Below you will find information about some different types of ecology surveys and services we provide in conjunction with our arboricultural reports. There are three main ecological survey



Extended Phase 1 Habitat survey or Preliminary Ecological Appraisal

This is usually the starting point for understanding the ecological constraints imposed on the development by the site itself. It is a comprehensive audit of all the existing biodiversity features on the site – these may include habitats (a place something could be living), flora and fauna, or protected animal species. Included are invasive species, hedgerows, bats, badgers, amphibians, water voles, otters, dormice etc.

You may find that different local authorities use a range of terms to denote this type of ecological survey. These may include a Baseline ecological survey, Preliminary Ecological Appraisal, Extended Phase 1 Habitat Survey, Ecological Constraints Survey, Phase 1 Survey, Ecological Site Assessment, Ecological Site Appraisal, Ecological Scoping Survey and Ecological Site Walkover Survey – and variants thereof.



Protected Species Identified in the Ecological Survey

Where protected species are identified that may be threatened by the development we are able to recommend mitigation strategies to ensure that the development remains within the confines of the law.

A desk study is carried out to identify any records of rare or protected species. Reports are provided showing locations and all known species existing in or around the site in question.

This type of ecological survey is will work to establish and record the following:

  • Identify and classify all the different habitats found on the site
  • Establish which species and habitats are currently at the site, as well as those species which may visit or appear at another time of year
  • Assesses the implications the proposed development could have on those habitats
  • Suggest practical and realistic measures that will preserve important habitats and encourage biodiversity
  • Identifies any nature conservation or planning policy issues, and whether you need further surveys and ecological impact assessments


Biodiversity Net Gain

Biodiversity Net Gain is a new type of ecological survey which is set to become extremely significant in building and landscape development. Although not mandatory until 2023, we have begun to see more and more local authorities requesting Biodiversity Net Gain assessments prior to considering a development proposal. So what is it?

The principle behind Biodiversity Net Gain surveys, BNG for short, is quite simple: it requires that developers make plans to leave a site in a better ecological state than when they found it. But how does that actually happen in practice?

First, it requires accurate quantification of the existing biodiversity on a site and the ecological benefits provided by such features. This is achieved using a standardised metric called The Biodiversity Metric 3.1, a detailed description of which can be found on Natural England’s website. After this is calculated, a suitably qualified ecologist will work with the project development team to see which biodiversity features can be retained, which may be lost, and what can be done subsequently to enhance the biodiversity provision at the development site. Finally, if there is still a residual loss of biodiversity on the site, off-site mitigation measures may be considered (such as supporting an increase of biodiversity elsewhere)

Although this seems daunting to some, the early involvement of arboricultural consultants and ecologists can help developers retain key biodiversity features whilst still maximising the value of the development site.

We are more than happy to discuss your requirements, get in touch with us by calling 08000 141330 or via our contact page.



Mitigation Strategies for Ecological Survey

The picture below shows a hibernaculae under construction.

buidling a hibernaculae in accordance with ecological survey

Building a hibernaculae for lizards to confirm to ecological survey recommendations


Crown Tree Consultants built this to house hibernating lizards adjacent to a development site.

hibernaculae for ecological survey

Ecological Survey for planning purposes – a finished hibernaculae for lizards

Other strategies could include Biodiversity Action and Management Plans, Biodiversity Compensation and Offsetting, Invasive Species Action and Management Plans. Each development site will have its own challenges and unique variables which will be considered within the ecological survey and no two action plans will be the same. We are experienced in what will work and what will not. Our experts will make recommendations according to each individual site’s requirements.