Climate Change Seen Pushing Plants to the Brink

By Jeremy Lovell
Reuters

Tuesday 12 September 2006

London - Thousands of plant species are being pushed to the brink of extinction by global warming, and those already at the extremes are in the greatest danger, a leading botanist said on Tuesday.

Paul Smith, head of Britain's Millennium Seed Bank, said the drylands of the world which cover 40 percent of the earth's surface and are home to more than one-third of the population faced the bleakest future.

"In the southern hemisphere the plants can either go up or south. But in South Africa's Cape they can't do either, so the 8,000 unique species of fijnbos (indigenous vegetation) there are a real worry," he told Reuters on a visit to London's Kew Gardens.

Smith's team is on target to have sorted and stored seeds from 10 percent of the world's plant species by 2010 in a race against time as global temperatures rise due to burning fossil fuels for transport and power.

"The trouble is that when we started collecting it was generally agreed that there were 242,000 plant species. But now some people believe it could be as high as 400,000.

"We really need to find out just what is out there before it has gone forever," he said, noting that on Robinson Crusoe island off Chile scientists found there had been eight extinctions in just the past decade.

But it is not just in the southern hemisphere that climate change is creating radical changes in the environment as warm weather expends steadily northwards, bringing with it new species and threatening the local vegetation.

In England not only had the climate already changed to favor drought-resistant Mediterranean plant and tree species, it had brought with it insect pests that were previously unknown there because they would not have survived the winter frosts.

Tony Kirkham, tree specialist at the world famous Royal Botanical Gardens at Kew in southwest London, noted that the Macedonian Leaf Miner moth had invaded in recent years and was attacking - and eventually killing - Horse Chestnut Trees.

While drought stress and pest attack was starting to cripple some indigenous species, dry climate trees like Eucalyptus from Australia, Turkish Hazel and the Sweetgum from the United States were finding the new growing climate very much to their liking.

Climate Change Minister Ian Pearson said scientists predicted that in Britain alone rainfall would have halved by 2080, with hotter, drier summers and warmer, wetter winters with frosts - essential to the natural cycle - a rarity.



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Climate Change Warning for a Nation of Gardeners
By Hilary Osborne
The Guardian Unlimited UK

Tuesday 12 September 2006

The quintessential English garden and lawn are "under threat" from climate change, a government minister warned today.

In a speech at Kew Gardens in west London, the environment minister, Ian Pearson, said in future gardeners would need to use water sparingly and choose Mediterranean plant species that could survive heatwaves and drought.

"Most gardeners in the UK will already know that changes have started. Some will have been struggling with serious drought during the last 18 months and all of us faced July's heatwave.

"If the majority of scientific opinion is right, and I think it is, these conditions will become commonplace in the future. They will put our gardeners in the front line of climate change," said Mr Pearson.

Mr Pearson said the UK was a nation of gardeners, with an estimated 27 million enthusiasts, and more than 27,000 parks, gardens and other landscapes of national, regional and local importance. Although attempts are being made to reduce climate change, Mr Pearson said the weather was likely to get warmer in the future.

"There's a time lag between when carbon is released into the atmosphere and when we feel its effects - so we've got the impact of the last 30-40 years worth of emissions still to come.

"It's like turning the thermostat up in your home - even though the boiler kicks-in immediately, it will take some time for temperatures to reach the new level," he said.

Mr Pearson said the growing season for plants was already a month longer than it was 100 years ago, and there had been changes in dates of leaf emergence, flowering, and appearance of many species of butterflies.

However gardeners would need to adapt further to changes caused by the heat, which could include more severe attacks from pests and disease and more extreme storms, causing plant damage and washing out soils.

The way plants respond to drought conditions, combined with increased temperatures, will be of most concern to gardeners.

Annual plants will often flower more rapidly in conditions of water stress and will subsequently set seed earlier. This will curtail the flowering season and they will wilt and die earlier.

"Gardeners need to think about drought-resistant bedding and perennial plants like marigolds, petunias or geraniums," the minister said.

Silver maple and black cherry trees could thrive in warmer weather, he said, while sycamore, yew and magnolia are resistant to storm damage.

"I should stress here that gardeners must avoid invasive species, species that squeeze native plants out of their habitat and thrive due to a lack of natural predators ... the quintessential English garden will have to adapt to our changing climate."

Mr Pearson's speech came as the Royal Botanic Gardens (RBG) at Kew announced its first policy statement on climate change.

RBG said it supported the view that we were experiencing global warming and action was needed to tackle climate change.

It said its interest lay in particular in areas of the world that predictions show to be most threatened by climate change, as they were often the countries with the richest and the most under-researched plant life.

In addition, said RBG, these areas included some of the poorest countries in the world, most dependent on their plants for food, and least able to take action for conservation.

The organisation said its plant scientists would continue to work to protect plants and plant habitats in other countries, with a focus on Sub-Saharan Africa, an area rich in biodiversity.

Next year's Summer Festival will be dedicated to the Mediterranean, focussing on plants that thrive in coastal areas with low water supplies, and in 2008 the organisation will increase efforts to promote public awareness and understanding of climate change.

RBG also published a study of flowering plants showing climate change was causing many species to flower earlier in the year.

Oak, rowan, box and cow parsley were all shown to be flowering nine to 15 days earlier than they did 20 years ago. Only the horse chestnut showed no change since the 1950s.

"This study does not prove climate change, but it does demonstrate the effect that milder winters and warmer summers are having on a range of plants at Kew. "It provides hard evidence to support more casual observations of staff," said Dr Nigel Taylor, head of horticulture and public education at Kew.

The environmental campaign group Friends of the Earth said there were lots of ways gardeners could help fight climate change.

As well as using a water butt to collect rainwater and composting waste instead of sending it to landfill sites, they could avoid energy draining items like patio heaters.

The group's director, Tony Juniper, said: "Gardeners can be green-minded as well as green-fingered by gardening in an environmentally-friendly way, and urging their MPs to back calls for a new law to tackle climate change."