Invasive Species

Last updated: April 2025

Author: Rob Lambert

Editor at Arbtech, Rob is a content specialist who manages our ecology and arboriculture services copy to ensure it is accurate, up to date, and insightful for current and future clients.

About Our Invasive Species Surveys

Our specialist team of ecologists can undertake a selection of invasive species surveys for property or land development projects that may be requested by the corresponding local planning authorities. During each and every assessment, we ensure adherence to relevant legislation and planning policies, and we display an equal balance of our attention towards efforts to satisfy relevant regulators and local authorities while enabling your development plans to continue.

Although potentially costly and time-consuming, invasive species surveys are an unavoidable part of development whenever an applicable species is present on the site. Disregarding the need for them would only incur severe penalties later in the planning process, and as such, the focus should be on sourcing a team such as ours to conduct the survey works in such a way that you are guaranteed an extensive understanding of your development site in relation to invasive species, navigation through the laws designed to protect and control them, and solutions that will make it possible for you to continue successfully and secure planning consent.

Invasive Species UK

Prior to being granted planning permission, local planning authorities are able to insist on developers providing evidence that any present invasive species have been dealt with accordingly. Likewise, an invasive species survey may be the result of an earlier ecological assessment or following observations of the site made by yourself or other individuals working on your planning project. Whatever the case, at any point that invasive species surveys are requested, an ecologist would attend the site to examine signs of proven or suspected native species in the vicinity.

Other than the clear legislative parameters that make the need for this category of assessment mandatory, invasive species surveys possess additional benefits, both for your development project and the natural environment. Throughout this page, we’ve supplied more information on invasive species and inspections intended to address them, enabling you to grow your knowledge of the process before choosing Arbtech as your service provider.

What is an Invasive Species?

A classification that can feature both animals, plants and any other type of living lifeforms, invasive species are a group of organisms that aren’t native to a specific area, making them particularly harmful once present. For a species to be considered invasive, it must adapt to a new location immediately, reproduce quickly, spread rapidly, and cause damage to nearby properties, the economy or other plants or animals that also inhabit the local area.

While it is true that animals and insects such as American mink, carp, fallow deer, grey squirrels, rabbits, rainbow trout, red-legged partridge and signal crayfish can be recognised as non-native invasive species, the term often refers to certain plants. For added clarity, we differentiate between the two by referring to listed animals as protected species and non-indigenous plants as invasive species.

Invasive Species Laws

A comprehensive list of animals and plants is displayed within specific legislation, confirming that they are protected by law. The primary piece of legislation created with the purpose of protecting listed animals and invasive non-native species of plants is the Wildlife and Countryside Act 1981, alongside other legislation in conjunction, such as the Controlled Waste (Registration of Carriers and Seizure of Vehicles) Regulations 1991, the Conservation of Habitats and Species Regulations 2017, and the Environmental Protection Act 1990.

If any person plants, possesses, picks, transports, sells, offers or exposes an invasive species of plant for sale, the Wildlife and Countryside Act 1981 states that this is an illegal offence and could lead to the punishment of an unlimited fine and/or imprisonment. Any of the actions that would be classed as a breach of Schedule 9 of the Act would likely contribute to the widespread growth of plants that aren’t native species, with the repercussions potentially posing risks to natural and man-made habitats, infrastructure, human health, and other flora or fauna.

For more details on the Wildlife and Countryside Act 1981, read our dedicated article HERE.

Invasive Species in the UK

In terms of the plants and animals situated all over Great Britain, hundreds appear within the Wildlife and Countryside Act 1981. From that selection, there are a number of plants that are considered invasive species.

List of Invasive Plant Species

Widely Spread

Not Widely Spread

What is an Invasive Species Survey?

An invasive species survey is a type of inspection that confirms whether or not invasive non-native species of plants are on a development site before addressing methods of allowing the project to continue without impacting or being impacted by the plant life. Unless it is already established that an invasive species assessment is needed in isolation, it would often be triggered by a previous ecological survey to gauge all present species of plant, such as a Preliminary Ecological Appraisal (PEA) or Ecological Impact Assessment (EcIA).

Once a non-native invasive species has been identified, an ecological consultant can undertake the corresponding assessment, making crucial decisions based on the outcome. The priority will be on retaining as much ecological value and fulfilling as much environmental protection as possible, but if compensation or mitigation measures are needed, the ecologist will consider altering the development plants, relocating or destroying present plants, and writing up a report with next steps as a way of minimising and eliminating the likelihood of posing risks to natural and man-made habitats, supporting the planning application as a by-product.

Invasive Species Solutions

Examples of the types of invasive species surveys available include:

• Advanced biosecurity planning and expert witness services
• Giant hogweed survey
• Himalayan balsam survey
• Injurious weed survey
• Japanese knotweed survey
• Problematic species audit
• Problematic species management plans

When Are Invasive Species Surveys Needed?

Under any circumstances where a development poses a chance of negatively affecting or being negatively affected by invasive species on the site or in close proximity to it, invasive species surveys will be vital. The identification of an invasive species could be evident following a prior ecology survey, from historical records or simply as the result of individual observations, leading to invasive species surveys tailored to the plant in question.

More often than not, invasive non-native species are found growing on burn sides, river banks and railways, in gardens, alongside watercourses, and all over unused or derelict buildings situated near to or within rural areas. In the ecology survey calendar, the seasonal constraints of each type of assessment are different. As full bloom occurs in the spring and summer months, the optimal period for non-native species of plants spans between April and September, with the months between October and March classed as suboptimal depending on the plant’s characteristics.

Ecological Impact of Invasive Species

Recognised as one of the top five major threats to the ecosystem, invasive species possess the ability to cause detrimental harm to the environment and other organisms. Sharing similarities to the negative influence of the common grey squirrel on the far rarer red squirrel, invasive non-native species of plant are capable of out-competing native species, potentially causing the extinction of native plants in an effort to utilise all land and resources.

Such an outcome can then cause a chain reaction, leading to reduced food supply and habitat opportunities for local wildlife, endangering native animals alongside native plants. Posing risks to human health is also a possibility, as non-native invasive species can formulate new diseases, aggravate existing conditions and physically harm the skin, causing wounds via allergens, bites, stings or toxins. Since the introduction of biodiversity net gain (BNG), there has been a clear effort to improve the standard of the environment, but due to invasive species, biodiversity value will only be made worse.

Through the influence of non-native species of plants such as Japanese knotweed, for example, the repercussions of leaving it without any intervention can prompt devastating results to a new development or existing infrastructure. As it searches frantically for moisture, Japanese knotweed grows thicker and stronger while spreading further, clogging pipes, forcing through gaps in brickwork and growing on buildings. Once it has found opportunities to grow, it can gain enough strength to damage brick walls and concrete, severely harming buildings and causing additional harm if roots are hidden and growing underground.

UK Invasive Plant Species Identification

In order for an invasive non-native species to be identified and addressed correctly, the developer or homeowner staging the planning project would need to reach out to our ecological consultancy team to conduct the necessary assessments and create an accompanying report for the local planning authority to look over.

Invasive Species Risk Assessment and Management

At the assessment stage, identifying present invasive species during a broad ecological survey is the first step in the process. If they can categorically state that no invasive species are present, no further surveys will be needed. If, however, it is not possible to confirm a lack of invasive species on the site or they witness the invasive species or evidence of them, the ecological consultant will move on to a dedicated inspection for the species of plant.

On a set date, an ecological surveyor will attend the site in person following a desk study of the local area that will uncover any existing information regarding invasive species. A more thorough examination of the local vicinity will then play out, using a combination of the development plans and the circumstances of the occupancy of invasive species to determine if the project will be affected by non-native species or vice versa.

Based on an advanced knowledge of the species and the infringement it could have on development, certain mitigation measures or compensation measures will be devised. The aim of ecology surveys will be to retain as much ecological value as possible, but in the case of invasive non-native species, the potential for ecological value is outweighed by the likelihood of damaging the natural environment, often prompting the ecologist to remove it entirely.

Invasive Species Reporting

Over the course of the inspection, notes will be taken by the ecological consultant, and once the assessment has been completed, all of the key findings, outcomes and decisions will be documented in a non-native species report. Alongside lengthy information about the site and project, an overview of the present invasive species and all mitigation and compensation measures, if additional surveys are required, recommendations will appear within the report.

The report will be full of accurate data from the assessment and insightful comments from the ecological surveyor. It can be used to enhance the development plans and process, but most importantly, it will play a pivotal role in securing planning applications. The completed report can be passed on to the planning officer from the local planning authority, and as it will directly settle all existing issues regarding invasive species, it will give the local council no reason to deny planning permission.

Invasive Species Survey Methods

Services involved in an assessment of invasive-non native species may include:

Our Team

Via a strict vetting process and training programme, we guarantee that every member of our specialist team has the skills, experience and knowledge of non-native invasive species to assist developers and homeowners accordingly. Each surveyor has the necessary licensing and qualifications, and by situating them all over the country, Arbtech can sufficiently satisfy the unique needs and specifications of clients in practically any location.

Following years of carrying out assessments to support planning, we are experts in invasive non-native species, initiating methods of environmental protection, gauging issues posing risks to development, judging the impact of species in the UK in relation to natural and man-made habitats, and acknowledging the relevant laws and policies, such as the Environmental Protection Act 1990, the Conservation of Habitats and Species Regulations 2017, the Controlled Waste (Registration of Carriers and Seizure of Vehicles) Regulations 1991 and the Wildlife and Countryside Act 1981.

Instructing Us to Conduct Survey Work

If you have reason to believe that any of the invasive non-native species in the UK are in the vicinity of your development site, or if you’ve been directly told by your local authority that you need an inspection, Arbtech is here to help. Between our specialist team, we can assist with advice to avoid posing risks to your development, help in dealing with controlled waste, guidance on satisfying environmental protection considerations, and provide you with everything needed to attain approved planning conditions.

Utilising our in-depth understanding of non-native invasive species such as Japanese knotweed (Fallopia japonica), Himalayan balsam (Impatiens gladulifera) and giant hogweed (Heracleum mantegazzianum), our ecological consultancy is ideal for performing invasive species surveys. Receive a free quote by sending your details to us over the phone, via email or on our website, and we can then choose a date to conduct an assessment of your development site and support your path through achieving planning permission.