2009 LTER All Scientists Meeting - Microbial Ecology

Investigating host feeding strategy as a determinant of gut microbial community profile

Cristina Takacs-Vesbach — Sat, 12 Sep 2009 22:01:34 +0000

Poster Number:

401

Presenter/Primary Author:

Cristina Takacs-Vesbach

Co-Authors:

Dan Colman

Co-Authors:

Eric Toolson

Diverse microbial communities live in the gut regions of animals. The precise ecological and evolutionary circumstances that govern relationships between hosts and their gut communities is unclear. In this study, we hypothesize that host feeding strategy shapes the microbial communities within the gut systems of insects. We collected five insect species from the Sevilleta National Wildlife Refuge that exhibited herbivorous, detritovorous and carnivorous diets.

Aeolian flux of microorganisms in the McMurdo Dry Valleys, Antarctica

Marie Sabacka — Wed, 02 Sep 2009 00:38:14 +0000

Poster Number:

380

Presenter/Primary Author:

Marie Sabacka

Co-Authors:

John C. Priscu

Co-Authors:

Mark C. Greenwood

The McMurdo Dry Valleys in Antarctica (MCM) forms one of the most extreme deserts on Earth. It consists of a mosaic of permanently ice-covered lakes, ephemeral streams, exposed soils, and glaciers. Microorganisms are the only life forms occupying these landscape units. Given the relatively low and seasonal growth rates of these organisms, we contend that the distribution of microorganisms within this environment is controlled by physical factors.

Student Poster:

Yes

Denitrification in desert soils: Importance of Fungi

Yevgeniy Marusenko — Tue, 01 Sep 2009 21:44:08 +0000

Poster Number:

378

Presenter/Primary Author:

Yevgeniy Marusenko

Co-Authors:

David Huber

Co-Authors:

Sharon Hall

Denitrification is a key step returning nitrogen from soils to the atmosphere. The primary denitrifiers in most ecosystems are heterotrophic bacteria. Although, fungi are also known to transform nitrogen compounds, such as the production of N2O, but few studies have explored this process in soils. Aridland systems experience high temperatutres and low moisture conditions, favoring fungi in these environments. Thus, we explored the role of fungi and bacteria in denitrification of Sonoran Desert soils.

Alder strategies for phosphorus assimilation across a boreal forest successional sequence

Michaela Swanson — Mon, 31 Aug 2009 21:14:19 +0000

Poster Number:

355

Presenter/Primary Author:

Michaela Swanson

Co-Authors:

Roger Ruess

Co-Authors:

Karl Olson

Co-Authors:

Knut Kielland

Co-Authors:

Lee Taylor

Co-Authors:

Jack McFarland

Ecosystem processes in northern systems depend heavily on inputs of biologically fixed nitrogen (N) from A. tenuifolia, which contributes the majority of N accumulated during boreal forest succession. However because of the high phosphorus (P) demands of this plant, we hypothesize that N-fixation inputs are controlled by the ability of alder to assimilate P through associations with ectomycorrhizal fungi (EMF), which produce enzymes that mobilize organic and recalcitrant P forms.

Student Poster:

Yes

SEVILLETA LTER Abiotic Pulses and Constraints: Dynamics and stability in an aridland ecosystem

Scott Collins — Mon, 31 Aug 2009 20:57:53 +0000

Poster Number:

352

Presenter/Primary Author:

Scott Collins

Co-Authors:

Cliff Dahm

Co-Authors:

Marchy Litvak

Co-Authors:

Will Pockman

Co-Authors:

Kristin Vanderbilt

Co-Authors:

Esteban Muldavin

Co-Authors:

Bob Sinsabaugh

Co-Authors:

Blair Wolf

The Sevilleta LTER is located at the intersection of several aridland ecosystem types. Although it is axiomatic that water is the key limiting resource in aridland ecosystems, most arid land soils are also chronically low in nutrients and organic matter. Resource availability is a function of the frequency and size of precipitation events as well as the time between events. As a consequence, NPP and organic matter decomposition are often decoupled in space and time, and soil nutrient supply rates may limit NPP during periods when soil moisture is sufficient for plant growth.

Environmental controls on benthic microbial food webs

James Hollibaugh — Mon, 31 Aug 2009 20:41:37 +0000

Poster Number:

348

Presenter/Primary Author:

James Hollibaugh

Co-Authors:

Matthew First

We examined benthic microbial communities in three contrasting subtidal salt marsh sediments over the course of a year to investigate the relationship between environmental conditions and benthic microbial community structure. Samples were collected monthly from a high energy, sandy beach, a tidal creek bed, and a Spartina alterniflora marsh border. The concentrations and biomasses of benthic microalgae (BMA), total and potentially active bacteria (measured by an enzyme-activated fluorogenic compound), heterotrophic protists, and metazoan meiofauna were measured at each location.

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.

Impacts of microbial competition, coevolution, and plant-microbe feedbacks on plant productivity and microbial communities in soil

Matthew Bakker — Mon, 31 Aug 2009 19:52:06 +0000

Poster Number:

344

Presenter/Primary Author:

Matthew Bakker

Co-Authors:

Rosenzweig N

Co-Authors:

Lange AJ

Co-Authors:

Otto-Hanson L

Co-Authors:

Manning DWP

Co-Authors:

Bradeen JM

Co-Authors:

Montgomery R

Co-Authors:

Muller-Landau H

Co-Authors:

Kinkel LL

Plant diversity has been studied extensively for its impact on a few basic measures, such as biomass production. However, relatively little is understood about interactions between plant diversity and microbial communities. Through removal of natural enemies with pesticide treatments, we found that foliar fungi have a significant impact on plant productivity, and that the impact is greater at higher than at lower plant diversity.

Spatial and Temporal Patterns of Bacterial Communities in Toolik Lake

Sarah Barbrow — Mon, 31 Aug 2009 13:56:02 +0000

Poster Number:

318

Presenter/Primary Author:

Sarah Barbrow

Co-Authors:

George Kling

Co-Authors:

Byron Crump

Much is known about the spatial and temporal distribution of macro-organisms and their activity rates. However, little is known about the spatial variability of microbial communities in lakes. In this study, we examined the spatial variability in both bacterial community composition and activity rates in Toolik Lake, Alaska. Community composition was characterized using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified rDNA, and activity rates were measured by uptake rates of 14C-leucine.

Student Poster:

Yes

Impact of Agricultural Practices on Bacterial Carbon Use Efficiency

Zarraz Lee — Sun, 30 Aug 2009 20:07:32 +0000

Poster Number:

312

Presenter/Primary Author:

Zarraz Lee

Co-Authors:

Thomas M. Schmidt

Impact of Agricultural Practices on Bacterial Carbon Use Efficiency
Z. M. Lee and T. M. Schmidt
Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI

Student Poster:

Yes