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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Synergistic Ecoclimate Teleconnections from Forest Loss in Different Regions Structure Global Ecological Responses

Forest loss in hotspots around the world impacts not only local climate where loss occurs, but also influences climate and vegetation in remote parts of the globe through ecoclimate teleconnections. The magnitude and mechanism of remote impacts likely depends on the location and distribution of forest loss hotspots, but the nature of these dependencies has not been investigated. We use global climate model simulations to estimate the distribution of ecologically-relevant climate changes resulting from forest loss in two hotspot regions: western North America (wNA), which is experiencing accelerated dieoff, and the Amazon basin, which is subject to high rates of deforestation. The remote climatic and ecological net effects of simultaneous forest loss in both regions differed from the combined effects of loss from the two regions simulated separately, as evident in three impacted areas. Eastern South American Gross Primary Productivity (GPP) increased due to changes in seasonal rainfall associated with Amazon forest loss and changes in temperature related to wNA forest loss. Eurasia's GPP declined with wNA forest loss due to cooling temperatures increasing soil ice volume. Southeastern North American productivity increased with simultaneous forest loss, but declined with only wNA forest loss due to changes in VPD. In conclusion, our results illustrate the need for a new generation of local-to-global scale analyses to identify potential ecoclimate teleconnections, their underlying mechanisms, and most importantly, their synergistic interactions, to predict the responses to increasing forest loss under future land use change and climate change.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Granick revisited: Synthesizing evolutionary and ecological evidence for the late origin of bacteriochlorophyll via ghost lineages and horizontal gene transfer

Photosynthesis—both oxygenic and more ancient anoxygenic forms—has fueled the bulk of primary productivity on Earth since it first evolved more than 3.4 billion years ago. However, the early evolutionary history of photosynthesis has been challenging to interpret due to the sparse, scattered distribution of metabolic pathways associated with photosynthesis, long timescales of evolution, and poor sampling of the true environmental diversity of photosynthetic bacteria. Here, we reconsider longstanding hypotheses for the evolutionary history of phototrophy by leveraging recent advances in metagenomic sequencing and phylogenetics to analyze relationships among phototrophic organisms and components of their photosynthesis pathways, including reaction centers and individual proteins and complexes involved in the multi-step synthesis of (bacterio)-chlorophyll pigments. We demonstrate that components of the photosynthetic apparatus have undergone extensive, independent histories of horizontal gene transfer. This suggests an evolutionary mode by which modular components of phototrophy are exchanged between diverse taxa in a piecemeal process that has led to biochemical innovation. We hypothesize that the evolution of extant anoxygenic photosynthetic bacteria has been spurred by ecological competition and restricted niches following the evolution of oxygenic Cyanobacteria and the accumulation of O 2 in the atmosphere, leading to the relatively late evolution of bacteriochlorophyll pigments and the radiation of diverse crown group anoxygenic phototrophs. This hypothesis expands on the classic “Granick hypothesis” for the stepwise evolution of biochemical pathways, synthesizing recent expansion in our understanding of the diversity of phototrophic organisms as well as their evolving ecological context through Earth history.

58 GEOSCIENCES↗
DOE OSTI2021

Flooding and ecological restoration promote wetland microbial communities and soil functions on former cranberry farmland

Microbial communities are early responders to wetland degradation, and instrumental players in the reversal of this degradation. However, our understanding of soil microbial community structure and function throughout wetland development remains incomplete. We conducted a survey across cranberry farms, young retired farms, old retired farms, flooded former farms, ecologically restored former farms, and natural reference wetlands with no history of cranberry farming. We investigated the relationship between the microbial community and soil characteristics that restoration intends to maximize, such as soil organic matter, cation exchange capacity and denitrification potential. Among the five treatments considered, flooded and restored sites had the highest prokaryote and microeukaryote community similarity to natural wetlands. In contrast, young retired sites had similar communities to farms, and old retired sites failed to develop wetland microbial communities or functions. Canonical analysis of principal coordinates revealed that soil variables, in particular potassium base saturation, sodium, and denitrification potential, explained 45% of the variation in prokaryote communities and 44% of the variation in microeukaryote communities, segregating soil samples into two clouds in ordination space: farm, old retired and young retired sites on one side and restored, flooded, and natural sites on the other. Heat trees revealed possible prokaryotic ( Gemmatimonadetes ) and microeukaryotic ( Rhizaria ) indicators of wetland development, along with a drop in the dominance of Nucletmycea in restored sites, a class that includes suspected mycorrhizal symbionts of the cranberry crop. Flooded sites showed the strongest evidence of wetland development, with triple the soil organic matter accumulation, double the cation exchange capacity, and seventy times the denitrification potential compared to farms. However, given that flooding does not promote any of the watershed or habitat benefits as ecological restoration, we suggest that flooding can be used to stimulate beneficial microbial communities and soil functions during the restoration waiting period, or when restoration is not an option.

Rubin, Rachel L. (ORCID:0000000284326811)↗
DOE OSTI2019

AmeriFlux US-EDN Eden Landing Ecological Reserve

This is the AmeriFlux version of the carbon flux data for the site US-EDN Eden Landing Ecological Reserve. Site Description - This tower located at Eden Landing Ecological Reserve, a 6400 acres reserve with diked marsh and newly (10 year old) restored salt ponds, managed by the California Department of Fish and Wildlife (CDFW) in the San Francisco Bay.

Oikawa, Patty↗
DOE OSTI2015

A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands

Salinization, a widespread threat to the structure and ecological functioning of inland and coastal wetlands, is currently occurring at an unprecedented rate and geographic scale. The causes of salinization are diverse and include alterations to freshwater flows, land-clearance, irrigation, disposal of wastewater effluent, sea level rise, storm surges, and applications of de-icing salts. Climate change and anthropogenic modifications to the hydrologic cycle are expected to further increase the extent and severity of wetland salinization. Salinization alters the fundamental physicochemical nature of the soil-water environment, increasing ionic concentrations and altering chemical equilibria and mineral solubility. Increased concentrations of solutes, especially sulfate, alter the biogeochemical cycling of major elements including carbon, nitrogen, phosphorus, sulfur, iron, and silica. The effects of salinization on wetland biogeochemistry typically include decreased inorganic nitrogen removal (with implications for water quality and climate regulation), decreased carbon storage (with implications for climate regulation and wetland accretion), and increased generation of toxic sulfides (with implications for nutrient cycling and the health/functioning of wetland biota). Indeed, increased salt and sulfide concentrations induce physiological stress in wetland biota and ultimately can result in large shifts in wetland communities and their associated ecosystem functions. The productivity and composition of freshwater species assemblages will be highly altered, and there is a high potential for the disruption of existing interspecific interactions. Although there is a wealth of information on how salinization impacts individual ecosystem components, relatively few studies have addressed the complex and often non-linear feedbacks that determine ecosystem-scale responses or considered how wetland salinization will affect landscape-level processes. Although the salinization of wetlands may be unavoidable in many cases, these systems may also prove to be a fertile testing ground for broader ecological theories including (but not limited to): investigations into alternative stable states and tipping points, trophic cascades, disturbance-recovery processes, and the role of historical events and landscape context in driving community response to disturbance.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Data-Model Needs for Belowground Ecology. A Summary Report from the Terrestrial Ecosystem Science (TES) Mini-Workshop, May 8, 2014

Terrestrial life on Earth depends on belowground cycling and storage of a significant portion of the planet’s biologically-active carbon. The interplay among organic inputs by primary producers, soil organic matter stabilization, and assimilation and mineralization by soil organisms drives belowground ecology. Understanding belowground carbon dynamics, including the stability and vulnerability of soil organic carbon stocks, is necessary to project the responses and feedbacks of terrestrial ecosystems to a changing climate. Although conceptually understood, belowground hydrobiogeochemical systems are not well characterized with quantitative and mechanistic representations of critical functions. As a result, these systems are inadequately represented in modeling efforts, limiting our ability to understand and project terrestrial carbon source/sink relationships at various temporal and spatial scales. The belowground science community lacks robust databases and data libraries against which model sensitivities and performance can be tested and enhanced. Improved understanding of belowground ecosystems, including biotic and abiotic interactions, is needed to ensure that model structures include and provide adequate representations of critical belowground processes, functions, and dynamics. A one-day workshop brought together experimental and modeling representatives from the four Department of Energy (DOE) National Laboratories where the Office of Biological and Environmental Research (BER) Terrestrial Ecosystem Science (TES) program has investments in belowground ecology. The group focused on identifying and characterizing (1) critical experimental and observational datasets for testing and developing existing and future belowground-process models and land models; (2) the limitations and needs for modeling belowground processes within ecosystem models; and (3) key areas for leveraging current research activities across the National Laboratories and BER-funded projects. Discussion results are organized in this report as: (I) over-arching data requirements for advancing understanding of belowground ecosystems; (II) efforts that could rapidly improve understanding and model representations of belowground components of terrestrial ecosystems; and (III) longer-term research needs that would benefit from greater and more sustained support.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Resilience: Concepts from Engineering, Ecology, and the Social Sciences

“Resilience” is fast becoming a key word for describing the desired result of the activities we group under the heading of “homeland security.” Department of Homeland Security (DHS) Secretary Napolitano has made resilience a key theme in her speeches, highlighting the efforts of DHS to “strengthen the resilience of ... infrastructure, computer networks, and of ... communities and citizens.” She has talked about resilience as “strengthening the ability for our systems, our cities, our towns, and our country to bounce back quickly from an attack or a natural disaster, and to be even stronger than before. This paper first provides an overview of resilience concepts from U.S. government and academic research sources. It then discusses resilience concepts and metrics from the academic literature in more detail, focusing on three types of resilience: engineering resilience, ecological resilience, and community and regional resilience. Next, it discusses system characteristics that have been associated with increased resilience. Based on this background, we propose a model of the infrastructure resilience analysis process. We then review LANL capabilities for each process element and indicate areas where capability development opportunities exist. Appendices provide additional information on funding sources and key players in infrastructure resilience, and a more detailed technical explanation of ecological resilience.

42 ENGINEERING↗
DOE OSTI2022

Scaling the Microbial Ecology of Soil Carbon (Final Report)

This work developed new techniques and discoveries in quantitative microbial ecology, focusing on soil carbon. The work advanced a new approach to stable isotope probing (SIP), adding a quantitative way to infer taxon-specific rates of growth, mortality, and associated carbon (C) fluxes in soil microbial communities, a framework that the work demonstrated can scale from individual microbial taxa to the integrated soil system. Among the “-omics” techniques in microbial ecology, those based on stable isotope probing (SIP) hold particular promise for addressing the challenge of scaling from molecules to the major biogeochemical element cycles. Because SIP measures directly the fluxes of elements into nucleic acids, it physically connects element flux to genetic information. The work explored new ways to quantify taxon-specific C-use and growth efficiency and tested hypotheses about responses of the soil microbial community to experimental warming and to latitudinal variation in temperature. This work pushed the frontier of –omics enabled techniques by demonstrating their applicability at the ecosystem scale, and by relating taxon-specific isotope assimilation to dissimilatory processes in the C cycle, thereby enabling the identification of organisms especially responsible for soil C loss, in other words, attributing ecosystem-scale element fluxes to individual microbial taxa.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Editorial: Hydrology, ecology, and nutrient biogeochemistry at the terrestrial-aquatic interface

Terrestrial-aquatic interfaces (TAI) play important roles in mediating the exchange of water and chemicals between land, surface and subsurface water systems, which is tightly coupled with biogeochemical transformations that influence water quality and ecosystem health (Harvey and Gooseff, 2015; Harvey et al., 2019). Understanding and predicting the interactions between the hydrologic, ecologic, and biogeochemical processes at those interfaces is crucial for the sustainable management of water resources and promotion of healthy ecosystems under different environmental stresses and disturbances, including climate change, human activities, and more frequent occurrence of extreme events. Both process-based and data-driven approaches have emerged to address critical challenges at TAIs as integral parts of the Earth system (e.g., Ward and Packman, 2019; Chen et al., 2021; Dwivedi et al., 2022). In this Research Topic, we sought research that advances the understanding of coupled hydrologic, ecologic, and biogeochemical processes along various TAIs from the summit to sea, e.g., river corridors and coastal TAI systems. We invited observational, experimental, theoretical, analytical, numerical, and data-driven research that aims to understand hydro-biogeochemical processes such as the redox dynamics and biogeochemical transformations of carbon, nutrients, and metals occurring at the TAIs and address their heterogeneity and scaling challenges.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Crowdsourcing Global Perspectives in Ecology Using Social Media

Transparent, open, and reproducible research is still far from routine, and the full potential of open science has not yet been realized. Crowdsourcing–defined as the usage of a flexible open call to a heterogeneous group of individuals to recruit volunteers for a task –is an emerging scientific model that encourages larger and more outwardly transparent collaborations. While crowdsourcing, particularly through citizen- or community-based science, has been increasing over the last decade in ecological research, it remains infrequently used as a means of generating scientific knowledge in comparison to more traditional approaches. We explored a new implementation of crowdsourcing by using an open call on social media to assess its utility to address fundamental ecological questions. We specifically focused on pervasive challenges in predicting, mitigating, and understanding the consequences of disturbances. In this paper, we briefly review open science concepts and their benefits, and then focus on the new methods we used to generate a scientific publication. We share our approach, lessons learned, and potential pathways forward for expanding open science. Our model is based on the beliefs that social media can be a powerful tool for idea generation and that open collaborative writing processes can enhance scientific outcomes. We structured the project in five phases: (1) draft idea generation, (2) leadership team recruitment and project development, (3) open collaborator recruitment via social media, (4) iterative paper development, and (5) final editing, authorship assignment, and submission by the leadership team. We observed benefits including: facilitating connections between unusual networks of scientists, providing opportunities for early career and underrepresented groups of scientists, and rapid knowledge exchange that generated multidisciplinary ideas. We also identified areas for improvement, highlighting biases in the individuals that self-selected participation and acknowledging remaining barriers to contributing new or incompletely formed ideas into a public document. While shifting scientific paradigms to completely open science is a long-term process, our hope in publishing this work is to encourage others to build upon and improve our efforts in new and creative ways.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Evidence for Ecological Flexibility in the Cosmopolitan Genus Curtobacterium

Assigning ecological roles to bacterial taxa remains imperative to understanding how microbial communities will respond to changing environmental conditions. Here we analyze the genus Curtobacterium, as it was found to be the most abundant taxon in a leaf litter community in southern California. Traditional characterization of this taxon predominantly associates it as the causal pathogen in the agricultural crops of dry beans. Therefore, we sought to investigate whether the abundance of this genus was because of its role as a plant pathogen or another ecological role. By collating >24,000 16S rRNA sequences with 120 genomes across the Microbacteriaceae family, we show that Curtobacterium has a global distribution with a predominant presence in soil ecosystems. Moreover, this genus harbors a high diversity of genomic potential for the degradation of carbohydrates, specifically with regards to structural polysaccharides. We conclude that Curtobacterium may be responsible for the degradation of organic matter within litter communities.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Editorial: Ecology, evolution, and biodiversity of microbiomes and viromes from extreme environments

Ecology, evolution, and biodiversity of microbiomes and viromes in extreme environments are key areas of research that explore how microbial communities adapt, survive, and thrive under harsh conditions. The studies published in our Research Topic advance our understanding of microbial and viral diversity, evolutionary processes, and the ecological roles of these communities, with implications for biotechnology, climate resilience, and even astrobiology.

adaptation↗
DOE OSTI2015

Is the “ecological and economic approach for the restoration of collapsed gullies” in Southern China really economic?

Collapsed gully erosion constantly plagues the sustainability of rural areas in China. To control collapsed gully erosion, an ecological and economic approach, which uses tree plantation to gain economic benefits and control soil erosion, has been widely applied by local governments in Southern China. However, little is known about the economic feasibility of this new method. The objective of this study was to determine the effectiveness and economic benefits of the new method. Based on a case study in Changting County, Southeast China, two farms were selected to represent a timber tree plantation and a fruit tree plantation, respectively. The Annual Capital Capitalization Method and Return on Investment (ROI) were selected to conduct cost-benefit analysis. In contrast to previous studies, we found that the new approach was far from economic. The value of the newly-built forestland in Sanzhou Village and Tufang Village is 2738 RMB ha -1 and 5477 RMB ha -1 , respectively, which are extremely lower than the costs of ecological restoration. Meanwhile, the annual ROI is –3.60% and –8.90%, respectively, which is negative and also far poorer than the average value of forestry in China. The costs of conservation were substantially over the related economic benefits, and the investors would suffer from greater loss if they invested more in the conservation. Low-cost terraces with timber trees had less economic loss compared with the costly terraces with fruit tree plantation. Moreover, the cost efficiency of the new approaches in soil conservation was also greatly poorer than the conventional method. The costs of conserving one ton soil per year for conventional method, new method for planting timber trees, and planting fruit trees were 164 RMB, 696 RMB, and 11,664 RMB, respectively. Therefore, the new collapsed gully erosion control methods are uneconomic and unsuitable to be widely carried out in China in the near future.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Constraining DALECv2 using multiple data streams and ecological constraints: analysis and application

We use a variational method to assimilate multiple data streams into the terrestrial ecosystem carbon cycle model DALECv2 (Data Assimilation Linked Ecosystem Carbon). Ecological and dynamical constraints have recently been introduced to constrain unresolved components of this otherwise ill-posed problem. We recast these constraints as a multivariate Gaussian distribution to incorporate them into the variational framework and we demonstrate their advantage through a linear analysis. By using an adjoint method we study a linear approximation of the inverse problem: firstly we perform a sensitivity analysis of the different outputs under consideration, and secondly we use the concept of resolution matrices to diagnose the nature of the ill-posedness and evaluate regularisation strategies. We then study the non-linear problem with an application to real data. Finally, we propose a modification to the model: introducing a spin-up period provides us with a built-in formulation of some ecological constraints which facilitates the variational approach.

58 GEOSCIENCES↗
NASA NTRS1973

The high energy multicharged particle exposure of the microbial ecology evaluation device on board the Apollo 16 spacecraft

The high energy multicharged cosmic-ray-particle exposure of the Microbial Ecology Evaluation Device package on board the Apollo 16 spacecraft was monitored using cellulose nitrate, Lexan polycarbonate, nuclear emulsion, and silver chloride crystal nuclear-track detectors. The results of the analysis of these detectors include the measured particle fluences, the linear energy transfer spectra, and the integral atomic number spectrum of stopping particle density. The linear energy transfer spectrum is used to compute the fractional cell loss in human kidney (T1) cells caused by heavy particles. Because the Microbial Ecology Evaluation Device was better shielded, the high-energy multicharged particle exposure was less than that measured on the crew passive dosimeters.

Benton, E. V.↗
NASA NTRS1976

An advanced concept that promises ecological and economic viability

The actuality of supersonic commercial service being provided by Concorde is demonstrating to the world the advantages offered by supersonic travel for both business and recreation. Public acceptance will gradually and persistently stimulate interest to proceed with a second generation design that meets updated economic and ecological standards. It is estimated that this concept could operate profitably on world-wide routes with a revenue structure based upon economy fares. Airplanes will meet all present day ecological requirements regarding noise and emissions.

Wright, B. R.↗
NASA NTRS1976

Particles, environments, and possible ecologies in the Jovian atmosphere

The possible existence of indigenous Jovian organisms is investigated by characterizing the relevant physical environment of Jupiter, discussing the chromophores responsible for the observed coloration of the planet, and analyzing some permissible ecological niches of hypothetical organisms. Values of the eddy diffusion coefficent are estimated separately for the convective troposphere and the more stable mesosphere, and equilibrium condensation is studied for compounds containing Na, Cl, or both. The photoproduction of chromophores and nonequilibrium organic molecules is analyzed, and the motion of hypothetical organisms is examined along with the diffusion of metabolites and the consequent growth of organisms. Four kinds of organisms are considered: primary photosynthetic autotrophs ('sinkers'), larger autotrophs or heterotrophs that actively maintain their pressure level ('floaters'), organisms that seek out others ('hunters'), and organisms that live at almost pyrolytic depths ('scavengers'). It is concluded that ecological niches for sinkers, floaters, and hunters appear to exist in the Jovian atmosphere.

Sagan, C.↗
NASA NTRS1979

Radar, Insect Population Ecology, and Pest Management

Discussions included: (1) the potential role of radar in insect ecology studies and pest management; (2) the potential role of radar in correlating atmospheric phenomena with insect movement; (3) the present and future radar systems; (4) program objectives required to adapt radar to insect ecology studies and pest management; and (5) the specific action items to achieve the objectives.

Vaughn, C. R.↗