Climate change could increase plant frost damage

Widespread damage to plants from a sudden freeze that occurred across the Eastern United States from 5 April to 9 April 2007 was made worse because it had been preceded by two weeks of unusual warmth, according to an analysis published as an open access article in the March 2008 issue of BioScience.

The authors of the report, Lianhong Gu and his colleagues at the Oak Ridge National Laboratory (ONRL) and collaborators at NASA, the University of Missouri, and the National Oceanic and Atmospheric Administration (NOAA), found that the freeze killed new leaves, shoots, flowers, and fruit of natural vegetation, caused crown dieback of trees, and led to severe damage to crops in an area encompassing Nebraska, Maryland, South Carolina, and Texas. Subsequent drought limited regrowth.

The findings could have serious implications for agriculture and for future climate predictions as both local photosynthetic activity and biomass productivity can dramatically decline as a result of such events. Lower biomass productivity means a lower capacity to sequester carbon dioxide, thus disturbing the carbon cycle. The potential for such freeze events preceded by warm periods, may also complicate farmers' planting decisions.

The event
The 2007 spring freeze was caused by a winter configuration of the jet stream, which brought an Arctic airmass deep into the eastern two-thirds of the conterminous United States, breaking low temperature records in dozens of locations. The spatial extent of the event is delineated approximately by the daily minimum temperature anomaly as determined by the terrestrial observation and prediction system (TOPS) (figure 1, click to enlarge).

Spring freezing events are not unusual in this part of the United States; it is unusual, however, to have such an extreme freeze event after extended periods of above-normal temperatures.

At an AmeriFlux site in central Missouri, the daily minimum temperature exceeded 15 degrees Celsius (°C) for a week just before the sustained April freeze, which at its coldest reached –7°C. The daily minimum temperature also exceeded 15°C eight times during the two weeks leading up to the freeze event, which at its coldest reached –5°C, at the Walker Branch watershed station in Tennessee (figures 2a and b, click to enlarge).

This stretch of high late-winter temperatures preceding the freeze, coupled with above-normal warmth earlier in March, caused that month in 2007 to be the warmest March on record at the Walker Branch station and also at the nearby Oak Ridge, Tennessee, station (mean temperature of 13.7°C; period of record, 1948–2007).

The unusually warm periods before the 2007 spring freeze caused plants to break dormancy early throughout the southern part of the central and eastern United States. When the cold, Arctic air subsequently moved into the region, the stage was set for the freeze to decimate newly grown tissues of crops, horticultural plants, and native forest species:
energy :: sustainability ::biomass :: bioenergy :: agriculture :: frost :: vegetation :: carbon cycle :: global warming :: climate change ::

The 2007 spring freeze hit agriculture particularly hard. Severe and widespread damage to crops was reported from Nebraska to Maryland in the north, and from Texas to South Carolina in the south. Farmers in several states considered this freezing event “the worst ever seen,” andmany sought federal farm disaster relief. For example, the agricultural loss in North Carolina alone was estimated at $111.7 million, and Governor Mike Easley requested federal disaster declaration for crop damage in 56 counties.

From a rushing “green wave” to a collapsing “green retreat”

The MODIS (Moderate-resolution Imaging Spectroradiometer) rapid response system provided timely spatial and temporal information about the impacts of the 2007 spring freeze on vegetation development (i.e., leaf canopy) in the affected region.

Images of the Normalized Difference Vegetation Index (NDVI) from MODIS before the freeze indicated that vegetation in the southeastern United States and the southern part of the Midwest was developing rapidly, and showed the vernal front reaching as far north as northern Missouri.

After the freeze, the vernal front was pushed back tomid-state locations in Arkansas, Mississippi, Alabama, and Georgia (figure 3, click to enlarge; compare the dark green areas in panels a and b). The regionwide phenological development in 2007 (figure 3a, 3b) also presented a marked contrast to that in 2006 (figure 3c, 3d). Before the spring freeze in 2007, the southeastern NDVI was developing much faster than in 2006 (figure 3, compare panels a and c). After the freeze, the opposite pattern is clearly evident (figure 3, compare panels b and d). The freeze effectively and nearly instantaneously turned a rushing green wave of vegetation development into a green retreat.

Impact on the carbon cycle and climate change
All signs have so far indicated that the 2007 spring freeze had at least a short-term, profound effect on the terrestrial carbon cycle inmuch of the central and eastern United States during the crucial period of spring phenological development. In fact, for the period 7–14 April 2007, the fraction of absorbed photosynthetically active radiation, a sensitive indicator of terrestrial primary production (computed by TOPS), was markedly lower than the 2001–2006 average for the same period.

At the Missouri Ozark AmeriFlux site, reduced forest carbon uptake and altered surface energy balance were observed after the freeze. It also appears that regrowth did not yield the normal maximal leaf area indices of major deciduous forest biomes found in the freeze-affected region in previous years.

Given the severity and spatial extent of the damage in 2007 to managed and natural vegetation throughout the southeast, onemight question how strong the terrestrial carbon sink was that year in the United States, and speculate on long-lasting impacts beyond the 2007 growing season.

We hypothesize on the basis of several considerations that this event will evoke both short-term and long-term responses. The level of tissue damage represents a substantial loss of carbon and nutrients that would have been remobilized to internal plant stocks during autumnal senescence. Plants cannot resorb nutrients and carbohydrates from freeze damaged tissues. The loss of energy-intensive resources disturbs the internal nutrient cycling and carbohydrate budgets. These disturbances may have lasting effects. - Gu et al.

The 2007 spring freeze coincided with the release of the fourth assessment report by the Intergovernmental Panel on Climate Change (IPCC). This report concluded that it is “virtually certain” that the 21st century will have “fewer cold days and nights overmost land areas”. In view of this prediction, what implications does the 2007 spring freeze have for terrestrial ecosystems in a warming global climate?

To address this question, the researchers draw a line between frost frequency and risk of frost damage in the context of climate change. Reduced frost frequency does not necessarily mean reduced risk of frost damage. Farmers and other landmanagers may respond to warming and reduced frost frequency by planting earlier or by planting alternative species.

Natural plant populations and animal species might advance the development of crucial phenological phases, or with sufficient time, shift their ranges poleward or to higher elevations. With such adjustments and adaptations, the risk of frost damage could remain the same or even become greater.

In addition to the distinction between frost frequency and risk of frost damage, the scientists also considered the myriad interactive effects among changing environmental factors crucial for plant growth, including atmospheric CO2 concentration, temperature,water availability, snowcover, ozone concentration, and ultraviolet-B (UV-B). Without taking these factors into account, it is impossible to fully appreciate the seemingly paradoxical risk of frost damage to plants in a warming climate.

An obvious issue of concern is the effect that higher atmospheric CO2 concentrations would have on plant tolerance and resistance to low temperatures both early and late in the growing season. Experimental results suggest that responses are most likely species-specific, but there is amounting consensus that, formany plant species, growth under elevated CO2 can reduce their resistance and tolerance to freezing temperatures.

The reduction in tolerance appears to be caused by a slowdown in low-temperature acclimation, which is caused by higher daytime leaf temperatures due to reduced stomatal conductance under elevated CO2. Furthermore, elevated CO2, alone or interacting with UV-B, may increase the foliar ice nucleation temperatures of both evergreen and deciduous species, and thus make them vulnerable even to moderately cold conditions.

Although warming may be the general climate trend, there is little certainty regarding future temperature variability. If, as predicted, temperatures in winters rise prominently, one may expect more frequent freeze and thaw fluctuations during future winters, a situation that would present several problems for plant growth. These fluctuations may delay plant hardening and hasten dehardening. Many plants’ tolerance to freeze increases only after a sustained period of exposure to low temperatures. If temperatures change too quickly, however, plants may not have enough time to acclimate. - Gu et al.

Gu and his colleagues propose that the 2007 spring freeze should not be viewed as an isolated event, but as a realistic climate-change scenario. Further study of its long-term consequences could help refine scenarios for ecosystem changes as carbon dioxide levels increase and the climate warms.

References:
Lianhong Gu, et. al. "The 2007 Eastern US Spring Freeze: Increased Cold Damage in a Warming World?", BioScience, March 2008 / Vol. 58 No. 3

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Income inequality in Latin America not persistent; poverty best tackled by development, less by redistribution

By western standards, the gap between rich and poor in Latin American countries is disproportionately wide. PhD candidate Ewout Frankema investigated the development of income inequality since colonial times and concludes that differences in income have fluctuated sharply. Contrary to what is usually assumed, income inequality according to Frankema is absolutely not persistent and there are definitely ways to close the gap between rich and poor. It would be wrong to assume that "things have always been this way" and can't change. The status quo can effectively be broken, Fraukema finds. One of the most effective strategies to do so consists of stressing development over redistribution. Land reform is key to a successful poverty alleviation concept across the continent. Fraukema will defend his thesis on 6 March 2008 at the University of Groningen.

The analysis is important for those involved in the bioenergy sector in Latin America - a region with a large potential - because in ultimo, biofuels and biomass are agricultural commodities the production of which is intertwined with a large set of social and land ownership issues. Biofuels offer a major opportunity for development, but only if these social issues are addressed in-depth. The sector could become a catalyst for social change and justice, by putting land reform high on the agenda. On the other hand, it could just as well strengthen "the continuation of colonisation by other means", and worsen the existing conditions of inequality.

Frankema compares the income and possessions inequality in Latin American countries in the period from 1870 to 2000 in his thesis. With the help of historical-comparative and economic-qualitative methods, he demonstrates that the inequality in this period varied and thus disposes of the idea that the current income inequalities in Latin America are determined by the colonial past. Frankema: ‘It’s definitely not as is often claimed in the literature; it was so, it is so and it will always be so.’

Colonial roots
According to Frankema, although the political climate has the most influence on income differences, the roots of the income and possession inequality lie in the colonial past. Ethnic discrimination of Indian/African groups by descendents of the white colonists, and the associated unfair distribution of land, are remnants of the colonial time. One of the consequences of this inequality is poor education facilities for the poor, because the elite sends its children to private schools and has little interest in a good public education system. Without good education possibilities for the poor, social mobility in Latin America will remain limited.

Frankema in particular focuses on land issues, as former European colonies have a large and lucrative agricultural potential and large rural populations. Current land ownership structures too are strongly marked by colonial history, but in Latin America in particular, a post-colonial elite emerged that dominates agriculture until this very day:

Given the large weight of the rural sector in low developed countries, one would expect that the relation between land and income inequality would be strongest in Sub Saharan African countries. The empirical analysis [...] points out the opposite however. This surprising conclusion reveals an important difference between the colonial heritage of West and Central Africa versus Latin America.

Both regions are characterised by abundant endowments of land suitable to the production of cash crops. In Latin America a powerful landowning elite developed under three centuries of colonial rule. During the first wave of globalisation in the last quarter of the 19th century this elite was able to consolidate and probably even enhance its position, as the agricultural export sector expanded. West and Central African income inequality in the second half of the 20th century is based on a systematic squeeze of the rural majority population in favour of a small predatory urban elite. This type of inequality is rooted in the weak protection of property rights in unstable independent “states without nations”. Both regions carry the burden of “disproportional” levels of economic inequality. Those in power want to hold on to what they have and feel threatened by demands for accountability. Yet, the incentives shaping the attitude and actions of the elites in both regions differ fundamentally.

A landowning elite not only derives income from rent extraction, but also from the accumulation of capital and investments in agricultural enterprise. If landowners see opportunities to defend their stakes in economic development and are able to negotiate credible and sustainable protection of property rights, they may be willing to lift their bans on institutional change and a transfer of power to other social groups. They may also allow for the development of an urban class of entrepreneurs competing for (scarce) sources of cheap labour.

If the stakes of the elite are primarily vested in the consolidation of a predatory bureaucracy, the economic and political position of the elite are maximal overlapping. In this context a transfer of power or the development of new sectors poses such a severe threat to the distributive status quo, that the elites are willing to bear the very high costs of violent repression and armed conflicts. - Doctorandus Ewaut Frankema

energy :: sustainability :: biomass :: bioenergy :: biofuels :: agriculture :: social justice :: colonialism :: globalisation :: land reform :: landless :: social inequality :: Latin America ::

Redistribution and economic decline
According to Frankema, social inequality is the leitmotif of Latin American politics. Both political and economic forces, both national and international, affect the extent of income inequality. Frankema makes clear that differences in income increased up to about 1920, then declined until in the 1970s they began to increase sharply again. In the period between 1920 and 1970, the increasing power of trades unions and left-wing political parties resulted in a redistribution:

The period after 1975 was a period of economic decline, caused by increasing international competition and a huge national debt. Frankema: ‘If factories have to close due to an economic crisis, it’s usually the poor who lose their jobs first. The inflation that struck Latin American countries hard in the 1980s also hit the poor the hardest. The rich with their money safely in Swiss bank accounts were not hit at all.’

Ending poverty
According to Frankema, poverty policy should be less about redistribution and more about development. If Latin American countries can put the past to rest by tackling ethnic discrimination and the inequality of land ownership, for example, then he thinks that it will be possible to tackle poverty issues in the region in a constructive way.

Frankema: ‘The redistribution of income via taxes is very nice in the short term, but is not effective enough in the long term. Before you can beat poverty in the long term you have to allow people to participate in the labour process, invest more in the quality of the public education system and ensure that the starting point for government policy is “equal opportunities for everyone”.’

Picture: child of a family of landless farmers in Brazil. The family has joined the Movimento Sem Terra (“The Landless Movement”), Latin America's largest social movement.

References:
Biopact: Income inequality in Latin America is not persistent - March 03, 2008.

Ewout Frankema, "The Colonial Origins of Inequality: Exploring the Causes and Consequences of Land Distribution" [*.pdf], Research Memorandum GD-81, Groningen Growth and Development Centre, July 2006.

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Researchers: large potential for sustainable cellulosic biofuels from softwood biomass in New Zealand

Biofuels generated from New Zealand-grown softwood feedstocks have been identified as a feasible, large scale option for meeting both the low-carbon transport vision of the Government’s 2007 Energy Strategy (NZES) and Biofuels Sales Obligation (BSO), say the authors of a report prepared for the New Zealand Lignocellulosic Bioethanol Initiative.

Results from a feasibility study have found that there are no significant technical or supply barriers to producing ethanol from New Zealand’s softwood feedstocks, despite previous concerns that it was technically too difficult and too expensive to utilise this resource.

These findings are the outcome of an international collaboration between New Zealand’s Crown Research Institutes Scion and AgResearch, New Zealand’s largest pulp and paper producer Carter Holt Harvey and US-based cellulosic ethanol and specialty enzyme development company Verenium Corporation.

The recently completed study into the development of biofuels for New Zealand evaluated the infrastructure, technology and economics of a transportation biofuel facility using New Zealand softwood plantation forests as feedstocks. It also considered opportunities to utilise existing infrastructure from the pulp and paper industry and Verenium’s proprietary enzymes to convert wood and wood residues into sugars which are then be fermented and refined into ethanol.

The study found there is both sufficient wood and wood residues available in New Zealand to supply a commercial-scale ethanol refinery, and a domestic market large enough to support it:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: ethanol :: cellulosic :: forestry :: New Zealand ::

Scion chief executive Dr Tom Richardson says that in contrast to recent concerns raised regarding the production of ethanol from food crops, the New Zealand study indicates biofuels produced from wood are a sustainable and environmentally beneficial option.

When this partnership was initially formed, we set out to explore options for using existing pulp and paper infrastructure to produce bioethanol from softwood resources. This is in contrast to the majority of international activity which is focused on using grains, sugarcane or grasses, which are often part of the world’s current food supply, or grown on land following deforestation. - Dr Tom Richardson

Softwood feedstocks are a resource that already exists here in abundance relative to our small population. We have some of the world’s largest man-made forests. If we were to introduce purpose-grown energy plantations on marginal lands we could increase that resource without placing pressure on land for food or crops, and alleviate concerns around deforestation while providing forest carbon sinks and other environmental benefits.

The results of the study provide a potential scenario where New Zealand’s entire vehicle fleet could run on nationally grown and manufactured wood-derived biofuels.

Carter Holt Harvey executive and project manager James Flexman says the next step is to refine the technical program, focus the research and development efforts further, and develop a collective strategy to make this opportunity a reality.

Having collectively invested nearly NZ$1 million to bring the study to this stage each of the partners is committed to seeing this opportunity progress which is fantastic as the potential for New Zealand is enormous. However, additional investment is now vital if the vision is to become a commercial reality. - James Flexman

Biofuels generated from softwood feedstocks actively addresses key aspects of the 2007 New Zealand Energy Strategy, a major focus of which is on transitioning New Zealand to a low-carbon energy future.

The New Zealand Government has established a Biofuels Sales Obligation (BSO) of 3.4% transport biofuels by 2012 and set a target to stabilise this country’s net greenhouse gas emissions to 1990 equivalent levels by 2030.

Due to the challenges in reducing carbon emitted from other contributing sources to New Zealand’s greenhouse gas emission profile, transportation fuels will need to be a major contributor to the overall reduction targets if the Government is to successfully meet its climate change objectives.

The logical strategy would be to establish a purpose built bioethanol plant that maximises the use of existing pulp and paper infrastructure without impacting on the mill’s current activity.

A facility located in the Central North Island producing 90 million litres of ethanol per annum could fulfil the petrol component of the government’s BSO by supplying a 10% ethanol gasoline blend (E10) to the North Island.

The bioethanol project’s U.S partner Verenium Corporation say they are enthusiastic about the future opportunities this research presents both here in New Zealand and globally.

Beyond New Zealand, Verenium is actively working to address some of the key challenges in biofuels production, including land use practices, sustainability demands, and economic drivers, says Geoff Hazlewood, senior vice president, research at Verenium.

AgResearch chief executive Dr Andrew West says the results of the study present New Zealand with an opportunity to become a pioneer in the technology of manufacturing bioethanol from lignocellulosics.

We believe bioethanol from plantation wood and wood residues presents an environmentally and commercially feasible opportunity here in New Zealand. - Dr Andrew West

Scion’s Tom Richardson says that by integrating industrial biotechnology with the effective utilisation of New Zealand’s forestry plantations and processing infrastructure, the forestry industry has the potential to support the New Zealand Government’s goal to be one of the world’s first carbon-neutral economies.

Carbon neutrality will only happen if technology, policy and industry work together closely in the manner that has been shown by the partners involved in this study.

Other supporting research has already been completed, adding further weight to the argument that New Zealand can provide renewable and sustainable energy alternatives from an environmentally beneficial resource, derived predominately from sustainably managed plantation forests, Richardson concludes.

Scion expects to release another report within the next month: Bioenergy Options for New Zealand, which outlines the volume of plantation forests that would be needed, and how they should be managed, for New Zealand to fuel itself from renewable resources.


Scion is a Crown Research Institute with a shared vision of developing sustainable biomaterials for future generations.

Formerly known as Forest Research, Scion is focused on applying a deep knowledge of plantation forestry, wood and fibre to the development of new biomaterials from renewable plant resources.

In 2003, the organisation launched a "Biomaterial Futures" strategy in response to a growing global demand for materials that can be used as an alternative to synthetic products. Scion is now focused on creating plant-based biomaterials and new manufacturing processes as a basis for sustaining the consumer markets of the future.

Scion continues to provide research and development services to the forestry sector through Ensis, a collaboration between Scion and Australia's CSIRO Forestry and Forest Products. Ensis has enabled the formation of large expert teams capable of tackling complex problems at a scale that will help the sector to remain globally competitive.

References:
Scion: Transport fuels from New Zealand biomass a reality - March 3, 2008.

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Chevron and Weyerhaeuser form biofuels joint venture

Chevron Corporation and forest products giant Weyerhaeuser Company have announced the creation of a 50-50 joint venture company focused on developing the next generation of renewable transportation fuels from nonfood sources.

The joint venture, Catchlight Energy LLC, will research and develop technology for converting cellulose-based biomass into economical, low-carbon biofuels. The formation of Catchlight Energy is the first milestone of a biofuels alliance announced by Chevron and Weyerhaeuser in April 2007 and reflects the companies’ shared view that nonfood biofuels will play an important role in diversifying the energy supply of the United States.

Michael Burnside of Chevron has been appointed chief executive officer of Catchlight. During his 33-year career with Chevron, Burnside has held a variety of positions in manufacturing, planning and analysis and finance, and has been involved with a number of joint ventures. W. Densmore Hunter of Weyerhaeuser has been named Catchlight’s chief technology officer. Since joining Weyerhaeuser in 1980, Hunter has held key research, technology and manufacturing positions and currently leads the company’s biofuels and bioproducts research and development efforts.

Both Chevron and Weyerhaeuser will contribute resources - including funding, background technology and employees - to Catchlight Energy. Catchlight’s initial focus will be on developing and demonstrating novel technologies for converting cellulose and lignin from a variety of sources into biofuels:
energy :: sustainability :: biomass :: bioenergy :: biofuels :: ethanol :: lignocellulose :: forestry :: wood ::

Both Chevron and Weyerhaeuser already have separate research partnerships under way to accelerate the development of cellulosic biofuels. Chevron has forged alliances with the Georgia Institute of Technology, the University of California at Davis, the Colorado Center for Biorefining and Biofuels, and the U.S. Department of Energy's National Renewable Energy Laboratory. Weyerhaeuser is collaborating with several research universities, national laboratories and technology-based companies in research on conversion of forest products into ethanol and other biofuels.

At Weyerhaeuser, we believe our timberlands hold solutions to important problems for people and the planet. Catchlight Energy represents an imaginative approach to releasing this potential as we work to develop a sustainable solution to the world's energy needs. - Miles Drake, senior vice president, Research and Development and chief technology officer for Weyerhaeuser

Catchlight Energy brings together two leaders in their industries and leverages their strengths – from feedstocks to fuel manufacturing to marketing – to create a sustainable, economic, nonfood biofuels business at commercial scale. - Mike Wirth, executive vice president, Global Downstream for Chevron

Chevron Corporation is one of the world’s leading integrated energy companies with subsidiaries that conduct business across the globe. It explores for, produces and transports crude oil and natural gas; refines, markets and distributes transportation fuels and other energy products and services; manufactures and sells petrochemical products; generates power and produces geothermal energy; and develops and commercializes the energy resources of the future, including biofuels and other renewables.

Weyerhaeuser Company, one of the world’s largest integrated forest products companies, was incorporated in 1900. In 2007, sales were $16.3 billion. It has offices or operations in 13 countries, with customers worldwide. Weyerhaeuser is principally engaged in the growing and harvesting of timber; the manufacture, distribution and sale of forest products; and real estate construction, development and related activities.

References:
Weyerhaeuser: Chevron and Weyerhaeuser form biofuels joint venture - February 29, 2008.

Weyerhaeuser: Chevron and Weyerhaeuser create biofuels alliance - April 4, 2007.

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