2009 LTER All Scientists Meeting - Primary Production

Positive feedback between increasing atmospheric CO2 and ecosystem productivity

Ilya Gelfand — Thu, 10 Sep 2009 18:35:54 +0000

Poster Number:

397

Presenter/Primary Author:

Ilya Gelfand

Co-Authors:

Hamilton, S.K.

Co-Authors:

Robertson, G.P.

Increasing atmospheric CO₂ will likely affect both the hydrologic cycle and ecosystem productivity. Current assumptions that increasing CO₂ will lead to increased ecosystem productivity and plant water use efficiency (WUE) are driving optimistic predictions of higher crop yields as well as greater availability of freshwater resources due to a decrease in evapotranspiration.

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.

The California Current Ecosystem (CCE) LTER Site

Mark Ohman — Tue, 01 Sep 2009 03:58:20 +0000

Poster Number:

369

Presenter/Primary Author:

Mark Ohman

Co-Authors:

24 coauthors

The California Current System is a coastal upwelling biome, as found along the eastern margins of all major ocean basins. These are among the more productive ecosystems in the world ocean. The California Current Ecosystem (CCE) LTER site (centered on 32.9° N, 120.3° W) is investigating nonlinear transitions in the California Current coastal pelagic ecosystem, with particular attention to long-term forcing by a secular warming trend, multi-decadal oscillations (e.g., PDO and NPGO), and ENSO in altering the structure and dynamics of the pelagic ecosystem.

Interaction of atmospheric nitrogen regulation, climate change, and elevated CO2 on the long term productivity of forested ecosystems in the Chesapeake Bay watershed

John Hom — Tue, 01 Sep 2009 03:58:07 +0000

Poster Number:

368

Presenter/Primary Author:

John Hom

Co-Authors:

Yude Pan

Co-Authors:

Kevin Mccullough

Co-Authors:

Richard Birdsey

Phytoplankton growth and grazing dynamics in California Current Ecosystem

Michael Landry — Mon, 31 Aug 2009 20:52:16 +0000

Poster Number:

351

Presenter/Primary Author:

Michael Landry

Co-Authors:

Mark D. Ohman

Co-Authors:

Ralf Goericke

Co-Authors:

Michael R. Stukel

Co-Authors:

Kate Tsyrklevich

Experimental studies of phytoplankton growth and grazing processes were conducted in the California Current Ecosystem off Point Conception, California to test the hypothesis that growth and grazing losses determine, to first order, the local dynamics of phytoplankton in the upwelling circulation.

Elevated CO2-induced increase in leaf photosynthesis across 13 grassland species is relatively modest, consistent and does not depend on soil N availability over 11 years of free-air CO2 enrichment

Tali D Lee — Mon, 31 Aug 2009 20:45:52 +0000

Poster Number:

350

Presenter/Primary Author:

Tali D Lee

Co-Authors:

Susan Barrott

Co-Authors:

Peter Reich

If long-term responses of plant photosynthesis to rising atmospheric carbon dioxide (CO₂) levels are similar or predictably different among species, functional types, and ecosystem types, general global models of CO₂ fertilization effects can effectively be developed. To address this issue we measured gas exchange rates of 13 perennial grassland species from four functional groups exposed to eleven years of long-term free-air CO₂ enrichment (eCO₂, +180 ppm above ambient CO₂, BioCON).

Arctic LTER: Goals and Results

John Hobbie — Mon, 31 Aug 2009 20:38:57 +0000

Poster Number:

347

Presenter/Primary Author:

John Hobbie

Co-Authors:

George Kling

Co-Authors:

Chris Luecke

Co-Authors:

Gus Shaver

Co-Authors:

Anne Giblin

Co-Authors:

Donie Bret-Harte

The goal of the Arctic LTER is to predict the future ecological characteristics of Arctic Alaska based upon our knowledge of the controls of ecosystem structure and function as exerted by physical setting and geologic factors, climatic factors, biotic factors, and the changes in fluxes of water and materials from land to water.

Ecosystem productivity and soil food web structure – paired forest and grassland transects across Oregon

Samantha Colby — Mon, 31 Aug 2009 18:25:35 +0000

Poster Number:

331

Presenter/Primary Author:

Samantha Colby

Co-Authors:

Andrew Moldenke

The vast majority of biodiversity on Earth lives in the soil; to what degree are this diversity and the ecosystem functions they perform regulated by climate and plant productivity? In this study, we seek to determine the relationship between climate/Net Primary Productivity (NPP) and soil food web structure. Research sites, each consisting of a forest and paired grassland, are located along east-west transects in Oregon; these transects encompass climates producing the greatest productivity and nearly the least productivity on the continent.

Student Poster:

Yes

Understanding and mapping plant distributions surrounding marsh hammocks within the Georgia Coastal Ecosystems LTER

Christine Hladik — Mon, 31 Aug 2009 14:28:20 +0000

Poster Number:

320

Presenter/Primary Author:

Christine Hladik

Co-Authors:

Alana Lynes

Co-Authors:

Chester Jackson

Co-Authors:

Merryl Alber

Co-Authors:

Clark Alexander

Co-Authors:

Steve Pennings

Accurate habitat mapping in salt marshes is important for both management and conservation goals, as it provides information essential for identifying sensitive areas and documenting changes over time as the result of sea level rise or human perturbations. The goal of this study is to characterize patterns of marsh plant distribution in the salt marshes surrounding back barrier islands (hammocks) within the Georgia Coastal Ecosystems LTER. In the summer of 2007 the GCE LTER surveyed over 50 hammocks of different origin and size.

Student Poster:

Yes

Hydraulic Conductivity and gas exchange vary along the length of individual grass blades

Troy Ocheltree — Fri, 28 Aug 2009 22:26:02 +0000

Poster Number:

306

Presenter/Primary Author:

Troy Ocheltree

Co-Authors:

Nippert, JB

The hydraulic architecture of parallel veined monocots is fundamentally different from the branched networks of dicot leaves. The functional significance of this difference on leaf level gas exchange is not well understood. In order to investigate how the hydraulic architecture of monocots affect gas exchange we measured the axial hydraulic conductivity and leaf level gas exchange from the base to tip of 7 grass species. Stomatal conductance (g_s) and photosynthesis (A) increased but hydraulic conductivity (K_h) declined along the length of the blade.

Student Poster:

Yes