Caring for Pollinators - Bundesamt für Naturschutz

Ssymank, Hamm, Vischer-Leopold & Wittmann Introduction
1 Introduction
by A. Ssymank, A. Hamm, M. Vischer-Leopold & D. Wittmann
Pollination is a key function in all terrestrial ecosystems, interlinking the fate of plants and
animals. Pollinating animals are themselves a major part of the biodiversity worldwide, they
are safeguarding plant biodiversity and indirectly all the animals depending on fruits or
leaves of animal pollinated plants for their food. A world without pollination is beyond imagination
and would have lost all its richness and most of its vegetation. Pollination services
cannot just be replaced by humans, are extremely valuable and are a precondition for or
affecting an estimated 35% of the world’s crop production, increasing outputs of 87 of the
leading food crops (FAO 2008). The total economic value of pollination services worldwide is
estimated to €153 billion, with vegetables, fruits (see fruit buffet, p. 121 as the leading crop
categories in value of insect pollination (Gallai et al. 2008).
There is direct and indirect evidence of pollinators decline worldwide in different regions,
which is likely to impact production of fruits and vegetables and to accelerate the loss of species
diversity. This is particularly important in highly modified agricultural landscapes, where
pollinators are most needed for food production and crop security.
Animal pollination is wide-spread among plant species (estimated 85 % of all plants) with
probably close to 300,000 flower visiting animal species worldwide (Nabham & Buchmann
1997). Pollen limited fecundity in wild plants is frequent and pollen transfer by animal is vital
for the biodiversity of all terrestrial ecosystems. For example many of the beautiful tropical
cacti (for example Pachycereus pringlei) are bat-pollinated, many ornamental plants with
large red or orange flowers are bird pollinated. However the large majority of plants are insect-pollinated:
wasps, beetles and butterflies visit flowers. Especially the bees and the true
flies are the main pollinator groups worldwide (see fact sheets of pollinator groups, p. 148).
They transfer the pollen between different flowers while using plant resources and ensure or
enlarge the reproduction success of cultivated and wild plants.
Bees were called “testimonies of the golden days” by Virgil, the Roman writer Publius Vergilius,
70-19 BC. In his book “Georgica” (about Agriculture), Virgil displayed no knowledge on
where nectar comes from. He thought that honey ‘drops from the sky as tears of Narcissus’.
He also had no notion of pollination by wind or by animals. Only as late as the 18th century
did such facts emerge, recorded by a school teacher and naturalist living in the small German
town of Jena. Christian Konrad Sprengel observed that in the fields and woods around
his home several insects, especially bees, transport pollen grains and deposit them on the
stigma of a flower. In a series of careful experiments he discovered that those pollen grains
are essential for the production of fruits and seeds. He published his results in the book “The
Discovered Secret of Nature in the Morphology and Fertilisation of Flowers”, in 1793. This
should have been a breakthrough for science. Instead, Wolfgang von Goethe, celebrated
writer of “Metamorphis of Plants” and well known nature scientist condemned Sprengel’s
findings. The non-scientific argument he gave was that such a wonderful creation as a flower
could not possibly depend for its reproduction on such an ugly creature as an insect.
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