Autumn Leaves

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The leaves are changing colour. 
As a treat I am adding a clip of that all time jazz classic :"Autumn Leaves" to put you in the mood. Eric Clapton doesn't do a bad job of it. Autumn Leaves
Deciduous trees do better without their leaves in winter. Broad leaves would lead to too much water loss and would present too much surface area to a gale that might blow the tree over so they lose their leaves in winter.
I was curious as to why some years give a better display of colours than others and so I have done a bit of research on the mechanism and thought others people might be interested too. Here goes !
Leaves usually appear green because plants manufacture chlorophyl that is green and is an essential part of the process of photosynthesis whereby plants use sunlight to make food. The Chlorophyl masks the underlying leaf colour which is usually yellow  (because of carotenes) or red (because of anthocyanin). In the autumn when light levels fall there is insufficient light for the plant to make food and the low temperatures kill off the chlorophyll and the underlying leaf colour becomes apparent. 

Cold nights destroy chlorophyll but if temperatures stay above freezing anthocyanin production increases and the leaves look redder.  Dry weather concentrates sugars which will also lead to more anthocyanin production and a redder colour.The situation has many variables. If there is a frost then the leaves die and turn brown. If it is a sunny autumn the leaves might stay green longer and go straight to brown if there is a frost. If we are unlucky all the colourful leaves blow off in the first autumn gale.
Having written all that I found this video by the woodland trust that does a much better job than me!
woodland trust

Diary
Nothing but rabbits on the camera traps. Daytime temps today at a max of 10C.

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