http://news.bbc.co.uk/1/hi/sci/tech/3502476.stm

Climate risk to UK apple orchards

By Alex Kirby
BBC News Online environment correspondent

The landscape of much of the southern UK will be altered for ever by climate
change, a gardening expert believes.
Dr Simon Thornton-Wood of the Royal Horticultural Society told BBC News
Online orchards would vanish, and some fruit varieties would no longer
thrive.
But as they move northwards, he thinks, peaches and other fruit from
southern Europe may move in and replace them.
He says he also expects "significant" drops in yields of several summer
fruit like pears, cherries and blackcurrants.
Too warm to fruit
Speaking before the RHS Science Exchange Dr Thornton-Wood, the society's
head of science, said the UK Climate Impacts Programme showed there would be
some frost-free winters during this century.

Orchards are likely to move north
Warmer winters would fail to provide the chill that some plants need if they
are to produce flowers and fruit.
Dr Thornton-Wood said: "We've lost a lot of orchards in the UK, but apples
are still an important crop.
"I think the climate will mean it becomes harder to get a decent crop in the
south of England, and apples may head north to find a cooler place to grow.
"Other fruit crops will be affected too, but I imagine it will be easier to
grow crops like peaches instead. It'll be a matter of swings and
roundabouts.
"Our members are becoming more aware. In these last few years we've seen
some quite significant variations in what people regard as the norm.
"We're getting many more queries now about waterlogging, and last year about
drought as well."
Usurped by aliens
A study on the possible implications for commercial fruit growers of warmer
winters has been commissioned by the Department for Environment, Food and
Rural Affairs.
The RHS is giving priority to two other climate-related problems which it
says are of particular interest to gardeners:
The need to find ways to offset the effects of winter flooding on what are
known as "Mediterranean" plants, which will thrive in hotter summers
The possibility that climate change may encourage some exotic weeds to
become problematic invaders.
Dr Thornton-Wood told BBC News Online: "Giant hogweed has already gone
haywire, and we think other invaders may do the same.
Inevitable upset
"Japanese knotweed is a problem, but we don't really know where the next
crisis will come from, so we're calling on gardeners to be observant.

"You never know how species like these are going to affect the ecology of
the British countryside, but they always do. They out-compete the native
fauna and flora and change what has become familiar."
The RHS Science Exchange, being held at the Darwin Centre in the Natural
History Museum in London on 16 March, brings together leading horticultural
scientists to discuss the future of gardening in the 21st Century.
Gardeners can attend the Exchange itself or participate online, either by
sending questions in advance or by a live webcast from the Darwin Centre's
website.