in climate, forest processes, and their consequences for streamflows. This study examines trends in long-term streamflow records from three headwater catchments in old growth f

Student Poster:

Yes