蜜蜂减少與下降中的生物多樣性有關

蜜蜂减少與下降中的生物多樣性有關
Bee decline linked to falling biodiversity
Page last updated at 08:40 GMT, Wednesday, 20 January 2010
By Richard Black
Environment correspondent, BBC News website
The decline of honeybees seen in many countries may be caused by reduced plant diversity, research suggests.
在許多國家見到的蜜蜂數量下降，可能是由於植物多樣性的減少，研究顯示。
Bees fed pollen from a range of plants showed signs of having a healthier immune system than those eating pollen from a single type, scientists found.
蜜蜂從一範圍的植物餵花粉，顯示跡象比那些吃單一類型花粉的，擁有一個更健康的免疫系統，科學家們發現。


Before and after: entire colonies of bees have collapsed in the US



Writing in the journal Biology Letters, the French team says that bees need a fully functional immune system in order to sterilise food for the colony.

Other research has shown that bees and wild flowers are declining in step.
其他研究顯示，蜜蜂和野花數量正在同步下降。
Two years ago, scientists in the UK and The Netherlands reported that the diversity of bees and other insects was falling alongside the diversity of plants they fed on and pollinated.
兩年前，英國和荷蘭的科學家報告說，蜜蜂和其他昆蟲的多樣性正在下降，與它們吃的和授粉的植物的多樣性同降。
Now, Cedric Alaux and colleagues from the French National Institute for Agricultural Research (INRA) in Avignon have traced a possible link between the diversity of bee diets and the strength of their immune systems.

"We found that bees fed with a mix of five different pollens had higher levels of glucose oxidase compared to bees fed with pollen from one single type of flower, even if that single flower had a higher protein content," he told BBC News.

Bees make glucose oxidase (GOX) to preserve honey and food for larvae against infestation by microbes - which protects the hive against disease.

"So that would mean they have better antiseptic protection compared to other bees, and so would be more resistant to pathogen invasion," said Dr Alaux.

Bees fed the five-pollen diet also produced more fat than those eating only a single variety - again possibly indicating a more robust immune system, as the insects make anti-microbial chemicals in their fat bodies.
Other new research, from the University of Reading, suggests that bee numbers are falling twice as fast in the UK as in the rest of Europe.

Forage fall
With the commercial value of bees' pollination estimated at £200m per year in the UK and $14bn in the US, governments have recently started investing resources in finding out what is behind the decline.

In various countries it has been blamed on diseases such as Israeli Acute Paralysis Virus (IAPV), infestation with varroa mite, pesticide use, loss of genetic diversity among commercial bee populations, and the changing climate.



Varroa mite infestation could be made worse by lower bee immunity
The most spectacular losses have been seen in the US where entire colonies have been wiped out, leading to the term colony collapse disorder.

However, the exact cause has remained elusive.
A possible conclusion of the new research is that the insects need to eat a variety of proteins in order to synthesise their various chemical defences; without their varied diet, they are more open to disease.
David Aston, who chairs the British Beekeepers' Association technical committee, described the finding as "very interesting" - particularly as the diversity of food available to UK bees has declined.

"If you think about the amount of habitat destruction, the loss of biodiversity, that sort of thing, and the expansion of crops like oilseed rape, you've now got large areas of monoculture; and that's been a fairly major change in what pollinating insects can forage for."

As a consequence, he said, bees often do better in urban areas than in the countryside, because city parks and gardens contain a higher diversity of plant life.

Diverse message
While cautioning that laboratory research alone cannot prove the case, Dr Alaux said the finding tied in well with what is happening in the US.
There, collapse has been seen in hives that are transported around the country to pollinate commercially important crops.

"They move them for example to [a plantation of] almond trees, and there's just one pollen," he said.

"So it might be possible that the immune system is weakened... compared to wild bees that are much more diverse in what they eat."

In the US, the problem may have been compounded by loss of genetic diversity among the bees themselves.
In the UK, where farmers are already rewarded financially for implementing wildlife-friendly measures, Dr Aston thinks there is some scope for turning the trend and giving some diversity back to the foraging bees.

"I'd like to see much greater awareness among land managers such as farmers about managing hedgerows in a more sympathetic way - hedgerows are a resource that's much neglected," he said.

"That makes landscapes much more attractive as well, so it's a win-win situation."
The French government has just announced a project to sow nectar-bearing flowers by roadsides in an attempt to stem honeybee decline.
Richard.Black-INTERNET@bbc.co.uk

http://news.bbc.co.uk/2/hi/science/nature/8467746.stm


蜜蜂和花卉同步減少
Bees and flowers decline in step
Last Updated: Thursday, 20 July 2006, 23:06 GMT 00:06 UK
By Richard Black
Environment correspondent, BBC News website


Diversity in bees and wild flowers is declining together, at least in Britain and the Netherlands, research shows.
蜜蜂和野花的多樣性一齊下降，至少在英國和荷蘭，研究顯示。
Scientists from the two countries examined records kept by enthusiasts dating back more than a century.
來自兩國的科學家，研究愛好者保存的紀錄，追溯至一個世紀前。
They write in the journal Science that habitat alterations, climate change and modern industrial farming are possible factors in the linked decline.
他們在科學雜誌上寫出，棲息地的改變，氣候變化及現代工業化的農業，都是相關下降的可能因素。
There is a chance, they say, that the decline in pollinating bees could have detrimental effects on food production.

"The economic value of pollination worldwide is thought to be between £20bn and £50bn ($37bn and $91bn) each year," said Simon Potts from the University of Reading, UK, one of the scientists involved.

While declines in Britain and the Netherlands might not indicate a global trend, the team says, it is an issue deserving serious future research.

Costs of specialism
Study leader Koos Biesmeijer from the UK's University of Leeds is not the first biologist to note the value of amateur enthusiasts to British conservation studies, and will not be the last.

"We have relied here on records kept by enthusiasts; just like bird-watchers keep records of bird-sightings, they keep records of bees and hoverflies and plants," he told the BBC News website.

"In the UK, insect records come from the Bees, Wasps and Ants Recording Society (BWars) and the Hoverfly Recording Scheme (HRS), while in Holland the Dutch Entomological Society does something similar.



The ultimate drivers are changes in our landscapes; intensive agriculture, extensive use of pesticides, drainage, nitrogen deposition


"The records go back even into the last part of the 19th Century, and then some of these enthusiasts have gone back into the scientific literature and verified records."

From these records comes a picture of reducing diversity among bees and wild flowering plants.
Bee species which rely on certain plants, and plants which rely on certain bees, have fared worse; more flexible species of both have done better.
In Britain, bee species which have increased since 1980 are those which were already common before.
The researchers also looked at hoverflies, and found a mixed picture, with diversity remaining roughly constant in Britain but appearing to increase marginally in the Netherlands.
Hoverflies do pollinate plants, but are less choosy than many bee species, and do not depend so directly on nectar to feed their young.
Overall, plants which pollinate via wind or water appear to be spreading, while those which rely on insects decline.

Holistic handling
If the diversity of bees and plants is decreasing, one question is: which declined first?
This study cannot provide an answer, though it appears the fates of both are intertwined; but the root causes of the decline are clear, Dr Biesmeijer argues.

"The ultimate drivers are changes in our landscapes; intensive agriculture, extensive use of pesticides, drainage, nitrogen deposition.

"All of these factors favour subsets of plants and subsets of bees.

"And if you want to prevent them you have to look at the ecosystem level, protecting the habitat and the groups of species."

Where habitats have been restored, for example under agro-environment schemes, bee and plant diversity has sometimes started to re-emerge, he said.
While such changes may have significant impacts nationally, the team points out that the environments of Britain and the Netherlands, with their high population densities and long histories of agriculture, contain two of the least "natural" landscapes on Earth.
Other countries, with a greater proportion of natural habitat, may not show the same declining trend, they say; but given the importance of bees for pollination, they suggest it would be worth finding out.
Richard.Black-INTERNET@bbc.co.uk

http://news.bbc.co.uk/2/hi/science/nature/5201218.stm
生物多樣性近住'不歸点'
Biodiversity nears 'point of no return'
Page last updated at 23:02 GMT, Sunday, 17 January 2010
The decline in the world's biodiversity is approaching a point of no return, warns Hilary Benn. In this week's Green Room, the UK's environment secretary urges the international community to seize the chance to act before it is too late.
世界上的生物多樣性正下降至走向一点不歸路，Benn警告說。在本週的綠廳，英國的環境大臣敦促國際社會在為時過晚前抓住機會採取行動。


"Much greater concerted effort is needed to stop the plunder of our ecosystems"

In 2002, the world's governments made a commitment to significantly reduce the rate of biodiversity loss by 2010.

Although it is hard to measure how much biodiversity we have, we do know these targets have not been met.
Our ecological footprint - what we take out of the planet - is now 1.3 times the biological capacity of the Earth.
In the words of Professor Bob Watson, Defra's chief scientific adviser and former chairman of the Intergovernmental Panel on Climate Change (IPCC), we are in danger of approaching "a point of no return".

So the action we take in the next couple of decades will determine whether the stable environment on which human civilisation has depended since the last Ice Age 10,000 years ago will continue.
To do this, we need to widen the nature of the debate about biodiversity. Flora and fauna matter for their own sake; they lift our spirits and nurture our souls.
But our ecosystems also sustain us and our economies - purifying our drinking water, producing our food and regulating our climate.
Climate change and biodiversity are inextricable linked. We ignore natural capital at our peril.


The number of species facing extinction continues to grow
Interdependence
The UK and Brazil are hosting a workshop in preparation for the next UN Convention on Biological Diversity (CBD).
Representatives from more than 60 countries - from the Maldives to China - will attend the three-day event to discuss how we can ensure that the post-2010 targets stand a better chance of being met than those set in 2002.The majority of those attending are from developing countries, including those with the rarest and greatest biodiversity. They need to be listened to.

It is easy to have principles when you can afford then - economics and ecology are interdependent.
So when it comes to biodiversity, we desperately need to start restoring links between science and policy, between taking action and evaluating it and between economies and ecosystems.
The big challenge will be for the real benefits of biodiversity and the hard costs of its loss to be included in our economic systems and markets.

Perverse subsidies and the lack of value attached to the services provided by ecosystems have been factors contributing to their loss. What we cannot cost, we don't value - until it has gone.

Investing in the future
Much greater concerted effort is needed to stop the plunder of our ecosystems.
Overfishing has reduced blue fin tuna numbers to 18% of what they were in the mid-1970s.

The burning of Indonesia's peat lands and forests for palm oil plantations generates 1.8bn tonnes of greenhouse gases a year, and demand is predicted to double by 2020 compared to 2000.
More than seven million hectares are lost worldwide to deforestation every single year.
The restoration of our ecosystems must be seen as a sensible and cost-effective investment in this planet's economic survival and growth.
I am optimistic. Talking about the danger of climate change has brought with it opportunities to tackle the biodiversity crisis.
While the 2010 targets have not been met, more than 160 countries now have national biodiversity action plans.

Mechanisms now exist for research, monitoring and scientific assessment of biodiversity, although we now need an Intergovernmental Panel on Biodiversity and Ecosystem Services to oversee progress in the same way the IPCC does for climate change.
One example of progress is the Brazilian Government's new target, which requires illegal deforestation to be cut by 80% by 2020.

Last year, deforestation rates in Brazil dropped by 45% against those of 2008, the largest fall since records began.
Other examples, closer to home, are the UK's Sites of Special Scientific Interest (SSSIs) - 89% are in a good or recovering condition.

Our ninth National Park, in the South Downs, was created last year and agri-environmental schemes are producing significant improvements in biodiversity.
2010 is the International Year of Biodiversity and later this year - in Nagoya, Japan - we will have the chance to halt the decline of our planet's biodiversity.

It is up to us to seize it.
Hilary Benn is the UK Secretary of State for Environment, Food and Rural Affairs

The Green Room is a series of opinion articles on environmental topics running weekly on the BBC News website

http://news.bbc.co.uk/2/hi/science/nature/8461727.stm

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