Saturday, March 10, 2012

Heavy Metal Pollution Causes Severe Declines in Wild Bees

We think that pollution affects only us and also think that getting out of its way is good enough in a pinch.  Yet agriculture can not do this.  What is more, agriculture depends on wild bees far more than the convenient honey bee.

Again an integrated approach to farming needs to be pursued.  The best and traditional haven for wild bees was and is the fence row which has been allowed to run wild.  Large fields militate against this form of refugia to say nothing about the use of pesticides.

The clear take home is that we need to seriously consider the application of deliberate row planting of carefully chosen trees that is generally well spaced to allow ample sunlight.  It should also be a natural source of fertilizer also as with the acacia in Africa.   Pasture land in particular should get this treatment.

My point is that a twenty foot wide band or even much less, eliminates less that ten percent of the available acreage even if it is allowed to run completely wild in an unproductive manner.  The key though is in the spacing of the trees themselves so that they may grow to be quite large.  The row itself could even be largely encroached upon so long as ample brush and wild plantings remain.

The future of agriculture will see the general acceptance of organic methods as well as biochar and this type of refugia based field management with little if any reduction in general productivity.  In fact it is likely to lead to a huge improvement in productivity with little effort applied once fully established.

Heavy metal pollution causes severe declines in wild bees

by Staff Writers

Washington DC (SPX) Mar 07, 2012

A red mason bee female feeds on ragged robin. Credit: Hajnalka Szentgyorgyi 

Wild bees are important pollinators and numerous studies dealing with pollination of wild plants and crops underline their vital role in ecosystems functioning.

While honey bees can be easily transported to various location when needed, wild bees' presence is dependent on the availability of high quality semi-natural habitats.

Some crops, such as apples and cherries, and many wild flowers are more effectively pollinated by wild bees and other insects rather than managed honey bees.

Although heavy metal pollution is recognized to be a problem affecting large parts of the European Union, studies giving insights into their effect on wild bees are scarce.

Researchers from Poland and the UK have conducted a study showing a decline in wild bee communities caused by heavy metal pollution. The experiment was carried out on a number of contaminated sites along gradients of heavy metal pollution from smelters in Poland and UK.

The results clearly show that the most polluted sites had no, or only single wild bees, in artificial nests, whereas in unpolluted sites, the same nests contained 4 to 5 different species of wild bees, with up to ten individuals.

Moreover, the proportion of dead bees increased with the level of heavy metal pollution, rising 20% in uncontaminated sites to 50% in sites with a high contamination. These findings highlight the negative impact of heavy metal pollution on the population of wild bees.

These results highlight the need for the careful restoration of polluted areas, ensuring that flowering vegetation does not expose wild pollinators to unnecessary risks from heavy metals.

The study was published in the Journal of Applied Ecology and was provided within the frame of the FP7 project STEP - 'Status and Trends of European Pollinators'. Original publication: Moron, D., Grzes, I. M., Skorka, P., Szentgyorgyi, H., Laskowski, R., Potts, S. G. and Woyciechowski, M. (2012), Abundance and diversity of wild bees along gradients of heavy metal pollution. Journal of Applied Ecology, 49: 118-125. doi: 10.1111/j.1365-2664.2011.02079.x

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