For more information please visit Tree Surgeon Cheltenham
Saturday, 12 May 2012
You will hear it said that there is as much of a tree below the ground as there is above. In some regards there is a truth to that. In fact most tree roots grow in the top 60cm of soil. The roots of a tree are essential to the health and stability of the tree. They draw up water and minerals and provide anchorage and storage for the tree.
Roots also have requirements of their own. Being below ground they lack the capacity for photosynthesis and therefore cannot produce their own carbohydrates that have to be transported down from the leaves via the phloem vessels just under the bark. They also respire, which means they need oxygen. The oxygen comes from the air and makes its way to the roots through pores in the soil which allow gaseous exchange through pores in the roots called lenticels and along channels in the wood called medullary rays (the prominent lines you can see in Oak timber). This is why you will rarely find tree roots below 60cm. The oxygen just doesn`t diffuse that far.
Tree roots also rely on certain types of micro organisms to help them with their job. The carbohydrates that are transported down from the crown don`t all get used by the tree. Some pour out into the soil where they are used by other organisms. In particular a type of fungus known as mycorrhizae are essential to the health of the tree. Mycorrhizae (meaning fungus roots) are a wide variety of fungi that have evolved alongside trees. Essentially they grow either into the trees roots (endomycorrhizae) or form sheaths outside (ectomycorrhizae) and they benefit from the tree`s carbohydrates whilst the tree benefits from their greater ability to take up minerals from the soil. Mycorrhizae are essential to the trees long term health. The area where tree, soil and microorganisms interact is known as the rhizosphere.
In the natural woodland environment trees will shed branches and leaves which are broken down by various saprophytic (dead eating) fungi, bacteria and animals. This increases the amount of organic material in the soil. Organic matter helps to stabilize soil Ph, increases the nutrient holding capacity of soil it also increases the water holding capacity of free draining soils (sand, chalk etc) and increases the draining capacity of soil prone to water logging (clay). In short it enhances soil texture and in the longer term, with the help of small animals, enhances the structure. The other result of having lots of little creatures moving around in the soil is they create channels for gaseous exchange.
Over millions of years trees have evolved alongside the creatures that live around them for mutual benefit.
In the garden environment soil can often be lacking organic matter. Foot traffic and vehicle traffic (mowers etc) cause soil compaction which crushes the channels in the soil that tree roots rely on for water and air to reach them. Fertilizers and pesticides interfere with nutrient levels and poison the tree. All this can make for a pretty tough environment for the tree to grow. Next to roads or driveways can be far worse. Soil compaction can be a significant problem and salt from winter gritting can cause serious issues for tree and soil organisms alike.
A simple organic remedy
Using mulched wood chip can significantly enhance the soil conditions over longer periods of time. It`s not the quick fix that fertilizer and mycorrhizal injection offer nor does it deal with compaction as quickly as using an air spade but in the long run it can provide significant benefits to trees, shrubs and general soil health. A layer of mulched wood chip spread over as much of the root crown as is possible and maintained at about 75mm deep will almost certainly improve the health of your trees in the long term.
Won`t that encourage fungus into my garden?
A healthy tree should be able to resist parasitic fungi. Healthy soil will contain a wide variety of saprophytic and mycorrhizal fungi which compete with opportunistic parasitic fungi like Honey Fungus. This is not a miracle cure, but the miracle cures rarely retain their miraculous status for very long. This is based on good soil science, trying to recreate the conditions that trees experience in the woods.
For more information please visit Tree Surgeon Cheltenham
Tuesday, 17 April 2012
Encouraging wildlife into your garden
With recent fashions for manicured landscaped gardens incorporating decking, gravel and other such materials the amount of available habitat for wildlife in towns, cities and even in rural areas is rapidly diminishing. It is therefore more important than ever that those who are interested and care about wildlife take steps to increase habitat in their gardens. Not everyone has loads of space. My garden is currently about 3.5 by 3.5 metres; however, even in such a small space there are plenty of things that can be done to encourage garden visitors. The following are just some ideas to get your garden teeming with life.
A small pond or pool will provide water to drink and a home for amphibious creatures. Small moulded ponds are easily available.
Dead wood makes excellent habitat. Deadwood on the ground is good, standing dead wood is even better. In my garden I have a few logs hidden under plants and shrubs which are just left to rot, as they do so they become home to all manner of insects which in turn are food to birds and other insects.
Standing dead wood should be left as long as is possible and safe. If a tree is dead or dying then leave some or all of it to rot away as a stump or monolith (a large stump). A flowering climber can turn an old tree into an attractive feature. Don`t over manicure trees, leave some dead wood on, it will do the tree no harm.
Make a compost heap
Compost heaps make excellent places for all kinds of wildlife. The heat generated by decomposing vegetable matter creates a warm place to live. Spreading compost on your garden enriches the soil and enriched soil is home to many worms and other creatures. Also, your plants will grow better so it a win win situation. Just make sure you leave meat and fish out or you will attract vermin.
Flowers, nectar and seeds or berries
Choose species that are useful to wildlife for much of the year. Hawthorn, for example, produces much needed early nectar with its profusion of white flowers in the spring followed by bright berries for birds in the later summer.
Make a wild corner
The easiest thing of all is a wild corner. All you need to do is leave it alone. It doesn`t have to be very big. An undisturbed corner can be home to all manner of small mammals, insects and birds.
Creating garden habitat for bees in especially important. Bees are declining at an alarming rate. We can all do something to help. The following are links to useful sites:
Bird boxes can easily be attached to a wall, tree or post. There are different types and sizes of box available depending which types of bird you wish to attract.
Feed the birds. There are many different types of bird feeders suited to different species. Make sure you buy special bird food and store it properly as poor quality bird food can cause problems for our feathered friends.
Planting native species will encourage native wildlife. Be it trees, shrubs, perennials or annuals, a native is always better for the wildlife.
Excellent Wildlife Plants
These are just a few suggestions, there are many more.
Small flowering plants
|Beech tree Avebury|
Trying to push the boundaries of modern ecological arboriculture
So, what is ecological arboriculture about?
Well, obviously it`s about try not to unnecessarily cut down trees, that goes without saying really. Perhaps maybe it`s about planting more trees, as many of them as possible, especially when we had to remove one. But then what?
Well, that`s what we are trying communicate. This whole ecology thing goes way beyond replanting. It`s about trying to preserve and enhance what we have and make sure there is more for the future. We all know that biodiversity is important and that the variety of species is diminishing, so I don`t need to go on about that. But what can we do? What can each of us do? I certainly don`t have all the answers but I could make a few suggestions.
Death is part of the natural cycle of life. Huge numbers of species live either in or on dead and decaying wood. Deadwood on the ground, dead wood in the tree, it`s all important, it`s all a source of life. There are many species that live exclusively in standing deadwood. These are not the big glamorous species we all know about lions, snow leopards, pandas and the like, but they do provide food for birds and small mammals and that`s important. We need to acknowledge that all forms of life no matter how insignificant they may seem are precious.
Don`t over manicure your trees
As tree surgeons we have been responsible for the removal of far too much deadwood and other habitat from our trees. Of course we don`t want them to be dangerous but an increasing culture of over manicured, chemical injected trees might look great to some people but personally I prefer something with a little more substance. Besides, a good bit of mulch is far better in the long run than quick fix chemical fertilizers.
|Ganoderma australe on a Beech tree|
A little wildlife haven in your garden.
So what can you do to make your garden a little more wildlife friendly?
Leave dead wood! Leave some in the trees, leave piles of it on the ground, if you do need a tree felled then leave a good sized stump. Leaving a dead standing stem is known as Monolithing, we normally cut them to about 3 metres but anything is better than nothing. If every garden in our neighbourhoods had a dead stump or two those little bugs and beasties would have new places to go when their previous dwellings finally become uninhabitable!
Try leaving a little wild corner. It doesn`t have to be much, but it all helps.
This is hardly radical stuff. You will see more and more of this in parks and nature reserves, but from a tree surgeon, not so common.
|Ancient Hornbeam pollard Hatfield forest|