Jianbang Gan

Effects of considering greenhouse gas consequences on fertilizer use in loblolly pine plantations.

Fertilizer use, widely practiced in forest plantation management to stimulate tree growth, contributes to greenhouse gas (GHG) emissions. We explore how accounting for GHG consequences affects optimal fertilizer application rates of commercial forest plantations. A generic model that maximizes the equivalent annual net benefit of timber production and GHG balance is developed and applied to loblolly pine (Pinus taeda L.) plantations in the southern United States. We find that fertilizer use still is a viable practice for managing loblolly pine plantations in the region although fertilizer application rate should be reduced when GHG consequences are valued. A greater reduction in fertilizer application rate is recommended where wood is used for paper production because life cycle GHG emissions of paper products are much higher than those of solid wood or bioenergy products. A higher fertilizer rate should be applied when forest residues are used for the production of bioenergy that offsets GHG emissions from consuming fossil fuels.

Integrating biomass and carbon values with soil productivity loss in determining forest residue removals.

Soil nutrient loss is a major concern with removing forest residues for biofuel production. Understanding the impact of residue removal on site productivity via field experiment is costly and time consuming. We developed an analytical framework and a simulation approach for determining optimal forest residue removals, which account for both the benefits of biomass and greenhouse gas offset and the cost of soil productivity loss. We derived the relationship between residue removals and the prices of timber, biomass and greenhouse gases. The marginal cost of soil productivity loss associated with residue removals from loblolly pine (Pinus taeda L.) plantations in southern USA ranges from US

An agent-based modeling approach for determining corn stover removal rate and transboundary effects.

2.18 to 11.20/oven-dry tonne depending upon removal intensity. Given the cost of soil productivity loss, residue removal intensity will be much smaller than the quantity of biomass physically available.

Forest fuel reduction and biomass supply: perspectives from southern private landowners.

AbstractBioenergy production involves different agents with potentially different objectives, and an agent’s decision often has transboundary impacts on other agents along the bioenergy value chain. Understanding and estimating the transboundary impacts is essential to portraying the interactions among the different agents and in the search for the optimal configuration of the bioenergy value chain. We develop an agent-based model to mimic the decision making by feedstock producers and feedstock-to-biofuel conversion plant operators and propose multipliers (i.e., ratios of economic values accruing to different segments and associated agents in the value chain) for assessing the transboundary impacts. Our approach is generic and thus applicable to a variety of bioenergy production systems at different sites and geographic scales. We apply it to the case of producing ethanol using corn stover in Iowa, USA. The results from the case study indicate that stover removal rate is site specific and varies considerably with soil type, as well as other factors, such as stover price and harvesting cost. In addition, ethanol production using corn stover in the study region would have strong positive ripple effects, with the values of multipliers varying with greenhouse gas price and national energy security premium. The relatively high multiplier values suggest that a large portion of the value associated with corn stover ethanol production would accrue to the downstream end of the value chain instead of stover producers.

Biomass Utilization Allocation in Biofuel Production: Model and Application

Removing excess biomass from fire-hazardous forests can serve dual purposes: enhancing the health and sustainability of forest ecosystems and supplying feedstock for energy production. The physical availability of this biomass is fairly well-known, yet availability does not necessarily translate into actual supply. We assess the perception and behavior of private forestland owners in the southern United States with respect to thinning overstocked forests for bioenergy production. Landowner perception is then integrated with the USDA Forest Services Fuel Treatment Evaluator to estimate the biomass supply from fuel treatments on non-industrial private timberlands in the region. Due to competing uses for lumber and pulp/paper products, only about one-third of this biomass could be used as bioenergy feedstock. Between 6 and 66% of landowners would consider thinning overstocked forests for bioenergy purposes depending upon whether financial incentives and technical assistance are provided. Accounting for competing uses, landowner willingness, accessibility, and recovery loss, annual feedstock supply from Southern private treatable timberlands is estimated between 0.9- and 11-million dry tonnes (dt). The average production cost is proximately

Measuring transnational leakage of forest conservation

48/dt. Government cost shares, biomass market development, and technical assistance could significantly stimulate private landowners to procure biomass from fire-hazardous forests while mitigating wildfire risk.

Availability of logging residues and potential for electricity production and carbon displacement in the USA.

Abstract Various biomass sources can potentially be used for biofuel production, and many of these same biomass sources also have other uses. This raises an important question about biomass utilization allocation. We demonstrate an economic principle for bio-mass allocation by examining the profitability of woody biomass utilization in a simple two-product case. We then develop a mixed-integer programming model for allocating multiple biomass resources in the production of different biofuels and bioprod-ucts. Our model combines biomass utilization allocation with biofuel supply chain optimization. The model is applied to solving the forest biomass utilization allocation problem for East Texas in the southern United States. We find that besides biofuel prices, production scale and CO2 offset credits also significantly affect biomass utilization allocation. Our findings validate our inte-grative model approach to addressing biomass allocation and provide useful implications for enhancing the efficient utilization of forest biomass.