The Wildfuels Alternative

The BBC and other news outlets are reporting on an experiment by Andrew Hector and colleagues, as published in Science.

Fertilisers 'reducing diversity'

Readers of this blog may already be tired by my stressing what is common knowledge amongst vegetation scientists, yet under-appreciated by most others involved with land management and biofuels: Harvesting grasslands tends to increase native biodiversity, and fertilization tends to decrease it.

The experiment in question examines why. In particular, it reveals that shading by productive overstory plants is directly responsible for reducing the diversity.

The experiment (using supplemental lighting) is clever and well-implemented. The results, I think most vegetation scientists would agree, are completely unsurprising. I find it quite refreshing to see results completely in line with expectation - it means that we are right!

Now the hard part. We need to find a way to convince those outside of the discipline that such basic, well-understood natural forces can be harnessed to produce biofuels systems that simultaneously promote biodiversity and produce fuel.

--Mike Palmer

Alpha Galileo reports that increasing European biofuels targets will harm biodiversity:

Is Biofuel Policy Harming European Biodiversity?

Bibliographic information:

Is biofuel policy harming biodiversity in Europe? by Jeannette Eggers, Katja Tröltzsch, Alessandra Falcucci, Luigi Maiorano, Peter H. Verburg, Erik Framstad, Gerald Louette, Dirk Maes, Szabolcs Nagy, Wim Ozinga and Ben Delbaere. GCB Bioenergy 1, 2009, pp. 18-34, doi 10.1111/j.1757-1707.2009.01002.x

The very important but widely ignored consequences of agrofuels-enhanced nitrous oxides emissions is finally getting some press outside of scientific journals. Indeed, we now have this from the Economist:

Farming biofuels produces nitrous oxide. This is bad for climate change

Despite all of the interest in cellulosic biofuels, biomethane seems to be sorely neglected. A new study from Ireland stresses the benefits of using biomethane from established stands of grass:

Murphy, J. D. and N. M. Power (2009). "An argument for using biomethane generated from grass as a biofuel in Ireland." Biomass & Bioenergy 33(3): 504-512.

The Biofuels Directive proposes 5.75% of transport fuel (by energy) to be replaced by biofuel in the year 2010. This equates to 11.3 PJ in Ireland, which equates to 538 million litres of ethanol or 323 million litres of biodiesel. However, if using biodiesel produced through bioesterification of rapeseed oil, then 6.3% of Irish agricultural land is required to produce 5.75% of transport fuel. Furthermore this equates to 70% of arable land. Using ethanol produced from wheat, 3.9% of Irish agricultural land is required to produce 5.75% of transport fuel. Ethanol produces less energy from a crop, than the energy in the biogas generated when the crop is digested. The ethanol production process uses up to 60% of the produced energy in the final ethanol product. It is shown for compressed biomethane generated from silage that the total parasitic demand of the process is of the order of 25%. Grass/silage is a crop that Irish farmers are familiar with, over 90% of Irish agricultural land is under grass. Grass does not require rotation, it does not require annual ploughing (releasing NO.), and it sequesters carbon into the soil. Digesting silage, scrubbing the biogas to biomethane, and compressing and utilizing it as a transport fuel, is suggested to be the optimum biofuel for Ireland. The 2010 biofuels target can be met with 1.6% of agricultural land; this is four times less land than required using rapeseed. A conservative economic analysis would suggest a lower cost than ethanol produced from wheat. (C) 2008 Elsevier Ltd. All rights reserved.

With very few changes in words, the following passage can hold for much of North America. Just replace "Irish" with "American", and change the numbers accordingly.

" Grass/silage is a crop that Irish farmers are familiar with, over 90% of Irish agricultural land is under grass. Grass does not require rotation, it does not require annual ploughing (releasing NO.), and it sequesters carbon into the soil. Digesting silage, scrubbing the biogas to biomethane, and compressing and utilizing it as a transport fuel, is suggested to be the optimum biofuel for Ireland."

A new paper in Conservation Biology stresses the climatic and biodiversity consequences of biofuels expansion:

Danielsen, F., H. Beukema, N. D. Burgess, F. Parish, C. A. Bruhl, P. F. Donald, D. Murdiyarso, B. Phalan, L. Reijnders, M. Struebig and E. B. Fitzherbert (2009). "Biofuel Plantations on Forested Lands: Double Jeopardy for Biodiversity and Climate." Conservation Biology 23(2): 348-358.

The growing demand for biofuels is promoting the expansion of a number of agricultural commodities, including oil palm (Elaeis guineensis). Oil-palm plantations cover over 13 million ha, primarily in Southeast Asia, where they have directly or indirectly replaced tropical rainforest. We explored the impact of the spread of oil-palm plantations on greenhouse gas emission and biodiversity. We assessed changes in carbon stocks with changing land use and compared this with the amount of fossil-fuel carbon emission avoided through its replacement by biofuel carbon. We estimated it would take between 75 and 93 years for the carbon emissions saved through use of biofuel to compensate for the carbon lost through forest conversion, depending on how the forest was cleared. If the original habitat was peatland, carbon balance would take more than 600 years. Conversely, planting oil palms on degraded grassland would lead to a net removal of carbon within 10 years. These estimates have associated uncertainty, but their magnitude and relative proportions seem credible. We carried out a meta-analysis of published faunal studies that compared forest with oil palm. We found that plantations supported species-poor communities containing few forest species. Because no published data on flora were available, we present results from our sampling of plants in oil palm and forest plots in Indonesia. Although the species richness of pteridophytes was higher in plantations, they held few forest species. Trees, lianas, epiphytic orchids, and indigenous palms were wholly absent from oil-palm plantations. The majority of individual plants and animals in oil-palm plantations belonged to a small number of generalist species of low conservation concern. As countries strive to meet obligations to reduce carbon emissions under one international agreement (Kyoto Protocol), they may not only fail to meet their obligations under another (Convention on Biological Diversity) but may actually hasten global climate change. Reducing deforestation is likely to represent a more effective climate-change mitigation strategy than converting forest for biofuel production, and it may help nations meet their international commitments to reduce biodiversity loss.

Here is a sobering report on the potential adverse effects of biofuels on the biosphere:

Unintended Environmental Consequences of a Global Biofuels Program

Jerry M. Melillo, Angelo C. Gurgel, David W. Kicklighter, John M. Reilly, Timothy W. Cronin, Benjamin S. Felzer, Sergey Paltsev, C. Adam Schlosser, Andrei P. Sokolov, and X. Wang

These findings should come as no surprise to ecologists, but certainly run against the modern push for agrofuels:

Cropland diversity reduces nitrogen pollution

This is another clear reason to seriously consider wildfuels.

Yet another reason why clearing 'marginal lands' for biofuels may be a huge mistake:

One-fifth of fossil-fuel emissions absorbed by threatened forests

AFP and other news distributors are reporting on a recent study by Holly Gibbs of Stanford:

Biofuels may speed up, not slow global warming: study

The main concern is the clearing of tropical forests for agrofuels.

Here is a new paper demonstrating the beneficial effects of diverse grasslands for pollinators. It leads support to the idea that diverse grasslands employed for biofuels would support multiple ecosystem services.

Ebeling, A., A. M. Klein, J. Schumacher, W. W. Weisser and T. Tscharntke (2008). "How does plant richness affect pollinator richness and temporal stability of flower visits?" Oikos 117(12): 1808-1815.
Pollinators play a key role in the reproduction of most plant species, and pollinator and plant diversity are often related. We studied an experimental gradient of plant species richness for a better understanding of plant-pollinator community interactions and their temporal variability, because in non-experimental field surveys plant richness is often confounded with gradients in management, soil fertility, and community composition. We observed pollinator species richness and frequency of visits six times in 73 plots over two years, and used advanced statistical analysis to account for the high number of zeroes that often occur in count data of rare species. The frequency of pollinator visits increased linearly with both the blossom cover and the number of flowering plant species, which was closely related to the total number of plant species, whereas the number of pollinator species followed a saturation curve. The presence of particularly attractive plant species was only important for the frequency of flower visits, but not to the richness of pollinators. Plant species richness, blossom cover, and the presence of attractive plant species enhanced the temporal stability in the frequency of pollinator visits. In conclusion, grasslands with high plant diversity enhance and stabilize frequent and diverse flower visitations, which should sustain effective pollination and plant reproduction.

The media have already described a new paper in PNAS that demonstrates yet another unintended consequence of corn biofuel production:

Landis, D. A., M. M. Gardiner, W. van der Werf and S. M. Swinton (2008). "Increasing corn for biofuel production reduces biocontrol services in agricultural landscapes." Proceedings of the National Academy of Sciences 105(51): 20552-20557.
Increased demand for corn grain as an ethanol feedstock is altering U.S. agricultural landscapes and the ecosystem services they provide. From 2006 to 2007, corn acreage increased 19% nationally, resulting in reduced crop diversity in many areas. Biological control of insects is an ecosystem service that is strongly influenced by local landscape structure. Here, we estimate the value of natural biological control of the soybean aphid, a major pest in agricultural landscapes, and the economic impacts of reduced biocontrol caused by increased corn production in 4 U.S. states (Iowa, Michigan, Minnesota, and Wisconsin). For producers who use an integrated pest management strategy including insecticides as needed, natural suppression of soybean aphid in soybean is worth an average of $33 ha. At 2007-2008 prices these services are worth at least $239 million y in these 4 states. Recent biofuel-driven growth in corn planting results in lower landscape diversity, altering the supply of aphid natural enemies to soybean fields and reducing biocontrol services by 24%. This loss of biocontrol services cost soybean producers in these states an estimated $58 million y in reduced yield and increased pesticide use. For producers who rely solely on biological control, the value of lost services is much greater. These findings from a single pest in 1 crop suggest that the value of biocontrol services to the U.S. economy may be underestimated. Furthermore, we suggest that development of cellulosic ethanol production processes that use a variety of feedstocks could foster increased diversity in agricultural landscapes and enhance arthropod-mediated ecosystem services.

The article gives some support to the idea of using diverse wildfuels as part of the solution:

"Mixed prairie communities could be used as a low-input high-diversity biofuel crop (28), contributing to flowering plant diversity and supporting a variety of pollinator and natural enemy arthropods (32). The vital services these arthropods provide to other crops may make such multispecies biofuel crops especially beneficial components of agricultural landscapes."

(note: reference #28 is the famous Tilman et al. 2006 paper in Science, and reference #32 is now in press, and is by some of the same authors as the current paper).

---Mike Palmer

A new study by Mark Jacobson of Stanford ranks wind, solar and hydro far above

A report from Science Daily:

Wind, Water And Sun Beat Biofuels, Nuclear And Coal For Clean Energy

Some quotes from the report:

"The energy alternatives that are good are not the ones that people have been talking about the most. And some options that have been proposed are just downright awful," Jacobson said. "Ethanol-based biofuels will actually cause more harm to human health, wildlife, water supply and land use than current fossil fuels." He added that ethanol may also emit more global-warming pollutants than fossil fuels, according to the latest scientific studies.

The sad fact is that the land conversion is already underway, and there is so much momentum behind biofuels already, that the environmental degradation is inevitable even if we eventually change our collective minds over the ethanol-based energy sector.

---Mike Palmer

Here is a review on environmental impacts in the UK. The operational phrase that reverberates the most with the main message of this blog is "Compared to replacement of set-aside and permanent unimproved grassland, benefits are less apparent." I read "less apparent" as "possibly nonexistent". --Mike Palmer

Rowe, R. L., N. R. Street and G. Taylor (2009). "Identifying potential environmental impacts of large-scale deployment of dedicated bioenergy crops in the UK." Renewable & Sustainable Energy Reviews 13(1): 260-279.

There is momentum, globally, to increase the use of plant biomass for the production of heat, power and liquid transport fuels. This review assesses the evidence base for potential impacts of large-scale bioenergy crop deployment principally within the UK context, but with wider implications for Europe, the USA and elsewhere. We focus on second generation, dedicated lignocellulosic crops, but where appropriate draw comparison with current first-generation oil and starch crops, often primarily grown for food. For lignocellulosic crops, positive effects on soil properties, biodiversity, energy balance, greenhouse gas (GHG) mitigation, carbon footprint and visual impact are likely, when growth is compared to arable crops. Compared to replacement of set-aside and permanent unimproved grassland, benefits are less apparent. For hydrology, strict guidelines on catchment management must be enforced to ensure detrimental effects do not occur to hydrological resources. The threat of climate change suggests that action will be required to ensure new genotypes are available with high water use efficiency and that catchment-scale management is in place to secure these resources in future. In general, for environmental impacts, less is known about the consequences of large-scale deployment of the C4 grass Miscanthus, compared to short rotation coppice (SRC) willow and poplar, including effects on biodiversity and hydrology and this requires further research. Detailed consideration of GHG mitigation and energy balance for both crop growth and utilization suggest that perennial crops are favoured over annual crops, where energy balances may be poor. Similarly, crops for heat and power generation, especially combined heat and power (CHP), are favoured over the production of liquid biofuels. However, it is recognized that in contrast to heat and power, few alternatives exist for liquid transportation fuels at present and research to improve the efficiency and energy balance of liquid transport fuel production from lignocellulosic sources is a high current priority. Although SRC, and to a lesser extent energy grasses such as Miscanthus, may offer significant benefits for the environment, this potential will only be realized if landscape-scale issues are effectively managed and the whole chain of crop growth and utilization is placed within a regulatory framework where sustainability is a central driver. Land resource in the UK and throughout Europe will limit the contribution that crops can make to biofuel and other renewable targets, providing a strong driver to consider sustainability in a global context. (C) 2007 Elsevier Ltd. All rights reserved.

The finding that plant diversity supporting soil carbon storage is not unique to Minnesota, and benefits of Low Input High Diversity (LIHD) systems may prove to be near universal in grasslands:

Steinbeiss, S., H. Bessler, C. Engels, V. M. Temperton, N. Buchmann, C. Roscher, Y. Kreutziger, J. Baade, M. Habekost and G. Gleixner (2008). "Plant diversity positively affects short-term soil carbon storage in experimental grasslands." Global Change Biology 14(12): 2937-2949.

Increasing atmospheric CO2 concentration and related climate change have stimulated much interest in the potential of soils to sequester carbon. In 'The Jena Experiment', a managed grassland experiment on a former agricultural field, we investigated the link between plant diversity and soil carbon storage. The biodiversity gradient ranged from one to 60 species belonging to four functional groups. Stratified soil samples were taken to 30 cm depth from 86 plots in 2002, 2004 and 2006, and organic carbon contents were determined. Soil organic carbon stocks in 0-30 cm decreased from 7.3 kg C m(-2) in 2002 to 6.9 kg C m(-2) in 2004, but had recovered to 7.8 kg C m(-2) by 2006. During the first 2 years, carbon storage was limited to the top 5 cm of soil while below 10 cm depth, carbon was lost probably as short-term effect of the land use change. After 4 years, carbon stocks significantly increased within the top 20 cm. More importantly, carbon storage significantly increased with sown species richness (log-transformed) in all depth segments and even carbon losses were significantly smaller with higher species richness. Although increasing species diversity increased root biomass production, statistical analyses revealed that species diversity per se was more important than biomass production for changes in soil carbon. Below 20 cm depth, the presence of one functional group, tall herbs, significantly reduced carbon losses in the beginning of the experiment. Our analysis indicates that plant species richness and certain plant functional traits accelerate the build-up of new carbon pools within 4 years. Additionally, higher plant diversity mitigated soil carbon losses in deeper horizons. This suggests that higher biodiversity might lead to higher soil carbon sequestration in the long-term and therefore the conservation of biodiversity might play a role in greenhouse gas mitigation.

These findings are important enough to warrant more broad-scale funding of LIHD research and demonstration projects. Instead of having biofuels crops replace natural grasslands, we should at least consider keeping diverse grasslands intact for the purpose of biofuels production AND conservation AND carbon sequestration.

---Mike Palmer

EScience News has a report on an upcoming paper by Evan Delucia (incidentally, a former grad school classmate of mine) and others on the carbon footprint of different biofuels crops:

Replacing corn with perennial grasses improves carbon footprint of biofuels

A quote from Evan:

"From a purely carbon perspective, our research indicates that putting perennial biofuel crops on landscapes that are dominated by annual row crops will have a positive effect on soil carbon."

I completely agree with this. But I also question its relevance. The current emphasis of the biofuels movement is to plant perennial grasses on 'marginal farmland' or 'wasteland', i.e. landscapes that are NOT currently dominated by annual row crops. In other words, landscapes that have high natural history value. But more to the point, replacing diverse natural and seminatural grasslands with miscanthus and switchgrass plantations are unlikely to have marked conservation benefits.
--Mike Palmer

A news item in Reuters alerts to the climatic (and conservation) dangers of clearing forests for biofuels plantations:

Clearing forests for biofuel hurts climate - study

I hope to read the study in detail when it comes out in Conservation Biology. However, I do have a concern with all of the focus on clearing of forests. In North America (and perhaps in other places) grasslands are at great risk. I have written elsewhere about the sodbusting that is already occurring due to biofuels, as well as the accelerating loss of CRP lands. Sodbusting is the grassland equivalent of clearcutting old-growth forests. Its effects on the climate are potentially severe: turning of the soil leads to enhanced nitrous oxide emissions, enhanced soil respiration, and under certain circumstances methanogenesis. All of these mean more greenhouse gas emissions. We are just beginning to understand the biodiversity of the grassland rhizosphere, and it seems that it does not recover after plowing. Indeed, the damage is likely to be permanent.

Grasslands are also being ignored in the food vs. fuel debate. The ethanol industry spokespeople (and researchers on cellulosic feedstocks) are continually saying there is no conflict between food and fuel, because we can always plant cellulosic fuels on 'marginal agricultural land' or 'waste land'. Do not be misled by these terms. An agronomist may view certain lands as marginal or waste, but these may be the very same lands that have high value for conservation and biodiversity. Many will have substantial soil carbon stores that will be lost (i.e. by conversion to greenhouse gasses) upon cultivation.

We definitely need to study the effects of biofuels development on the world's forests, as well as the conflict between food and fuel. I look forward to continuing literature on these subjects. But let us not forget the grasslands

E! Science News has a news item, apparently based on a Cornell University Press release (though I could not find the press release on Cornell's press office page):

Which grass is greener? Study to select Northeast grasses that can power the bioenergy era

I found this news item to be more perplexing than promising, and it is difficult to know how much of that is the fault of the scientists or the reporters. The report critiques the use of 'monoculture food crops such as corn', yet fails to mention that the research seeks to improve new monoculture crops. It is almost as if the word 'monoculture' is conveniently used as a derogatory word to justify the research, while not considering the relevance.

The report also stresses native plants, e.g. "In the wild, many of these native perennial grasses can survive, and even thrive, on marginal land." However, two paragraphs earlier, tall wheat grass and tall fescue are specifically mentioned. both of these species are EXOTIC, not native. Tall fescue, in particular, is highly invasive throughout much of its North American range.

So the verdict is unclear. Is the news story a case of incomplete scientific reporting, or is it greenwashing?

As mentioned before in this blog, bioprospecting can be a winning game in the search for environmentally-friendly biofuels.

I am an amateur woodworker, and I have been impressed by how hard hardwood is.
We also heat our house with wood, and I have been even more impressed by how longhorn beetle (Cerambycidae) larvae are able able to chew their way through oak and hickory.

Now a new study describes how this happens, as reported in escience news:

Novel fungus helps beetles to digest hard wood

The implications for biofuels are clear: lignin is a tough molecule to break down. Why bother to reinvent a way to do so, when other organisms have been doing this for millions of years?

Groom, M. J., E. M. Gray and P. A. Townsend (2008). "Biofuels and biodiversity: Principles for creating better policies for biofuel production." Conservation Biology 22(3): 602-609.
Biofuels are a newpriority in efforts to reduce dependence on fossil fuels; nevertheless, the rapid increase in production of biofuel feedstock may threaten biodiversity. There are general principles that should be used in developing guidelines for certifying biodiversity friendly biofuels. First, biofuel feedstocks should be grown with environmentally safe and biodiversity friendly agricultural practices. The sustainability of any biofuel feedstock depends on good growing practices and sound environmental practices throughout the fuel-production life cycle. Second, the ecological footprint of a biofuel, in terms of the land area needed to grow sufficient quantities of the feedstock, should be minimized. The best alternatives appear to be fuels of the future, especially fuels derived from microalgae. Third, biofuels that can sequester carbon or that have a negative or zero carbon balance when viewed over the entire production life cycle should be given high priority. Corn-based ethanol is the worst among the alternatives that are available at present, although this is the biofuel that is most advanced for commercial production in the United States. We urge aggressive pursuit of alternatives to corn as a biofuel feedstock. Conservation biologists can significantly broaden and deepen efforts to develop sustainable fuels by playing active roles in pursuing research on biodiversity friendly biofuel production practices and by helping define biodiversity-friendly biofuel certification standards.

A report in e! science news describes a project on sequencing the duckweed genome, with an eye towards biofuels production. I have long thought that duckweed should be promising - as it quickly reaches high biomass on eutrophic (fertilizer-polluted) waters, and could potentially play a role in cleaning up such waters. Harvesting can be done with a scoop, and we don't have to worry about soil erosion...

Duckweed genome sequencing has global implications

The Global Invasive Species Programme (GISP) has just released a Briefing document on potentially invasive biofuels crops:

GISP briefing documents

BBC has a short article on the GISP's concerns about biofuels:

Fuel crops 'pose invasion risk'
By Mark Kinver
Science and nature reporter, BBC News
Nations should avoid planting biofuel crops that have a high risk of becoming invasive species, a report warns.

Biomass Magazine described a new report by consulting company Context Network. Despite all the hype about cellulosic technology as the savior for biofuels, this report is sharply critical about its prospects:

Study: Cellulosic ethanol a long shot

Biomass Magazine described a new report by consulting company Context Network. Despite all the hype about cellulosic technology as the savior for biofuels, this report is sharply critical about its prospects:

Study: Cellulosic ethanol a long shot

Conference on the Ecological Dimensions of Biofuels
Washington DC
March 10, 2008

These are some highlights from the conference on the Ecological Dimensions of Biofuels, which took place yesterday.

After a few brief introductory talks and acknowledgments we heard from John Sheehan of LiveFuels, Incorporated. While he was at first dismissive of ‘feel good’ concepts of sustainability, he stressed the importance of life cycle assessment (LCA) of biofuels. He is to be applauded for his call for dialogue between industry, policy makers, and scientists. He stated,

“I am personally disappointed by the reaction of the biofuels industry to the two Science papers”

(meaning the recent Fargione et al. paper and the Searchinger et al. paper as previously discussed in this blog). It was refreshing to hear that, given the degree of vilification these papers have enticed. He stressed that the papers should be an opportunity to engage the parties. My quick reaction to that is the difficulty of engaging ecologists: when there is such a flood of funding for biofuels science yet a tiny trickle for the ecological aspects, the ecologists response that ‘we have no data’ is not likely to be very engaging.

Robin Jenkins of Dupont reported on that company’s integration of LCA into the planning process and project development was enlightening. She stressed the importance of collaboration with sustainability experts early in the planning process. I have seen many industry presentations before, and this is one of the few ones that really seemed 100% sincere. She made a convincing case that sustainability should be an organizing principle, and is indeed what her company is currently based on.

Catherine Kling, an economist from Iowa State University, reported on some of the water quality impacts of converting row crop acreage to switchgrass in the upper Mississippi valley. Her models showed that there were only modest improvements in nitrogen pollution, but she stressed the sensitivity of the models to scientific assumptions. The model exercise, she stated, was largely a framework for learning how to ask the right questions.

Philip Robertson of Michigan State University spoke on the Biogeochemistry of bioenergy landscapes. He started immediately by stressing the difference between cellulosic and noncellulosic fuels:

“Let me not mince any words: grain-based biofuels are an ecological train wreck”.

His promotion of cellulosic ethanol did not mention that we do not yet have a demonstrated capacity. With only a few pilot plants out there, we do not even know whether cellulosic production is feasible. The feasibility is based on projections and modelling.

Robertson reported that mid-successional systems have the most to offer with respect to ecosystem services and biofuel feedstocks. It is unclear whether repeated harvests of such systems will continue to have positive benefits from the greenhouse gas perspective.

One of Roberston’s surprising findings (surprising to me – but not to biogeochemists who have known it for a long time) is that forests have a very high methane oxidation potential. This means they are actively able to reduce the amount of a nasty greenhouse gas. Therefore, clearing forests for other biofuels is not likely to be very good for GHG emissions.

Virginia Dale of Oak Ridge National Laboratory stressed the complexity of the land use change issue, and argued that ecologists were being very simplistic. Although this talk was well-organized, and given by a well-respected landscape ecologist, the message was deeply frustrating. It sounded like “the system is too complex to possibly understand. What may seem like a good idea might actually be a bad idea, and vice versa”. Thus, it almost seemed like a call for inaction.

Jose Goldemberg of the Universidade do Sao Paulo gave the lunchtime keynote address, stressing the positive effects of sugar cane ethanol. He argued that “the problems with biofuels do not compare with those of fossil fuels” but later used harsh words against clearing the Amazon for soy biodiesel, and even harsher words against palm oil. He implied that the food vs. fuel debate was not a serious issue in Brazil.

John Wiens of The Nature Conservancy gave an excellent talk on the potential biodiversity consequences of biofuels developments. His organizing principle was that “land use is local but the economic drivers are global”. He placed landscapes on a scale of land use intensity (related to productivity), in which the most conserved (undisturbed) landscapes were at one end of the continuum, and the most productive (disturbed) at the other end. A high valuation of conservation will expand protection towards the productive end, yet a high valuation of agricultural products (including biofuels) will facilitate conversion of wildlands (such as CRP lands) or the infamous ‘marginal lands’ to production. Implicit to this model is the idea of a monotonic decline of conservation value as a function of intensity of land use. I found this a useful framework, though a bit misleading in certain circumstances. In particular, there are landscapes in which an intermediate intensity of management might actually be good for conservation. I think this is one area where John and I will agree to disagree.

Wally Wilhelm of USDA prepared a talk on biofuels on ‘marginal’ lands, but could not present due to illness. Rob Mitchell spoke in his stead. This talk implied that switchgrass could go a long way towards supplying domestic needs for ethanol, but pointed out potential problems exist.

Linda Wallace of the University of Oklahoma discussed perennial grassland systems, and presented data on a warming experiment implying that diverse systems, through the insurance effect, are far more resilient and resistant to disturbance than are monocultures. She stressed the importance of head-to-head comparison of LIHD vs. HILD systems, and lamented the fact that most current ‘comparisons’ are not truly comparable, and that we are relying far too much on modeled results and so little on actual data.

Marilyn Buford of the USDA Forest Service presented an optimistic view of biofuels from forest land. The talk was high on generalities but low on data. Thus, it is difficult to summarize here.

Donna Perla of US EPA pled with the audience to consider Municipal Solid Waste (MSW) as a prime potential feedstock. I think there was widespread support for this idea, but this talk was also low on specifics. The audience got no sense for what the major limiting technological factors were preventing the conversion of MSW into fuel. But the case that the resource could be significant was convincing.

Jerry Melillo of the Ecosystems Center presented a very pessimistic 50-year global model for the implications of biofuel development. To quote him,

“There will be almost certainly be massive biodiversity losses as biomass crops replace natural vegetation”

Other environmental and human impacts were also discussed. Nevertheless, Melillo stated some positive roles biofuels could play.

Otto Doering of Purdue University concluded the conference with a captivating talk, with no audiovisual aids except for the microphone. His entertaining style was almost uplifting – until we finally realized what his message was: many of the past policies that were good for conservation were implemented for reasons totally unrelated to conservation, and science has rarely been effectively integrated into policy. External drivers, rather than policy, has played the dominant role in land use change, whether in a positive or negative direction. While Doering did mention a few cases where ecologists (if they pose the argument appropriately) can make a difference, there was a strong implication that factors other than logic or values will continue to determine policy and its effects.

In addition to the talks, there were a number of posters, ranging from theory and modelling to experiments. Two posters (one by Hank Stevens, and one by Gregory Houseman) dealt directly with LIHD. Both ended up supporting the concept. The Stevens poster dealt more deeply with ecological theory, and the Houseman poster presented the results of an experiment. Interestingly, the Houseman poster backed up the famous Cedar Creek (Minnesota) results, but on a Kansas system: diverse systems can do remarkably well in unfertilized systems, comparably to low diversity fertilized systems.

Today (March 11) and tomorrow a select group (why I got selected is beyond me – perhaps this blog has something to do with it) is continuing with a workshop, to assess what is known and what needs to be known about the ecological consequences of biofuels. We expect to produce a number of print (and electronic) products, both specialized and not, related to the outcome of the workshop. It is too early to report on those, but I will blog about them when they become available! One thing is striking though: several of the ecologists in attendance say that this is the first workshop they have been to in which biofuels are being considered as having a possible role in a sustainable future. In contrast, I am from a geographic area (and institution) where few people question the beneficence of biofuels. I was surprised by the stark regional differences in attitudes towards biofuels (I suspected they existed but were more subtle).

Perhaps King is Corn, but Queen Soy is also flexing her muscles:

U biofuels study has farmers upset
Two soybean growers' groups decided to suspend grants to the U to protest research that found growing biofuels could actually worsen global warming.

See also:

Biofuels study upsets farmers
Results showed that some biofuels added to global warming, and did not benefit the environment.

Does it make feedstock production more sustainable if you stifle research on biofuels sustainability?

There is so much that is good about the system of Land-Grant Universities in the US. However, the system is so beholden to the growers' groups, who understandably are concerned when their crops are criticized. Ideally, it is experts in the Land-Grant Universities who should lead the way with respect to sustainability research. But who will support such research? It is not coming from the feds, nor the states (at least not in a big way). Conservation groups do not have the necessary financial clout. The universities themselves do have some discretionary budget, but (I know from experience at OSU) there is little interest in a topic that could threaten to slow acceleration of the biofuels industry (which means much to the State's economy in the short term, but could be disastrous in the long term).

The major funding will likely come after the ecological damage occurs.

Can someone help rescue me from this pessimism?

--Mike

The two provocative articles in Science deal almost entirely with the carbon cycle. But perhaps the most important Greenhouse Gas related to land clearing and agricultural inputs is ignored: N20. The authors are not at fault for failing to deal with it in depth; the regulatory focus is all on carbon, and there is hardly any good data on N2O (we do know that the warming potential of N2O is almost 300 times that of CO2). However, there is reason to suspect that even if we balance the carbon budget with respect to biofuels, the industry will still have a network effect. N2O deserves, at the very least, a prominent footnote.

[note added Feb 20: I stand corrected. N2O is indirectly considered in the Fargione et al. paper, in one of the appendices. Thanks to an anonymous colleague for pointing this out.]

The articles:

Fargione, J., J. Hill, D. Tilman, S. Polasky, and P. Hawthorne. 2008. Land Clearing and the Biofuel Carbon Debt. Science:1152747.

Searchinger, T., R. Heimlich, R. A. Houghton, F. Dong, A. Elobeid, J. Fabiosa, S. Tokgoz, D. Hayes, and T.-H. Yu. 2008. Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land Use Change. Science:1151861.

The British Royal Society is taking an enlightened view of biofuels, urging life cycle analysis, assessment of warming potential, and other aspects of environmental health:

An interview with Professor John Pickett, who chaired the report, is featured here: http://royalsociety.org/biofuels/video.html

The full text of the report is available here:
http://royalsociety.org/document.asp?id=7366

A summary paragraph:

The Society convened a working group of leading experts to consider the science and technology prospects of delivering efficient biofuels for transport in the broader context of the environmental protection and sustainability.

The working group concluded that biofuels have a potentially useful role in tackling the issues of climate change and energy supply. However, important opportunities to reduce greenhouse gas emissions from biofuels, and to ensure wider environmental and social benefits, may be missed with existing policy frameworks and targets. Unless biofuel development is supported by appropriate policies and economic instruments then there is a risk that we may become locked into inefficient biofuel supply chains that potentially create harmful environmental and social impacts. New technologies need to be accelerated that can help address these issues, aided by policies that provide direct incentives to invest in the most efficient biofuels.

The report makes a series of recommendations about policies and research needs in order to help develop sustainable biofuels for transport.

The sentence "Unless biofuel development is supported by appropriate policies and economic instruments then there is a risk that we may become locked into inefficient biofuel supply chains that potentially create harmful environmental and social impacts." is particularly insightful. The global market seems to be 'locked into' the King Corn and Queen Oil Palm supply chain. And while there has been talk of regicide, and scientists are nearly unanimous on their harmful effects, both rulers are as powerful as ever.

This new paper proposes a rigorous screening of proposed biofuel feedstock species:

Barney, J. N. and J. M. Ditomaso (2008). "Nonnative Species and Bioenergy: Are We Cultivating the Next Invader." BioScience 58(1): 64-70.
Biofuel feedstocks are being selected, bred, and engineered from nonnative taxa to have few resident pests, to tolerate poor growing conditions, and to produce highly competitive monospecific stands—traits that typify much of our invasive flora. We used a weed risk-assessment protocol, which categorizes the risk of becoming invasive on the basis of biogeography, history, biology, and ecology, to qualify the potential invasiveness of three leading biofuel candidate crops; switchgrass, giant reed, and miscanthus (a sterile hybrid);under various assumptions. Switchgrass was found to have a high invasive potential in California, unless sterility is introduced; giant reed has a high invasive potential in Florida, where large plantations are proposed; miscanthus poses little threat of escape in the United States. Each biofuel crop shares many characteristics with established invasive weeds with a similar life history. We propose genotype-specific preintroduction screening for a target region, which consists of risk analysis, climate-matching modeling, and ecological studies of fitness responses to various environmental scenarios. This screening procedure will provide reasonable assurance that economically beneficial biofuel crops will pose a minimal risk of damaging native and managed environs.

It seems that many of the strongest proponents of cellulosic biofuels, at least from the academic sector, and plant physiologists. This is not surprising: There are so many fascinating scientific questions related to cell wall design and the determinants of primary productivity. A decent infusion of funding from the biofuels sector could help further the science dramatically.

But the voice is not unanimous. Photosynthesis expert and the 1998 Nobel Prize Winner in Chemistry, Dr. Hartmut Michel, has issued some very strong cautions against biofuels in a lecture in Manila:

Rethink biofuel, says Nobel laureate

Most of Michel's comments are related to the inefficiency of biofuels, and the tremendous consequences of land conversion for biofuels. According to Michel, "We should not put money in biofuel development. It’s counterproductive.”

--Mike Palmer

Although most of the biofuels feedstocks research is devoted towards dedicated monocultures, on rare occasion you will find a serious report on species mixtures. Here is one.

Mulkey, V. R., V. N. Owens and D. K. Lee (2008). "Management of warm-season grass mixtures for biomass production in South Dakota USA." Bioresource Technology 99(3): 609-617.

Switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), and indiangrass (Sorghastrum nutans (L.) Nash) are native warm-season grasses commonly used for pasture, hay, and conservation. More recently switchgrass has also been identified as a potential biomass energy crop, but management of mixtures of these species for biomass is not well documented. Therefore, the objectives of our study were to: (1) determine the effects of harvest timing and N rate on yield and biomass characteristics of established warm-season grass stands containing a mixture of switchgrass, big bluestem, and indiangrass, and (2) evaluate the impact of harvest management on species composition. Five N rates (0, 56, 112, and 224 kg ha I applied annually in spring and 224 kg ha(-1) evenly split between spring and fall) and two harvest timings (anthesis and killing frost) were applied to plots at two South Dakota USA locations from 2001 to 2003. Harvesting once a year shortly after a killing frost produced the greatest yields with high concentrations of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) along with lower concentrations of total nitrogen (TN) and ash. This harvest timing also allowed for the greatest percentage of desirable species while maintaining low grass weed percentages. While N rates of 56 and 112 kg ha-1 tended to increase total biomass without promoting severe invasion of grass and broadleaf weed species, N application did not always result in significant increases in biomass production. Based on these results, mixtures of switchgrass and big bluestem were well suited for sustainable biomass energy production. Furthermore, N requirements of these mixtures were relatively low thus reducing production input costs. (c) 2007 Elsevier Ltd. All rights reserved.

The NAS report discussed previously on this blog, "Water Implications of Biofuel Production in the United States" is reposted in an easy-to-read format, along with commentary by Nate Hagens, in the following link from The Oil Drum:

The Implications of Biofuel Production for United States Water Supplies

The premise that biofuels is helping us to sequester carbon in the soil is highly questionable, especially if a high proportion of crop biomass is harvested. This is particularly true if we harvest a large proportion of the corn stover (field residue after removing grain) for cellulosic fuels.

Limited Biofuel Feedstock Supply?

A news item by Quirin Schiermeier on today's Nature web page may have implications for biofuels:

Methane mystery continues:
Perhaps only woody plants, not grasses, emit the greenhouse gas.

If you can't access the link, the title describes the content pretty well: new tests seem to show that plants do indeed emit methane aerobically (this has been in dispute over the past couple of years)but the magnitude is not as high as has once been feared. The puzzling new finding is that woody plants have a higher emission than herbaceous species.

If this finding ends up being broadly verified, it would strongly imply that grasslands have an inherent advantage over forests when it comes to designing a system with no net warming potential. Methane is a powerful greenhouse gas, which has a warming potential of 72 times that of carbon dioxide, if measured over twenty years. If dedicated biofuel trees (such as hybrid poplars) emit significant quantities of methane, this must be added to the list of greenhouse gases considered (including the nitrous oxides produced during fertilization and land conversion, and the carbon dioxide emitted during initial land conversion plus mechanization and transportation).

It is increasingly clear that 'carbon sequestration' is far from the complete solution when it comes to mitigating greenhouse gas emissions.

--Mike

When looking for ways to derive fuels from natural substances, the best approach may be to figure out how nature does it. A couple of billion years of evolution has resulted in many solutions to the problem.

Termite guts are an obvious place to look. You may have heard that termites themselves cannot digest cellulose, but they have a diverse gut biota(protozoans, yeasts, bacteria) that permits them to derive nutrition from wood.

A recent article in Science Daily describes an ambitious project to catalogue the biota associated with termite guts, with an eye towards finding efficient ways to extract biofuels from wood:

Termite Guts May Yield Novel Enzymes For Better Biofuel Production

It seems that much of 'bioprospecting' is geared towards finding the 'right' enzyme or compound to perform a function. I suspect this is not the right approach. The complexity of biological substances will necessitate a whole community of microorganisms to accomplish the degradation.

Termites tend to degrade only one source of biological material: wood (although there are termites that feed on other substances). For biofuels production, and more relevant for this list, for LIHD biofuels production, it may be more fruitful to look for places in nature where heterogeneous feedstocks are digested: in guts of generalist herbivores, or perhaps more simply, in compost piles.

Regardless of my particular recommendations, it seems to be clear that biofuels science is expanding to include not only chemistry and biochemistry, but microbiology, entomology, and phylogeny. Let us hope that when the science begins to incorporate ecology, it does not do so from scratch. There is at least a century of ecological research that has bearing on community structure and function. It would be a waste of effort to ignore this progress.

--Mike

One of the authors of the article cited in the preceding blog post is further quoted in the followign article:

Guebert -- Morrow Plots is hallowed ground for ag research

In the article, Richard Mulvaney says,

"It proves that our addiction to massive nitrogen injections is killing our most precious resource. ... I now view those giant anhydrous ammonia tanks injecting nitrogen all over as giant soil burners ... and the farmers driving them as unguided missiles."

And, as if an echo of Peter Donovan's comment on my last blog post,

"Equally striking is that their results are nothing new. Other studies the authors encountered in their research also showed that the over-application of nitrogen burned more soil-based carbon than it added."

And yet the "myth" continues -- even to the point that farmers now sell "carbon credits" to heavy carbon emitters as a way for the emitters to appear "green." Mulvaney views such schemes as akin to "fraud because the way we farm burns, not banks, carbon."

If there is hope, it is in the fact that some agronomists as well as (even fewer) ecologists, even in farm states, are willing to speak out.

--Mike

When I attended the Agronomy Society of America meetings in New Orleans earlier this month, there seemed to be a widespread assumption that increased nitrogen fertilization was necessary for biofuels production and enhanced sequestration of soil carbon. Now a new paper strongly challenges this view:

The Myth of Nitrogen Fertilization for Soil Carbon Sequestration
S. A. Khan*, R. L. Mulvaney, T. R. Ellsworth and C. W. Boast
J Environ Qual 36:1821-1832 (2007)

This paper presents a careful analysis of the famous Morrow Plots under continuous corn production (established more than a century ago), and is a must read for anyone interested in the effects of nitrogen fertilization on the global carbon cycle (and hence the greenhouse effect). I quote from the conclusions:

A half century of synthetic N fertilization has played a crucial role in expanding worldwide grain production, but there has been a hidden cost to the soil resource: a net loss of native SOC and the residue C inputs. This cost has been exacerbated by the widespread use of yield-based systems for fertilizer N management, which are advocated for the sake of short-term economic gain rather than long-term sustainability. Fertilization beyond crop N requirements could be reduced substantially by a shift from yield- to soil-based N management, ideally implemented on a site-specific basis. This strategy may be of value for reversing the ongoing organic matter decline of arable soils, but several decades will likely be necessary before any such benefit can realistically be expected to emerge. In the meantime, caution is warranted in avoiding excessive N fertilization, and especially with the current trend toward the use of crop residues for bioenergy production.

This conclusion, along with concerns about nitrous oxide emissions (recall a single molecule of N2O has the warming potential of almost 300 molecules of CO2) AND the distinct possibility that 'peak nitrogen' will be roughly coincident with 'peak oil', should be a wake-up call for anyone planning a sustainable biofuels-based economy.

---Mike Palmer

The biofuels push is almost exclusively focused on ethanol and biodiesel. But so much is to be gained by focusing on alternatives.

This first news item (thanks to Jason Hill for bringing it to my attention) is a case study in the use of pelletized prairie grasses for heating. The technology is not new; indeed, pelletization of biomass-derived feedstocks is used throughout much of northern Europe. If this approach was more widely adopted, it could be used as justification for prairie restoration efforts. The other plus side to this approach is that it might be optimized at small scales, allowing more energy independence of families and communities.

Switching fuels: Family-owned greenhouse to experiment with prairie pellets for heat

This second news item implies that the hydrogen-based economy may not be as far away as previously thought. The supply of hydrogen has been one of the limiting factors for the design of efficient fuel cells (which, at least hypothetically, have many environmental benefits). A wide range of biomass (including LIHD or waste stream biomass) could be utilized, and the conversion to hydrogen is at extremely high efficiencies.

Scientists Make Advances in Extracting Hydrogen

The major factor limiting widespread adoption of hydrogen-based transportation systems appears to be the necessary infrastructure. If indeed fuel cells end up being the most efficient and environmentally sound, let us hope that there is the political will and courage to make the necessary changes.

--Mike

A new paper in PNAS demonstrates that complementarity does indeed play an important role in the high productivity of polycultures, and that the frequent observation of polycultures yielding no greater than that of the 'best' species does not negate the role of complementarity:

Cardinale, B. J., J. P. Wright, M. W. Cadotte, I. T. Carroll, A. Hector, D. S. Srivastava, M. Loreau and J. J. Weis (2007). "Impacts of plant diversity on biomass production increase through time because of species complementarity." Proceedings of the National Academy of Sciences 104(46): 18123-18128.
Accelerating rates of species extinction have prompted a growing number of researchers to manipulate the richness of various groups of organisms and examine how this aspect of diversity impacts ecological processes that control the functioning of ecosystems. We summarize the results of 44 experiments that have manipulated the richness of plants to examine how plant diversity affects the production of biomass. We show that mixtures of species produce an average of 1.7 times more biomass than species monocultures and are more productive than the average monoculture in 79% of all experiments. However, in only 12% of all experiments do diverse polycultures achieve greater biomass than their single most productive species. Previously, a positive net effect of diversity that is no greater than the most productive species has been interpreted as evidence for selection effects, which occur when diversity maximizes the chance that highly productive species will be included in and ultimately dominate the biomass of polycultures. Contrary to this, we show that although productive species do indeed contribute to diversity effects, these contributions are equaled or exceeded by species complementarity, where biomass is augmented by biological processes that involve multiple species. Importantly, both the net effect of diversity and the probability of polycultures being more productive than their most productive species increases through time, because the magnitude of complementarity increases as experiments are run longer. Our results suggest that experiments to date have, if anything, underestimated the impacts of species extinction on the productivity of ecosystems.

Thus, the basic premise of LIHD is increasingly being shown to be scientifically solid. The time is ripe for large-scale trials, compared on a common ground with HILD.

--Mike palmer

A new report from Reuters discusses the possibility (or probability) that dedicated feedstock crops can become invasive:

New biofuel crops pose risks to farms, ecosystems

It includes extensive quotes from Richard Mack, the leading U.S. invasive plant biologist.

One neglected aspect of invasive plant biology with respect to biofuels: plowing up virgin soil for the sake of biofuels, such as is occurring in much of the US Great Plains, will create opportunities for new invasions or range expansions of non-crop exotic species. Weeds follow the plow.

--Mike Palmer

Carbon sequestration in grass mixtures (and in switchgrass monocultures) is, not surprisingly, much higher than in HILD annual crops:

Omonode, R. A. and T. J. Vyn (2006). "Vertical distribution of soil organic carbon and nitrogen under warm-season native grasses relative to croplands in west-central Indiana, USA." Agriculture Ecosystems & Environment 117(2-3): 159-170.

Establishment of grasslands can be an effective means of sequestering soil organic carbon (SOC) and reducing atmospheric CO, that is believed to contribute to global warming. This study evaluated the vertical distribution and overall sequestration of SOC and total nitrogen (N) under warm-season native grasses (WSNGs) planted 6-8 years earlier relative to a corn (Zea mays L.)-soybean (Glycine max L.) crop sequence, and switchgrass (Panicum virgatum) relative to tall mixed grasses of big bluestem (Andropogon gerardi), indiangrass (Sorghastrum nutans), and little bluestem (Andropogon scopurius). Paired soil samples from 0-15, 15-30, 30-60 and 60-100 cm depth increments were taken from WSNGs and adjoining croplands at 10 locations, and from switchgrass and adjoining tall mixed grasses at four locations in three major soil types of alfisols, mollisols, and entisols in Montgomery County, Indiana. Significant differences in SOC and N concentrations of WSNGs and croplands were limited to the surface 30 cm. On average, SOC concentrations in the surface 15 cm depth were higher in WSNGs than croplands (average: 22.4 and 19.8 g kg(-1) C, respectively) but significant differences were observed in just 4 of 10 locations. Similarly, surface soil SOC concentrations were not different for switchgrass (22.1 g kg(-1)) relative to tall mixed grasses (21.4 g kg(-1)). Soil N concentrations never differed significantly among land use treatments. On average, SOC mass calculated to 1.0 m depth was 9.4 percent higher under WSNG than cropland (P0.058), and 8.1 percent higher in switchgrass relative to tall mixed grass (P0.054), but soil N mass was the same for both WSNGs and cropland. Vertical distribution under WSNG of SOC mass was 26, 21, 28, and 25 percent, and of total N mass was 3 1, 25, 28 and 16 percent, in the 0-15, 15-30, 30-60, and 60-100 cut depth intervals, respectively. Even though we acknowledge the potential influence of soil variability or prior landscape processes on our results at some locations, we estimated that WSNGs sequestered an average 2.1 Mg C ha(-1) yr(-1) more than the corn-soybean sequence.

I strongly suspect that adding forbs (especially legumes) and C3 grasses into the mix would have substantially increased yields AND C storage of grass mixes.

Non-ecologists are often surprised to learn that mowing (as for LIHD biofuels) can be compatible with conservation. Here is a case study, just published in Applied Vegetation Science. There are plenty of other examples in the recent literature.

Citation:
Patrick Endels, Hans Jacquemyn, Rein Brys, and Martin Hermy. 2007. Reinstatement of traditional mowing regimes counteracts population senescence in the rare perennial Primula vulgaris. Applied Vegetation Science 10:351-360.

Abstract

Question: Traditional management of grassland verges or ditch banks included mowing as a way to provide additional harvest¬ing of hay. Nowadays, such sites are often left unmanaged, as mowing verges is no longer profitable in modern agricultural systems. Are vulnerable plant species able to withstand com¬petition with the surrounding vegetation and maintain viable populations under these circumstances? How do they respond to reinstatement of traditional mowing regimes?

Location: Oedelem, northwestern Belgium.

Methods: To investigate the effect of reinstatement of the rare perennial Primula vulgaris, demography and adult plant performance were monitored in a grassland verge between 1999 and 2003 under different mowing regimes. Year transitions between life stages were analysed with matrix population models. To disentangle the contributions of the deviations in different life stage transitions to the variation in overall population growth rate, life table response experiments were used.

Results: Both management and year had a strong impact on demographic traits of P. vulgaris. If plots were left unmanaged, lower plant performance and declining population growth rates were observed. While population growth rates differed significantly between mowing regimes, mowing of plots only in July did not differ from mowing in July and October in terms of vegetative and reproductive output of adults. Mowing twice a year appeared to be most efficient in increasing population growth rate both by raising recruitment and growth of individu¬als into large reproductive adults.

Conclusions: Large P. vulgaris populations show a good ability to recover from recent abandonment of traditional management regimes. By mowing twice a year, managers are able to target vital rates that are most influential: growth and flowering of adult individuals

A recent article in Science Daily entitled "Switchgrass: Bridging Bioenergy And Conservation" describes a project by Michael Casler, who documents that the genetics of most modern switchgrass cultivars tends to mirror natural variation in nature. He suggests that these cultivars might be good simultaneously for biofuels and prairie restoration.

This recommendation seems reasonable for the upper Midwest, where almost every corner of every county has experienced the plow. Planting a monoculture of switchgrass on barren, degraded land might be a reasonable start. However, I still would suggest that native legumes be added early on.

In much of the Great Plains, however, we have native stands of switchgrass, mixed with a tremendous diversity of other grasses and perennial forbs, already present in situ. However, the biofuel industry seems to demand establishment of pure stands of switchgrass. And in Oklahoma, it is the low-lignin, high yielding transgenic switch that is the lead variety. There is no clear connection between switchgrass establishment and prairie restoration. Indeed, a number of ecologists in the state fear the a correlation between switchgrass establishment and prairie destruction. Ironically, Oklahoma is a state with a heritage of sustainable yields of prairie hay - but hay meadows have declined over the past decades.

I applaud Casler's genetic sleuthing on switchgrass. But before we assume that biofuels production equals prairie restoration, we need to look at the whole agronomic picture. I still think there is room for a biofuels rewilding of America.

--Mike

I am currently at the Oklahoma Biofuels Conference in Oklahoma City. Predictably, the presentations are all from the industry perspective.

Particularly telling was the lunchtime presentation by Anna Rath of Ceres, Incorporated. She stressed that Ceres has three priorities in developing transgenic biofuels crops. The three priorities are:
1) yield
2) yield
3) yield

It would have nice to have sustainability or environmental responsibility, or even a positive carbon balance be at least one of the priorities. But in the present market, responsibility does not necessarily translate into profitability.

--Mike

Hooray for the National Research Council of the U.S. National Academies of Science. Instead of following the biofuels-as-panacea approach of USDA, DOE, DOT, and state R&D agencies, the National Academies has taken a serious look at the environmental consequences of expanded biofuels production:

Water Implications of Biofuels Production in the United States (2007)

I hope the NRC will take a close look at other issues related to biofuels, such as biodiversity, invasive species, biocides, sodbusting, and changes in the nitrogen cycle.

Another round of applause: the current report actually mentions mixed prairie grasses as a possible biofuels feedstock. (though this is not surprising, since David Tilman is one of the committee members authoring the report).

The report states that not much is known about the water use implications of mixed grass biofuels.

Some things we definitely DO know about our mixed grass hay meadows in the Southern Great Plains are:

1) Prairie Hay Meadows are typically not irrigated
2) Even in drought years, you do not have total crop failure
3) Abandoning hay meadows (note that there are more abandoned hay meadows than there are hay meadows) are rapidly colonized by fast-growing weedy tree species. These weedy tree species transpire tremendous amounts of water, and are widely recognized as a serious hydrological concern in the area.

Thus, the use of native prairie hay meadows (in the regions that can support them, of course) as a biofuels feedstock is a win-win proposition for water, biodiversity, and biofuels.

---Mike Palmer

The August 2007 issue of Scientific American has an excellent article on perennial agriculture:

Future Farming: A Return to Roots?
By Cindy M. Cox and Jerry D. Glover and John P. Reganold (the online content is for paying customers only).

The main argument is that perennial wild plants have extremely extensive and efficient root systems, in contrast to annual agriculture which degrades the soil. Intensive breeding and hybridization can create a perennial-based agriculture that feeds the world and replenishes the soil. The visuals and the statistics in the article are quite striking.

The link to biofuels might seem obvious: why not breed perennial biofuels crops? Of course, this is what is being done: with poplar, switchgrass, prairie cordgrass, miscanthus, etc. But the next question is WHY breed perennial biofuels crops? In the case of food crops, the case for breeding is clear. Most perennial wild plants do not provide substantial qualities of food products. On the other hand, for biofuel feedstocks production, there is no evidence that intensive breeding will help produce are more sustained production of biomass. Indeed, fitness of wild perennials in grasslands is often correlated with sustained production of biomass. Nature has done the breeding for us. Even better, ecological filtering plus natural selection has resulted in combinations of species that complement each other in biomass production. There is no major technological hurdle for us to overcome in the production end for biofuels, in contrast to the situation for perennial food crops.

--Mike Palmer

Switchgrass isn't just for ethanol anymore:

Reddy, N. and Y. Q. Yang (2007). "Natural cellulose fibers from switchgrass with tensile properties similar to cotton and linen." Biotechnology and Bioengineering 97(5): 1021-1027.

We report the production and characteristics of natural cellulose fibers obtained from the leaves and stems of switchgrass. In this paper, the composition, structure and properties of fibers obtained from the leaves and stem of switchgrass have been studied in comparison to the common natural cellulose fibers, such as cotton, linen and kenaf. The leaves and stems of switcligrass have tensile properties intriguingly similar to that of linen and cotton, respectively. Fibers were obtained from the leaves and stems of switchgrass using a simple alkaline extraction and the structure and properties of the fibers were studied. Fibers obtained from switchgrass leaves have crystallinity of 51%, breaking tenacity of 5.5 g per denier (715 MPa) and breaking elongation of 2.2% whereas the corresponding values for fibers obtained from switchgrass stems are 46%, 2.7 g per denier and 6.8%, respectively. Switchgrass is a relatively easy to grow and high yield biomass crop that can be source to partially substitute the natural and synthetic fibers currently in use. We hope that this research will stimulate interests in using switchgrass as a novel fiber crop in addition to being promoted as a potential source for biofuels.

This is indeed a promising development. While monocultures of switchgrass are still problematic from an ecological point of view, if they substitute for cotton, the change is for the better. Switchgrass is much less water-greedy, nitrogen-greedy and biocide-greedy than cotton. Indeed, there are not many impediments for switchgrass to be produced organically. Furthermore, switchgrass is a perennial, and thus annual plowing would not be necessary (and thus there will be less soil respiration and nitrous oxides released, thereby reducing greenhouse gases).

--Mike Palmer

No joke at all. As I have speculated in previous postings, nitrous oxide (laughing gas; a potent greenhouse gas) is an inevitable byproduct of HILD biofuels production.

Now, nobel-prizewinning chemist Paul Crutzen has shown that this is not mere speculation, as posted in Chemistry World. It is becoming increasingly clear that the life-cycle analysis of biofuels must include not only the carbon cycle, the water cycle, but also the nitrogen cycle. It is indeed quite possible that the cure is worse than the disease when it comes to biofuels.

--Mike Palmer

There is a new report out by Environmental Defense:

Potential Impacts of Biofuels Expansion on National Resources: A Case Study of the Ogallala Aquifer System

The take-home message is that the Ogallala Aquifer is being depleted and cannot sustainably support productivity of HILD biofuels systems.

The idea that we can support biofuels on 'marginal farmland' so that we do not compete with crops is questionable. "Marginal" is practically a synonym of "unproductive". To make an unproductive system productive, you need to have substantial inputs. For arid regions, the main input needed is water (to state the obvious). If there is not a sustainable supply of water, you cannot maintain the productivity.

If you don't provide massive inputs, you can possibly maintain yields - but the yields will be low. This means that there are substantial transportation costs to transport biomass to processing facilities and fuel to the consumers. Thus, 'marginal lands' are not the solution to the biofuels dilemma.

---Mike palmer

A news item in the biofuels journal entitled Georgia Tech Takes Comprehensive Approach to Cellulosic Ethanol Research seems to redefine 'comprehensive'. I was eagerly reading this article, expecting a mention of how biofuels are expected to be produced sustainably. Without an understanding of the ecology behind primary productivity, and how it relates to the global carbon and biodiversity, we cannot have a comprehensive approach to biofuels, cellulosic or not.

Of course, The Georgia Tech situation is merely an example. Any review of the biofuels literature, or biofuels in the news, will show that development of the sector is uneven. Despite the general impression among the public that biofuels are 'good for the environment', the environment is the last item on the list when it comes to R&D. Biofuels may be a very important part of the solution to global warming, but not if it continues the direction it is going now.

---Mike Palmer

Robert Anex et al. have written an excellent paper, promoting 'closing the loop' with respect to nutrient flows in agroecosystems. This objective may be obvious to the academic ecologist, but I have not seen it widely recognized among policy makers or agricultural scientists. Further research and larger trials will be needed to assess whether the particular suggested systems will prove feasible, but the general principals advocated are solid. Since we are on the verge of transforming the entire agricultural sector (many will argue we already have), now is the time to take these arguments seriously AND TO MAKE THEM POLICY.

My only addition to such a policy would be to make conservation of biodiversity intrinsic to the system.

Potential for Enhanced Nutrient Cycling through Coupling of Agricultural and Bioenergy Systems

Robert P. Anex, Lee R. Lynd, Mark S. Laser, Andrew H. Heggenstaller and Matt Liebman

Emerging markets for fuels and energy from crop biomass are creating new opportunities for redesigning agricultural systems for improved ecological function and energy-use efficiency. Innovative bioconversion processes configured to recover key plant nutrients from biomass will allow recycling nutrients to crop fields, thereby closing nutrient cycles and reducing the energetic and economic costs of fertilization. Such advanced bioconversion matched with complementary biomass production may promote the development of highly productive agricultural–industrial systems that protect environmental quality. A generally representative example of nutrient recovery from an integrated biological and thermochemical conversion process designed to produce ethanol and synthetic fuels from switchgrass (Panicum virgatum L.) indicates that approximately 111 kg ha–1 yr–1 of N can be recovered. This is equivalent to 78% of the N-fertilizer input required. This example illustrates that N recovery and cycling could significantly improve the sustainability of biomass production as well as the overall energy balance of ethanol production from lignocellulosic biomass. Demand for lignocellulosic biomass as an industrial feedstock may also allow the introduction of new crops and cropping systems. In addition to perennial grasses, double-crop sequences and systems incorporating greater use of legumes, cover crops, and living mulch may be able to produce large amounts of biomass while improving resource use efficiency and reducing environmental impact.

--Mike

It appears that the USDA is no longer 'hot' on cellulosic ethanol.
See from Gristmill: The USDA goes all lukewarm on cellulosic ethanol

If cellulosic technologies are really the wave of the future, it should be funded by venture capitalists and other parts of the private sector. And indeed, it is. The role of government funding should be to research 'how to get it right' with respect to environmental effects, or to facilitate the design of production systems where the benefits are great but diffuse (see for example, biofuels and biochar).

We do not need more incentives for plowing up prairies to plant switchgrass or Miscanthus.

---Mike

When I posted the ESA abstracts relevant to biofuels, I neglected to add this one.

Low-lignin transgenic poplar: Is there a trade-off between enhanced fiber production and biomechanical stability?

Steven L. Voelker, Oregon State University, Frederick C. Meinzer, USDA Forest Service, Steven H. Strauss, Oregon State University, and Barbara Lachenbruch, Oregon State University.

Society depends heavily on wood for structural material, energy, and for its component fibers. Most end uses for wood fiber require the removal of lignin, an energy intensive process. Fermentation of wood to produce bioethanol, a growing source of transportation fuels, would benefit from reduction of lignin content. In poplar (Populus spp.), antisense downregulation of the gene Pt4CL1 that encodes 4-coumarate:coenzyme A ligase (4CL), has been previously shown to inhibit the deposition of lignin by up to 45 %, while enhancing cellulose content by 15%, in greenhouse environments. To evaluate the effects of transgenic modification of lignin on wood properties in the field, we studied biomechanical properties of trees derived from 14 transgenic events of a hybrid white poplar (P. tremula × P. alba). We conducted >1,100 bending tests. The wood of the transgenic lines had a significantly lower modulus of elasticity (MOE), modulus of rupture (MOR), and material toughness than branches of similar size from non-transgenic trees (P<0.05). The effect was greater for larger branches (range in diameter 1.8-5.4 mm). If larger branches have lower mechanical properties, one could expect either poorer survival and/or productivity in transgenics due to wind and ice-related breakage, or altered tree form and tensionwood development to maintain similar stress distributions. These results suggest that evaluation of biomechanics during field trials of trees with transgenic modifications to wood chemistry is important to understand their value and risks. Studies of transgene expression, lignin content, and rate of growth during a second year of field evaluation are underway.

Thus, what many of us botanists have been pretty sure about - removing lignin makes weak trees - seems to be correct. But sometimes it is necessary to demonstrate the obvious. I think it will probably soon be shown that fiddling with the cell wall of grasses will also cause structural failure, and most likely susceptibility to fungal pathogens as well.

---Mike

I have written about how roadside mowing can enhance biodiversity as well as provide biomass fuels. It is probably better to use the term ‘haying’ to avoid implying the use of manicured bermudagrass roadsides. Here is an interesting article from the New York Times:

Wildflowers Find Favor with Highway Gardeners

My capsule summary of the article is as follows: wildflower enthusiasts and people concerned with biodiversity are advocating planting roadsides across the US with native plants – including switchgrass. While it is somewhat problematic with respect to ‘roadside vegetation management’, a relaxed mowing schedule ends up saving highway departments a lot of money. Reactions from the public range from wildly enthusiastic to disgusted. The ‘disgusted’ people think wildscaping looks unkempt, and that roadsides should look like lawns. According to the article, a “poll showed that the public prizes neatness more than nativeness.”

I wonder whether both opinions could be reconciled if an annual harvest lead to the production of biomass fuels. Those who like the idea of things looking neat might be the sort who favor economic development and land ‘being put to use’. Those who value diversity and wildflowers might be convinced that annual mowing is necessary to keep the biological diversity high (which is true in most grasslands with the exception of very arid areas, as long as the seed supply is high, naturally or artificially).

The article implied a bit of grumbling amongst highway crews about annual mowing causing problems with the lawnmowers breaking down. If the mental switch was made to thinking of the harvest as ‘haying’ instead of ‘mowing’, perhaps more appropriate equipment would be used.

On the subject of roadsides: it could be argued that roadside mowing is not a viable fuel because they are so widely dispersed so that transportation costs would be high. However, note that the harvest would largely be done in areas accessible by road (well, duh) and there would be less energy spent in reversing directions, as one would in a normal hay meadow. It would be fascinating to study the energetics and costs associated with harvesting roadsides vs. fields.

Roadside harvesting for biofuels appears to be a win-win-win situation for biodiversity and biofuels. A serious analysis is sorely needed.

---Mike

A good example of 'closing the loop' biofuels:

Thermochemical process converts poultry litter into bio-oil

One aspect of this process is especially admirable:

"The self-contained transportable pyrolsis unit will allow poultry producers to process the litter on site rather than having to haul the litter to a separate location."

In other words, transportation of feedstocks is not a big energetic loss - one of the biggest concerns with most biofuels. Here is yet another example of 'small is beautiful'.

There is an excellent 1-page policy forum in the latest issue of Science:

Righelato, R. and D. V. Spracklen (2007). Carbon Mitigation by Biofuels or by Saving and Restoring Forests? Science 317(5840): 902.

These authors state dramatically something that has been ignored:

“Clearance results in the rapid oxidation of carbon stores in the vegetation and soil, creating a large up-front emissions cost that would, in all cases examined here, outweigh the avoided emissions.”

As readers of this blog know, I think the role of soil respiration (one form of oxidation) has been vastly underestimated, and can undermine most of the perceived advantages of biofuels.

“Moreover, it may be possible to avoid environmental problems associated with extensive monoculture by harvesting from standing forests.” In this case, soil and above-ground carbon stocks may be built up in parallel with sustainable harvesting for fuel production.”

One puzzlement is why only forests are considered. Why not harvest standing grasslands? The big advantage of grasslands from an ecological perspective is that they NEED to be harvested. Biomass removal is what makes a grassland a grassland.

“If the prime object of policy on biofuels is mitigation of carbon dioxide–driven global warming, policy-makers may be better advised in the short term (30 years or so) to focus on increasing the efficiency of fossil fuel use, to conserve the existing forests and savannahs, and to restore natural forest and grassland habitats on cropland that is not needed for food.”

This is a breath of fresh air in the debate. Restoration is the key. But why not perform biofuels rewilding, and serve both purposes simultaneously?

“In addition to reducing net carbon dioxide flux to the atmosphere, conversion of large areas of land back to secondary forest provides other environmental services (such as prevention of desertification, provision of forest products, maintenance of biological diversity, and regional climate regulation), whereas conversion of large areas of land to biofuel crops may place additional strains on the environment”

Yes. But we can retain ecosystem services and have biomass fuels with biofuels rewilding, or other forms of CLT-LIHD.

---Mike Palmer