Woodland Watch Week 22 – 14/08/2013

This week, we’re focusing on just one of the creatures that have made the woodland their home not just here in the Woodland Watch wood but all over the UK. I have seen many of these little mammals racing about in the coppice canopy and even more evidence of them all around the wood through the last few months. Have you worked out what we’re talking about yet?…Yep, you got it…The grey squirrel!

The Grey Squirrel

The Grey Squirrel

The grey squirrel (Sciurus vulgaris) is a familiar sight all over Britain, despite being a non-native, and most would argue, an invasive species. Grey squirrels were introduced from North America in 1876 by the Victorians who considered them an exotic species. Since then they have spread throughout most of the UK, almost completely displacing the native red squirrel .

Grey squirrels are not fussy eaters, which to a certain extent explains their displacement of their red counterparts. They are mainly herbivorous, eating predominantly acorns, hazelnuts, berries, fungi, bark, buds and shoots. However, on rare occasions when food is scarce they will also eat insects, smaller rodents, bird eggs and nestlings. Red squirrels have a similar diet, but they are unable to digest seeds with high tannin content, such as acorns, which limits the food sources. They are also able to make much better use of unripe acorns and hazelnuts and this is clearly visible in the woodland.

Unripe hazelnuts broken open by squirrels for food

Unripe hazelnuts broken open by squirrels for food

Although my iPhone camera has let me down again here, you can get the idea! The woodland floor is littered with unripe hazelnut shells which have been split open by squirrels enabling them to get to the nuts for food before other species are able to consume this resource.

The introduced grey squirrel has been so successful in displacing its native cousin partly because it is bigger and stronger, able to find more food and store more fat in its body for winter. This allows it to out-compete the red squirrel, which has lower survival and breeding rates. A second reason is the Parapoxvirus, which causes a fatal infection in red squirrels. Grey squirrels are not affected, but act as carriers, spreading the virus to red squirrels in the vicinity.

As well as the feeding signs around the woodland, there are also a lot of signs of squirrel damage to the trees. Grey squirrels strip bark around stems and branches of trees. Bark stripping damage usually starts at the end of April and continues until the end of July (early September in high-risk years). Grey squirrels do not strip bark at any other time of year. Trees may be stripped anywhere on the main stem and branches, with vigorously growing and dominant trees generally being most affected.

An example of squirrel damage in the wood

An example of squirrel damage in the wood

The Forestry Commission have produced a great publication all about grey squirrel damage in woodlands which can be viewed at:

http://www.forestry.gov.uk/pdf/fcpn004.pdf/$file/fcpn004.pdf

Now, it wouldn’t be one of my blogs if there wasn’t some mention of eating something, so if you’re a vegetarian, you might want to stop reading at this point! Squirrel arguably provides one of the most ethical meats you can eat in the UK. Completely free range, low in fat and as the countryside is overrun with squirrels and population control is often deemed necessary, why not eat them?

There’s a great recipe here for spanish braised squirrel:

http://www.wildmeat.co.uk/orderform.htm?ac=EZKF4-6

Spanish Braised Squirrel

Spanish Braised Squirrel

While the woods have a lot of signs of squirrels, they’re not causing any huge problems here and are likely to be left alone at least for the near future. However, across the wider countryside, there are many areas where squirrels are causing major problems to woodlands and population control is an ongoing options.

As an arboricultural company we see many examples of squirrel damaged trees and I can certainly appreciate the need for population control. However I also hate to see any creature being wasted, so if we’re going to control squirrel populations, why not eat them?

That’s it for this week. Join us next week for another walk in the woods as we’re heading closer and closer to autumn.

Until then, enjoy your own walks in the woods!

Treecreeper Arborists – http://www.tree-creeper.com

Woodland Watch Week 21 – 7/08/2013

Another week has gone by and we’re getting closer and closer to the end of summer. Keeping everything crossed for a late summer/early autumn heatwave as i’m just not ready for autumn yet!!!

So, what’s been going on in the woods this week? One of the creatures we haven’t touched upon yet is the butterflies, but the meadows around the wood and the wood itself have been swarming with all sorts of butterflies this year. The main reason I’ve not mentioned them is because try as I might to get a photograph of any of them, i’ve not been particularly successful! The iPhone is wonderfully portable and easy to take photos with but it’s not really set up for fleeting glimpses of fluttering butterflies taken from several metres away!

So, this photo was the best I managed to get and i’m sure you’ll agree it’s not a lot of help! It does lend itself to a good game of “spot the butterfly” though!

Butterfly in the meadow approaching the field which I can only describe as "little brown butterfly"!!!

Butterfly in the meadow approaching the field which I can only describe as “little brown butterfly”!!!

According to Butterfly Conservation, “three-quarters of British butterflies are in decline and many moths are also facing an uncertain future.The 56 species in Britain and Ireland are under threat today from unprecedented environmental change”.

It has been lovely to see so many butterflies around this year, but it is still worrying that they are decreasing so rapidly. So why are butterflies important besides the fact that the y look pretty fluttering around during the summer months? The butterfly conservation website has a great section on “Why Butterflies and Moths Matter” and i’ve pasted a short exert below:

Ecosystem value

  • Butterflies and moths are indicators of a healthy environment and healthy ecosystems.
  • They indicate a wide range of other invertebrates, which comprise over two-thirds of all species.
  • Areas rich in butterflies and moths are rich in other invertebrates. These collectively provide a wide range of environmental benefits, including pollination and natural pest control.
  • Moths and butterflies are an important element of the food chain and are prey for birds, bats and other insectivorous animals (for example, in Britain and Ireland, Blue Tits eat an estimated 50 billion moth caterpillars each year).
  • Butterflies and moths support a range of other predators and parasites, many of which are specific to individual species, or groups of species.
  • Butterflies have been widely used by ecologists as model organisms to study the impact of habitat loss and fragmentation, and climate change.

There’s also a great butterfly and moth identification tool on their website

http://butterfly-conservation.org/50/identify-a-butterfly.html

Last week we saw the conkers forming on the horse chestnut trees, this week we’re looking at the hazel for signs of autumn approaching. These hazel nuts are appearing fast on the coppiced hazel throughout the woodland and will ripen over the coming months.

Unripe hazel nuts

Unripe hazel nuts

Once ripe, these hazelnuts will fall out of the husk, which generally happens around 7-8 months after pollination. These nuts still have a way to go yet before they are ready to be harvested, but unfortunately not all species are as patient as we are as we’ll look at next week!

As you’ve probably noticed by now i’m a forager by nature! No walk in the countryside is complete without picking something to eat along the way! So, I couldn’t resist a few hazlenut recipes to get you thinking while the nuts ripen!

How about this amazing looking chocolate and hazelnut cake:

chocolate_and_hazelnut_38207_16x9

check out the recipe at http://www.bbc.co.uk/food/recipes/chocolate_and_hazelnut_38207

Or this gorgeous Italian hazelnut and chocolate torte:

torte

Recipe at http://www.bbcgoodfood.com/recipes/9727/italian-hazelnut-and-chocolate-torte

So, moving back to the woodlands and away from chocolate recipes that are making my tummy rumble! We’ll keep an eye on the hazelnuts over the autumn and watch them as they ripen ready to eat.

This week I had a bit of a closer look around the stems of some of the mature oak trees. Last week we looked at one of the trees with a lot of burrs, this week we’re going to take a look at another growth habit known as epicormic growth.

In many woody species, epicormic buds lie dormant underneath the bark , their growth  suppressed by hormones produced by active shoots higher up the tree. Under certain conditions, these dormant buds are activated resulting in epicormic growth as you can see here on the oak trees around the wood:

Epicormic shoots on the stem of one of the mature oak trees

Epicormic shoots on the stem of one of the mature oak trees

Epicormic shoots are the means by which trees regrow after operations such as pruning, or in the case of some species, pollarding/coppicing. This is why it is possible to cut some species back to just a trunk or even to ground level and the tree will re-shoot and continue to grow healthily. While a lot of species have epicormic buds, many others don’t such as many conifer species. This is why it is possible to pollard a willow and it will re-grow but if you carry out the same operation on a conifer it will not. Only species with strong epicormic growth abilities can be pruned in this way.

Continuing through the wood and out the other side into the neighbouring meadow I couldn’t help but stop for a look around the hedgerow. Native hedgerows are a forager’s heaven, often containing fruits, nuts and edible flowers all within easy reach for picking. Its easy to see why small mammals, birds and insects thrive in the hedgerow habitat and why it is so important that we conserve our native hedgerows.

My mind is already planning ahead to autumn recipes and where better to begin than the blackberry? The flowers of the blackberries came out earlier in the year and now in many places the fruits themselves are starting to form as tight little hard green berries.

Blackberry flowers and the beginnings of fruit production

Blackberry flowers and the beginnings of fruit production

Blackberries are perennial plants (living for more than 2 years) with biennial stems which grow from the perennial root system (taking 2 years to complete their life cycle. In the first year, the new stem grows vigorously to its full length of around 3-6m, generally trailing along thr ground or any other support structure it can find, bearing large palmate leaves.

In its second year, the cane does not grow any longer, but instead produces flowering lateral stems from the main stem which have smaller leaves. Both the stem and lateral shoots are covered in sharp prickles.

Canes can be trained when cultivated, however wild blackberries usually form a tangle of dense arching stems, with the branches rooting from the node tip on many species once they reach the ground. The flowers are produced in late spring and early summer with 5 white or pale pink petals. Drupelets then form around ovules that are fertilised by the male gamete from a pollen grain.

I’m looking forward to returning from my walk with a basket of blackberries in the autumn ready for jam and pudding making!

So, that’s it for another week and another walk in the woods. Apologies for the slight delay in getting these blogs written! Its such a busy time of year for tree surgeons and we’re just battling to keep on top of everything!

We hope you’re enjoying your walks in the woods and seeing everything continue to change as we approach the autumn.

See you next week!

Woodland Watch – Week 20 – 31/07/2013

Well, another week, another walk in the woods and I can’t believe that we’re seeing signs of autumn emerging already. It seems like only yesterday I was walking through the woods with thick frost underfoot and no signs of growth, then we came through the spring and everything slowly started to emerge and grow, heading into a massive growth spurt in late spring and early summer. Where does the time go?!

So, the first sign of autumn approaching emerged before I even entered the woodland. On my way to the wood I passed a young horse chestnut tree (Aesculus hippocastanum). The horse chestnut is a broadleaf, deciduous tree, commonly found in the British landscape but actually non-native to the British Isles. The familiar Aesculus hippocastanum is a native of the Balkans, and believed to have been introduced to Britain in the 1500s.

The species doesn’t make up a significant component of British woodlands except in a select few cases in Britain. Mainly found along strees and in parks and gardens, there are horse chestnuts to be found dotted as individual trees, either planted or self seeded, in many woodland areas. In this wood, there are several large, mature horse chestnut trees growing towards the south of the site.

Undoubtedly the most exciting thing about the horse chestnut, especially for children is its seed, known more commonly as conkers and you can start to see the developing conkers inside their green spiny shells on the trees right now.

Developing conkers

Developing conkers

The horse chestnut has become naturalised in the UK and many people would think of it as a native British tree. The wood tends to be rather weak, so has never been widely used for timber or wood products, although its absorbent properties do make it ideal for fruit racks and storage trays as it keeps the fruit dry, preventing rotting. Extracts from the leaves including aescin or aesculin are marketed as herbal remedies because of their anti-inflammatory properties and the trees also have wildlife value with the nuts providing food for deer and other mammals and the flowers providing pollen for insects.

From personal experience I can also recommend using the leaves if you’re caught camping or wild cooking without washing up facilities. The leaves provide a useful lather for scrubbing dirty plates which has helped me on many occasions after a wild cooked meal!

Unfortunately, more recently, horse chestnuts have been a cause for concern as people have watched the leaves turn brown long before autumn. As tree surgeons we have lost count of the number of conversations we have had with people asking what they can do about their “declining” horse chestnut trees.

Rather than re-inventing the wheel here, i’ll point you to a very good Forest Research article about the leaf miner which is affecting horse chestnut trees:

http://www.forestry.gov.uk/fr/infd-68jjrc

The trees in the woodland have not escaped this pest and are showing clear signs of infestation with the leaves starting to turn brown. Larvae of C. ohridella mine within the leaves of horse chestnut, and the damage caused by large numbers of larvae can be striking. Up to 700 leaf mines have been recorded on a single leaf under favourable conditions. Severely damaged leaves shrivel and turn brown by late summer and fall early, well before normal leaf fall in the autumn.

Signs of leaf miner infestation on horse chestnut leaves

Signs of leaf miner infestation on horse chestnut leaves

Now, on to a happier note and from childhood games we move on to hedgerow fruits! Autumn is a wonderful time of year for foraging in the woodlands and I can remember many happy childhood days collecting blackberries and sloes with my family and friends. Although we’re not into autumn yet and I certainly wouldn’t want to wish the remaining summer days away, the hedgerows are starting to burst with early signs of food production.

A common hedgerow tree which we have looked at earlier in the season is the elder. The flowers have now gone and turned to young berries, clearly visible in the hedgerows, still green and yet to ripen but promising a good crop in the autumn.

Elderberries starting to develop ready for autumn

Elderberries starting to develop ready for autumn

From elderberry liqueur to elderberry jelly, there are a great variety of things to do with this wonderful fruit. Mixing it with sweeter fruits like blackberries and making into autumn pies and crumbles brings back wonderful childhood memories! I’ll keep you posted on recipes over the autumn!

Now then, on to something a bit more scientific…Although there’s a lot of science in making elderberry liqueur! Last week we looked at the spores developing on the ferns around the woodland and I said I would look into sporogenesis! My understanding is still pretty limited, but we’ll take a brief look!

Sporogenesis is basically a long word which means “the production of spores”, although the terms is also used to refer to the process of reproduction via spores. Reproductive spores are formed in many eukaryotic organisms such as plants, algae and fungi. If you’ve ever brought home a piece of King Alfred’s Cake fungus and left it on top of the stereo (as I once did) you’ll know the mess the spores make as they spread all over the surface!

Fern spores

Fern spores

Spores are distributed in many ways including by wind and by water. Organisms such as the puffball fungi dramatically expel their spores into the surrounding environment in order to reproduce. In ferns, the spores are expelled at a microscopic level and can be viewed in this video:

http://www.youtube.com/watch?v=-xF83pHEx6Q

For those of you interested in some more of the science behind sporogenesis I came across this video which explained it to me! Although not exactly a cinematic masterpiece, it will give you the basics!

http://www.youtube.com/watch?v=c6JNu0Vra-4

Lastly for this week, I wanted to look at a tree which has captured my attention many times walking through the woods. Take a look at this mature oak:

Oak tree with burrs up the main stem

Oak tree with burrs up the main stem

Burrs are commonly found on trees as a rounded outgrowth on a trunk or branch that has filled with small knots from dormant buds. These growths result from the tree undergoing some form of stress, which could be an injury, virus or fungus, among other causes.

The largest burrs have been recorded at 26 feet, occurring in coast redwoods in the US and can encircle the whole trunk where moisture is present.

They yield a very peculiar and highly sought after wood used by furniture makers, artists and sculptors. Every time I walk past this tree I would love to know what is going on under the bark and imagine the beautiful things you could make with the wood.

Well, that’s it for this week’s walk in the woods. I’m sorry it has taken a while to get to you, but the Treecreeper team have been so busy this summer! Join us soon for another walk in the woods!

Until then, enjoy your own walks and let us know how you’re getting on!