Ecosystem Modifications of C
Sequestration and GHG Evolution by Soil Macro-Aggregates at Multiple LTER Sites
ASM/LTER Workshop
Moderator: Alvin Smucker, KBS/LTER
Summary: This workshop identified
areas which new multidisciplinary projects can contribute to at least four of
the major LTER ASM themes. This
workshop included four short presentations on the most efficient and accurate
methodologies for identifying changes in terrestrial carbon (C). The majority
of time focused on an open discussion, among the 16 workshop participants
(Appendix A). These discussions produced the following general conclusions:
Scientists from 10 LTER sites, including 2 ILTER, (Appendix A) demonstrated an acute interest in forming collaborative projects that generate new information or at least the following major LTER themes:
Project Description: Principle contributors to climate change are anthropogenic modifications of the landscape. These include 1) Expanded reliance upon petroleum and coal energy sources in industry and transportation and 2) Land use change. Land use changes include urban expansion, N fertilization, biomass decay and hydrocarbon energy sources that generate increasing quantities of carbon dioxide, methane, and nitrous oxide. This workshop identified novel and rapid approaches for identifying short-term changes in the sequestration of soil C, methanogenic enzymes, concentric layer gradients of C, N, bacteria, pH, and intra-aggregate porosities. These approaches can be used to identify most critical biogeochemical processes that reduce greenhouse gas (GHG) production within the confined communities of soil macro-aggregates for all soil types.
Direct measurement of bulk soils for absolute amounts of C sequestered across a landscape or region is difficult and expensive. Total C contents are highly variable across landscapes and the mean residence times are unknown. Integrated predictive models are needed to identify above and belowground biomass, biomass turnover and mineralization rates, C retention time and climatic modifications of C changes within the soil profile. These models would provide strategic parameters beyond current conceptual models, eg., CENTURY and others that require intensive site-specific calibration before the evaluation of GHG changes across the soil-plant-atmosphere continuum (SPAC). Specific SPAC process-level models are essential for the quantification of climate change associated with specific land use changes at both regional and national levels.
We identified several baseline forest, grassland and agricultural experiments at both LTER and non LTER sites that should be expanded to include feed-forward terrestrial C sequestration. Incorporation of water cycling, N fertilization, pH control, and detritus residue management treatments to current small and medium scale LTER research sites, containing decades of baseline information, would provide new process-level mechanisms associated with the dynamics of C sequestration and GHG emissions. These new data would provide essential information missing from current models used to predict soil-plant-atmosphere generation/sequestration of GHG.
We propose to implement new cross site studies and use the novel analytical approaches for identifying the critical feed-forward and feed-back biogeochemical mechanisms within soil macro-aggregates that serve as reservoirs of GHGs in equilibrium with the atmosphere. This Workshop identified a group of strategic interactions, using current experiments with long term data and metadata, located at several LTER forest, grass, and agroecosystem sites. At least 8 LTER sites were identified to have continuing nitrogen fertilization sites on native and modified forest, grassland, and agroecosystems within the LTER Network. Additionally, at least 9 parallel programs among DOE, ARS, and university experimental sites could be incorporated into these synthesis projects. Mechanisms identified by these expanded projects will be highly useful for up-scaling information to regional levels and beyond. Expanding these long term research sites will provide additional information by incorporating the vast array of metadata for soil, biomass, and climate accumulated by current LTER sites, forest and agricultural research centers.
Management of these efforts will be coordinated by a consortium of scientists from at least three LTER and non LTER sites (eg., Smucker (KBS), Lajtha (AND), Nippert (KNZ) and Graham (HFR). Data will be compiled by data managers at current LTER sites. It is anticipated that a new research associate trained in the areas of climate ecology who has considerable data processing skills will be needed to best incorporate metadata into the process-level information generated by this network of scientists. At least three national agencies, eg., ARS, DOE, and the National Forest Service plus various state agencies will be included in this expanded network of multidisciplinary scientists.
Anticipated calendar
of events and budgets: Total $14,500
1.
October – December 2003
Estimated cost: $4,200
2. Intense writing meeting of principle co-PIs
Two days in January 2004
Estimated travel and per diem costs: $9,550
3. Telephone, fax, copying, and printing
Estimated cost: $750
Appendix A
Participants Workshop Ecosystem Modifications
of Carbon
Sequestration and
Greenhouse Gas Evolution by Soil Aggregates
at LTER Sites
Saturday PM
West Room
Name: LTER Site: Email:
Kate Lajtha AND lajthak@science.oregonstate.edu
Colin Saunders FCE saunders@fiu.edu
Liz Burrows HFR eburrows@mbl.edu
Margaret Graham HFR margaret.graham@dartmouth.edu
Mark Richer JRN mricher@nmsu.edu
Heather Dopp KBS doppheat@msu.edu
Stuart Grandy KBS grandyai@kbs.msu.edu
Eun-Jun Park KBS parkeun2@msu.edu
Clare McSwiney KBS cmcswiney@kbs.msu.edu
Alvin Smucker KBS smucker@msu.edu
Jesse Nippert KNZ nippert@ksu.edu
Duncan McKinley KZ dlmc@ksu.edu
Heather Erickson LUQ ericksonheather@yahoo.com
Erika Marin-Spiotta LUQ aurios@nature.berkeley.edu
Anghel Vadineanu
Zueng-Sang Chen TAIWAN soilchen@ccms.ntu.edu.tw