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
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 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
No comments:
Post a Comment