Early Vegetation Growth is Not Linked to Global Warming

[stephenprudence]

I see in the papers every year the same old headlines "early flowering a sign of global warming"

Rubbish!!

Right now we are in possibly the coldest (but driest) start to December I've known for a while, and as a result you would expect death, tranquility and nothing stirring the air.. as a matter of fact this could not be more incorrect. It seems to relatively sunny, cold weather has promoted the early flowering of Cherry Blossom, and even the early stage budding of young leaves on trees, this is something I've never seen before and certainly is not to do with warming.

So the conclusion is next time that the papers say the early flowering has been caused by global warming, it's likely the press are giving the runaround, because actually it seems the dry, and sunny weather, and possibly cold, have promoted early growth of blossom and young leafing of trees.

[Guy]

Stephen, I suspect that the huge array of biological markers of climate change can't so easily be classified. The 17 day increase in the growing season over the past 20 years and the earlier flowering of natural spring flowers that have been documented for 200 years is hard to dismiss.

I know that I now make the last cut of my lawn in December, whereas it used to be in early November 20 years ago. I know that the leaves used to be all off the trees and cleared up by Nov 5th, whereas now its at least 3 weeks later. Similarly Blue tit babies starve because they are nesting too early for the insect life. The list is fairly endless.

[stephenprudence]

Indeed Guy, I'm aware there are so many different types of blossom which react different conditions, and vegetation what does react to warmth. My post was more about lambasting the press over their sensationalist headlines. There are indeed plants that do react to changing temperatures, but its just not long ago I think it was either the Sun or the Mirror ran an article on how Daffodils were out earlier due to warming, and today I saw 1st stage cherry blossom (the stuff that normally flowers in January) as well as Camellias and Oak buds, which are now trying to come into leaf (despite just losing them), in what is the coldest start to winter I've ever known, yet the sunniest start to winter I've known.

I read a while ago, that a family of Camellias were struggling through the winter in Chicago, and because it was getting so cold in winter they were flowering in October, insteasd of their normal range which is January to March. When they got transported to Ness Gardens here on Wirral they were flowering in January which is the normal time for them to start flowering. It was said by a scientist in Chicago that the earlier flowering of the Camellia was due to it being colder than normal, and they had flower in order to pollinate before it became to cold. This therefore is linked the the early flowering of 'stage 1' winter flowers now (the earliest flowers), I think the flowers have been tricked into thinking a cold winter on it's way and so they are getting it done now, rather than in early Spring.

This also may go to explain the early flowering over the last few years, because there has been a constantly mild January, followed by a colder Spring.

[Dave Brown]

Stephen I don't think a lot of that stands up to scruteny really. We force spring bulbs into flower all year by cooling them off for 6 to 8 weeks than bringing them into the warm. Also many plants may be fooled by a very dull period followed by a sunny spell. I certainly would not believe January plants flower early because the PREDICT a cold winter. What would normally happen is flowering would be delayed until the weather warmed up enough.

Spring 2006 was a classic example. As the winter went on into february and March, being at average January figures, April saw an expolsion of colour as all spring flowers from Snowdrops, Crocuses, Tulips Daffadils ext all flowered at the same time.

[stephenprudence]

Dave. I wasnt suggesting that plants could predict the forthcoming winter but what I was suggesting that they react the changes in certain conditions (ie real time/now), ie The cold and the sun may have mirrored conditions they are used to in late January (when it is colder) rather than early December which may have caused them to flower ealier.

My post (of which the title was orginally a ironic satire of newspaper headlines) was just basically refuting that the likes a daffodils, and cherry blossom was moving forward due to global warming, based on experience which I have gained recently especially with the recent weather being much colder than the last few winter starts.

I for one am a firm believe that a gradual warming is happening, due to man-made emissions, however I do not subscribe to the press theories on native flowering spring bulbs changing due to 'global warming'

[Guy]

Records have been kept for over 200 years through naturalist's diaries about the flowering dates of common native flowers eg primroses. They have moved forward, which is where the extra 17 days of growing season figure comes from. Also why I have to still cut my lawn in early December now It's probably all those lawnmowers that are causing the gobal warming