2009 LTER All Scientists Meeting - Ecosystem Ecology

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.

The Malawi Environmental Observatory Network(MEON): Constitution, Strategy and Implementation Plan

James Chimphamba — Wed, 02 Sep 2009 16:37:05 +0000

Poster Number:

381

Presenter/Primary Author:

James Chimphamba

Malawi is a land of farmers and facing rampant environmental problems whose capability for restoration is made dimmer by the looming shadow of climate change and variability. The Malawi Environmental Observatory Network is a small candle flickering with light for identification of prioritized environmental problems and setting of the road map of how such monumental problems could efficiently be tackled with the available meager resources.

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.

Japanese LTER Network (JaLTER) - Collaborated Activities for Integrated Ecosystem Observation and Research

Akiko Ogawa — Tue, 01 Sep 2009 16:01:15 +0000

Poster Number:

375

Presenter/Primary Author:

Akiko Ogawa

Co-Authors:

Nobuhito Ohte

Co-Authors:

Hideaki Shibata

Co-Authors:

Hiroyuki Murakami

Japan Long Term Ecological Research (JaLTER) Network was established in 2006, currently consisting of 18 core sites and 38 associated sites that represent forest, grassland, lake, and marine ecosystems.
JaLTER is an official member of International LTER (ILTER) Network since 2007.

Comparison of soil respiration in young and old forests in the White Mountains of New Hampshire

Kikang Bae — Tue, 01 Sep 2009 03:33:04 +0000

Poster Number:

367

Presenter/Primary Author:

Kikang Bae

Co-Authors:

TImothy J. Fahey

Co-Authors:

Ruth D. Yanai

Co-Authors:

Byung Bae Park

Soil respiration is a major pathway of flux in the terrestrial ecosystem carbon cycle and has received a great deal of attention recently. This is largely because even a small change in soil respiration can exacerbate the annual input of CO2 into the atmosphere. Soil respiration represents the combined respiration of roots and soil micro- and macro-organisms, and a number of studies on soil respiration have been undertaken in a variety of ecosystems.

Student Poster:

Yes

Relative timing and magnitude of response by plants, microbes and soil fauna to an experimental precipitation event on the Shortgrass Steppe L

Sallie Sprague — Mon, 31 Aug 2009 21:32:59 +0000

Poster Number:

356

Presenter/Primary Author:

Joe Von_Fischer

Co-Authors:

A. Angert, D. Augustine, C. Brown, F. Dijkstra, J. Derner, N. Hanan,

Co-Authors:

R. Hufbauer, N. Fierer, D. Milchunas, J. Moore, H. Stelzer, M. Wallenstein

A key climatic feature of the Shortgrass Steppe is the summertime pattern of moderate to large precipitation events, separated by weeks of hot, dry conditions. These precipitation events have potential to revive plants, microbes and soil fauna that became less active in the intervening dry period, and thus structure ecosystem-scale patterns including net carbon exchange.

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

Effects of forest die-back on soil biological and chemical characteristics of a Colorado Lodgepole pine forest

Tim Seastedt — Mon, 31 Aug 2009 21:03:50 +0000

Poster Number:

353

Presenter/Primary Author:

Yanmei Xiong

Co-Authors:

Tim Seastedt

A forest die-back caused by a beetle outbreak on lodgepole and limber pine was used to assess the relative importance of root inputs to the soil food web and chemistry of soils in the Colorado Front Range. We measured a suite of biological and chemical parameters at six sites containing both live and dead trees. We found an increase in amounts of soil inorganic N, decreased soil lable C, and thus a decreased soil labile C:N ratio.

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.