Climate change is disrupting flower pollination, research shows

http://www.theguardian.com/environment/2014/nov/06/climate-change-is-disrupting-flower-pollination-research-shows?CMP=share_btn_fb

Damian Carrington
Nov. 6, 2014

Sexual deceit, pressed flowers and Victorian bee collectors are combined in new scientific research which demonstrates for the first time that climate change threatens flower pollination, which underpins much of the world’s food production.

The work used museum records stretching back to 1848 to show that the early spider orchid and the miner bee on which it depends for reproduction have become increasingly out of sync as spring temperatures rise due to global warming.

The orchid resembles a female miner bee and exudes the same sex pheromone to seduce the male bee into “pseudocopulation” with the flower, an act which also achieves pollination. The orchids have evolved to flower at the same time as the bee emerges.

But while rising temperatures cause both the orchid and the bee to flower or fly earlier in the spring, the bees are affected much more, which leads to a mismatch.

“We have shown that plants and their pollinators show different responses to climate change and that warming will widen the timeline between bees and flowers emerging,” said Dr Karen Robbirt, at the Royal Botanic Gardens, Kew and the University of East Anglia (UEA). “If replicated in less specific systems, this could have severe implications for crop productivity.”

She said the research, published in Current Biology on Thursday, is “the first clear example, supported by long-term data, of the potential for climate change to disrupt critical [pollination] relationships between species.”

Three-quarters of all food crops rely on pollination, and bees and other pollinators have already suffered heavily in recent decades from disease, pesticide use and the widespread loss of the flowery habitats on which they feed. In the UK alone, the free fertilisation provided by pollinators is estimated to be worth £430m a year to farmers.

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Scientists have already identified a few timing mismatches caused by global warming between species and their prey. Oak tree buds are eaten by winter moths, whose caterpillars are in turn fed by great tits to their chicks, but the synchronicity of all these events has been disrupted.

Suspected mismatches have occurred between sea birds and fish, such as puffins and herring and guillemots and sand eels. The red admiral butterfly and the stinging nettle, one of its host plants, are also getting out of sync.

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