Positive link between High Nature Value farmland and bird biodiversity

kristy Earth Systems Science

Positive link between High Nature Value farmland and bird biodiversity

High Nature Value (HNV) farmland is agricultural land that supports biodiversity and can be identified by its environmentally sound farming practices. New research on bird biodiversity on French HNV farmland has concluded that conservation of HNV farmland is important as well as conserving areas that were previously HNV and have undergone recent agricultural intensification.

HNV farmland supports, or is associated with, either a high species and habitat diversity or the presence of species that are rare or endangered. Typical examples of HNV farmland are extensively grazed uplands, alpine meadows and pastures, and areas combining crops, trees and pasture (agro-silvo-pastoral areas) in Spain and Portugal (dehesas and montados). It can be identified with a score or index which assesses the use of environmentally sound practices such as minimum use of chemical pesticides and fertilisers, crop rotation and farmland structure in terms of presence of natural and semi-natural vegetation. Due to agricultural intensification there have been dramatic losses in HNV farmland.

The study was funded by the Joint Research Centre of the European Commission, Institute for Environment and Sustainability1 and investigated the relationship of bird biodiversity to the assignment of farmland as High Nature Value. It investigated the relationship between measures of bird biodiversity and past changes in HNV farmland in France within a 30-year period. Three farmland types were analysed: (1) land that has experienced intensified agriculture, (2) land with relatively recent history of agricultural intensification and (3) land with low-intensity agriculture identified as HNV. Across the three farmland types, researchers compared farmland bird species abundances as measured by the French Farmland Bird Index (FBI) and examined the composition of bird communities as measured by the community specialisation index (CSI) in relation to the HNV indicator.

According to the study, in 1970 there was over 21.3 million hectares of HNV farmland in France, compared to 6.9 million hectares in 2000. Between 2001 and 2008 there has been an increase in bird species abundance in both HNV farmland (9.9 % increase) and land that has only recently been intensively farmed (4.5 % increase). However on land that has historically been non-HNV there was a decrease in species abundance of 5.4%. The study analysed the effect of temporal changes in value (as measured by the HNV score) and community structure of species. In lands where the HNV score has been increasing i.e. there has been an improvement in environmentally sound practices and presence of semi-natural vegetation including landscape elements, there has also been an increase in birds that are habitat specialists, indicating that HNV farmland plays a role in supporting these specialist species. The opposite is true in lands where the HNV score has been decreasing and the community has become more dominated by habitat generalists.

This indicates that past and current HNV farmland positively affects the composition of bird communities. In areas that have recently lost their value due to agricultural intensification bird abundances were maintained at higher levels than in areas that have never reached the HNV status in the analysed period. The study suggests that in areas currently considered HNV farmland, conservation efforts should target the preservation of crop diversity and extensive farming practices that use less fertilisers. In farmlands of relatively recent agricultural intensification, conservation measures should focus on the preservation of landscape elements that may potentially buffer the effects of intensification for some bird species.

The results are positive as they suggest that, to some extent, it is possible to reverse biodiversity decline caused by agricultural intensification, if appropriate management actions take place in the near future. Benefits of HNV farmland could be maximised by identifying large-scale conservation areas or HNV farmland networks.

1. See http://ies.jrc.ec.europa.eu/

Source: Doxa A., Paracchini M.L., Pointereau P., Devictor V. & Jiguet F. (2012) Preventing biotic homogenization of farmland bird communities: The role of High Nature Value farmland. Agriculture, Ecosystems and Environment 148: 83–88

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Theme(s): Agriculture, Biodiversity

Fukushima’s effects on nuclear policy in Germany and the UK

The Fukushima accident in Japan has sparked international debate on nuclear energy. A new study has identified five factors which may have influenced the contrasting energy policy responses to the incident in the UK and Germany. Following the disaster, the UK is continuing to back nuclear power generation, whilst Germany is withdrawing support.

When disaster hit the Fukushima Daiichi nuclear plant following the Tohoku earthquake and tsunami in 2011, political debate on the future of nuclear energy came to the forefront worldwide. Interestingly, there were very different responses in EU Member States, illustrated by this study which compares reactions of the UK and Germany to the event.

In the UK, policymakers have stood firm on their decision to increase nuclear power generation, whereas in Germany, the federal government has decided to at least temporarily shut down older nuclear reactors and to re-evaluate the safety of all nuclear power facilities. As with all political responses, these decisions were not made in a contextual vacuum and the study identified five possible influences that are likely to have affected policymakers’ choices in these two countries.

Imminent Elections. Germany was set to have two regional elections only two weeks after the Japanese earthquake, which meant that national policy response would directly affect voter-popularity of the regional candidates. In the UK, there were no elections so there was no need to appease voters in the short-term.
Intensity of media reports. The Fukushima incident dominated German headlines for weeks and media reports provided in-depth scientific explanations. The public were therefore well informed on nuclear energy and able to demand greater transparency. In the UK, media reports were initially frequent but were soon eclipsed by reports on the conflict in Libya, which directly involved UK troops.
Trust in renewable energy innovation. Germany is an established leader in the technology and generation of renewable energy, creating new jobs, economic wealth and public support. With renewables as a viable player in the energy market, there is less dependence on nuclear energy than in the UK. The uptake and development of renewable energy in the UK has been much slower, and is still seen as high-cost, thus nuclear energy appears a more attractive option.
History of nuclear resistance. Germany has a stronger history of public resistance to nuclear energy and more organised activism than in the UK. Much of this has stemmed from its anti-nuclear weapons sentiment since the Second World War, whereas nuclear weapons are considered a necessary deterrent in the UK.
Perceived cultural proximity. Despite being geographically distant, Germany and Japan are culturally similar as they both rebuilt their infrastructure after the Second World War and are proud of their engineering prowess As such, Germany could have felt that, if the Fukushima accident could happen in Japan, a similar incident (although not triggered by earthquakes) could occur in Germany due to unforeseen failures in engineering and quality control. As the UK’s historical experience is not so similar to Japan, perhaps it could not conceive that a similar series of events could occur in the UK, focusing more on the earthquake than on the issues with engineering infrastructure.

It is clear that the Fukushima incident has affected public and policy reactions to nuclear energy and that this response varies from country to country. This has implications for energy companies working internationally. There are also lessons to be learnt for policymakers should similar environmental incidents occur in the future, specifically an awareness of the contextual factors that influence public and policy response.

Source: Wittneben, B.B.F. (2012) The impact of the Fukushima nuclear accident on European energy policy. Environmental Science & Policy. 15:1-3.

Contact: [email protected]

Theme(s): Climate change and energy

Bioengineered microbes turn seaweed into biofuels

Turning brown seaweed into biofuels is one option that has been proposed to help meet the world’s growing energy demands from renewable sources. Recent research has overcome a major barrier to converting the majority of sugars in seaweed into bioethanol and other valuable products by using genetically engineered bacteria to break down the seaweed.

Harvesting algae as a feedstock to produce biofuels could be part of a future mix of renewable energy sources. One type of algae suitable for this purpose, macroalgae (seaweed), grows naturally in the sea, which could help overcome the contentious issue of whether land should be used to grow crops for food or fuel – an issue that concerns biofuels produced from land-based crops, such as maize. Unlike many other biofuels, its cultivation requires no fertilisers or freshwater. An additional advantage of macroalgae is that it does not contain lignin, the stiff plant material found in land crops that require energy-intensive pre-treatment to break down the biomass before conversion to biofuels. Seaweed simply needs to be milled or crushed before fermentation.

However, industrial microorganisms that are commonly used in fermentation processes are not able to digest all of the sugars found in algae, in particular, the most abundant one, alginate. This means the process is inefficient and the full potential of seaweed to produce ethanol cannot be achieved.

This study describes how the researchers have bioengineered Escherichia coli, a common bacterium found in the human digestive system and used in the laboratory and industry, to digest all of the sugars found in seaweed, including alginate. The technique converts seaweed into ethanol or other useful chemicals in a single process. However, the study does not address environmental impacts of large scale application of the technology.

The researchers identified the genes in a marine microbe, Vibrio splendidus that are responsible for breaking down the complex sugars in seaweed into simpler sugars. These genes were inserted into samples of E. coli. The genetically modified E. coli strain was further engineered to turn the simple sugars into ethanol. The advantage of this bioengineering technique is that the genetically modified E. coli bacteria can also be engineered to turn the sugars into other valuable chemicals instead of ethanol.

Laboratory tests on the widely available brown kombu seaweed (Saccharina japonica) suggest the engineered strain of E. coli could achieve 80% of the theoretical maximum yield of ethanol at temperatures between 25°-30° C. The potential yield of ethanol from brown seaweed using this technique is twice that of sugarcane and five times that of maize.

Seaweed grows along the coastline in many parts of the world, and is already cultivated for food, but is not a staple crop. The researchers estimate that seaweed farms along 3% of the world’s coastlines could produce 60 billion gallons (about 227 billion litres) of ethanol a year, using this technique. It is unlikely any accidental release of engineered E. coli could damage seaweed growing in the sea, as the microbes are not suited to the ocean environment.

This preliminary research in the laboratory has demonstrated a new way to produce bioethanol using brown seaweed as the feedstock. The technique overcomes the limitations of using marine organisms to ferment seaweed under ordinary industrial conditions. Further work is being carried out to scale up the technology to commercial production. A pilot facility using aquafarmed seaweed is under development in Chile.

Source: Wargacki, A.J., Leonard, E., Win, M-N. et al. (2012) An Engineered Microbial Platform for Direct Biofuel Production from Brown Macroalgae. Science. 335: 308-313.. 15:1-3.

Contact: [email protected]

Theme(s): Biotechnology, Climate change and energy

Wind farms: new perspective needed to assess risks to birds

Risk assessments of potential bird mortality caused by planned wind farms should be assessed at the scale of the individual turbine rather than the whole farm, according to new research. It indicated that risk assessments made prior to building are not predicting the actual level of mortality when the farm is built.

Although most recorded collision rates of birds at wind farms are low, some poorly sited farms have caused higher mortality rates. In an attempt to prevent this, environmental authorities conduct environmental impact assessments (EIA) of proposed wind projects, which cover likely effects to the site’s bird population. These EIAs are conducted at the scale of the wind farm.

This study analysed the relationship between the risk prediction according to EIAs, and the actual recorded mortality of the birds for wind farms in Southern Spain after they became operational. Twenty wind farms (consisting of 252 turbines) were investigated in Andalusia, Spain near the Strait of Gibraltar, an important bird migration route. The EIAs for these wind farms included risk assessments of bird mortality from collision, which was calculated using two indices, both of which assumed that mortality risk is strongly dependent on abundance of birds.

The proposed wind farm locations were classified into three risk levels (1, 2 or 3) with 1 representing lowest risk and 3 representing highest risk. Most of the farms that finally obtained permission were at risk level 1, although some had a risk level of 2. Between 2005 and 2008, when the farms were operational, the actual bird mortality caused by collision with turbines was monitored on a daily basis. Using these data, the study calculated two mortality rates: total bird mortality across all species and mortality for just raptor (bird of prey) species.

The researchers conducted daily surveys of the number of dead birds found in the close vicinity of the turbines between 2005 and 2008. 596 dead birds were found in total for all the wind farms. Taking into account the amount of time the wind farms were operational (between 11 and 34 months), the (mean) average number of bird mortalities per turbine per year was estimated to be 1.33. This is one of the highest mean collision rates reported for all bird species. There were 214 raptor mortalities (36% of total mortality), the majority of which were griffon vultures (138 birds, 23% of total mortality).

This study found no significant relationship between EIA risk indices calculated and the actual recorded bird mortality when the turbine became operational. There was also no clear relationship between abundance of birds, in terms of observed birds per hour and bird collisions per turbine per year. The lack of a clear relationship could be partly due to gaps in data. Nonetheless, the study suggests it is too simplistic to assume a clear relationship between frequency of birds and mortality, and that the individual species and topography of the individual turbine should also be considered in EIA studies.

EIAs assess risk on the basis of local abundance of birds, but previous research has found that the probability of bird collisions with turbines also depends on species behaviour and wind currents, which are affected by topography and landscape. This suggests that environmental authorities may be using inadequate criteria to assess potential risk of wind farms to birds and there may be a need for a new or modified tool, conducted at the level of individual turbines.

Source: Ferrer, M., de Lucas, M., Janss, G.F.E. et al. (2012) Weak relationship between risk assessment studies and recorded mortality in wind farms. Journal of Applied Ecology. 49:38-46.

Contact: [email protected]

Theme(s):Biodiversity, Climate change and energy, Risk assessment

Ensuring bio-based plastics are truly sustainable

A new study has shed light on the sustainable credentials of bio-based plastics. It indicates that, as yet, no bio-based plastics are sustainable, owing to practices including pesticide use. However, this could change with further technological development.

Plastic is very useful, but there is increasing concern about its impact on the environment and human health. Two major sustainability concerns are: it relies on non-renewable resources, and it cannot degrade. Traditional plastics are manufactured using carbon from petroleum. Bio-based plastics are considered more sustainable because they use carbon from renewable resources, such as corn starch, soybean protein and cellulose. In some cases, they can be biodegradable.

The researchers assessed the existing evidence on the sustainability of bio-based plastics and conducted interviews with manufacturers of bio-based plastics that are commercially available or in development. Sustainability assessments were based on the materials’ environmental, health and safety impacts throughout their life cycle.

The study considered possible sustainability impacts to be those that arise from using GMOs and hazardous pesticides to cultivate the feedstock (e.g. corn, soy), the use of hazardous chemicals during production and processing, the use of harmful additives or untested materials for which health effects are not well known, potential hazards in workplaces, as well as efficiency in the use of resources including water, energy and materials. The study was limited as much information about commercial materials is not publicly available.

Although in some aspects bio-based plastics are more sustainable than traditional plastics, the analysis identified several environmental and occupational health and safety hazards in their production. Some bio-based plastics are preferable from a health and safety perspective; these include polyhydroxyalkanoates (PHAs), poly-lactic acid (PLA) and starch. However, they also have some potential hazards, for example, production of PHA may expose workers to chemicals that are possibly carcinogenic, and PLA production uses a tin-based chemical that could have toxic effects on the hormonal system. Some bio-based plastics are preferable from an environmental perspective, such as starch, PHA and soy protein. However, all bio-based plastics require land for production, which may compete with land needed for food. In addition the feedstock for bio-based plastics may be genetically modified or grown using toxic pesticides, which can pollute the environment.

Research is currently underway to develop a second generation of bio-based plastics from sources that do not compete with food production, for example, agricultural by-products including corn straw and algae. In addition, processing bio-based feedstocks to produce plastics requires significant amounts of energy and water, but since the processes are in their infancy and on a small-scale, they may become more efficient as they develop.

The study lists a number of recommendations for improving the sustainability of bio-based plastics. In terms of feedstock production, it suggests using agricultural or industrial by-products and sustainable agriculture methods to grow crops for bio-based plastics. In terms of plastic production, it suggests using materials that generate useful by-products, avoiding using any engineered nanoparticles for which risks are not well understood or for which the human health and environmental effects are not well known at present, as well using renewable energy and recycling water. Alongside this, the study recommends better education of consumers to encourage the use of more sustainable plastics, as well as work with governments to put in place the infrastructure needed to successfully compost and/or recycle bio-based plastics.

Source: Alvarez-Chavez, C.R., Edwards, S., Moure-Eraso, R. & Geiser, K. (2012) Sustainability of bio-based plastics: general comparative analysis and recommendations for improvement. Journal of Cleaner Production. 23:47-56.

Contact: [email protected]

Theme(s): Sustainable consumption and production

Microbes degrade oil from Deepwater Horizon spill

Marine microorganisms responded to the Deepwater Horizon oil spill by boosting the abundance of species capable of breaking down crude oil, according to new research. This method of ‘bioremediation’ could help manage crises in deep sea environments, where other clean-up methods are ineffective.

Nearly 5 million barrels of crude oil were spilled into the Gulf of Mexico following the Deepwater Horizon explosion in April 2010. Initially, most of the oil was found to be trapped in a deep sea plume at around 1000-1200m, but oil is now barely detectable at this depth. Scientists have therefore been uncertain as to the ultimate fate of the oil in the marine ecosystem.

In the new study, researchers used GeoChip-based metagenomic technologies (which comprises an array of gene probes that can be used to detect a large number of functional genes at one time) to test the hypothesis that the microbial communities living in the sea played an important part in degrading the oil and thus reducing the long-term effects on marine life. The scientists took eight seawater samples from within the plume and five samples from outside the plume, all between 1099-1219m deep. For each sample, they analysed the genes present in the microbial population using GeoChip and compared the results to the presence of benzene, toluene and other hydrocarbons found in crude oil.

The results revealed a dramatically different microbial community composition – the abundance of each species – in the plume samples compared to non-plume samples from the same depth. The difference was more closely linked to the concentration of different hydrocarbons than to temperature or to phosphate or iron, which microbes need to grow.

When the scientists looked at the DNA of the microbial species present, they found that genes responsible for breaking down potentially toxic constituents of oil, such as toluene and Poly Aromatic Hydrocarbons (PAH), were enriched in the plume samples compared to the non-plume samples. For example, they found 19-26 alk b genes – which oxidise alkanes – in the oil-contaminated samples compared to 11-15 in the non oil-contaminated samples. Genes responsible for the release of phosphate in seawater were higher in plume samples compared to non-plume samples, indicating enhanced microbial activity. Genes involved in generating methane, chemically reducing sulphate and assimilating iron from seawater – processes that are associated with microbial breakdown of hydrocarbons – were also up to ten times more abundant in the plume samples.

Some genes, particularly for breaking down PAHs, were found only in the plume samples while some other genes were found only in the non-plume samples. This suggests that the microbial community underwent a dramatic change in response to the oil spill, selecting against some resident species and favouring those that contained genes for hydrocarbon breakdown. This confirms previous research that microbes capable of hydrocarbon breakdown become dominant following an oil spill.

The full impact on the marine ecosystem in the Gulf of Mexico now needs to be further assessed by monitoring changes in the resident microbial community alongside chemical analysis of the seawater and other factors that may influence the ultimate fate of the oil, such as ocean currents.

The natural ‘bioremedial’ capability of resident microbial communities to mitigate the ecological impact of oil spills should help design appropriate emergency response measures to deal with incidents that occur in the deep sea, say the researchers. At such depths, current technology is unable to remove oil and gas directly and chemical dispersants are also ineffective.

Source: Source: Lu, Z., Deng, Y., Van Nostrand, J.D. et al. (2012). Microbial gene functions enriched in the Deepwater Horizon deep-sea oil plume. The ISME Journal. 6: 451-460.

Contact: [email protected]

Theme(s): Chemicals, Marine ecosystems