Preliminary Ecological Appraisal Archives -

14 April 2022

The Power of Plants – why are plants vital?

Lucy Larkman Biodiversity, Ecology, Preliminary Ecological Appraisal 1

Our planet would not be able to support life if we did not have plants. Plants define different habitats that can support fauna species which contributes to biodiversity. The more numerous plant species there are within an area, the higher habitat diversity is present, which will therefore have a higher biodiversity value, leading in turn to a heathier and more stable ecosystem. Due to the increased pressures from industry, agriculture and development, the UK is one of the most nature-depleted countries in the world. The current levels of wildlife abundance is still declining, which would cause a disastrous effect on our country’s ability to support healthy ecosystems. The introduction of Biodiversity Net Gain (BNG) aims to increase the biodiversity value of new developments by a minimum of %10 net gain. If BNG is successful, then there is still a possibility that we can reverse the decline in the UK biodiversity.

How is biodiversity calculated?

The biodiversity value of a site is calculated by identifying and assessing the onsite habitats present prior to the development
being undertaken by using the extended Phase 1 habitat survey methodology. This survey involves an experienced ecologist identifying the various plant species and habitat types that are present onsite. The habitat is then classified by mapping the species assemblages identified onsite.

Conditions

The conditions of the habitats are also assessed, which is an important step when calculating the biodiversity value of the site as it can identify priority and protected habitats onsite, as well as identify which habitats can be enhanced to gain further biodiversity value. The information then influences the recommended mitigations measures that are required for the project to be undertaken.

Phase 1 Survey

Phase I survey is carried out as part of a Preliminary Ecological Appraisal (PEA) which uses the data taken from the site survey as well as species records and designated site data from the surrounding area to identify what ecological constraints could be present onsite. This information is then used to provide recommendations as to what further surveys and mitigation should be carried out for the development to proceed without triggering legislation.

Why is plant identification so important?

Plant identification is the fundamental aspect when classifying and assessing the conditions of habitats onsite. Plants provide an indication of the soil type, the nitrogen content, soil moisture and salt content, climate, light exposure, and temperatures. Habitats can be identified through indicator species, which are specific species that only grow in certain soil types and conditions. The habitat condition can also be assessed by recording the number and abundance of plant species within a certain habitat.

What is the optimal time to survey habitats?

A Phase I can be undertaken throughout the year, however, the optimum period for the survey is between April to September. This is because there are more identifiable features on a flowering plant and in some cases, you can only identify plants to species level if the flower is present. If the survey is undertaken within the suboptimal period, or certain types of habitats are present, that require a more detailed survey, a botanical survey may be required depending on what habitats are being affected by the proposed development.

Habitat identification and Biodiversity Net Gain (BNG)

Natural England developed the biodiversity metric to help calculate the BNG score of a development which has brought up a lot of debate on how effective the metric is. One of the most fundamental points is that for the calculation to work, the baseline habitat assessment needs to be accurate. An accurate evaluation of the habitat condition also identifies which habitats can be enhanced onsite as well what habits can be created to increase the biodiversity value of the development.

UK Habitat Classification System

The way that Natural England has addressed this need is by using the UK Habitat Classification System (UKHab). The UKHab classification system[1] was published in 2018 after extensive trialling by volunteers.

UKHab acts as a middle ground between the quicker Phase 1 habitat assessment and the more comprehensive and slower National Vegetation Classification (NVC) survey.

UKHab can classify habitats quicker than the NVC but with more information than the Phase 1 survey. UKHab also attempts to create a less subjective approach to habitat classification using a system similar to an identification key to help guide an ecologist to the correct habitat. Therefore, UKHab can be an accurate way of classifying the onsite habitat condition and type.

High rise buildings surrounded by flower meadow

Prior to it being used for the metric only a small number of consultants used UKHab it as its main classification system.

However, with this new introduction it is now vital for ecologists to learn and develop their skills with using the new system. Fortunately, BNG will be mandatory in the autumn of 2023, this means that there is now an opportunity for ecologists to get to grips with using UKHab.

This period of grace is also a fantastic opportunity to develop a good understanding of plant identification, especially as we are entering into spring and summer when it is easier to do so.

What can be done to increase the biodiversity in a development?

– Involving and consulting an ecologist in the earliest stages of a new development means that they can recommend what habitats can be created and enhanced, to increase the biodiversity of a site post-development.

– Plan to have a wide variety of habitats comprised of native species of local provenance and grown in the UK, which will support our native populations of insects and mammals. This also reduces the chance of introducing plant diseases and pests from abroad.

– Designing green infrastructure as part of a development have shown to not only increase environmental benefits but has also shown benefits for social and economic benefits.

– Create wildlife-friendly gardens to support local wildlife all year round.

Laoise Wilder, Assistant Ecologist

13 May 2021

What’s it like to work with an Ecologist?

Lucy Larkman Development & Planning, Ecology, Mitigation, Preliminary Ecological Appraisal, Preliminary Roost Assessment, Training bat survey, ecological appraisal, PEA, PRA 0

Onsite with the Ecologists

When invited to join our ecologists on a site visit of significant interest, as part of a whole team training exercise, I jumped at the chance. As Marketing Manager, my days are spent devoted to the screen, so I was dying to find out what these ecologists get up to when out in the field. It was the perfect opportunity to put the jargon into context; to learn what a Preliminary Ecological Appraisal (PEA) entails, how a Preliminary Roost Assessment (PRA) is executed and witness first-hand the work of our expert ecologists.

The Wildwood Ecology Team

On a delightfully bright, crisp, spring morning, the Wildwood team met at a disused RAF airfield near Avebury in Wiltshire. Led by ecologist, Peter Hacker, supported by Principal Ecologist Ivi Szaboova, this was a prime opportunity to bring the team together and allow our newest members to learn how these key services, the PEA and PRA, are performed.

The Site

The site was certainly captivating with far reaching views across open countryside; it felt like an abandoned war film set, with an eerie array of derelict buildings in various states of disrepair. An impressive aircraft hangar, built in 1916, is a key feature and understood to be one of a number of Grade II listed buildings onsite to be converted.

A majestic avenue of poplar trees provided a glimpse of the future development’s potential for a statement entrance. Restored and converted to form an exclusive residential development, the site clearly boasts huge potential. Sensitive and creative conversion aims to retain as much historic fabric as possible in keeping with the surrounding landscape, whilst maintaining and enhancing the natural habitats and biodiversity of the site.

The Project

At Wildwood Ecology, we relish the opportunity to work with like-minded, innovative architects such as those responsible for the development of this particular site. Developers recognised its ecological significance and understand the likelihood of potential constraints associated with protected species. By appointing Wildwood well ahead of works taking place, and working together from the outset, they have the best chance of meeting planning requirements and eliminating delays. Wildwood’s experienced ecologists will provide a comprehensive assessment of the site, advising on necessary surveys, and offering pragmatic solutions to meet the demands of planning regulations.

The Preliminary Roost Assessment

High-visibility clothing, protective headgear and site maps distributed, risk assessments completed and signed, the team split to complete the PRA for two distinct areas of buildings.

Ecologists boast rare superpowers that I never quite appreciated – with the nose of a bloodhound, they’re able to sniff out bat urine at 20m and have hawk-eye vision for spotting signs of life. Their attention to detail is second to none and I can immediately see that no stone goes unturned in carrying out a large-scale exercise such as this. At first glance, and when standing inside as the wind whipped through the window openings, the buildings devoid of rooves seemed to offer very little protection for a hibernating bat.

The PRA is an assessment, not only of the indication that bats are present and actively using the building but also the potential suitability of the building for roosting bats. It also takes into account the land surrounding the building. In this case, the landscape provided ample foraging ground, with little noise disturbance or light pollution from local residences. Looking for crevices and spaces in the brickwork where bats might find shelter and scouring the floor for bat droppings was the first job in hand. Whilst no bat droppings were located, an impressive selection of owl pellets were collected and identified as those of a barn owl.

Peter Hacker explained “When looking for roosts, bats prefer stable conditions with constant temperatures and humidity. The buildings we have here will have highly variable internal conditions and thus offer low suitability for use by bats”.

Crevice in the brick work

Finding owl pellets

The Preliminary Ecological Appraisal

Meeting for an alfresco lunch to compare notes and discuss findings provided an appreciation of the complexities of moderating the assessment process. What one ecologist might initially consider a building of low suitability for bats, another might grade of greater significance. Conversation and collaboration is critical and I begin to understand the significance of effective communication as an ecologist, amongst each other and with clients too.

Following assessment of the buildings and structures onsite, it was time to carry out the Preliminary Ecological Appraisal – a scoping survey where all habitats on site are recorded using either the Phase 1 or UK Habitat classification system, with details of flora present within each habitat recorded, along with any observations of fauna (or evidence of).

These preliminary surveys give ecologists a great baseline, enabling them to determine the potential for protected or notable species to utilise the site, plan species specific surveys that may be required, and gain an initial insight into the possible constraints and opportunities for the project.

For such a large area it was important to take time to walk the site systematically, ensuring to take in all areas and habitats. Starting with recording the floral species in the grassland that covered the majority of the site, the team then began mapping and recording areas of scrub, hedgerows and treelines. An active badger sett was uncovered, and time was taken to assess the feature for signs of activity. Old barbed wire adjacent to the sett entrances showed evidence of badger hair caught in the barbs. The holes were the characteristic D shape, with no debris or cobwebs covering the entrances – definitely one to note for further surveys! Working with clients in the early stages of a project allows for the least disturbance to wildlife. Although mitigation equates to further work, it is always preferable to be able to leave a badger sett undisturbed and plan the project around it; allowing the two to co-exist.

Preliminary Ecological Appraisal

Mapping and recording areas of scrub

It was amazing to see how quickly nature can take over a disused area and how species reside happily in a habitat that is a mix of man-made infrastructure and greenery. An area of open grassland on the edge of the site, was littered with rubble piles and building materials including corrugated iron sheets, roofing felt and plywood. It’s important for developers not to underestimate these habitats as they can become ideal refugia for a number of species. The ecologists’ eyes lit up with thoughts of the reptiles that might be utilising this particular area! Some of these materials are frequently used by ecologists when carrying out reptiles surveys, so their presence, along with tussocky unmanaged grassland, is a great sign that reptiles may be present. Ecologists too noted the habitats in the vicinity when determining suitability for protected species. They need to be pragmatic – if the habitat in the footprint of the development isn’t suitable for a species or there are considerable barriers to movement between their habitat and the development, there may not be a need to investigate further. However in this case, the suitable habitat will be directly affected, and there were no barriers to movement between the site and the wider landscape.

People Planet Purpose

My day onsite with the team was time well spent. So what have I learnt? I’ve learnt more than anything just how important it is to get out of the office and experience how we deliver our services! I have a far greater understanding of the day-to-day work of an ecologist, but I am also able to better appreciate the professionalism, expertise and attention to detail demonstrated by the Wildwood Ecology team. As a company, we take pride in our strong vision and clear values, but it was satisfying to see the team show just how far we go to do more than just ‘talk the talk’.

I especially look forward to seeing this project progress, under the careful guidance of our expert team, who will undoubtedly be working closely with the client to ensure this development secures the best possible outcome for both people and planet – one that works with, and alongside, nature.

Lucy Larkman, Marketing Manager