Results for “ECOSYSTEMS” — Page 40

DOE OSTI2019

Soil Carbon Accumulation and Nutrient Availability in Managed and Unmanaged Ecosystems of East Tennessee

In the last two decades, urban and suburban lands grew by 34% in the United States, with 16 to 20 million ha maintained under turfgrass systems. Side-by-side comparison of turfgrass systems with other managed and unmanaged ecosystems have not been comprehensively conducted in the climate transition zone of the United States, despite the environmental significance of land use changes. Our objective was to determine the relative effects of C 3 and C 4 turfgrasses on soil organic carbon (SOC) accumulation and nutrient availability, in comparison with managed row crop and unmanaged woodlot and grassland systems. Soil samples from depths of 0 to 5, 5 to 15, and 15 to 30 cm were collected during March 2017 at the University of Tennessee’s East Tennessee Research and Education Center from seven ecosystems: (i) corn ( Zea mays L.)–soybean ( Glycine max L.) rotation, (ii) continuous soybean, (iii) tall fescue ( Festuca arundinacea L.), (iv) Kentucky bluegrass ( Poa pratensis L.), (v) bermudagrass ( Cynodon dactylon L.), (vi) unmanaged grassland, and (vii) unmanaged woodlot. All turfgrass species were established in 2012 and were managed like low-input residential lawns. Within the 30-cm soil profile, turfgrass systems contained 4.2 kg m –2 SOC at the time of sampling, which was 33% more than croplands and 34% less than unmanaged systems, and the C 4 turfgrass system contained 2.3 kg m –2 SOC and 0.4 mg kg –1 inorganic N, which were 56 and 57% lower than C 3 systems, respectively. Here, the results from this study highlight that low-input lawns with suitable grass species can offer higher SOC stock and nutrient availability than conventional cropland systems.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2023

The Next-Generation Ecosystem Experiment Arctic Rainfall Simulator: a tool to understand the effects of changing rainfall patterns in the Arctic

Rainfall frequency and intensity are expected to increase in the Arctic, with potential detrimental impacts on permafrost, leading to enhanced thawing and carbon release to the atmosphere. However, there have been very few studies on the effect of discrete rain events on permafrost in the Arctic and sub-Arctic. Conducting controlled rainfall experiments within permafrost landscapes can provide an improved understanding of the effect of changing intensity, duration, and timing of rain events on permafrost tundra ecosystems. Here, we describe the design and implementation of the Next-Generation Ecosystem Experiment Arctic Rainfall Simulator (NARS), a variable intensity (4–82 mm/h) rainfall simulator that can be used to study the effects of rainfall on permafrost stability. The NARS design includes a 3D-printed 4 cm H-flume and uses an eTape resistivity sensor that was calibrated (R 2 = 0.9–0.96) to measure discharge from the system. NARS is designed to be lightweight, simple to construct, and can be easily deployed in remote locations. As a field validation of updated rainfall simulator design and modernized controls, NARS was tested on the Seward Peninsula, AK. Because of its portability, versatility in deployment, dimensions, and rainfall intensity, NARS represents a methodological innovation for researching the impacts of rainfall on permafrost environments.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2012

Ecosystem-Atmosphere Exchange of Carbon, Water and Energy over a Mixed Deciduous Forest in the Midwest

During the project period we continued to conduct long-term (multi-year) measurements, analysis, and modeling of energy and mass exchange in and over a deciduous forest in the Midwestern United States, to enhance the understanding of soil-vegetation-atmosphere exchange of carbon. At the time when this report was prepared, results from nine years of measurements (1998 - 2006) of above canopy CO 2 and energy fluxes at the AmeriFlux site in the Morgan-Monroe State Forest, Indiana, USA (see Table 1), were available on the Fluxnet database, and the hourly CO 2 fluxes for 2007 are presented here (see Figure 1). The annual sequestration of atmospheric carbon by the forest is determined to be between 240 and 420 g C m -2 a -1 for the first ten years. These estimates are based on eddy covariance measurements above the forest, with a gap-filling scheme based on soil temperature and photosynthetically active radiation. Data gaps result from missing data or measurements that were rejected in qua)lity control (e.g., during calm nights). Complementary measurements of ecological variables (i.e. inventory method), provided an alternative method to quantify net carbon uptake by the forest, partition carbon allocation in each ecosystem components, and reduce uncertainty on annual net ecosystem productivity (NEP). Biometric datasets are available on the Fluxnext database since 1998 (with the exclusion of 2006). Analysis for year 2007 is under completion.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2013

Ecosystem Controls on C & N Sequestration Following Afforestation of Agricultural Lands

The controls affecting soil organic carbon (SOC) and soil organic nitrogen (SON) dynamics and their sequestration are receiving increasing attention from both scientists and the public as impacts of global change start to affect our environment and natural resources. Soil organic matter (SOM) studies are conducted not only for sequestration and ecosystem sustainability, but also for food security and global change effects. The need to understand the role of soils in ecosystem functioning for 1) soil nutrient storage in a changing climate, 2) increased, organic agriculture production, and 3) increased food needs, even as biofuel production utilizes an expanded acreage of our soil resources, all point to the need for a better knowledge of the controls on SOM dynamics.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2013

The Effects of Iron Complexing Ligands on the Long Term Ecosystem Response to Iron Enrichment of HNLC waters (Final Activity Report)

Substantial increases in the concentrations of the stronger of two Fe(III) complexing organic ligand classes measured during the mesoscale Fe enrichment studies IronEx II and SOIREE appeared to sharply curtailed Fe availability to diatoms and thus limited the efficiency of carbon sequestration to the deep. Detailed observations during IronEx II (equatorial Pacific Ocean) and SOIREE (Southern Ocean –Pacific sector) indicate that the diatoms began re-experiencing Fe stress even though dissolved Fe concentrations remained elevated in the patch. This surprising outcome likely is related to the observed increased concentrations of strong Fe(III)-complexing ligands in seawater. Preliminary findings from other studies indicate that diatoms may not readily obtain Fe from these chemical species whereas Fe bound by strong ligands appears to support growth of cyanobacteria and nanoflagellates. The difficulty in assessing the likelihood of these changes with in-situ mesoscale experiments is the extended monitoring period needed to capture the long-term trajectory of the carbon cycle. A more detailed understanding of Fe complexing ligand effects on long-term ecosystem structure and carbon cycling is essential to ascertain not only the effect of Fe enrichment on short-term carbon sequestration in the oceans, but also the potential effect of Fe enrichment in modifying ecosystem structure and trajectory.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2013

The Oncor Geodatabase for the Columbia Estuary Ecosystem Restoration Program: Handbook of Data Reduction Procedures, Workbooks, and Exchange Templates

This Handbook of Data Reduction Procedures, Workbooks, and Exchange Templates is designed to support the Oncor geodatabase for the Columbia Estuary Ecosystem Restoration Program (CEERP). The following data categories are covered: water-surface elevation and temperature, sediment accretion rate, photo points, herbaceous wetland vegetation cover, tree plots and site summaries, fish catch and density, fish size, fish diet, fish prey, and Chinook salmon genetic stock identification. The handbook is intended for use by scientists collecting monitoring and research data for the CEERP. The ultimate goal of Oncor is to provide quality, easily accessible, geospatial data for synthesis and evaluation of the collective performance of CEERP ecosystem restoration actions at a program scale.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2013

The Oncor Geodatabase for the Columbia Estuary Ecosystem Restoration Program (Annual Report, 2012)

The study reported herein was conducted by researchers at the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (Corps). The purpose of the project is to develop a geospatial, web-accessible database (called Oncor) for action effectiveness and related data from monitoring and research efforts for the Columbia Estuary Ecosystem Restoration Program (CEERP). The intent is for the Oncor database to enable synthesis and evaluation, the results of which can then be applied in subsequent CEERP decision-making. This is the first annual report in what is expected to be a 3- to 4-year project, which commenced on February 14, 2012. This report covers project activities conducted from February 2012 through February 2013. The specific objectives and tasks for the 2012 study year were as enumerated here. 1) Coordination - Coordinate with CEERP funding agencies and regional stakeholders to finalize key analysis questions and database needs for research, monitoring, and evaluation (RME) and ecosystem restoration in the lower Columbia River and estuary (LCRE) within CEERP’s adaptive management framework. 2) Database Development - Develop and demonstrate a web-based proof-of-concept geospatial database management system and analysis system for CEERP. 3) Analysis and Synthesis - Draft the CEERP 2012 Strategy Report, 2012 Action Plan, and 2013 Synthesis and Evaluation Memorandum, and provide other analytical and programmatic support. Work products for Objective 3 were reported separately.

Coleman, Andre M.↗

DOE OSTI2015

Threshold responses to interacting global changes in a California grassland ecosystem

Building on the history and infrastructure of the Jasper Ridge Global Change Experiment, we conducted experiments to explore the potential for single and combined global changes to stimulate fundamental type changes in ecosystems that start the experiment as California annual grassland. Using a carefully orchestrated set of seedling introductions, followed by careful study and later removal, the grassland was poised to enable two major kinds of transitions that occur in real life and that have major implications for ecosystem structure, function, and services. These are transitions from grassland to shrubland/forest and grassland to thistle patch. The experiment took place in the context of 4 global change factors – warming, elevated CO 2 , N deposition, and increased precipitation – in a full-factorial array, present as all possible 1, 2, 3, and 4-factor combinations, with each combination replicated 8 times.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2015

XVis: Visualization for the Extreme-Scale Scientific-Computation Ecosystem (Mid-year report FY15 Q2)

The XVis project brings together the key elements of research to enable scientific discovery at extreme scale. Scientific computing will no longer be purely about how fast computations can be performed. Energy constraints, processor changes, and I/O limitations necessitate significant changes in both the software applications used in scientific computation and the ways in which scientists use them. Components for modeling, simulation, analysis, and visualization must work together in a computational ecosystem, rather than working independently as they have in the past. This project provides the necessary research and infrastructure for scientific discovery in this new computational ecosystem by addressing four interlocking challenges: emerging processor technology, in situ integration, usability, and proxy analysis.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2014

An open source platform for multi-scale spatially distributed simulations of microbial ecosystems

The goal of this project was to develop a tool for facilitating simulation, validation and discovery of multiscale dynamical processes in microbial ecosystems. This led to the development of an open-source software platform for Computation Of Microbial Ecosystems in Time and Space (COMETS). COMETS performs spatially distributed time-dependent flux balance based simulations of microbial metabolism. Our plan involved building the software platform itself, calibrating and testing it through comparison with experimental data, and integrating simulations and experiments to address important open questions on the evolution and dynamics of cross-feeding interactions between microbial species.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2015

Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) Science Plan

Cumulus convection is an important component in the atmospheric radiation budget and hydrologic cycle over the Southern Great Plains and over many regions of the world, particularly during the summertime growing season when intense turbulence induced by surface radiation couples the land surface to clouds. Current convective cloud parameterizations contain uncertainties resulting in part from insufficient coincident data that couples cloud macrophysical and microphysical properties to inhomogeneities in boundary layer and aerosol properties. The Holistic Interactions of Shallow Clouds, Aerosols, and Land-Ecosystems (HI-SCALE) campaign is designed to provide a detailed set of measurements that are needed to obtain a more complete understanding of the life cycle of shallow clouds by coupling cloud macrophysical and microphysical properties to land surface properties, ecosystems, and aerosols. HI-SCALE consists of 2, 4-week intensive observational periods, one in the spring and the other in the late summer, to take advantage of different stages and distribution of “greenness” for various types of vegetation in the vicinity of the Atmospheric Radiation and Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site as well as aerosol properties that vary during the growing season. Most of the proposed instrumentation will be deployed on the ARM Aerial Facility (AAF) Gulfstream 1 (G-1) aircraft, including those that measure atmospheric turbulence, cloud water content and drop size distributions, aerosol precursor gases, aerosol chemical composition and size distributions, and cloud condensation nuclei concentrations. Routine ARM aerosol measurements made at the surface will be supplemented with aerosol microphysical properties measurements. The G-1 aircraft will complete transects over the SGP Central Facility at multiple altitudes within the boundary layer, within clouds, and above clouds.

Fast, JD↗

DOE OSTI2015

XVis: Visualization for the Extreme-Scale Scientific-Computation Ecosystem: Year-end report FY15 Q4.

The XVis project brings together the key elements of research to enable scientific discovery at extreme scale. Scientific computing will no longer be purely about how fast computations can be performed. Energy constraints, processor changes, and I/O limitations necessitate significant changes in both the software applications used in scientific computation and the ways in which scientists use them. Components for modeling, simulation, analysis, and visualization must work together in a computational ecosystem, rather than working independently as they have in the past. This project provides the necessary research and infrastructure for scientific discovery in this new computational ecosystem by addressing four interlocking challenges: emerging processor technology, in situ integration, usability, and proxy analysis.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2016

Cryptic Methane Emissions from Upland Forest Ecosystems

This exploratory research on Cryptic Methane Emissions from Upland Forest Ecosystems was motivated by evidence that upland ecosystems emit 36% as much methane to the atmosphere as global wetlands, yet we knew almost nothing about this source. The long-term objective was to refine Earth system models by quantifying methane emissions from upland forests, and elucidate the biogeochemical processes that govern upland methane emissions. The immediate objectives of the grant were to: (i) test the emerging paradigm that upland trees unexpectedly transpire methane, (ii) test the basic biogeochemical assumptions of an existing global model of upland methane emissions, and (iii) develop the suite of biogeochemical approaches that will be needed to advance research on upland methane emissions. We instrumented a temperate forest system in order to explore the processes that govern upland methane emissions. We demonstrated that methane is emitted from the stems of dominant tree species in temperate upland forests. Tree emissions occurred throughout the growing season, while soils adjacent to the trees consumed methane simultaneously, challenging the concept that forests are uniform sinks of methane. High frequency measurements revealed diurnal cycling in the rate of methane emissions, pointing to soils as the methane source and transpiration as the most likely pathway for methane transport. We propose the forests are smaller methane sinks than previously estimated due to stem emissions. Stem emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration, resolving differences between models and measurements. The methods we used can be effectively implemented in order to determine if the phenomenon is widespread.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2016

Carbon-water Cycling in the Critical Zone: Understanding Ecosystem Process Variability Across Complex Terrain

One of the largest knowledge gaps in environmental science is the ability to understand and predict how ecosystems will respond to future climate variability. The links between vegetation, hydrology, and climate that control carbon sequestration in plant biomass and soils remain poorly understood. Soil respiration is the second largest carbon flux of terrestrial ecosystems, yet there is no consensus on how respiration will change as water availability and temperature co-vary. To address this knowledge gap, we use the variation in soil development and topography across an elevation and climate gradient on the Front Range of Colorado to conduct a natural experiment that enables us to examine the co-evolution of soil carbon, vegetation, hydrology, and climate in an accessible field laboratory. The goal of this project is to further our ability to combine plant water availability, carbon flux and storage, and topographically driven hydrometrics into a watershed scale predictive model of carbon balance. We hypothesize: (i) landscape structure and hydrology are important controls on soil respiration as a result of spatial variability in both physical and biological drivers: (ii) variation in rates of soil respiration during the growing season is due to corresponding shifts in belowground carbon inputs from vegetation; and (iii) aboveground carbon storage (biomass) and species composition are directly correlated with soil moisture and therefore, can be directly related to subsurface drainage patterns.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2016

XVis: Visualization for the Extreme-Scale Scientific-Computation Ecosystem. Mid-year report FY16 Q2

The XVis project brings together the key elements of research to enable scientific discovery at extreme scale. Scientific computing will no longer be purely about how fast computations can be performed. Energy constraints, processor changes, and I/O limitations necessitate significant changes in both the software applications used in scientific computation and the ways in which scientists use them. Components for modeling, simulation, analysis, and visualization must work together in a computational ecosystem, rather than working independently as they have in the past. This project provides the necessary research and infrastructure for scientific discovery in this new computational ecosystem by addressing four interlocking challenges: emerging processor technology, in situ integration, usability, and proxy analysis.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2016

Move Towards a Balanced 7-County Ecosystem

This report describes the entrepreneurial ecosystem in NNM, either at LANL or within entrepreneurial ecosystem. Its purpose is to attract and retain technical talent and Millennials.

99 GENERAL AND MISCELLANEOUS↗

DOE OSTI2017

XVis: Visualization for the Extreme-Scale Scientific-Computation Ecosystem: Mid-year report FY17 Q2

The XVis project brings together the key elements of research to enable scientific discovery at extreme scale. Scientific computing will no longer be purely about how fast computations can be performed. Energy constraints, processor changes, and I/O limitations necessitate significant changes in both the software applications used in scientific computation and the ways in which scientists use them. Components for modeling, simulation, analysis, and visualization must work together in a computational ecosystem, rather than working independently as they have in the past. This project provides the necessary research and infrastructure for scientific discovery in this new computational ecosystem by addressing four interlocking challenges: emerging processor technology, in situ integration, usability, and proxy analysis.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2017

XVis: Visualization for the Extreme-Scale Scientific-Computation Ecosystem: Year-end report FY17.

The XVis project brings together the key elements of research to enable scientific discovery at extreme scale. Scientific computing will no longer be purely about how fast computations can be performed. Energy constraints, processor changes, and I/O limitations necessitate significant changes in both the software applications used in scientific computation and the ways in which scientists use them. Components for modeling, simulation, analysis, and visualization must work together in a computational ecosystem, rather than working independently as they have in the past. This project provides the necessary research and infrastructure for scientific discovery in this new computational ecosystem by addressing four interlocking challenges: emerging processor technology, in situ integration, usability, and proxy analysis.

54 ENVIRONMENTAL SCIENCES↗