Buds Ahoy!

These posters are available as downloads and as prints in my online shop microscosmic.shop


Leaves of British Trees

Buds of British Trees

Bark of British Trees

A Hawthorn bud, bursting over the course of two weeks

Sycamore from bud to budburst. The stem of the bud begins to elongate and the bud scales are pushed apart. The leaves unfold and spread out their surface, as the stem grows in length.  The bud scales curl back and then after a few weeks fall off. The chlorophyll in the leaves develops fully on exposure to light, then photosynthesis begins. The leaves are available almost at once having already formed in the bud.

If buds are an arboreal version of a bird’s egg, then the miniature shoots are the chicks encased in eggshells.  All over patch these embryonic shoots are breaking out.

It’s one big beautiful budburst!

The explosion of fresh green foliage is a such a notable feature of springtime that it’s easy to forget that the buds were products of the previous year’s growing season.

Trees have come up with a clever strategy. As soon as the days start of lengthen, and temperatures rise, conditions for photosynthesising to return  - so  ‘hit the photosynthetic ground running’ – have leaves ready and waiting to burst into the sunlight.

A dissected sycamore bud with extracted leaf. The stem of these condensed shoots is very short and its leaves are packed so tightly that they overlap, each one wrapping round the next above it. The inner leaves are folded and crinkled so that large surface area can be packed into a small space.

The buds scales are the outermost leaves which are thicker and tougher and often a darker colour. Scales protect the delicate inner foliage leaves against predation, disease and drying up.

So the buds were produced during the abundance of the previous summer. Inside each of these buds are coming year’s new shoots in miniature. They see out the harshness of winter in a dormant state waiting for the springtime return to favourable conditions.

A bud gallery

Ash

Alder

Beech

Silver Birch

Horse Chestnut

Dog Rose

Goat Willow

English Oak

Blackthorn

Budburst timing varies between species, elders and hawthorns have already broken out with a vengeance, oaks and ashes are still biding their time. It also varies from year to year with temperature playing a big role. For this reason budburst is a very useful indicator in phenology - the study of nature’s calendar – the timing of events in nature.

In the UK there are records of this kind going back to 1684. What these records show is that many springtime events (migrant bird arrival, butterfly emergence being others) are happening progressively earlier in response to warmer spring temperatures.

One study shows that horse chestnut has advanced by 12 days over the last three decades, oak 10 days and ash 6. So some species are responding more rapidly than others to a changing climate, this may well bestow a competitive advantage to the species which are the ‘early adopters’.

Many other species have to synchronise their life cycles with budburst - for example the insects that eat the fresh leaves, and the birds that they rely on them to feed their chicks. These species will need to be adapt very quickly to a changing world.

An elder shoot coming into leaf. The leaves at the end of  shoot emerge from terminal buds, they extend the length of the shoot. Further back are the lateral buds which make new branches.

Bud gallery 2

Cherry

Hazel

English Elm

Hawthorn

Hornbeam

Whitebeam

White Poplar

Lombardy Poplar

Elder

White Willow

Golden weeping willow

Goat Willow (leaf bud)

This is like those 'making of' bits at the end wildlife documentaries - that I usually turn off...only a fairly crap version. I took a photo every day for two weeks
...er...that's it.

Get this