What to do if you find a stag beetle

During work, tree surgeons ( especially while removing decaying tree stump) sometime find large black beetles. They may be concerned that they are Greater Stag Beetle Lucanus cervus and want to know what action to take to protect them.

Greater Stag Beetles are protected against sale in the UK under the Wildlife and Countryside Act, 1981 and are also a Priority Species under the NERC Act and an Annex II European Species.  They do occur in Norfolk, but are much commoner futher south in Ipswich and Suffolk.

Often though they will be stag beetles but the easily confused Lesser Stag Beetle Dorcus parallelipipedus , which is more widely distributed.

Lesser stag beetle Lucanus cervus

Decaying wood is important to all mini-beasts, especially in the “tidier” urban areas like Norwich.  An easy approach if possible is to reduce any stump in large sections and re-sited somewhere safer (something the lesser stag beetle colony will appreciate).

If you do find any text a photograph to us and we are happy to identify for you and let you know what to do.

We are also happy to carry out full invertebrate surveys of sites and make recommendations for managing them for charismatic stag beetles.

What is a root protection area ?

The root protection area

The root protection area is the minimum area around a tree that it is considered is necessary to protect its root system from damage such as construction or compaction.

Arborists calculate it either by a formula or by drawing it manually.

How is a root protection area calculated?

Under the British Standard BS5837 for each tree, the arborist calculates the RPA by multiplying the diameter breast height ( DBH ) of the tree in meters by 12.  A simple circle is then drawn around the centre point of the trunk to this distance.  A maximum RPA of a radius of 15m is assumed.  There are more complex rules for calculating trees with multiple stems.

The arborist can hence provide a simple diagram of the root protection areas for trees, which is easy to calculate and understand.

How is a root protection area estimated manually ?

Although root protection areas are drawn simplistically as a circle, often in practice they are asymetrical or even irregular shapes.

Drawing a root protection area manually is more complicated than the formula approach  and requires input from an experienced arborist. The estimation may also often involve further ground investigations. This might include digging of small test pits to look for roots or other specialist equipment. The arborist will allow for the factors like :

  • hard surfaces,
  • previous trenching works,
  • water sources,
  • soil conditions
  • and the ecology of the tree.

Accurate manual drawing of root protection areas is particularly important on resticted sites or for large trees and important specimens.

How is a root protection area used ?

Architects and planners can use root protection area in site design for buildings and roads, but service trenches as well.  The arborist will use it later for a detailed Arboricultural Method Statement to show how to protect tree roots in constuction.

 

 

TLC for trees : watering in hot weather

Why do trees need TLC in hot weather ?

A newly planted tree arrives from the carefully controlled conditions of a tree nursery into a potentially hostile setting with all the attendant stresses.  Hot dry weather can quickly kill a newly planted tree during the first five years before it becomes established, especially if planted into a hot urban environment.

Birch trees dead from water stress ( not ours !)

The right tree for the right location

Picking the right tree species is key : where a tree is planted into an unsuitable location then it becomes more easily stressed by extremes of weather, especially prior to it becoming fully established in the first five years.

We always suggest to our clients that they make their choice of species based on what we know will thrive in an area rather than what looks nicest in the catalogue.  Whilst you can grow most trees in most locations, an unsuitable location will most likely lead to higher maintenance needs and either potentially slower growth or complete failure.  Obvious examples include many conifer or Japanese maple species planted in chalky soils.

Good preparation

Getting the root environment right for your tree is key to it flourishing in its’ new environment.  The planting pit and surrounds should provide well prepared soil to easily expand into and after planting the surface should be mulched heavily with compost or manure.

How much, how often to water

For your trees survival regular frequent irrigation is more important than the volume, so maintenance plans should include the logistics of staff getting water out to site.  When you consider the “how often” and “how much” of your irrigation regime, you need to consider the water holding capacity of the soils.  These points should be covered in the design stage so that irrigation can be done.  Trees though aren’t fussy, so any water (including grey water sources like washing-up water) will serve in a pinch.

As a rough indication, then 40-60 litres ( 3-4 buckets of water ) twice per month are likely to be required in areas of low rainfall and high temperatures.  When you water a tree, take into account the prevailing weather conditions, soil moisture release characteristics (sandy/ chalky/ clay ) and how that tree species responds to potential water deficits (drought ) or prolonged soil saturation ( flooding ).

Watering creates significant issues where drainage is poor, as adding water will create waterlogging and airless conditions for roots. Poor pit preperation for planting is a frequent cause of this, creating a bucket effect that gathers water.

Techniques for avoiding drought stress in trees

Tree planting will normally be designed with a watering pipe or tube, embedded underground, which allows water to quickly reach the roots rather than flow down the pavement. This also avoids disturbing roots during watering and reduces risk of fungal infection.

Where the soil becomes hard baked ( as in many clay soils in East Anglia ) then mulches can help not only be reducing evaporation, but by increasing organic content of the soil.  They may need a top up regularly post planting.  Gaiter bags and mulch mats can reduce water stress by reducing evaporation.

Good tree stakes and ties with appropriate irrigation system.

Monitoring tree stress is especially important if there are prolonged high temperatures. As a guideline for East Anglia, check trees when there are ten consecutive days during the growing season with temperatures of 25 oC or greater.  When monitoring be aware of the visual signs, something we come back to below.

Overwatering for some species can be as deleterious as underwatering as roots will waterlog and rot.  The symptoms of waterlogging are easily confused with those of water stress, includiong wilting. A waterlogged plant actually is water stressed due to roots drowning and not functioning to absorb any water or nutrients for the tree.

What does this mean in practice ?

Looking after trees in the first few years whilst they become established is critical to their survival and water stress can either quickly kill them or lead to die-back causing later poor growth or fungal infection.

Pick the right tree for the right location and consider their watering needs.

Once established with a well-established root system, trees are drought-proof and will not generally need watering. Getting them to this stage is critical for successful establishment.

How can we help ?

We can help you with a full planting plan for your site, including :

  • Soil testing and ground preparation
  • Choice of species and sizes
  • Design of planting pits
  • Costings for plantings
  • Alternatives to pit planting
  • Planting and aftercare
  • Monitoring

If you have issues with your existing plantings, then please do call us as we may still be able to offer advice.

 

 

Suction solution for no-cut root route

In June 2017, Anglian Water began work on a pipeline renewal scheme at Belstead Water Tower, Ipswich. Trenching 1.2m deep by 0.5m wide was required to allow pipe-laying, but the only route out of the compound was in the Root Protection Area (RPA) of large oak, an important group of TPO trees.

Norfolk Wildlife Services worked with Anglian Water and Conroys to create an Arboricultural Method Statement [AMS].   An innovative solution  practical  technology –  a suction excavator [Conroy Vac Ex] – to prevent need to cut roots with ground protection techniques to protect tree roots of the protected trees from vehicle damage.

The suction excavator removes the soil around the roots, eliminating the need to cut through them in order to create the trench.  Major roots were left intact which means the trees ability to take up water and nutrients was not compromised.  Exposed roots were wrapped with wet hessian to prevent desiccation.  The pipe was then laid underneath the routes and the trench was then backfilled with the original soil, minimising disruption to the trees’ water supply in a period of dry weather.

Ground protection techniques help prevent compaction of the soil around the tree roots

 

Work begins on suction excavation of trench around tree roots using Conroy Vac Ex

Work with Conroy Vac Ex suction excavator continues on open trench and tree roots

 

Wet hessian bags were wrapped around the roots to avoid desiccation.

 

Pipe laying commences