A multi-benefit framework for funding forest management in fire-driven ecosystems across the Western U.S.

Forests across the Western U.S. face unprecedented risk due to historic fire exclusion, environmental degradation, and climate change. Forest management activities like ecological thinning, prescribed burning, and meadow restoration can improve landscape resilience. Resilient forests are at a lower risk of high-intensity wildfires, drought, insects, and other disturbances and provide a wide range of benefits to ecosystems and communities. However, insufficient funding limits implementation of critically needed management. To address this challenge, we propose a multi-benefit framework that leverages the diverse benefits of forest management to engage a suite of stakeholders in sharing project costs. We take a three-pronged approach to develop our conceptual model: examining existing frameworks for environmental project implementation, conducting a literature review of forest management benefits, and evaluating case studies. Through our framework, we describe the steps to engage partners, starting by identifying benefits that could accrue to potential public and private beneficiaries, and moving through an iterative and collaborative process of valuing benefits, which can accrue over different spatial and temporal scales, in close consultation with potential beneficiaries themselves. The aim of this approach is to stack funding streams associated with each valued benefit to fully fund a given forest management project. The multi-benefit framework has the potential to unlock new sources of funding to meet the exceptional challenges of climate and wildfire disturbances. We apply the framework to dry forests of the Western U.S., but opportunities exist for expanding and modifying this approach to any geography or ecosystem where management provides multiple benefits.

Valuing the benefits of forest restoration on enhancing hydropower and water supply in California's Sierra Nevada.

Forest restoration through mechanical thinning, prescribed burning, and other management actions is vital to improving forest resilience to fire and drought across the Western United States, and yields benefits that can be monetized, including improvements in water supply and hydropower. Using California's Sierra Nevada as a study area, we assess the water and energy benefits of forest-restoration projects. By using a scalable top-down approach to track annual evapotranspiration following forest disturbance, coupled with hydropower simulations that include energy-price information, and marginal prices for water sales, we project the potential economic benefits of hydropower and water sales accruing to water-rights holders. The results found that water-related benefits from strategically planned fuels-reduction treatments now being carried out can be sufficient to offset costs of management actions aimed at forest restoration, especially in the face of climate change. Our findings justified investments in restoring forests and reinforce the central role of water and hydropower providers in partnerships for management of source-water watersheds. Results also highlighted the importance of accurate, scalable data and tools from the hydrology and water-resources community.

Mechanisms controlling the impact of multi-year drought on mountain hydrology.

Mountain runoff ultimately reflects the difference between precipitation (P) and evapotranspiration (ET), as modulated by biogeophysical mechanisms that intensify or alleviate drought impacts. These modulating mechanisms are seldom measured and not fully understood. The impact of the warm 2012-15 California drought on the heavily instrumented Kings River basin provides an extraordinary opportunity to enumerate four mechanisms that controlled the impact of drought on mountain hydrology. Two mechanisms intensified the impact: (i) evaporative processes have first access to local precipitation, which decreased the fractional allocation of P to runoff in 2012-15 and reduced P-ET by 30% relative to previous years, and (ii) 2012-15 was 1 °C warmer than the previous decade, which increased ET relative to previous years and reduced P-ET by 5%. The other two mechanisms alleviated the impact: (iii) spatial heterogeneity and the continuing supply of runoff from higher elevations increased 2012-15 P-ET by 10% relative to that expected for a homogenous basin, and iv) drought-associated dieback and wildfire thinned the forest and decreased ET, which increased 2016 P-ET by 15%. These mechanisms are all important and may offset each other; analyses that neglect one or more will over or underestimate the impact of drought and warming on mountain runoff.

Increased portion size leads to increased energy intake in a restaurant meal.

OBJECTIVE: Eating frequently in restaurants is one of the behaviors associated with obesity. This study examined whether increasing the portion size of an entrée affected energy intake at a restaurant meal. RESEARCH METHODS AND PROCEDURES: In a cafeteria-style restaurant on different days, the size of a pasta entrée was varied from a standard portion (248 g) to a large portion (377 g). The entrée price was not changed. Intake of the entrée was determined by covertly weighing each dish before and after the meal; intake of all other foods was determined by estimating the percent consumed. The 180 adult customers who purchased the entrée also completed a survey in which they rated characteristics of the meal, including the appropriateness of the entrée portion size and the amount that they ate compared with their usual meal. RESULTS: Portion size had a significant effect on intake of the entrée (p < 0.0001). Compared with customers who purchased the standard portion, those who purchased the larger portion increased their energy intake of the entrée by 43% (719 kJ; 172 kcal) and of the entire meal by 25% (664 kJ; 159 kcal). There was no difference between the two groups of customers in ratings of the appropriateness of the portion size or of the amount that was eaten in relation to their usual meal. DISCUSSION: In a restaurant setting, increasing the size of an entrée results in increased energy intake. These results support the suggestion that large restaurant portions may be contributing to the obesity epidemic.

The effects of reaction-product formation on the reductive dissolution of MnO2 by Fe(II).

We conducted batch-reactor experiments to measure the reductive dissolution of pyrolusite-coated (beta-MnO2) quartz by Fe(II) under conditions representative of an acid mine-drainage subsurface plume. The results reveal that reductive dissolution rates were initially rapid but declined considerably as Fe(III)(aq), a product of the reductive-dissolution reaction, was removed from solution by heterogeneous precipitation. The inhibition of reductive-dissolution was attributed to blocking of the beta-MnO2 surface sites by the Fe(III)(s) precipitate. Calculations of a simple model that accounts for the effects of Fe(III)(s) precipitate formation on reductive dissolution rates closely match temporal changes in Mn(II), Fe(II), and Fe(II) concentrations measured in 10 experiments, distinguished on the basis of the initial Fe(II)-to-Mn(IV) mole ratio and the initial Fe(III)(aq) concentration. The model-data comparisons reveal that the initial reaction rate on a clean beta-MnO2 surface exceeds the long-term reaction rate by 3 orders of magnitude, highlighting the importance of linking Fe(III) precipitation with the reductive dissolution of beta-MnO2 by Fe(II).

Electrochemical study of arsenate and water reduction on iron media used for arsenic removal from potable water.

Zerovalent iron filings have been proposed as a filter medium for removing As(III) and As(V) compounds from potable water. The removal mechanism involves complex formation of arsenite and arsenate with the iron surface and with iron oxides produced from iron corrosion. There is conflicting evidence in the literature on whether As(V) can be reduced to As(III) by iron filter media. This research uses electrochemical methods to investigate the redox reactions that occur on the surface of zerovalent iron in arsenic solutions. The effect of arsenic on the corrosion rate of zerovalent iron was investigated by analysis of Tafel diagrams for iron wire electrodes in anaerobic solutions with As(V) concentrations between 100 and 20,000 microg/L. As(V) reduction in the absence of surface oxides was investigated by analysis of chronoamperometry profiles for iron wire electrodes in solutions with As(V) concentrations ranging from 10000 to 106 microg/L. The effect of pH on As(V) reduction was investigated by analyses of chronopotentiometry profiles for iron wire electrodes at pH values of 2, 6.5, and 11. For freely corroding iron, the presence of As(III) and As(V) decreased the iron corrosion rate by a factor of 5 as compared to that in a 3 mM CaSO4 blank electrolyte solution. The decrease in corrosion rate was independent of the arsenic concentration and was due to the blocking of cathodic sites for water reduction by arsenic compounds chemisorbed to the iron surface. The chronoamperometry and chronopotentiometry experiments showed that elevated pH and increased As(III) to As(V) ratios near the iron surface decreased the thermodynamic favorability for As(V) reduction. Therefore, reduction of As(V) occurred only at potentials that were significantly below the apparent equilibrium potentials based on bulk solution pH values and As(III) to As(V) ratios. The potentials required to reduce more than 1% of the As(V) to As(III) were below those that are obtainable in freely corroding iron media. This indicates that there will be minimal or no reduction of As(V) in iron media filters under conditions relevant to potable water treatment.

Understanding soluble arsenate removal kinetics by zerovalent iron media.

Zerovalent iron filings have been proposed as a filter medium for removing arsenic compounds from potable water supplies. This research investigated the kinetics of arsenate removal from aqueous solutions by zerovalent iron media. Batch experiments were performed to determine the effect of the iron corrosion rate on the rate of As(V) removal. Tafel analyses were used to determine the effect of the As(V) concentration on the rate of iron corrosion in anaerobic solutions. As(V) removal in column reactors packed with iron filings was measured over a 1-year period of continuous operation. Comparison of As(V) removal by freely corroding and cathodically protected iron showed that rates of arsenate removal were dependent on the continuous generation of iron oxide adsorption sites. In addition to adsorption site availability, rates of arsenate removal were also limited by mass transfer associated with As(V) diffusion through iron corrosion products. Steady-state removal rates in the column reactor were up to 10 times faster between the inlet-end and the first sampling port than between the first sampling port and the effluent-end of the column. Faster removal near the influent-end of the column was due to a faster rate of iron oxidation in that region. The presence of 100 microg/L As(V) decreased the iron corrosion rate by up to a factor of 5 compared to a blank electrolyte solution. However, increasing the As(V) concentration from 100 to 20,000 microg/L resulted in no further decrease in the iron corrosion rate. The kinetics of arsenate removal ranged between zeroth- and first-order with respect to the aqueous As(V) concentration. The apparent reaction order was dependent on the availability of adsorption sites and on the aqueous As(V) concentration. X-ray absorption spectroscopy analyses showed the presence of iron metal, magnetite (Fe3O4), an Fe(III) oxide phase, and possibly an Fe(II,III) hydroxide phase in the reacted iron filings. These mixed valent oxide phases are not passivating and permit sustained iron corrosion and continuous generation of new sites for As(V) adsorption.

Equilibrium partitioning of chlorinated solvents in the vadose zone: low f(oc) geomedia.

A series of gas (vapor)-advecting water-unsaturated column experiments using a low organic content (f(oc)) silica sand was conducted to determine mass distributions of chlorinated-volatile hydrophobic organic compounds (C-VHOCs) in a natural sorbent system. C-VHOCs used were trichloroethene (TCE), tetrachloroethene (PCE), chlorobenzene (CB), and 1,3-dichlorobenzene (DCB). Four volumetric water contents (theta(w) = 0.07, 0.12, 0.17, 0.20) and several influent gas-phase C-VHOC (solute) concentrations were considered. The method of temporal first moments was applied to complete breakthrough curve data to determine total C-VHOC gas-phase retardation and associated gas-phase C-VHOC mass fraction. Results were compared to an equilibrium partitioning advective-dispersive formulation of total gas-phase retardation. Literature-derived values of Henry's law constants and independent measurements of gas/water interface areal extent and interface phase adsorption allowed quantification of C-VHOC mass fractions in the aqueous and gas/water interface phases. Unaccounted C-VHOC mass, derived from comparison of measured C-VHOC retardation to independent phase prediction, was attributed to solid-phase sorption. Results indicate that for all conditions tested, gas/water interfacial adsorption exhibited only a small effect on C-VHOC vapor retardation (accounting for < or = 10% of the total C-VHOC distributions). Solid-phase association was the dominant uptake mechanism, accounting for 46-91% of the total C-VHOC mass in the porous system. Evaluation of the solid-phase C-VHOC uptake results in terms of a modified form of the Dubinin-Radushkevich (DR) isotherm equation provided strong evidence supporting the mechanism of pore-filling in this natural, low f(oc) sorbent.