Poplars and willows have been used for environmental applications throughout human history. There is archaeological and historical evidence of their use for cooking, heating, and shelter in ancient times in China and the Middle East. Native Americans used them in riparian zones for irrigation over 2000 years ago. Explorers in North America also used them for fuel and shelter, and pioneers used them for windbreaks and shelterbelts as they settled the West. In the 17th century European settlers admired native North American poplar and willow and took specimens back to Europe for their gardens. Spontaneous hybrids arose with European poplar and willow that proved handsome and productive thereby prompting breeding efforts. Soon American and Canadian geneticists patterned their breeding programs after European breeding successes. Poplar and willow are valued for traits including wide adaptation, rapid growth rate, cross-ability, deep rooting, ease of rooting, and large leaf areas that allow them to take up large quantities of water and nutrients. The “Oil Embargo” of 1973 led to an explosion of basic research by worldwide organizations in the use of poplar and willow for bioenergy. This research included multiple breeding programs and the advent of short rotation woody crops. During the environmental movement of the 1980’s, researchers’ efforts turned to environmental applications of poplar and willow. The interest in using “green technology” led to the emergence of phytoremediation (phyto) in the early 1990’s; the science of using plants for cleaning up contaminated soils and water. Poplar and willow are used in multiple phyto applications including buffers, vegetative filters, in situ plantings and vegetative landfill caps. There are promising opportunities for using poplar and willow for wastewater re-use, riparian buffers, landfill leachate recycling, animal confinements, carbon sequestration and urban amenities. Lessons can be learned from the long history of poplar and willow use for environmental applications. Bioenergy opportunities have fluctuated greatly since 1973, reflecting oil prices and production costs. But, new biotechnologies have recently been discovered that will expand our opportunities for environmental applications of poplar and willow. Many challenges remain including the costs of biomass products, market values of those products, lack of funding, climate change and resulting disease/insect problems, regulatory issues, public policies and politics, GMO issues, and public awareness problems.
Google, Apple, Amazon, Uber: companies like these have come to embody innovation, efficiency, and success. How often is the environmental movement characterized in the same terms? Sadly, conservation is frequently seen as a losing battle, waged by well-meaning, but ultimately ineffective idealists. Joe Whitworth argues it doesn’t have to be this way. In fact, it can’t be this way if we are to maintain our economy, let alone our health or the planet’s. In his new book “Quantified: Redefining Conservation for the Next Economy,” Whitworth draws lessons from the world’s most tech-savvy, high-impact organizations to show how we can make real gains for the environment. The principles of his approach, dubbed “quantified conservation,” will be familiar to any thriving entrepreneur: situational awareness, bold outcomes, innovation and technology, data and analytics, and gain-focused investment. This no-nonsense strategy builds on the inspirational environmental work begun in the 1970s, while recognizing that the next economy will demand new solutions. As President of The Freshwater Trust, a nonprofit freshwater conservation group based in Portland, Oregon, Whitworth has put quantified conservation into practice, pioneering the model of a “do-tank” that is dramatically changing how rivers can get restored. For example, The Freshwater Trust works with the city of Medford, Oregon, to plant native trees along the banks of the Rogue River that provide shade and offset the warm water discharged into the river by the city’s wastewater treatment plant. Using new tools and technologies, shade generated from the trees is quantified and expressed as credits that the city can purchase. This natural infrastructure solution ended up saving taxpayers more than $8 million when compared to the other solutions proposed for cooling the water. Whitworth will walk through why ensuring a future with clean, healthy rivers will require bringing conservation into the 21st century and being adamant about achieving outcomes.
Hybrid poplar trees are fast-growing with high absorption capacity for water, nutrients, and soil contaminants. They are therefore well-suited as a complement to wastewater treatment. Poplar can utilize approximately twice the mass of nitrogen per acre than grass crops, thereby doubling the capacity of farmland to apply nutrient-rich biosolids reclaimed from wastewater processing. Furthermore, growth rates improve with summer irrigation, which can be provided by recycled water from the treatment plant. Poplar irrigation provides further water quality benefits at the root zone and reduces direct discharge to streams, which may have restrictive water quality limitations during dry summer months. Within fairly short growth rotations of 10-12 years, the poplar reach harvest sizes suitable for sawlog and veneer milling as well as reaching suitable yields for chips and biomass markets. The MWMC in Eugene/Springfield, Oregon manages 400 acres of poplar for wastewater treatment and is one of the largest of its kind in the nation.
The land application of municipal and industrial wastewaters to hardwood and mixed hardwood/softwood forest systems is a well-established practice in North Carolina. These waste treatment systems provide an important opportunity to evaluate qualitative and quantitative impacts on the food, energy, fiber, and water nexus. Current research is quantifying ecosystem services, water resiliency, and the sustainability of these systems across urban and rural landscapes in North Carolina. In particular, current research is evaluating how these systems manage non-regulated contaminants and how these systems can be interfaced with other agricultural systems to improve sustainability for food, energy, forest, and water resources.
Poplars and willows are the first species to naturally revegetate disturbed and contaminated soils. They have also been planted for centuries for environmental reclamation and restoration. In the 1990’s a “green technology” emerged termed “phytoremediation” (phyto) where plants are used to clean up contaminated soils and water. Clean up goals are accomplished using six mechanisms: phytoextraction, phyto- volatilization, rhizosphere degradation, phytodegradation, phytostabilization, and hydraulic control. Poplars and willows are preferred “phyto” species used in hundreds of applications across North America, because they grow rapidly, have many deep roots and take up large quantities of water. Their roots also provide surface area for beneficial microbes that facilitate remediation. Important aspects of phyto are: choosing species, meeting regulator clean-up goals, maintaining plantings, and monitoring contaminant uptake. Examples of representative current phyto applications will be given.
Legacy cities throughout the Midwest and Northeast must deal with the difficult problem of vacant and contaminated land coupled with rising costs of infrastructure necessary to reduce sewer overflow events as well as and declining populations and tax base to pay for the necessary cleanup and infrastructure. To help solve these problems, Fresh Coast Capital plants hybrid poplar and other species on vacant and/or contaminated land in a public-private partnership contract structure with cities and land banks. Currently, Fresh Coast has three operational working landscape tree farms and anticipates operational farms in at least seven cities by the end of 2016. We are launching various aspects of this business model in select cities for future scaling within these cities and throughout the region, including working with future land developers and including “working landscape” tree farms as part of citywide greening plans. Future scaling for phytoremediation as a scalable business model will also be discussed.
Since the 1972 Clean Water Act PL 92-500, the definition of adequate and sustainable pollution treatment has changed. The old 30;30 discharge standard (30 mg/l ammonia and BOD) was not adequate to reach defined goals – fishable and swimmable – for all waters of the state. Since 1972, measured damage to a healthy fishery and community sustainable has changed waste water treatment strategies. Plants were not any part of the 1972 treatment design options. The criteria for successful design – feasible, practical, economical, safe, legal, moral, politically acceptable and ecological – will be used to compare modern alternatives now considered for large and small waste water sources.
The NMSU Agricultural Science Center at Farmington (NMSU-ASC) is involved in a long-term research project to examine the phytoremediation ability of hybrid poplars at a petroleum-contaminated site. The project, located at an abandoned oil refinery in northwestern New Mexico, was initiated in early 2010 at the invitation of two local environmental remediation firms tasked with cleaning up the site. The goal of the project is to clean up the soil and groundwater via the documented phytoremediation ability of poplars, plus establish an underground root barrier that will help prevent contaminant movement from the site.
The refinery, which was in operation from 1973 to 1991, was selected for the current study due to the high levels of soil and groundwater contamination with free product floating on the water table. Analysis of groundwater shows levels of total dissolved solids (TDS) exceeding 4,500 mg/L and concentrations of methyl tertiary butyl ether (MTBE) near 55 µg/L. Levels of Gasoline Range Organics (GRO C6-C10) are ~0.11 mg/L. Since 2010, nearly 800 trees have been planted, in four phases. Drip irrigation is supplied from an on-site well ~1,500 feet deep, although the water is heavily saline (TDS 1,000 to 2,700 mg/L).
Many of the trees are surviving and growing at the site. Current observations suggest hybrid poplar, native cottonwood, and the xeric species four-wing saltbush (Atriplex canescens) are capable of adequate initial growth on the petroleum-contaminated site when supplied with sufficient irrigation for initial root establishment. Since there are many similar contaminated sites in the arid western U.S. where trees could theoretically be used for such purposes in combination with compromised irrigation water, long-term results from this project may be useful in helping to develop environmental remediation strategies for the region.
Wastewater management includes multiple approaches for treating wastewater and increasing water quality. Poplar and willow plantings have the capacity to assist in these efforts and include many benefits for the community. Learn more about how these trees are being used in a cost-effective way to remove contaminants, treat wastewater, and improve water quality, as well as a case study from Woodburn, OR. There will be time to ask questions from current growers as well as time to compare notes.
This brief presentation will provide an overview of the science of using poplar plantations to manage wastewater. It will cover wastewater constituents and contaminants of concern, the short and long term fate of the contaminants of concern in the root zone, soil matrix, and plant structure. Each contaminant is unique in how it behaves in the environment and how it may be taken up by poplar, adsorb to soils, biodegrade (chemical dissolution of materials by bacteria, fungi, or other biological means), volatilize, leach, photodegrade, or degrade over time.
With ever-tightening water quality rules, tertiary treatment to remove the last 2% of polluting ammonia and pathogens is mandated for small towns in Iowa. Lagoons and sand filters work in the warm weather but fail 5 months of the year for legal discharge. Small towns in rural America often have financial and talent limitations so meeting new treatment require a new technical approach. Proposed upgrades using ‘conventional’ civil engineering technology will cost small town their biggest tax increase ever. Rhizosphere microbes and root functions can adequately treat this low-concentration waste water year-round if dose matches capacity. Future phyto is a solution but regulations and technology upgrades are needed to enable broad adoption that works. Biomass and sustainability are two benefits when Salicaceae family plants are core design species for these projects.
Poplar trees have been used successfully at a number of sites to beneficially reuse water and nutrients from recycled water and biosolids produced at wastewater treatment facilities. In doing so, municipalities have found more cost effective solutions than the conventional treatment alternatives to meet stringent discharge limitations. Similar to other conventional treatment alternatives, however, poplar tree systems also need to be designed and operated carefully to ensure that applied water and nutrients are managed responsibly. The planning and design of these systems requires good science and engineering while operations require continual monitoring and adaptive management.
Transportation and supply chain logistics are critical components of the bioenergy industry. This session will discuss transportation logistics and ways to optimize the supply chain based on the distribution of feedstocks arising from residual and purpose-grown sources. The challenge of maximizing the efficiency of producing, aggregating, and transporting the resource will be examined using the pulp and paper industry as an example. The components of the biomass cost profile will also be presented for hybrid poplar bioenergy plantations. A discussion session with the presenters will follow.
A key factor in evaluating investment in biofuel production must be the availability and cost of biomass feedstock. In contrast with crude oil which tends to be highly concentrated in geologic deposits, biomass tends to be distributed in varying concentrations across large geographic areas. Understanding the feedstock supply chain logistics and cost allow bioenergy project developers to develop a supply curve reflective of the resources available at a particular location. This talk will introduce the biomass supply chain generally, discuss key cost centers in the supply chain and present some tools and approaches for developing site specific biomass supply curves, and address particular challenges associated with aggregating biomass derived from moderate-sized parcels primarily developed for environmental uses.
Speaker: Bruce Summers
Breakout Session B | Discussion Group – Supply Chain Optimization for a Distributed Feedstock Resource
The oil production and refining industry is mature. Large capacity refiners require, and have developed an integrated transportation system to deliver large quantities of crude oil to refineries on a just in time basis. Production of biofuels using cellulosic material such as chips, hog fuel, and herbaceous material will also require a similar large scale transportation infrastructure as the oil industry. The Pulp & Paper industry, a large scale industry, has developed an infrastructure to store and transport its raw material in a similar manner as had the oil industry. This optimization of biomass transportation includes interim storage, both on plant site and off site, and water, rail, and truck transportation. These independent activities can be singular or combined in order to minimize costs on a real time basis.
The Advanced Hardwoods Biofuels Northwest program (AHB) is developing hybrid poplar as an integral component of the biomass supply chain for Pacific Northwest bio-refineries. Future refineries will require dedicated tree plantations as an indispensable component of their feedstock supply portfolios in order to secure their capital investments. A strategic component of purpose-grown trees reduces feedstock supply and pricing uncertainties thereby improving refinery economics. Moreover, residual supplies alone are unlikely to support the extraordinary biomass volumes that will be needed to produce bio-fuels and bio-products. Using a hypothetical example of a 20 million gallon per-year bio-refinery, this presentation will illustrate how the scale, economics logistics, and production of a dedicated hybrid poplar operation can be integrated into the supply chain of Pacific Northwest bio-refineries.
There is great diversity in the potential supplies of biomass in terms of supply density, production costs, temporal availability and quality. Due to this diversity and technology characteristics, there is no one size fits all solution to biomass supply chains. This talk will explore the cost components of delivered biomass, what factors influence these cost components, and how the different costs impact the siting and sizing of economically viable biorefineries.
Society faces many overarching global challenges such as climate change, energy price volatility, energy security and environmental pollution. Within Europe, these challenges cascade directly down to each member state where we must play our part in meeting European Union (E.U.) directives targeted at reducing greenhouse gas emissions, de-carbonizing our energy supply, and improving the quality of our environment, particularly water. In the UK we strive to meet certain goals, such as our Renewable Heat and Electricity Targets, while reducing the levels of pollution in the environment and complying with the demands of the E.U. Water Framework Directive. Local national strategies are also putting pressure on achieving these goals such as the Northern Ireland and Ireland Agri-Food industry ambition of increasing the growth of agriculture by 2020 to incorporate significant growth in sales, exports, and employment. The coupling of this strategy to the delivery of the E.U. Water Framework Directive to improve water quality is indeed a challenge. The difficulty of protecting the environment and meeting water quality goals is further compounded with our legacy high soil phosphorus content and its current significant impact on our environmental water quality. There are methods by which we can sustainably manage increasing quantities of waste water compliantly and for water utilities to adopt low carbon sustainable waste water treatment solutions while simultaneously contributing to an indigenous biomass energy supply chain. This talk will describe how energy plantations of short rotation coppice willow are currently being utilized for the sustainable recycling of waste waters.
Biofuels are important alternatives for meeting our future energy needs. Successful bioenergy crop production requires preservation of environmental sustainability and minimal impacts on current net annual food, feed, and fiber production. Therefore placement of energy crops on strategically selected subfield areas in an agricultural landscape has the potential to simultaneously provide in situ recovery of the excess nutrient leachate for high biomass yields and the opportunity to improve water quality. This presentation will focus on differences in biomass yields, nutrient recovery and GHG emissions on eroded and frequently flooded soils at a field scale. Also, landscape assessment of nutrient recovery and opportunity costs of growing willows on subfield areas in the Indian Creek watershed (IL) instead of current land use, will be discussed as the basis for required levels of payment for ecosystem services, to compensate for lost revenue.
Environmental Policy and Regulations and Government Support
Poplar and willow have potential for multiple uses beyond bioenergy and wastewater management. These trees can be used for riparian buffers, to improve water quality, as wildlife habitat, and can provide ecosystem services while being grown for bioenergy feedstocks. In addition, certification programs, which are becoming more common for typical forest plantations are also in development for poplar and willow when grown as short rotation woody crops. We will discuss how ecosystem services can be better implemented into certification programs to support a sustainable bioenergy and bioproduct industry.
Responsibly managed wood biomass plantations can showcase their commitment to sustainable management practices through third-party certification programs, and have the added benefit of managing their environmental and social risks. These certification programs tend to provide guidance with regards to chemical usage, social interactions, and environmental impacts. The certification program available to a given grower will depend on their desired end product, target market, and/or crop rotation length. While these options are somewhat limited currently, this crop class (short rotation woody species) has been gaining traction with some of the larger certification bodies (FSC & SFI). We will explore some of the options available to growers and some challenges associated with utilizing a certification program.
Our research seeks to understand how the future bioenergy landscape could change ecosystem services, including provision of energy, regulation of water quality, and support of habitat for biodiversity. We evaluated these ecosystem services under projections of biomass potential under two scenarios that contrast spatially intensive vs. extensive feedstock production. These scenarios were developed by manipulating future yield assumptions within the Policy Analysis System economic model (POLYSYS) for the US agricultural sector. We developed a tool, Bioenergy Ecosystem Services Tool (BioEST) to project future change in ecosystem services including energy feedstock yields and habitat for multiple species of grassland birds. As the first step, species distribution models (SDMs) were developed with climate, elevation, and land use as predictors. As the second step, we developed local landuse/landcover (LULC) effect models to estimate for habitat quality as a function of crop cover and management. LULC-effect models estimated marginal effects of different crops in the current landscape on species presence from fitted SDMs. We developed LULC-effect models for 2nd generation energy crops and for lands managed for residue removal by compiling relative densities between current LULCs and advanced bioenergy crops for each bird species. In addition to local effects of each LULC, BioEST considers spatial juxtaposition with the surrounding matrix – i.e., habitat is considered suitable only if, together with surrounding parcels, it exceeds minimum habitat area for the species. Finally, we allocate bioenergy production among parcels within individual counties to achieve maximal potential habitat for representative species of birds. Preliminary results demonstrated potential for finding landscape arrangements that support both biodiversity and bioenergy as complementary ecosystem services.
One of the reasons of continued failure to improve riparian management on agricultural lands has been our traditional “no touch” approach to creating riparian zones. Farmers in Washington State face high-risk and low profit margins, so losing productive land to these no touch buffers is not usually an economically feasible option. We must figure out how to improve fish habitat and water quality while increasing agricultural viability at the same time. One way to provide increased buffering functions on agricultural land is by integrating well-designed agroforestry and runoff management practices near water. This “working buffers” approach offers the middle ground.
Nutrient pollution from agricultural sources has been a large contributor to the decline in the health of the Chesapeake Bay. U.S. Environmental Protection Agency (EPA) developed the Chesapeake Bay Total Maximum Daily Load (TMDL) which sets pollution limits at 185.9 million pounds of nitrogen. However, the EPA estimates that over 250 million pounds of nitrogen are carried into the Chesapeake Bay in a year with average rainfall. Replacing row crops with perennial bioenergy feedstocks can reduce nitrogen runoff into the bay and therefore provide ecosystem services benefits in addition to those from producing the bioenergy itself. We investigate how payments for the ecosystem service of reduced nutrient loading could facilitate the growth of the bioenergy industry in the region by increasing the price paid to farmers for producing feedstocks. Specifically, ongoing work is looking at the costs and benefits of nitrogen reduction by a) replacing maize with switchgrass and b) by establishing riparian buffers. The switchgrass analysis determines the nitrogen loading reduction from replacing maize with switchgrass and the estimated payment (in terms of reduced nitrogen runoff) that would incentivize farmers to convert to switchgrass. The riparian buffer analysis examines using a Nutrient Credit Trading Program as a revenue producing mechanism to incentivize buffer adoption by farmers. The variation in geographic location, buffer type and size, and farming practices in nitrogen credit trading profits were evaluated to determine the feasibility of nitrogen credits as an adequate incentive for buffer establishment. Nitrogen credit trading is compared to alternative buffer incentive programs such as the Conservation Reserve Enhancement Program (CREP).
While poplar and willow have potential markets for bioenergy, we recognize that a full scale market and production industry for poplar and willow biofuels will not appear overnight. The challenges lie primarily in the area of policy and economics. Our panel will discuss the realities and the emerging markets for biofuels, talk about the obstacles and opportunities ahead, and consider the other markets for poplar and willow that could bridge our pathway to a more biobased economy.
Speaker: Tom Platt
Breakout Session D | Discussion Group
The City of Missoula, Montana established a 130 acre hybrid poplar plantation in 2013 – expanded to 185 acres in 2015 – to serve as a land application site for municipal wastewater treatment. Missoula initiated the project to provide tertiary nutrient removal treatment under its municipal wastewater discharge permit, in order to reduce summer impacts to the Clark Fork River and utilize the valuable, nutrient-rich water. The plantation will provide environmental services throughout the life of the project, diverting 117 million gallons of effluent during its first full irrigation season in 2015. In addition to ongoing environmental services, the project will provide wood products sold to offset project construction and operation expenses. Target products will be saw logs milled and sold locally; poplar and willow cuttings for local and regional conservation projects; wood chips for bulking material at the city’s adjacent biosolid composting facility; and other innovative uses of poplar and willow that arise during the life of the project.
Hybrid Energy Group (HEG) was selected as project contractor to develop and manage the site, based on its experience developing small scale renewable energy projects; its solid relationships with Montana conservation nonprofits; and its familiarity with the regional forest products industry. Tom Platt serves as HEG’s project manager and coordinates activities with Missoula’s Wastewater Division; the Montana Department of Environmental Quality; Watershed Consulting, the project forestry consultant; and researchers at the University of Montana.
In addition to providing nutrient abatement services for Missoula’s Wastewater Treatment Plant, the hybrid poplar and native willow plantation offers many opportunities for the marketplace including nursery stock for poplar establishment and providing willow propagation stock for stream bank stabilization projects. Currently we market materials for fencing and shade structures and, as the trees mature, we will sell saw logs and provide a steady supply of chips for compost, mulch or as a carbon source for local fungi growers. To optimize monetary returns we stress maintaining ownership of the logs and adding value by saw milling in-house.
Speaker: Sarah Wurzbacher
Session V | Case Study 4
In this session, learn more about AHB and IBSS, which include poplar as a potential feedstock for bioenergy and have explored pathways for moving the industry forward. Shrub willow, also has potential as a bioenergy feedstock, but can be used for much more, including phytoremediation, which has successfully been tried in central New York state.
AHB and IBSS are two USDA National Institute of Food and Agriculture (NIFA) research projects investigating how to produce biofuels and biochemicals from sustainably grown poplar trees. AHB is focused on the Pacific Northwest (PNW) and IBSS is focused on the Southeastern US. Both projects collaborate with GreenWood Resources and have regional demonstration sites where the poplar is grown as a short-rotation crop for bioenergy.
In the PNW, AHB has identified municipal and industrial wastewater treatment facilities as key early-adopters of hybrid poplar bioenergy crops. By engaging with wastewater treatment facilities, AHB hopes to support the establishment of an initial supply of feedstock for developing biorefineries that may one day use the crop as a feedstock to create renewable biofuels and biochemicals. These stakeholders could achieve duel benefits of treating wastewater and biosolids while producing biomass for existing and developing biomass and wood product markets.
In the Southeast, IBSS has started multiple field trials of hybrid poplar to better understand varietal and planting differences. Hybrid poplar is not well-established in the southeastern region and different varieties are being tested for growth and yield patterns, as well as lignin and cellulose content. These trials will contribute to better recommendations for planting and management guidelines, along with improved varieties specific for bioenergy growth. Hybrid poplar, with its fast growth rate and abundant biomass is a strong candidate for a biomass feedstock in the southeastern region- data from this effort will inform potential growers on best practices.
Together the two projects are exploring ways that poplar can be grown for multiple environmental and economic benefits as well as bioenergy. We plan to collaborate on developing a roadmap that outlines the challenges and opportunities in growing poplar for environmental benefits as well as establishing a renewable fuels industry.
A phased phytoremediation strategy is being used to effectively develop an alternative vegetative cap using shrub willows on former industrial land in Camillus, NY. The substrate in this area is a byproduct of soda ash production using the Solvay process that occurred in the area from 1884 – 1986. This substrate has a high pH, low nutrient content, limited structure and elevated salt concentrations making it a difficult growing environment for plants. The goal of the project is to develop and deploy an effective vegetative cover that will reduce the percolation of chloride salts into groundwater and surrounding surface water and simultaneously produce a source of woody biomass for the production of renewable energy. Several steps were involved in the phased phytoremediation strategy including screening of willow varieties in a greenhouse, small scale field tests of willow varieties on the site, and trials with different locally available organic amendments to create conditions that would support the rapid growth of willows. Over the years the system has been tested and refined. With the proper combination of organic amendments and site preparation, willow production on this site has reached, and in some cases exceeded, levels that have been measured on agricultural soils in the region. The system is now being deployed at the site and through the spring of 2015 almost 50 ha are in place. An ongoing program of monitoring, optimizing the system and screening new willow varieties is underway to ensure the long term performance of this vegetative cap.
In this discussion panel, leaders from four of the USDA National Institute of Food and Agriculture bioenergy projects will present their views on how to move the bioenergy industry forward by utilizing environmental plantings to generate biomass for renewable energy. Each panelist will provide a brief overview of his or her project, provide comments on the barriers to commercialization of biomass from environmental plantings, and suggest solutions to enhance the potential for commercialization.