Woodland Watch – Week 19 – 24/07/2013

After a couple of weeks away from walking through the woodland on my own with plenty of opportunity to look at the changing flora, I am amazed to see how everything has changed in such a short space of time.

Only a couple of weeks ago, the meadow approaching the woodland was covered in lush green grasses and bright yellow buttercups. Dry hay meadows such as these are characterized by mixures of grasses such as Cocksfoot (Dactylis glomerata), Timothy (Phleum pratense), Common Bent (Agrostis capillaris), Sweet Vernal-grass (Anthoxanthum odoratum) and Crested Dog’s-tail (Cynosurus cristatus). I am certainly no expert on grasses and struggle to identify anything beyond the basic species, however even my untrained eye can clearly see the difference between these diverse hay meadows and monoculture manicured lawns.

Meadow grasses on the approach to the woodland

Meadow grasses on the approach to the woodland

This is a very different picture to just a few weeks ago when the meadow was awash with bright yellow buttercups. One of the main features of meadows is the sheer diversity of plants which they contain. Mixed in among the variety of native grasses are a great many other flowering plants. These include plantains, docks, buttercups, vetches and clovers, dandelions, nettles, selfheal, Lesser knapweed, scabious, thistles, hawkbits, Ox-eye Daisies, Yellow-rattle and on rare occasions, Cowslips.

Within a few months of sprouting, the mature grass plant reproduces sexually. The plant grows a tall stem with an inflorescence at the end, which contains small flowers. Each flower contains a male organ, called the anther and a female organ called the pistil. When the pollen from the anther contacts the pistil, it releases sperms cells that enter the pistil to fertilise the ovules inside. These eventually become seeds. The grass seeds, once mature, will fall to the ground to germinate and continue the grass plant’s life cycle.The grass in the meadow approaching the woodland has moved on from the mature green leafy growth of previous weeks to flowering and reproducing to produce seed to continue their life cycle.

Meadow flora going to flower and seed

Meadow flora going to flower and seed

And its not only the meadow plants thinking about reproduction. As we enter the woodland, the bluebells which we have followed since early spring when their first lush, green, leafy growth now have brittle seed pods full of black seeds.

Bluebell seeds now maturing all over the coppice woodland floor

Bluebell seeds now maturing all over the coppice woodland floor

Bluebell seeds take around 3 years to produce flowers from seed. In 3-4 years time, these tiny seeds will hopefully be contributing to the beautiful spread of bluebells covering the woodland floor.

Our native bluebells are coming under threat from competition and hybridization, habitat loss, unsustainable collection and climate change. The native bluebell’s Spanish relative is more vigourous than our native species and can readily cross-breed with it to create a fertile hybrid Hyacinthoides hispanica x non-scripta. To find out more about the future of and the threats facing our native bluebell, take a look at this link from plantlife:

http://www.plantlife.org.uk/uploads/documents/Blubells-for-Britain-report.pdf

Also moving from its flowering stage to producing seed is the cow parsley which we have looked at several times over previous weeks as it developed. Now, the flower heads are covered in tiny black seeds.

Cow parsley plants going to seed among the nettles on the ditch bank

Cow parsley plants going to seed among the nettles on the ditch bank

Cow Parsley is a biennial plant; it takes two years to flower from seed. It puts on leaves, stems and roots during the first year and then flowers the following summer. Once they have flowered they die. These plants will self seed freely unless you remove the spent flower heads. These seeds should grow into flowering cow parsley plants over the coming 2 years as they drop to the ground once mature and begin their life cycle.

Seeds are not the only way that plants in the woodland are reproducing. If you look at the underside of the fern leaves on the woodland floor, the spores are clear to see easily with the naked eye.

Fern spores

Fern spores

Sporogenesis is not a reproductive method I am familiar with, so next week we’ll have a look at this in more detail.

Until then, enjoy your own walks in the woods. We will see you next week and see whats happening in the woods and what you should be looking out for on your own travels.

From the Treecreeper Arborists Team

http://www.tree-creeper.com

Woodland Watch – Week 15 – 26/06/2013

Summer seems to finally be here and although it is neither as warm or as predictable as we would like, at least it is not as cold as it has been! This week my walk in the woods was overcast, but warm and I hope you will join me to have a look at what is going on this week.

The grass in the meadow approaching the wood is getting taller and taller but closer to ground level you can see lots of little purple clover flowers.

Clover growing in the hay meadow

Clover growing in the hay meadow

This red clover (Trifolium pratense) is a native, herbaceous perennial plant which can grow 20-80cm tall. The genus is so named because of the leaf structure consisting of three leaflets, known as trifoliate leaves. Clover is an interesting plant, widely grown as a fodder crop and highly valued for its nitrogen fixing capabilities which increase soil fertility.

Nitrogen fixation is the process by which nitrogen in the atmosphere is converted into ammonia. In the atmosphere nitrogen exists as a diatomic molecule (the atoms go around in pairs, like oxygen). In this inert state it does not easily react with other chemicals to form new compounds. Nitrogen fixing nodules in the clover plant frees up the nitrogen atoms from their chemical diatomic form (N2) to be used in other ways.

Before the establishment of science, when peopled looked to religion and magic for medicinal cures, red clover was already playing a part in people’s lives. To early Christians, it was a sign of the Trinity while during the Middle Ages, it was regarded as a charm against evil. A mutation resulting in the well-known four-leaf clover is considered good luck when found, even to this day.

Heading into the woodland, the first difference that was immediately apparent was how dark the wood was compared to previous weeks. The canopy has now almost completely closed over with a hazel lower canopy and an upper canopy made up of a range of other broad leaf trees including oak and horse chestnut.

The woodland was noticeably darker now the canopy has closed over

The woodland was noticeably darker now the canopy has closed over

One of the lower level tree species that we haven’t yet touched on but which I have noticed on my walks is the holly (Ilex aquifolium). An evergreen shrub which most people can easily recognise it can grow 10-25m tall with sharp spiney leaves which last around 5 years. What many people don’t realise, and to the relief of tree surgeons such as ourselves, is that leaves on the upper branches of mature trees do not have spines as they are well out of the reach of grazing animals and do not require this particular defense mechanism. 

Lower leaves of a mature holly tree

Lower leaves of a mature holly tree

Holly is dioescious which means there are male and female plants, unlike the hazel which we saw developing the male catkins and female flowers on the same trees. The sex of the plants cannot be determined until they begin flowering, usually between 4 and 12 years of age. Between October and November, the flowers on the female plants will grow into red fruit which is eaten by birds and rodents.

Interestingly in the Irish/Gaelic ogham alphabet holly is called Tinne, a word believed to have originally meant ‘fire’. From this was derived the word ‘tinder’, referring to dry, inflammable matter used for kindling fire from a spark. This association between holly and fire has been known since ancient times when charcoal made from holly wood was used by armourers to forge swords and axe heads.

The holly will remain fairly constant through the changing of the seasons, but it is a highly valuable woodland species.

Sticking with the theme of trees, another species to note is the English elm. Once a classic English tree like the English Oak, the elm all but disappeared from our countryside after Dutch Elm Disease reached Britain in 1927.

Now, these small elm saplings around the edge of the wood, although relatively common at this stage of their lives, are unlikely to reach maturity.

English Elm saplings

English Elm saplings

The current DED epidemic is caused by the fungus Ophiostoma novo-ulmi which is dispersed by various elm bark beetles within the Scolytus genus. The fungus blocks water conduction, resulting in wilting and eventual death of the foliage.

The first signs of the disease are often yellowing/browning of foliage tips as the affected branches are gradually starved of water.  When the leaves fall, the remaining twigs often turn down to form ‘shepherds crooks’ which can be valuable for disease detection in winter.

The diagram below shows how the disease progresses.

Dutch Elm Disease

Dutch Elm Disease

Although the English landscape has certainly lost the majority of its mature English elms, the Ulmus procera species has not disappeared completely from the landscape. This is because the elm bark beetles require bark to be of a certain thickness for breeding to be successful.

When an English Elm is killed by the disease, some roots remain alive and new elms regenerate from these. This means that for every mature elm killed by DED, many more are able to replace it. We may not have many large elms, but there are millions of young elms growing all over the English countryside, such as these young saplings in our wood.

That’s it for this week. Join us again next week for another walk in the woods.

http://www.tree-creeper.com

Woodland Watch – Week 14 – 19/06/2013

It seems as fast as I get used to warm spring/summer weather everything turns around and its back to miserable grey again! This week wasn’t great weather for a walk in the woods, but me and the dog made it out anyway and here’s what we saw this week!

Despite the dreary looking sky and cold, blustery wind that felt more like early spring than early summer, the meadow approaching the woodland was still beautiful, covered in buttercups and a wide range of flora.

Stormier skies than in previous weeks as we approached the woodland

Stormier skies than in previous weeks as we approached the woodland

The buttercup family is comprised of about 2,252 species, including wildflowers and ornamentals, such as larkspur, marsh marigold and clematis. It used to be thought that the rich yellow of the buttercup made better butter from cows feeding in buttercup-rich meadows. This is a myth however, as we now know that the stem and leaf are actually toxic, especially to cattle, and the animals avoid eating it.

The meadow is full of a wide variety of flowers, herbs, grasses etc and I am the first to admit that my meadow species identification needs a lot of work, so please feel free to correct any mistakes!!! Species such as the common plantain and clover are widespread among the buttercups.

Ground level vegetation in the meadow approaching the woodland

Ground level vegetation in the meadow approaching the woodland

Inside the wood, the woodland floor has changed again. The green bluebell leaves from previous weeks have turned yellow and collapsed as they come to the end of their life for this year. The stems and seed pods are still upright, bare looking without their foliage.

Bluebell stems left after the leaves have wilted

Bluebell stems left after the leaves have wilted

While these areas of the woodland look bare now that the bluebells have died back, other areas are overrun with weeds. On entering the woodland area there are large patches of young brambles which will continue to dominate the vegetation where they can through the summer months.

Young brambles taking over the area close to the entrance to the woods

Young brambles taking over the area close to the entrance to the woods

Although generally considered a woody week and certainly difficult to eradicate once they become established, brambles are a very useful plant to a wide range of wildlife. Hundreds of creatures use brambles at different times of the year: Insects visit the flowers for pollen and nectar, including bumblebees, honey bees, hoverflies, wasps, butterflies, moths, flies and lacewings.Spiders spin webs to catch the bounty of visiting insects. Moths such as buff arches, peach blossom and fox moths lay their eggs on bramble as it is their larval foodplant. Blackbirds, thrushes, chaffinches, starlings, robins, pheasants, foxes, mice and other small mammals eat the fruits. Robins, wrens, thrushes, blackbirds, warblers and finches will nest in bramble and small mammals use it for protection from predators.

A weed the bramble may be, but it is certainly a very valuable woodland plant as long as it is not allowed to out compete other valuable vegetation. The key to any habitat is variety.

That’s it for this week. Join us again next week for another walk in the woods.

http://www.tree-creeper.com

Woodland Watch – Week 13 – 12/06/2013

Welcome to another week and another walk in the woods. I have been amazed watching this woodland week by week, seeing all the changes and this week was just as exciting. So, here we go!

One of the standard trees in this woodland that we haven’t really looked at yet is the oak. There are several oak trees around the site, both young and mature specimens. This year, with the cold start to spring it took the oak trees a while to come into leaf. As you can see now, the oaks are properly in leaf and their vibrant green leaves provide a beautiful upper canopy to a few areas of the wood.

Looking up through the oak canopy

Looking up through the oak canopy

Of all our native trees, the oak is probably one of the most commonly recognised by people. Widespread in fields, hedgerows and woodlands it is arguably one of the classic English trees. There are over 400 species of oak worldwide including trees, shrubs, deciduous and evergreen varieties and they can live up to 700 years old, outliving all other trees in the UK except the yew.

In this woodland we have the native English Oak. Male catkins appear on the tree with the leaves in April and become long, pollen-filled pendulous by May. Then the female catkins open as upright flowers which await the touch of fertilising pollen from the males. They hold the seed vessels which will become acorns, the fruit of the oak tree.

I will look out for these in the coming weeks. For now, here’s another beautiful picture of the leaves of a young oak tree, bright and vibrant with new life.

Bright young oak leaves

Bright young oak leaves

We already noted last week the dramatic change in the colour of the woodland floor. Only a couple of weeks ago it was covered in the vivid blue of the bluebell flowers. Last week we saw the change to green as the flowers disappeared and the leaves started to wilt.

Bluebells reproduce through propagation by seed using sexual reproduction. They are usually pollinated by insects and after fertilisation occurs, the seeds are produced and dispersed. In the woodland, now that the flowers have disappeared you can clearly see all of the seed pods still standing on the upright stalks. Right now the seeds are still green, but they will turn darker as they mature before they are ready to disperse.

Bluebell seed pods

Bluebell seed pods

Going back a few weeks, before the hazel leaves burst into life we looked at the male catkins and female flowers and how the hazel reproduces. Now that this has happenned and the female flowers have been fertilised, the male catkin has fulfilled its purposes and drops off, leaving the female to produce the nuts that we will see in autumn. Walking around the wood, you can see many of the used, male catkins on the woodland floor.

Male catkins drop off once they have fertilised the female flowers, leaving them to develop into nuts ready for autumn.

Male catkins drop off once they have fertilised the female flowers, leaving them to develop into nuts ready for autumn.

And sticking with the theme of reproduction, the hawthorn has also just come into flower. Later than in most years but making a beautiful sight, especially around the boundaries of the wood where this photo was taken.

Hawthorn flowers coming into bloom on the edge of the wood

Hawthorn flowers coming into bloom on the edge of the wood

These blossoms contain both male and female reproductive parts and are fertilised by passing insects. By summer the seeds will grow into small green berries which will turn dark red by autumn to attract birds who will eat the berries and propagate the seeds. We will watch the hawthorns in the woodland as they move through this cycle.

And that’s it for another weekend of woodland watch. Join us next week for another walk in the woods!

In the meantime don’t forget to check out our website http://www.tree-creeper.com and send us any of your own woodland watch pictures from your own walks to office@tree-creeper.com or send them through our facebook page!

Woodland Watch – Week 12 – 05/06/2013

This week, I decided to focus on the coppice. There’s such a lot going on in the woodland at the moment now that the weather has finally warmed up, but over the last 11 weeks we have takes a lot about the “coppice woodland” and never really elaborated on what this means.

So, here we go. Lets go for a walk in the woods and take a look at one of the earliest forms of woodland management.

Coppicing is a traditional method of woodland management which takes advantage of the fact that many trees produce new growth from the stump or roots if they are cut down. Coppice stools have multiple stems growing out of previously cut stools which arise from dormant buds on the stool. The resulting structure looks like this.

Regrowth from a coppice stool

Regrowth from a coppice stool

Most frequently coppiced species are oak, hazel, ash, willow, field maple and sweet chestnut. In this woodland, most of the coppice is hazel but management has lapsed and many of the stools are in need of management to bring them back into the coppice cycle.

Stools such as this one have been allowed to regrow for too long.

Old coppice stool in need of recoppicing

Old coppice stool in need of recoppicing

Coppicing allows for the production of a large quantity of fast growing, sustainable timber products without the need for replanting. Although trees can be grown from seed, coppicing allows the tree to regrow from a fully established root system.

Different species respond differently to coppicing. Some species such as alder and beech coppice poorly, while species such as hazel and willow respond very well, quickly sending up vigorous, straight growth which can be utilised in a range of ways.

Most notable in this woodland is the way that the coppice affects the general feel of the woodland area. In traditional broad leaf woodland, the canopy is usually quite high and the understorey more sparse than in a coppice woodland. Here, especially now that the leaves are out, there is much more vegetation at eye level than you would usually find in non-coppiced woodlands.

Looking up through the coppice canopy

Looking up through the coppice canopy

We have said before that the structure of this woodland is “coppice with standards”. This means that there is a coppice understorey with scattered larger standard trees. These standards need to be sufficiently spaced apart to avoid shading the coppice.

The standards in this woodland are primarily oak and horse chestnut, however in some areas these trees have been allowed to grow too large and too close together and the coppice understorey has disappeared, out competed and overshadowed by the larger standards.

Hopefully, some of these lapsed coppice stools can be brought back into a coppice cycle in the near future.

If you would like to learn more about the fascinating history of coppicing which dates back to neolithic times, take a look at these links:

http://smallwoods.org.uk/our-work/woodland-products/a-brief-history-of-coppicing/

http://jncc.defra.gov.uk/pdf/pubs93_Coppicedwoodlands.pdf

Join us again next week for a walk in the woods.

http://www.tree-creeper.com

Woodland Watch – Week 11 – 29/05/2013

Approaching the woodland through the beautiful meadows I couldn’t help but take some photos for woodland watch! Although the surrounding meadows are very different to the woodland area, they have a large impact on the woodland environment, especially given the small size of the wooded area.

Here you can see the meadow approaching the coppice area.

Meadow approaching the coppice

Meadow approaching the coppice

Eight small meadows surround the coppice and are an excellent example of how meadows used to be before intensification made them the rarity they are today. The site has been protected as a SSSI as a high quality hay meadow.

But what does this have to do with the woodland? The answer is simple. No environment can be taken as independent of its surroundings. Habitats do not simply observe the boundaries between themselves with woodland species staying in the woodland and meadow species staying in the meadow. The ecological boundary or transition zone between the two habitats is known as the ecotone.

EcotonesGrassland species will extend as far as they can until they are out competed by the woodland species. Woodland species will extend as far as they can until they are out competed by the woodland species. Between the two habitats is an area of intense competition where species of both habitats compete for space and nutrients.

As you enter the woodland, a hedgerow and grassy stream bank comprise the ecotone between the hay meadow and the coppice woodland. Back during the winter months, these banks were sparsely vegetated at a low level. Now, the vegetation is well over a metre high.

Ecotone between the coppice woodland and the surrounding hay meadow

Ecotone between the coppice woodland and the surrounding hay meadow

The boundary comprises a mix of both woodland and meadow vegetation and at this time of year Cow Parsley (Anthriscus sylvestrisis one of the most abundant plants. Cow Parsley is a hollow-stemmed, tall plant that grows rapidly in the summer before dying back. It likes shady habitats in particular, and can be found decorating woodland edges, roadside verges and hedgerows with masses of frothy, white flowers.

A native wildflower which is often considered a weed, cow parsley is nevertheless a valuable species, providing important links in the food chain for many other animals, as well as areas for shelter and material for nesting.

On entering the woodland, the first thing I noticed was the dramatic colour change. Last week, the floor was a carpet of bluebells, in just the space of a week, the woodland floor has changed dramatically from blue to green.

The green woodland floor is a dramatic change from last week's carpet of bluebells

The green woodland floor is a dramatic change from last week’s carpet of bluebells

While some of these beautiful spring flowers still remain, we will have to wait for next year to see their flush of spring colour again. Some estimates suggest the UK has up to half of the world’s total bluebell population and 71% of native bluebells are found in broadleaved woodland or scrub.

Emerging out the other side of the woodland back into the hay meadow SSSI, it was lovely to look back and finally see the oak trees in full leaf. With the poor weather this spring, the oaks were one of the last species to come into leaf and I’m sure you agree they look beautiful here in the sunshine.

Oak trees now in leaf on the boundary of the coppice woodland

Oak trees now in leaf on the boundary of the coppice woodland

Well, that’s all we have have time for this week’s walk in the woods. Hope you can join us next week and see what changes are happenning!

http://www.tree-creeper.com

Woodland Watch – Week 10 – 22/05/2013

Another week and yet more unpredictable weather! We’re a few weeks away from summer and finally the woods are looking like they have come completely out of hibernation! This week, there was so much going on around the small area of woodland that I decided to focus on one species in particular that has been changing and developing on a week by week basis.

Common in woodland ecotones and hedgerows, this small tree of the rose family grows quickly and sends out many side shoots and branches which make a sturdy, impenetrable barrier to livestock. Unlike Blackthorn which sends out suckers, hawthorn does not have a large root system and is therefore not greedy with the soil’s nutrients. This encourages many forms of plant life to grow in its vicinity.

The hawthorn trees growing in the woodland are generally found around the borders of the wood within the woodland-meadow ecotone. Last week, the leaves were fully out and enjoying the late spring sunshine.

Young hawthorn leaves in woodland understorey

Young hawthorn leaves in woodland under storey

This week, there is a new development on the larger hawthorn trees in the hedgerows surrounding the woodland. Between May and June, the hermaphrodite flowers are produced in groups of 5-25 together. These can be seen developing now on the trees bordering the woodland. Like everything else this year, they are a little late developing!

Developing hawthorn flowers

Developing hawthorn flowers

Hawthorn blossoms along with its newly opened leaves and in a few weeks the flowers will have five snow white petals set around slender stamens with bright pink heads. Hawthorn blossoms contain both male and female reproductive parts and are fertilized by insects moving between them.

In the summer, the seeds will grow into small green berries which will turn red by autumn. We will watch the hawthorn trees in the wood over the coming months and see how they develop and change over time.

Join us next week for a walk in the woods as we approach the summer seasons.