Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Wild bees and the flowers they pollinate are disappearing together

21.07.2006
The diversity of bees and of the flowers they pollinate, has declined significantly in Britain and the Netherlands over the last 25 years according to research led by the University of Leeds and published in Science this Friday (21 July 2006). The paper is the first evidence of a widespread decline in bee diversity.

Concerns have been raised for years about the loss of pollination services, but until recently most of the evidence has been restricted to a few key species or a few focal sites. To test for more general declines, an international team of researchers from three UK universities (Leeds, Reading and York) and from the Netherlands and Germany compiled biodiversity records for 100s of sites, and found that bee diversity fell in almost 80% of them. Many bee species are declining or have become extinct in the UK [for detailed examples, see the attached case studies].

Lead author, Dr Koos Biesmeijer from the University of Leeds said: “We were shocked by decline in plants as well as bees. If this pattern is replicated elsewhere, the ‘pollinator services’ we take for granted could be at risk. And with it the future for the plants we enjoy in our countryside.”

Pollinators are essential for the reproduction of many wild flowers and crops. Co-author Simon Potts (of the University of Reading) said: “The economic value of pollination worldwide is thought to be between £20 and 50 billion each year.”

The team examined pollinator and plant data, collected by professional and volunteer researchers and naturalists in Britain and the Netherlands, comparing records from before and after 1980. The results showed bee diversity had declined consistently in both countries, whereas the diversity of hoverflies (another group of pollinating insects) stayed roughly constant in Britain, but increased in the Netherlands.

Loss of bee diversity in itself might not be too worrying, so long as other surviving insect pollinators are similar, and capable of pollinating the same flower species. However, this is not the case. The research found for both bees and hoverflies, the “winners” and “losers” were consistently different; insects which pollinate a limited range of flower species or which have specialised habitat needs were most often lost. Overall, a small number of common generalist pollinators are replacing a larger number of rarer specialist species.

Stuart Roberts from the University of Reading pointed out: “In Britain, pollinator species that were relatively rare in the past have tended to become rarer still, while the commoner species have become even more plentiful. Even in insects, the rich get richer and the poor get poorer.”

There have been parallel shifts in the plant world, with the plants that depend on pollination by bees disappearing too.

Dr Bill Kunin, coordinator of the project at the University of Leeds explained: “We looked at plant changes as an afterthought, and were surprised to see how strong the trends were. When we contacted our Dutch colleagues, we found out that they had begun spotting similar shifts in their wildflowers as well.”

In Britain, where bee diversity has fallen and hoverflies have at best held steady, there have been declines in 70% of the wildflowers that require insects for pollination. However, wind-pollinated or self-pollinating plants have held constant or increased.

The pattern is slightly different in the Netherlands, where bees have declined on average but hoverfly diversity has increased. In that country there has been a decline in plants that specifically require bees for pollination, but not in plants that can make use of other insect pollinators. Thus the plant declines closely mirror those of the pollinators.

This difference between the countries suggests the declines in pollinators and plants are causally linked. Researcher Dr Ralf Ohlemüller from the University of York explained: “The parallel declines of wildflowers and their pollinators seem too strong to be a coincidence.”

The research can’t tell us whether the bee declines are causing the plant declines, or vice versa, or indeed whether the two are locked in a vicious cycle in which each is affecting the other. It’s also not clear as of yet what the ultimate causes of the declines are, although land use change, agricultural chemicals and climate change may be important factors. The researchers hope to clarify these issues with follow-up studies.

Dr Biesmeijer said: “Whatever the cause, the study provides a worrying suggestion that declines in some species may trigger a cascade of local extinctions amongst other associated species.”

The research may not yet prove a global decline in pollination, but in two countries at least there is strong evidence that both wild pollinators and the wildflowers that they visit are in serious trouble.

Examples of bees and the flowers they visit are in Notes to editors. Photos of the bees are available from the University of Leeds press office on +44 (0)113 343 4100 or email h.e.b.love@leeds.ac.uk

For more information, contact:

Koos Biesmeijer
University of Leeds, j.c.biesmeijer@leeds.ac.uk, Tel: 0113-3432837 (work), 0113-2263507 (home), 07979287867 (mobile). - Lead author with good overview of all aspects of the study
Stuart Roberts
University of Reading and Bees Wasps, and Ants Recording Scheme, s.p.m.roberts@reading.ac.uk , eucera@yahoo.com , Tel: 0172 2320072 (home), 0118 378 8964 (work) 0779 947 2746 (mobile). - Wild bee ecology and conservation in UK and throughout Europe
Mike Edwards
Hymettus Ltd., the Aculeate Conservation Group, ammophila@macace.net, Tel: 01730 810482 Wild bee ecology and conservation in UK
Bill Kunin
University of Leeds, w.e.kunin@leeds.ac.uk, Tel: 0113 3432837 (work) 0113 266 2891 (home); 0787 563 7334 (mobile) - Team leader; Plant ecology, pollination, and landscape ecology
Simon Potts
University of Reading, s.g.potts@reading.ac.uk, 0118 378 6154 (work), 0790 9977 618 (mobile). – Plant-pollinator interactions, economic value of pollination.

Hannah Love | alfa
Further information:
http://www.leeds.ac.uk

More articles from Ecology, The Environment and Conservation:

nachricht Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Tracking movement of immune cells identifies key first steps in inflammatory arthritis

23.01.2017 | Health and Medicine

Electrocatalysis can advance green transition

23.01.2017 | Physics and Astronomy

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>