Arboriculture & Invasive Weeds

  • Arboriculture

Arboriculture & Invasive Weeds Consultants

Delta Simons Arboriculture team offers a full range of arboricultural consultancy services supported by over 20 years’ experience in both private and public-sector roles. Our highly skilled Arboriculturists are Quantified Tree Risk Assessors (QTRA) registered users and members of the Arboricultural Association (TechArborA).

The Forestry Commission consider that trees contribute to developments and urban environments by increasing resilience to climate change, improving air quality, improving biodiversity, transforming appearances, adding benefits to the local economy and creating healthy places with stronger communities.  We deliver bespoke services in line with industry standards and best practice guidelines.

Working closely with our in-house Ecology team, we have a thorough understanding of ecological constraints associated with trees and woodlands, enabling us to identify and offer advice in the early stages of the development process.  Use following links to view more:

Tree Surveys Arboricultural Impact Assessments
Arboricultural Method Statements Arboricultural Supervision & Site Monitoring
Tree Preservation Orders Tree Risk Assessment & Safety (QTRA)
Woodland Surveys & Management Plans Tree Felling Licence Application & Liaison
Assessment of Tree Habitats Aerial Tree Surveys
Invasive weeds  

Services we offer

Tree Surveys (BS5837:2012)

When considering a site for development, it is important to make allowances for trees early in the planning process; more emphasis is being placed on identifying the importance of individual trees within a potential development site due to their ecological and landscape value.

Our team of Arboriculturists can undertake tree surveys for both developers and private clients, assessing trees on site and providing detailed reports of individual trees following current best practice guidelines outlined in BS5837:2012 for Trees in relation to design, demolition and construction.  The British Standard for Trees is the accepted approach to tree survey for Local Planning Authority (LPA), enabling them to evaluate the impact of any proposal on adjacent trees.  The tree survey is an inspection of all the trees within a red line boundary area and up to 15m beyond it, including a hedgerow assessment where present.  In addition, the LPA is contacted to determine whether or not the site falls within a conservation area, and if any trees are protected through a Tree Preservation Order (TPO).

During assessments, biometric data such as height, girth, spread and age of a tree are measured to inform the scheme. We then assess their structural and physiological condition for health and safety, and identify any tree works that are required to mitigate against harm to people or property. The information collated is included within the report with advice to ensure that those trees selected to be kept through the development process are protected both during and after the development.

Our report contains a Tree Constraints Plan. This illustrates the locations, the canopy extents and the Root Protection Areas (RPA) for each recorded tree. The RPA is the minimum area around a tree that must be preserved in order to help maintain the future health and stability of the tree. The extent of the RPAs for those trees to be retained will help you to determine the footprint available for the development.

Arboricultural Impact Assessment (AIA)

The Arboricultural Impact Assessment considers the impact that the proposed development may have on trees within a given area.  It provides details of how any adverse impacts will be mitigated (including indicative protection measures) and includes an Arboricultural Impact Plan (AIP). 

The Arboricultural Impact Plan (AIP) shows the location of the trees in relation to the proposed development and the above and below ground constraints posed by the trees, those trees that will require removal, those to be retained, and how retained trees will be protected during construction.  It also illustrates the tree protection measures on a draft Tree Protection Plan.

Arboricultural Method Statement (AMS)

The Arboricultural Method Statement is usually drawn up once planning permission has been obtained and the construction phase decided.  However, a Local Planning Authority can ask to see generic method statements at the planning submission stage.

Various points need to be covered within the AMS such as protective fencing specification, any necessary tree surgery, land regrading, movement of heavy machinery and soil compaction during the build, installation of underground/over-ground services, storage of materials and the handling of materials hazardous to tree health and, when appropriate, any road construction techniques.

Adherence to the approved AMS is often conditional upon planning consent.  The Local Planning Authority has the power of enforcement via fines and cessation of works.  It is essential that an AMS is realistic and successfully balances the developer’s requirements on the ground with those of the LPA.

Arboricultural Supervision & Site Monitoring

Arboricultural site supervision is regularly used to alleviate any concerns a Local Planning Authority may have over construction works, and gives our clients the confidence that their activities are not having a detrimental effect on the retained trees by enrolling in a clearly auditable system of site monitoring.

During construction work close to trees, we undertake regular arboricultural site supervision in accordance with the Arboricultural Method Statement to ensure that tree protection measures are being carried out to the required specifications. This may involve checking the positioning of tree protection fencing and temporary ground protection, ongoing supervision during excavation works within the RPAs of retained trees, and ensuring that installation techniques for new hard surfacing and specialist foundations are carried out without any adverse impacts on retained trees. Construction site monitoring may require regular visits to ensure protection measures are correctly implemented throughout the entire construction period.

Should the tree protection measures require alteration, one of our arboriculturists would report to the relevant LPA and provide advice.

Should an event that is not within the scope of the impact assessment or method statement occur during construction works, or one that cannot be adequately predicted in advance such as excavations within the RPA, a member of our Arboriculture team can be called upon at any point for advice and attend site as required.

Tree Preservation Order (TPO) - Applications & Advice on Protected Trees

A Tree Preservation Order is an order made by a Local Planning Authority in England to protect specific trees, groups of trees or woodlands in the interests of amenity.  Our Arboriculturalists can act on behalf of a developer or landowner when applying for works to trees under a TPO or within a Conservation Area, advising the tree owner of the best way forward to apply for permission whilst we assess your tree(s) and provide the LPA with an appropriate report detailing the works required to a tree under a TPO.

Tree Risk Assessment & Safety Management Strategies

Property owners and managers have a duty of care to ensure that people and property are not exposed to unreasonable levels of risk from the mechanical failure of trees on their land.

Types of Tree Survey

Depending on the extent of the tree population in question, different levels or types of inspection are acceptable to fulfil the ‘reasonable’ criteria. These may comprise of:

  • A tree report for a single tree
  • Low volume condition surveys
  • High volume surveys for large landowners, such as LPAs, usually undertaken on a rolling basis
  • Surveys of dense populations of roadside trees undertaken from the car

Quantified Tree Risk Assessment Method (QTRA)

Quantified Tree Risk Assessment provides a framework for the assessment of the three components of tree-failure risk – 'Target' (land-use), 'Size' and 'Probability of Failure’.  Our QTRA-registered consultants assess the probabilities of the three components and by calculating their product; it is possible for the skilled tree assessor to quantify the risk of significant harm from tree failure in a way that enables owners and managers to make balanced management decisions, whether it be one tree, several trees or a woodland.

The use of quantification in the assessment of tree-failure risk enables property owners and managers to reasonably operate predetermined level of acceptable risk, effectively reducing the risk in the most cost efficient or appropriate manner.  By quantifying the risk from tree failure as a probability, QTRA enables a tree owner or land manager to manage the risk in accordance with those widely applied and internationally recognised levels of risk tolerance.

Following a QTRA approach reduces the time tree owners and land managers spend on resources to assess and manage tree risk than they had previously, whilst maximising the many benefits their trees provide.  In the event of a 'tolerable' or 'acceptable' risk being realised, they are in a position to demonstrate the risk has been managed reasonably and proportionately.

Woodland Surveys & Management Plans

Whether you are seeking advice relating to woodland creation, ancient woodland, veteran trees, planting schemes or woodland and hedgerow management, we can provide a range of woodland management plans, depending on the clients’ requirements, for the following:

  • Replanting schemes
  • Management for outdoor recreation
  • Species selection
  • Natural regeneration and thinning regimes
  • Rotational coppicing
  • Silvicultural management
  • Agroforestry management
  • Enhancing wildlife value
  • Safety management

Tree Felling Licence Application & Liaison

A Felling Licence is required if you are to fell more than five cubic metres of a woodland in a given calendar year; the licence must be in place before any works commence unless the trees are in a garden, orchard (not ancient), churchyard or Designated Open Space (Commons Act 1899).

In relation to this, we offer services and advice on:

Conditions on a Felling Licence;

  • Grant Schemes;
  • Tree Preservation Orders; and
  • European Protected Species Mitigation Licensing (Bats, Great Crested Newts).

Assessment of Tree Habitats for Wildlife

We offer ground based and aerial assessments of trees and their potential to support wildlife; in particular species of bats and birds.

Of the 17-bat species in the UK, 13 are known to roost in trees. Whilst we know a number of bat species rely exclusively on trees for roost sites, others may use them for part of the year.  Trees that bats use to roost in can be difficult to identify, particularly when viewed from the ground. The variety of features that bats can make use of make it difficult to say with any certainty whether or not a particular tree(s) supports a bat roost.

Our experienced Arboricultural Surveyors are City & Guilds NPTC certified climbing arborists, bolstered by a dual qualified Bat Licenced Ecologist for bat presence determination (bat survey services).

Aerial Tree Services

The majority of our tree inspection work is undertaken from ground level, however where required detailed aerial inspections are undertaken, particularly of over-mature and veteran trees. This is a recognised technique to scope out potential bat roosts as acknowledged by the Bat Conservation Trust (BCT).

A single aerial tree survey can provide an accurate presence/absence assessment. This may limit the need to complete dusk and dawn activity surveys (usually up to three) that are restricted to bats active months of the year (Ecology Survey Calendar). Aerial tree surveys can be done at any time of year and can substantially reduce waiting times, survey effort, therefore enabling work costs. Aerial tree surveys are also considered to provide greater rates of success than traditional dusk and dawn activity surveys, given that bats switch between roost sites on a regular basis at different times of year but their evidence remains. It is important to be aware that whilst bats may not use the same tree year-round to roost, untenanted roosts enjoy legal protection.

We produce high quality reports containing a detailed analysis of the surveyed trees and their potential for roosting bats. We will provide recommendations with appropriate mitigation and compensation for any licensable activity that may be required. We can undertake installation of bat and / or bird boxes at height as part of the compensation effort.

Invasive Weeds

Invasive weeds, such as Japanese Knotweed, Giant Hogweed, Himalayan Balsam and other Schedule 9 species (Wildlife and Countryside Act, 1981, as amended), normally should be eradicated if found on a development site before development commences. Under certain circumstances failure to do so could result in onerous planning conditions and untimely delays.

We can identify invasive weeds on site and provide the developer with the most cost-effective eradication solution based on the development programme. Our ecology team will work with specialist contractors to oversee and manage the removal of invasive weeds on site, and verify the works to satisfy planning conditions.

Related article: But is it Japanese knotweed...?