Author Archive

B for Bacteria is all around us

Tuesday, February 4th, 2020

Bacteria are microscopic single-celled organisms, and when it comes to trees and ecology they can be good and bad just the same as the ones which affect us as humans. And the bacteria doesn’t need to be on the trees such as bacterial canker often found on the prunus species, it can be in the soil or elsewhere. Bacteria in the soil are plentiful around 100 million to 1 billion in a teaspoons worth! Most bacteria in soil are good an are the decomposers of the plant world. Some even decompose pollutants too, but there are also other types including mutualists, these work with the plants doing good such as nitrogen fixing, particularly working well with Alder and Locust trees. Bacteria are so plentiful they probably merit their own blog or two!

 

Bark can be attractive, or not, bark can be a great way of determining the health of a tree and damage to bark can be a major problem. Choosing trees for their ornamental bark is becoming popular again

Silver birch Betula pendula with their bright stems

Tibetan cherry tree Prunus serrula with the high coppery shine.

But bark is much more than decoration, we use the bark from Cork oak Quercus suber for our wine bottle corks and placements amongst other uses. Other barks are used for rope and spices and even Asprin is derived from the bark of a Willow. For trees however their bark is a often the first to show signs of poor health, from fungal or bacterial diseases to drought or pesticides, the visual appearance of the bark is one of the first checks arboriculturalists make. Damage made by man or nature to the barks surface allows pests and disease in and prevent nutrients reaching the leaves, the phloem layer of tissue just below the bark is responsible for carrying food produced in the leaves by photosynthesis to the root.

 

Basidiomycotina (Basidiomycetes) is one of the major taxonomic groups of fungi which can have one of three roles in a forest;
• Saprobes – processing of decaying matter
• Pathogens – cause disease
• symbionts – mutually beneficial
understanding the impact of the fungi on a particular tree in a particular settings is complicated, fungi are overwhelmingly the most important pathogens of trees.

 

Bifurcation is a tree fork in the trunk giving rise to two roughly equal diameter branches. These forks are a common feature of tree crowns. Whilst not necessarily a problem, areas with bifurcation need close inspection due to their higher rate of failure.

Image credit to Wikipedia – Typical wood grain pattern at a mature tree fork, Slater et al.2014[1]

 

Bolling A term sometimes used to describe pollard heads, particularly when a tree is pollarded repeatedly. The initial point is then referred to as a Bolling.

 

Bottle-butt Perfect description but be careful if you choose to Google the term. As shown in the image below, bottle-butt is when excess broadening occurs or near the base of a tree, causing a distinct bottle shoulder shape. This can be caused by decay.

 

Bracing The use of rods or cables to restrain the movement between parts of a tree, more often used for veteran trees, or where public access is required.

 

Branch
• Primary. A first order branch arising from a stem.
• Lateral. A second order branch, subordinate to a primary branch or stem and bearing sub-lateral branches.
• Sub-lateral. A third order branch, subordinate to a lateral or primary branch, or stem and usually bearing only twigs.

 

Branch bark ridge and branch collar
The bark ridge it a strip of raised bark seen at the top of a join from a branch to a stem.
Branch collar is a visible swelling formed at the base of a branch.

Image credit to Wikipedia – A branch collar on a common oak

Both are important when pruning, so as not to damage the tree.

 

Brown-rot A type of wood decay in which cellulose is degraded, while lignin is only modified.

 

Buckling Another sign of stress in the buttress area, similar to bottle-butt, usually caused by compression due to weather or environmental stresses. The adaptive growth gives rise to a ring-like bulge.

A is for Arboriculture and other A’s

Friday, April 5th, 2019

As short series of blog posts, we thought it might be interesting to our readers to go through our glossary and discuss the various technical terms which appear in our reports and discussions. Whilst common place to us in our industry they can be like a foreign language to our customers, so let’s start with the A’s

 

Abscission is the first to appear in our glossary and what a term to start with! Not unique to arboriculture, abscission is the term used to describe the shedding or disposal of a part of the whole, such as the dropping of leaves, berries or seeds. It is also the term used by zoologists to describe the intentional shedding of skin (reptiles), claws, tails etc.
Whilst Abscission can be a normal and natural consequence of the plant’s reproduction or seasonal cycle, it can also be a symptom of stress or defence. Early fruit drops can be a symptom of water stress and premature leaf abscission can be caused by a natural defence to infestation by gall aphids.
Abscission can be either normal or abnormal and abnormal abscission is a good indicator of poor plant health and should be a trigger to take a closer look.

 

Abiotic, pertaining to non-living agents; e.g. environmental factors, the inverse to biotic factors, examples of abiotic agents we are interested in are light intensity, temperature, soil pH, soil moisture, pollution to name a few. Many abiotic factors can influence the health and growth of a tree or group of trees. By identifying and observing abiotic factors impacting a specimen, we can more accurately predict the health and lifespan expected.

 

AAdaptive Growthdaptive growth and adaptive roots go hand in hand, adaptive growth is the rate of wood formation in the cambium (the area of wood directly underneath the bark, the most outer ring – see below) in a perfect location this will grow evenly around the tree, under stress or ‘abiotic’ influences such as wind, gravity, physical obstructions, this can grow non uniformly and cause stress to the tree.

 

Adaptive roots are beautifully illustrated here –Adaptive roots
The adaptive growth of existing roots; or the production of new roots in response to damage, decay or altered mechanical loading

 

 

 

 

Adventitious shoots are shoots that develop other than from the usual places such as apical, axillary or dormant buds. Sometimes used to the advantage of propagating gardeners to grow new plants from cuttings, examples are where you may see new growth forming on a leaf, or at both ends of a cut stem.

 

Anchorage is a well described term. The anchoring effect of the tree roots into the soil holding the tree firmly and securely. Poor anchorage can be caused by disease, lack of water, obstructions all of which can cause the tree to grow poorly or become unstable.

 

Architecture, like a balanced building each family of trees will have a distinct and predictable architecture, a balance to the structure of the tree and the reason for the clear and distinguishing outline of the mature specimen.

 

Axil, as mention in the adventitious shoots paragraph, the axil is where a bud may form between a leaf and it’s parent shoot. Not to be confused with a car axle
Axil

 

And that as they say is ‘A’ wrap, come back to see the B’s soon.

Arboricultural Association Registered Consultant (AARC) and what it means to me.

Monday, February 6th, 2017

What does it mean to be an Arboriculturalist Association Registered Consultant?

For me it means I am at the very top of my game, that the last 20+ years working as an Arboriculturalist, the hours and money invested as an initially as employee and later running my own Consultancy have been recognised. (more…)

Sleeper’s Hill Hampshire

Monday, February 6th, 2017

Sleeper’s Hill, is a development site on George Eyston Drive in Winchester, Hampshire. The drive was named after Captain George Edward Thomas Eyston MC OBE (28 June 1897 – 11 June 1979) who was a British racing driver in the 1920s and 1930s, and he broke the land speed record three times between 1937 and 1939.[1] (more…)

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