Large river basins integrate the signal of water from atmospheres to oceans. Climate change is widely expected to alter streamflow and potentially disrupt water management systems. We tested the ecological resilience -- capacity of headwater ecosystems to sustain streamflow under climate change – and the engineering resilience – capacity of...
Paleoclimate proxies based on the measurement of xylem cell anatomy have rarely been developed across the temperature range of a species or applied to wood predating the most recent millennium. Here we describe wood anatomy-based proxies for spring temperatures in central North America from modern bur oaks (Quercus macrocarpa Michx.)....
Long-term ecological data are crucial in helping ecologists understand ecosystem function and environmental change. Nevertheless, these kinds of data sets are difficult to analyze because they are usually large, multivariate, and spatiotemporal. Although existing analysis tools such as statistical methods and spreadsheet software permit rigorous tests of pre-conceived hypotheses and...
Coastlines have traditionally been engineered to maintain structural stability and to protect property from storm-related damage, but their ability to endure will be challenged over the next century. The use of vegetation to reduce erosion on ocean-facing mainland and barrier island shorelines – including the sand dunes and beaches on...
Photobiological hydrogen production -- the use of photosynthesis to split water into hydrogen and oxygen -- presents an opportunity for efficient and large-scale solar biofuel development. One of the major challenges in this area is competition for reductant between the hydrogen-evolving hydrogenase enzyme and other metabolic pathways. In this work...
An online survey of river restoration practitioners, engineers, and researchers was conducted to examine current practices and perspectives on how climate change is integrated into engineering designs for river restoration. Seventy-six responses were submitted to the survey. While the responses came from a wide range of demographies, respondents were most...
Vegetation at the aquatic–terrestrial interface can alter landscape features through its growth and interactions with sediment and fluids. Even similar species may impart different effects due to variation in their interactions and feedbacks with the environment. Consequently, replacement of one engineering species by another can cause significant change in the...
Shewanella oneidensis MR-1 is a gram-negative, facultative anaerobic bacteria with the capability of dissimilatory metal reduction. The ability of the organism to reduce a wide range of solid metal-oxides during anaerobic respiration makes it an ideal candidate for the powering of microbial fuel cells (MFCs), which capture the electrons discharged...
Bioethanol produced from the lignocellulosic feedstock is a potential alternative to fossil fuels in transportation sector and can help in reducing environmental burdens. Straw produced from perennial ryegrass (PR) and wheat is a non-food, cellulosic biomass resource available in abundance in the Pacific Northwest U.S. The aim of this study...
Vegetation growing on the surface of a streambank has been shown to alter the shear stresses
applied to the boundary, but basic questions remain regarding the influence of vegetation and
streambank configurations on near-bank hydraulics. In the present study, Froude-scaled flume
experiments were used to investigate how changes in vegetation...
Rapid hydropower development is occurring in China's Yunnan province in response to increasing clean energy demands, exposing potential vulnerabilities of the area's ecosystems, communities, and geopolitical systems. Here, we present original data on the cultures, economics, hydro-politics, and environments of the Nu River basin, based on household surveys, analysis of...
The 2010 Deepwater Horizon oil release posed the challenges of two types of spill: a familiar spill characterized by buoyant oil, fouling and killing organisms at the sea surface and eventually grounding on and damaging sensitive shoreline habitats, and a novel deepwater spill involving many unknowns. The subsurface retention of...
The movement of air in natural porous media is complex and challenging to measure. Yet gas transport has important implications, for instance, for the evolution of the seasonal snow cover and for water vapor transport in soil. A novel in situ multi-sensor measurement system providing high-resolution observation of gas transport...
Ethanol from corn is produced using dry grind corn process in which simultaneous saccharification and fermentation (SSF) is one of the most critical unit operations. In this work an optimal controller based on a previously validated SSF model was developed by formulating the SSF process as a Bolza problem and...
The residual of the surface energy budget is represented as the linearized sum of energy losses due to storage, advection and flux underestimation. Individual contributions to the residual can be quantified through constrained multiple linear regression which identifies the site specific processes that are responsible for the lack of energy...
Shrinkage cracks in soil function as a dominant control on the partitioning and distribution of moisture fluxes in the vadose zone. Their dynamics influence moisture balance and control water availability for runoff, deep infiltration, and near-surface storage. We present a new low-cost field instrument to monitor the temporal change in...
Support for low-carbon energy and opposition to new large dams encourages global development of small hydropower facilities. This support is manifested in national and international energy and development policies designed to incentivize growth in the small hydropower sector while curtailing large dam construction. However, the preference of small to large...
The growth characteristics of Thermosynechococcus elongatus on elevated CO₂ were studied in a photobioreactor. Cultures were able to grow on up to 20% CO₂. The maximum productivity and CO₂ fixation rates were 0.09 ± A 0.01 and 0.17 ± A 0.01 mg ml⁻¹ day⁻¹, respectively, for cultures grown on 20%...
A new multi-telescope scanning Raman lidar designed to measure the water vapor mixing ratio for a complete diurnal cycle with high raw spatial (1.25 m) and temporal (1 s) resolutions is presented. The high resolution allows detailed measurements of the lower atmosphere and offers new opportunities for boundary layer research,...
Taylor’s frozen turbulence hypothesis is the central assumption invoked in most
experiments designed to investigate turbulence physics with time resolving sensors. It is also
frequently used in theoretical discussions when linking Lagrangian to Eulerian flow formalisms.
In this work we seek to quantify the effectiveness of Taylor’s hypothesis on the...
Current laboratory methods for determining volume and bulk density of soil clods include dipping saran-coated clods in water (a destructive process due to the permanent coating), performing physical measurements on samples with well-defined geometries, or using expensive equipment and proprietary software (such as laser scanners). We propose an alternative method...
Hydrologic research is a very demanding application of fiber-optic distributed temperature sensing (DTS) in terms of precision, accuracy and calibration. The physics behind the most frequently used DTS instruments are considered as they apply to four calibration methods for single-ended DTS installations. The new methods presented are more accurate than...
Background, aim and scope: The aim of this study was to perform a well-to-pump life cycle assessment (LCA) to investigate the overall net energy balance and environmental impact of bioethanol production using Tall Fescue grass straw as feedstock. The energy requirements and green house gas (GHG) emissions were compared to...
Simulation of local atmospheric flows around complex topography is important for several applications in wind energy (short term wind forecasting and turbine siting and control), local weather predictions in mountainous regions and avalanche risk assessment. However atmospheric simulation around steep mountain topography remains challenging and there exist several way to...
Increase in energy demand has led towards considering lignocellulosic feedstocks as potential for ethanol production. Aim of this study was to estimate the potential of grass straws from conservation reserve program (CRP) lands as feedstocks for ethanol production. The CRP was initiated to ensure reduction in soil erosion with a...
The performance of an over 10 times larger microbial fuel cell (MFC) with double cloth electrode assembly (CEA) during 63 days of continuous operation demonstrates that the excellent performance of CEA-MFC can be further improved during scale-up. With a new separator material and U-shaped current collectors, the larger MFC produced...
Cyanobacteria inhabit nearly every ecosystem on earth, play a vital role in nutrient cycling, and are
useful as model organisms for fundamental research in photosynthesis and carbon and nitrogen fixation.
In addition, they are important for several established biotechnologies for producing food additives,
nutritional and pharmaceutical compounds, and pigments, as...
Over the past five years, Distributed Temperature Sensing (DTS) along fiber optic cables using Raman backscattering has become an important tool in the environmental sciences. Many environmental applications of DTS demand very accurate temperature measurements, with typical RMSE < 0.1 K. The aim of this paper is to describe and...
Accurate estimates of water losses by evaporation from shallow water tables are important for hydrological, agricultural, and climatic purposes. An experiment was conducted in a weighing lysimeter to characterize the diurnal dynamics of evaporation under natural conditions. Sampling revealed a completely dry surface sand layer after 5 days of evaporation....
The role of evapotranspiration (ET) in the global, continental, regional, and local water cycles is reviewed. Elevated atmospheric CO₂, air temperature, vapor pressure deficit (D), turbulent transport, radiative transfer, and reduced soil moisture all impact biotic and abiotic processes controlling ET that must be extrapolated to large scales. Suggesting a...
Thermal diffusivity of snow is an important thermodynamic property associated with key hydrological phenomena such as snow melt and heat and water vapor exchange with the atmosphere. Direct determination of snow thermal diffusivity requires coupled point measurements of thermal conductivity and density, which are nonstationary due to snow metamorphism. Traditional...
A field campaign, the Slope Experiment near La Fouly (SELF-2010), was conducted to monitor the evening transition of slope flows on clear-sky days from July to September 2010 in a narrow valley of the Swiss Alps. A steep west-facing slope with inclinations ranging from 25° to 45° was instrumented from...
Background: During cellulosic ethanol production, cellulose hydrolysis is achieved by synergistic action of cellulase
enzyme complex consisting of multiple enzymes with different mode of actions. Enzymatic hydrolysis of cellulose is
one of the bottlenecks in the commercialization of the process due to low hydrolysis rates and high cost of
enzymes....
Ecosystem services play a crucial role in sustaining human well-being and economic viability. People benefit substantially from the delivery of ecosystem services, for which substitutes usually are costly or unavailable. Climate change will substantially alter or eliminate certain ecosystem services in the future. To better understand the consequences of climate...
Species invasions have a range of negative effects on recipient ecosystems, and many occur at a scale and magnitude that preclude complete eradication. When complete extirpation is unlikely with available management resources, an effective strategy may be to suppress invasive populations below levels predicted to cause undesirable ecological change. We...
As we contemplate the future of forest landscapes under changing climate conditions and land-use demands, there is increasing value in studying historic forest conditions and how these landscapes have changed following past disturbances. Historic landscape paintings are a potential source of data on preindustrial forests with highly detailed, full-color depictions...
The concept of sustainable resource management can be applied at multiple scales.
Monitoring is an essential component of sustainable natural resource management
schemes, and as we begin to confront the need to manage natural resources at the
global scale, the importance of monitoring at the global scale is also growing....
Predicting the effects of climate change on ecological communities requires an understanding of how environmental factors influence both physiological processes and species interactions. Specifically, the net impact of temperature on community structure depends on the relative response of physiological energetic costs (metabolism) and energetic gains (ingestion of resources) that mediate...
The methods for conducting reductionist ecological science are well known and widely used. In contrast, those used in the synthesis of ecological science (i.e., synthesis science) are still being developed, vary widely, and often lack the rigor of reductionist approaches. This is unfortunate because the synthesis of ecological parts into...
Managing multiple ecosystem services (ESs) across landscapes presents a central challenge for ecosystem-based management, because services often exhibit spatiotemporal variation and weak associations with co-occurring ESs. Further focus on the mechanistic relationships among ESs and their underlying biophysical processes provides greater insight into the causes of variation and covariation among...
Land-use change significantly contributes to biodiversity loss, invasive species spread, changes in biogeochemical cycles, and the loss of ecosystem services. Planning for a sustainable future requires a thorough understanding of expected land use at the fine spatial scales relevant for modeling many ecological processes and at dimensions appropriate for regional...
Complex systems science provides a transdisciplinary framework to study systems characterized by (1) heterogeneity, (2) hierarchy, (3) self‐organization, (4) openness, (5) adaptation, (6) memory, (7) non‐linearity, and (8) uncertainty. Complex systems thinking has inspired both theory and applied strategies for improving ecosystem resilience and adaptability, but applications in forest ecology...
National-scale analyses of fire occurrence are needed to prioritize fire policy and
management activities across the United States. However, the drivers of national-scale
patterns of fire occurrence are not well understood, and how the relative importance of human
or biophysical factors varies across the country is unclear. Our research goal...
We analyzed the sedimentological characteristics and magnetic properties of cores from the three basins of Clear Lake, California, USA, to assess the depositional response to a series of land use changes that occurred in the watershed over the 20th century. Results indicate that distinct and abrupt shifts in particle size,...
Intrinsic and extrinsic factors affect vital rates and population-level processes, and understanding these factors is paramount to devising successful management plans for wildlife species. For example, birds time migration in response, in part, to local and broadscale climate fluctuations to initiate breeding upon arrival to nesting territories, and prolonged inclement...
Intrinsic and extrinsic factors affect vital rates and population-level processes, and understanding these factors is paramount to devising successful management plans for wildlife species. For example, birds time migration in response, in part, to local and broadscale climate fluctuations to initiate breeding upon arrival to nesting territories, and prolonged inclement...