CLM – Hoopoe – A blog by nhbs

The Winter 2023 issue of Conservation Land Management

The Winter issue of Conservation Land Management (CLM), out soon, marks the end of volume 21. This issue covers a breadth of topics, including a discussion on the implications of rewilding on Britain’s native herpetofauna, the restoration of heathland on former conifer plantation sites, the native Black Poplar in Norfolk, the exciting potential of ecoacoustic monitoring for Hazel Dormouse surveys and the impressive Eddleston Water Project in Scotland. Read a more detailed summary of the articles featured in this issue below.

Eddleston Water is a tributary of the River Tweed, joining at the Scottish town of Peebles and draining a catchment of 69km². Over the last 200 years, land-use changes in the river valley have altered how the land drains and the river itself has been straightened to allow for the construction of a road and railway. As a result, the connection between the river and its floodplain has been severed, resulting in an increased risk of flooding downstream towards Peebles and changes to in-stream habitats important for wildlife such as Atlantic Salmon, Otter and lampreys. The Eddleston Water Project was set up in 2009 with the aim of reducing the flood risk to downstream communities and improving riparian habitats while maintaining local farm businesses. Interestingly, hydrological and ecological monitoring began two years before natural flood management (NFM) measures were first implemented, and so the Eddleston Water Project has provided, and continues to provide, empirical evidence for the effectiveness of NFM. Professor Chris Spray, the Tweed Forum’s Science Manager for the Eddleston Water Project, describes the NFM interventions that have been used, such as riparian tree planting, re-meandering the straightened channel, the creation of flood-storage ponds and the placement of high-flow restrictor log structures, and the benefits that these have provided across the Eddleston catchment.

Aerial image of a straight river being redirected around some trees at the Eddleston Water Project. The Eddleston water Project has involved a number of natural flood management measures, such as re-meandering straightened river channels. Image taken by Colin McLean. — The Eddleston water Project has involved a number of natural flood management measures, such as re-meandering straightened river channels. Colin McLean.

Ecoacoustic monitoring, the use of sound to determine a species’ presence or absence, has grown in popularity, but ecoacoustic studies have generally focused on ‘noisier’ animals, such as birds and bats. If this approach could offer a viable alternative to traditional monitoring methods for other species, it could provide a useful tool for ecologists and conservationists while also being less invasive for the animals themselves. A previous article in British Wildlife magazine demonstrated that the vocalisations of small terrestrial mammals (rodents and shrews) could be readily assigned to species with careful examination of recordings and spectrograms, suggesting that ecoacoustics could offer a new means of monitoring these animals. In this article, Jonathan Down, Stuart Newson and Alex Bush look specifically at the potential of acoustic methods in surveys of the Hazel Dormouse, a protected species that has experienced significant declines in the UK. The authors conducted a field test in south Cumbria in two areas where Hazel Dormice had recently been reintroduced in order to investigate how effective two different types of acoustic recorders, AudioMoth (a low-cost option) and the Song Meter Mini Bat Detector, were in detecting the presence of dormice. Here they describe their findings and highlight both the limitations and promise of ecoacoustics for dormouse surveys.

The native Black Poplar is the rarest hardwood tree in Britain – approximately only 7,000 trees remain in Britain. Unfortunately, the population is also heavily male-biased; in the Victorian era many female trees were felled due to the fluffy white seeds that they produce, which were considered unsightly. This and the isolated nature of the remaining trees means that sexual reproduction is essentially non-existent in the wild and many individuals are genetic clones of a small number of trees. Due to their rarity, native Black Poplars have been well recorded in most parts of the country, but in Norfolk records have not been updated since a 2007 census survey. To address this, the Otter Trust launched the Norfolk Black Poplar Project to formulate an accurate and up-to-date picture of the status of the Black Poplar in the county The locations of individual trees recorded in previous surveys were updated and mapped, and cuttings were taken from each tree for genetic testing and propagation. Genetic analysis has allowed each tree’s clonal type and sex to be identified, and here Ben Grief outlines the results from this work and discusses the potential to expand the Black Poplar population in Norfolk.

The Sandlings Heaths in Suffolk, once a vast unbroken landscape, have undergone significant landscape-scale changes in the last century. The planting of coniferous plantations played a part in this, but in 2006 the RSPB entered an agreement with the Forestry Commission to manage areas of clearfell in Dunwich Forest with the aim of restoring heathland and acid grassland habitats of high conservation value (compared to the scrub and trees likely to develop in the absence of management). Here, the authors focus on three cleared areas, describing the management that has been carried out since 2008 to restore the sites to high-quality heathland and what extensive vegetation monitoring has shown regarding the habitats that have since developed.

In Viewpoint, the final article in this issue, John Baker and Jim Foster from the Amphibian and Reptile Conservation Trust discuss the implications of rewilding for Britain’s reptiles and amphibians. The authors broadly refer to rewilding as an approach that aims to restore natural processes with minimal or no intervention, generally applied over larger spatial scales, and highlight why, particularly for our specialist and rare species, rewilding in this sense may not always be the most suitable approach.

A Natterjack Toad photographed sat in a field on the grass. — Natterjack Toad. Jim Foster/ARC.

A green tractor ploughing a field as part of a reserve management programme. — Continued reserve management is needed to maintain specific conditions for our rare herpetofauna. Jim Foster/ARC.

In this and every issue you can expect to see Briefing, keeping you up to date with the latest training courses, events and publications, and On the ground, which provides helpful tips and updates on products relevant to land management. Other features, such as Review, which can include letters from readers or updates from our authors, also regularly appear in CLM.

CLM is published four times a year, in March, June, September and December, and is available by subscription only. Subscriptions start from £22 per year. If you would like to read any of these articles, contact info@britishwildlife.com to pre-order a copy and receive the Winter 2023 issue when it is published, in mid-December.

The Autumn 2023 issue of Conservation Land Management

The Autumn 2023 issue of Conservation Land Management (CLM), out soon, is filled with an informative mix of articles, including the management of conifers for saproxylic invertebrates as part of our Habitat Management for Invertebrates series; the advantages and disadvantages of wildflower seed sowing; assessing and mitigating the disease risk associated with conservation translocations; and the story of Lower Bridge Meadow and how it is managed today. Read on below for a more detailed summary of what you can expect to see in this issue.

‘Wildflowers’ sown in an urban park near Harrogate, North Yorkshire. Kevin Walker

The sowing of wildflower seeds has increased over the past few years, and we now often see colourful wildflower displays in urban greenspaces or along road verges. These mixtures, however, are often made up of non-native species, and so their value can be questioned by botanists and ecologists. Dr Kevin Walker, Head of Science at the BSBI, discusses some of the key issues related to wildflower seed sowing, and looks at the advantages and disadvantages that this can have for native plants and other wildlife.

Approximately 129 species of beetle are associated with pine in Britain, 44 of which are specialist species of old-growth pine forests, but the ecology of saproxylic invertebrate assemblages associated with pine and other conifers remains poorly known. In the third article of the Habitat Management for Invertebrates series, Keith Alexander describes the features of conifer woodlands that are vital for saproxylic invertebrates, key considerations for landowners involved in managing areas with coniferous trees, and areas where new research is needed to improve our understanding of how to manage these habitats for dead-wood invertebrates.

Conservation translocations refer to the movement of animals or plants from one location to another for the purposes of conservation. One important aspect to consider during translocation is the risk of disease; the movement of an animal also includes all the viruses, bacteria and parasites it may carry. Sophie Common and Tony Sainsbury, who are both involved with the Disease Risk Analysis and Health Surveillance project, part of the Institute of Zoology at the Zoological Society of London, describe the impact that introduction of a novel pathogen can have on a translocated animal itself and also on other wildlife, and provide some UK-based case studies, such as the treatment of tapeworm in Hazel Dormice and the screening of the pathogen Crithidia bombi in Short-haired Bumblebees prior to their reintroduction, to illustrate how the risk of disease is assessed and managed.

Quarantining and screening protocols were used to ensure that translocated Short-haired Bumblebees were free from the pathogen Crithidia bombi. DRAHS

Bucklebury Common, in West Berkshire, is a 340ha stretch of land and the largest open heath in the county. Used as a truck depot in the Second World War, the common is now in part designated as a Local Wildlife Site for its heathland, veteran trees and woodland. The heath is an important habitat for rare birds such as Nightjars and Woodlark, and a necessary part of its management is to control colonisation by Silver Birch from surrounding secondary woodland to prevent it from dominating the heath. After several methods, such as weed-wiping and hand pulling, were attempted with mixed success, an excavator was brought to the site with three different attachments (a flail head, a root fork and a grab) to trial an effective and possibly novel technique for removing birch seedlings. In this article, Alex Cruickshank describes the success of the different methods that were tested, and outlines how management of Bucklebury Common might develop in future.

The nine-tonne excavator with a rotating selector grab. Alex Cruickshank

The final article in this issue focuses on a much smaller fragment of land. Lower Bridge Meadow is a 0.86ha Local Wildlife Site in Herefordshire, designated as such for its diversity of wildflowers. Interestingly, the meadow has a long-recorded land-use and management history, and here James Marsden and Helen Woodman describe both past and current approaches to management and speculate what the future may hold for this species-rich grassland. Lower Bridge Meadow is likely to be just one example out of hundreds of small sites that are set aside for the wildlife, but the failures and successes of their management are seldom shared among landowners. CLM is an ideal place to share these experiences – if you are managing a slice of land for wildlife, no matter how compact or inconsequential it might seem, we would love to hear about it. Feel free to get in touch with us to find out more about writing for CLM.

Hay cutting at Lower Bridge Meadow. James Marsden

In this and every issue you can expect to see Briefing, keeping you up to date with the latest training courses, events and publications, and On the ground, which provides helpful tips or updates on products relevant to land management. Other features, such as Review, which can include letters from readers or updates from our authors, also regularly appear in CLM.

CLM is published four times a year, in March, June, September and December, and is available by subscription only, delivered straight to your door. Subscriptions start from £22 per year. If you would like to read any of these articles, back issues are also available to purchase individually (subject to availability).

The Summer 2023 issue of Conservation Land Management

Soon to hit our readers’ doormats, the Summer 2023 issue of Conservation Land Management (CLM) is filled with a mix of informative and practical articles. Excitingly, this issue delves into the marine world with a look at seagrass restoration approaches in southern England. Other articles include river restoration in the Ullswater Valley in Cumbria, the management of problem umbellifers and the conservation of the European Turtle Dove. Read a summary of the articles and other features in this issue below.

Seagrass seed harvesting by Esther Farrant

More than 90% of the UK’s seagrass has been lost over the past few centuries, driven by disease, pollution and physical damage to the seabed caused by trawling and other fishing methods. To halt and reverse this trend, several projects during recent years have sought to restore seagrass meadows where they are no longer present. One of these, supported by the ReMEDIES partnership, is focusing on five Special Areas of Conservation (SACs): Isles of Scilly Complex, Essex Estuaries, Fal and Helford, Plymouth Sound and Estuaries, and Solent Maritime. The Ocean Conservation Trust is leading the work in Plymouth Sound and Solent Maritime, and in this article, Esther Farrant details the various methods being trialled to cultivate and plant seagrass seeds and seedlings to restore seagrass meadows in southern England. In addition to planting, one other important aspect of seagrass recovery is to prevent further damage to existing seagrass meadows, and so Advanced Mooring Systems (AMS) have been designed as an alternative to traditional swing moorings, the chains of which can drag along the seafloor – Esther describes the design and installation of AMS in Plymouth Sound and Solent Maritime and explains why these are a less damaging option.

There are around 70 umbellifer species, both native and non-native, in the UK. A family of mostly herbaceous plants, umbellifers provide many benefits for wildlife, particularly invertebrates, but some species can pose a risk to people and livestock in certain situations. Robert Mitchell and Max Wade highlight the most troublesome species – such as Giant Hogweed and Hemlock – that land managers should be aware of, and describe their identification and the problems that these plants can cause, including biodiversity loss and phytophotodermatitis, which commonly appears as ‘strimmer’s rash’. The authors also cover the different treatment options available to manage these plants, and provide examples of control programmes that dealt with different species of umbellifers that posed a risk at two different sites.

Adult Turtle Dove drinking from a pond by John Buckingham

The European Turtle Dove has experienced a dramatic decline in the UK and elsewhere in Europe, leading to the launch in 2018 of the International Species Action Plan for the Turtle Dove. This identified four conservation objectives: maintain and increase good quality breeding habitat, eradicate illegal killing in Europe, ensure that hunting levels do not exceed sustainable levels, and maintain and increase good quality habitats at migratory stopover sites and wintering grounds. Operation Turtle Dove, a partnership between the RSPB, Pensthorpe Conservation Trust and Natural England, works with landowners and farmers to deliver suitable feeding and nesting habitats for the Turtle Dove in the UK. In this article, Rick Bayne, Guy Anderson and Jos Ashpole describe the actions landowners can take to achieve this aim, including sowing bespoke seed mixtures as supplementary feed, providing an accessible drinking source and maintaining a dense vegetation structure for suitable breeding habitats.

Goldrill Beck, Ullswater, post-restoration by Jonathan Holdsworth

Rivers as we know them in the UK are the result of modification by humans over time. Images of neat and straightened single-thread channels are usually what spring to mind, but, if left untamed, rivers would naturally consist of multiple channels weaving their way through wet woodlands and floodplains. Restoring rivers to achieve this more dynamic system can sometimes be met with hesitation by landowners, however, especially when the end result is uncertain. Riverlands, a partnership between the National Trust and the Environment Agency, has delivered two large-scale restoration projects in the Ullswater Valley in Cumbria keeping the sensitivity of the farmed landscape in mind, and in this article Rebecca Powell explains the approaches used in both of these projects and what the impact has been on the river habitats post-restoration.

In response to the articles on weir and dam removal from rivers and the restoration of ghost ponds in the Spring 2023 issue, Review includes a letter from one of our readers offering an insight into the cultural value of these features and the risk of damaging a registered heritage asset. In this and every issue you can also expect to see Briefing, keeping you up to date with the latest training courses, events and publications, and On the ground which provides helpful tips or updates on products relevant to land management.

CLM is published four times a year, in March, June, September and December, and is available by subscription only, delivered straight to your door. Subscriptions start from £22 per year. If you would like to read any of these articles, back issues are also available to purchase individually (subject to availability).

If you are involved in a conservation project and think your experiences could be useful to other practitioners, we would love to hear from you. Feel free to contact us if you are interested in writing for CLM – we will be happy to discuss your ideas with you.

Conservation Land Management: Spring 2023

The Spring 2023 issue of Conservation Land Management (CLM) is now out, the first of volume 21, which marks CLM’s 20th year in existence. This issue features an exciting addition to CLM, a brand new Habitat Management for Invertebrates series, beginning with two articles. The remaining articles in this issue cover a range of subjects, including ghost pond restoration and the removal of weirs and dams to improve river habitats – read a summary of the articles below.

The new Habitat Management for Invertebrates series aims to encourage those who are involved in making management decisions on a site to consider invertebrates. In the series’ first article, Roger Morris, Keith Alexander and Robert Wolton highlight the key factors that site managers need to think about when incorporating invertebrates into management plans, discussing the types of data that are most useful and how to interpret these data.

The next article in the series goes on to focus specifically on the management of Aspen forests in the Scottish Highlands. There are around 15 rare or notable species of fly that are associated with the decaying cambium layer under the bark of dead Aspen, the Aspen Hoverfly Hammerschmidtia ferruginea being one of these. The Aspen Hoverfly is considered a flagship species – the correct management for the Aspen Hoverfly benefits several other key species. The priority in management is to make sure that there is a fresh supply of dead wood, and Iain MacGowan describes how this achieved in a way that provides optimal conditions for Aspen Hoverfly larvae, by either moving snapped branches with a diameter over 25cm closer to ground or by bringing in dead wood from adjacent sites. Look out for more articles in the Habitat Management for Invertebrates series in future issues of CLM.

Aspen in the Scottish Highlands. Iain MacGowan/NMS

Only 1% of the rivers in England, Wales and Scotland are free from artificial barriers, which pose a major threat to river wildlife. They lead to habitat fragmentation, interrupt the flow of sediment and obstruct the movement of fish and other organisms. Although some of these barriers have their uses, such as for hydropower, drinking water and irrigation, many are now obsolete. Tim Jacklin outlines the benefits to river habitats of removing these barriers and illustrates possible approaches by describing several different weir removal projects in the UK.

Before and after the removal of a weir in the Dovedale valley. Tim Jacklin

With the move to more intensive farming during the last century, many farmland ponds, which were once dotted across much of the British countryside, were filled in. But not all is lost. These former ponds, known as ‘ghost ponds’, can be resurrected; the seeds of wetland plants and stonewort oospores are still viable and, once a pond is restored, wetland plant communities are quick to recolonise. Carl Sayer et al. describe how to locate ghost ponds, the methods used for excavation, and the management of ponds post restoration.

Soils play a key role in a number of ecosystem services, such as carbon sequestration, water management and nutrient cycling, and although they were once largely ignored, there is an emerging understanding of the importance of improving the health of soil, particularly in an agricultural context. With a focus on soils on farms, Becky Willson, from the Farm Carbon Toolkit, discusses what soil health is and why it is important, and the key characteristics of good-quality soil.

In this and every issue you can expect to see Briefing, keeping you up to date with the latest training courses, events and publications, and On the ground which provides helpful tips or updates on products relevant to land management. Other features, such as Review, which can include letters from readers or updates from our authors, also regularly appear in CLM.

A look back over volume 20 of Conservation Land Management

The Winter issue of Conservation Land Management magazine (CLM) landed on our readers’ doormats in December, marking the end of volume 20. Read on to discover what featured in the most recent issue, and some highlights of articles across the entire volume.

The Winter 2022 issue of CLM

Reedbed restoration has benefited a large number of species, the bittern being a classic example; by 1997, ‘booming’ (territorial) males of this species had declined to 11, but this has now increased to over 200. Various techniques and machinery are used to manage reedbed habitats, and in this article Graham White and Steve Hughes provide an overview of the different methods and key strategic issues, such as what to do with cuttings, that need to be considered for the future.

Up until 2010, Nethergill Farm, in the Yorkshire Dales, was managed for intensive sheep rearing. Now under new owners, the current management ethos is to promote biodiversity. Gordon Haycock describes how, in addition to other ecological restoration work, a change to reduce sheep stocking densities and introduce free-roaming cattle across the farm has benefited biodiversity and increased the area of Priority Habitats, such as blanket bog and lowland meadow.

In 1965, the Nature Conservation Review was initiated by the Nature Conservancy, with the aim to identify and assess areas important to nature conservation in the UK. In the 1960s/70s, as part of the review, 26 calcareous grasslands in Dorset were surveyed, and in 2018/19, nearly half a century later, six of these were surveyed again. Peter Hawes et al. compare the results of the two surveys, with the aim of determining if the vegetation had markedly changed during the time between surveys, and discuss the gains and losses that have been made.

During the recent political turmoil in the UK, there were rumours that England’s new agri-environment scheme, Environmental Land Management (ELM), would be scrapped in favour of a return to area-based payments. Thankfully, the future of ELM is now looking more certain, but there are still many unanswered questions surrounding the details. In light of this, Alice Groom provides the latest on farming policy development in England, and also in Wales, Northern Ireland and Scotland.

The selection process behind the formal designation of Sites of Special Scientific Interest (SSSIs) in England is based entirely on the compartmentalisation of a site based on the habitat types within it and the rarity of the species found there. Lacking from this process, however, is consideration of habitat connectivity and the ecosystem services that these habitats provide. In the context of two peat bogs in the north of England, one of which is currently threatened by development, Roger Meade asks if the current selection process is up to scratch.

Highlights from volume 20

This volume has included some fantastic articles, from conservation efforts tailored to specific species to wider management approaches and techniques. Below is a selection of articles from 2022:

Spring 20.1

· Habitat translocations: risks, advantages and key considerations – John Box explains the possible risks and potential benefits of habitat translocations, and sets out the key considerations of this approach.

· Conserving breeding goldeneye in Scotland through nestbox construction – Peter Cosgrove et al. share their observations and lessons learnt from constructing and installing nestboxes for the rare goldeneye duck along the River Spey.

· Environmental DNA for ecologists – Dr Helen Rees provides an overview of eDNA analysis and demonstrates how ecologists can use this technique in conservation.

Summer 20.2

· A guide to conservation land management and greenhouse gas emissions – Malcolm Ausden and Rob Field describe how different habitats and their maintenance impact the climate, and highlight the management practices that provide the greatest climate benefits.

· Viewpoint: Dams without beavers: could Beaver Dam Analogues yield benefits in the UK? While we wait for beavers to become more widespread in the UK, Richard Fleming argues that we need to replicate the benefits of natural beaver dams through the use of Beaver Dam Analogues.

Autumn 20.3

· Eleven years of manual eradication of Japanese knotweed – Claire Malone-Lee reflects on 11 years of manual control of Japanese knotweed in Aston’s Eyot nature reserve, in east Oxford, and demonstrates that it is possible, particularly on small sites or where knotweed is not overly dominant, to successfully eradicate this troublesome invasive without the use of herbicides.

· Time to rewet, replant and restore Yorkshire’s peatlands – Jenny Sharman describes the work of the Yorkshire Peatland Partnership and the process of peatland restoration in Yorkshire where signs of recovery have quickly become apparent.

Three years after peatland restoration began. Jenny Sharman/YPP

Twenty years of CLM

The end of volume 20 is an important milestone for CLM, marking its 20th year in print. Throughout this time, the magazine has strived to showcase innovative conservation projects, novel management techniques and personal experiences and insights of those working on the ground. Volume 21 is set to feature all of this and more, including a brand new series on habitat management for invertebrates and a look at some of the restoration approaches used in marine conservation.

CLM is published four times a year in March, June, September and December, and is available by subscription only, delivered straight to your door. Subscriptions start from £22 per year. If you would like to read any of these articles, back issues are also available to purchase individually (subject to availability).

Conservation Land Management: Autumn 2022

From a close look at two very different restoration projects in Yorkshire to the eradication of Japanese knotweed without the use of herbicides, the Autumn issue of Conservation Land Management (CLM) covers a variety of topics and themes relevant to those involved in managing land for nature. Below is a summary of the articles featured in this latest issue.

The first of the Yorkshire-based articles, authored by Sarah Lonsdale of the North York Moors National Park Authority (NYMNPA), describes the River Esk Restoration Project. The River Esk flows through the North York Moors and is the only river in Yorkshire to support populations of the rare freshwater pearl mussel. Agricultural pollution and sedimentation threaten the mussel’s habitat and the Esk’s water quality, however, and the Esk Restoration Project aims to address these pressures through habitat creation and restoration, farm infrastructure grants and targeted one-to-one farm advice. Sarah describes how, through this project, the NYMNPA has worked with farmers and landowners to reduce agricultural pollution via riparian habitat creation and improvements in on-farm infrastructure. This has involved, for example, the installation of in-field solar-powered water troughs to reduce riverbank erosion caused by livestock trampling and the creation of wide habitat buffers to help reduce the amount of pollutants reaching the river – Sarah describes these and other approaches in more detail, and discusses the future of the project.

Before (left) and after (right) riverbank restoration. Chris Watt (left); Sarah Lonsdale (right)

The second article set in Yorkshire is focused on peatlands. Yorkshire’s peatlands contain 27% of England’s blanket bog and support an abundance of wildlife, but changes in land management, for example through drainage and heavy grazing, have led to their degradation. In this article Jenny Sharman describes the impressive work undertaken by the Yorkshire Peatland Partnership to reverse this trend and restore and rewet Yorkshire’s peatlands. Signs of recovery have quickly become apparent, and Jenny guides us through the process of peatland restoration, which begins with initial surveys to assess the extent of the damage using satellite imagery in preparation for work on the ground where a myriad of approaches are used, from using diggers to revegetate exposed peat to installing timber sediment traps and coir logs to help slow the flow of water and retain sediment.

Looking now to a different habitat, Robin Pakeman discusses the management of machair, an extremely rare coastal habitat only found in western Ireland and western and northern Scotland. It develops on shell sand in exposed coastal areas, and refers to the plain behind sand dunes. Human use of machair has a long history, and traditional management combined with specific environmental conditions has produced this wonderfully unique habitat, famous for its spectacular floral displays and bird and insect communities. Crofting, a form of land tenure that only occurs in north and west Scotland, has had a strong influence on Scotland’s machair, and in this article Robin explores the management of both arable and grassland machair, and describes the diversity of wildlife associated with this habitat.

Machair is known for its spectacular floral displays. Robin Pakeman

The infamous Japanese knotweed is a problematic non-native invasive species in the UK, and the general consensus regarding its control suggests that the use of glyphosate-based herbicides is required. Aston’s Eyot nature reserve, in east Oxford, was previously a rubbish dump, and since it was badly capped in the late 1940s Japanese knotweed established itself there, suppressing the growth of many other plants that would otherwise thrive. To combat this issue, the Friends of Aston’s Eyot, a group formed in 2010 to care for the nature reserve, decided to trial different approaches to management of knotweed. The trial area was divided into three; two of these were to be treated with glyphosate. In the third area knotweed was to be cut and its emerging shoots would be pulled out by hand. Claire Malone-Lee took responsibility for this third area, and in this article reflects on eleven years of manual control and demonstrates that it is possible, particularly on small sites or where knotweed is not overly dominant, to successfully eradicate Japanese knotweed without the use of herbicides.

When the Able Marine Energy Park project on the Humber Estuary was given the go-ahead, Roger Morris was concerned for the internationally important flock of black-tailed godwits that resided there, and the mudflats that they depended on. The final article in this issue, a viewpoint piece by Roger, asks if it is possible to create sustainable mudflats as a mitigation measure, and explains why it is difficult to stop or slow the process of mudflat becoming saltmarsh. He describes the processes behind saltmarsh and mudflat development, and addresses the different approaches that have and can be used for mudflat creation.

In this and every issue you can expect to see Briefing, keeping you up to date with the latest training courses, events and publications, and On the ground which provides helpful tips or updates on products relevant to land management. Other features, such as Review, which can include letters from readers or updates from our authors, also regularly appear in CLM.

A guide to conservation land management and greenhouse gas emissions

Managing habitats for the benefit of wildlife can often contradict climate priorities. In the Summer 2022 issue of Conservation Land Management (CLM), Malcolm Ausden and Rob Field describe how different habitats and their maintenance impact the climate, and highlight the management practices that provide the greatest climate benefits. Here you can read a summary of the article.

Quantifying the impacts of habitat management on the climate

The influence of different habitats and their management on the climate can be measured by estimating the net flux of the most important greenhouse gases (GHGs): carbon dioxide, methane and nitrous oxide. The contribution of the latter two is usually expressed in terms of the amount of CO₂ needed to produce the same level of warming (tonnes of CO₂ equivalent; _t CO_2e), as determined by global warming potential (GWP) of the different gases. A positive GWP indicates a positive warming effect, whereas a negative GWP shows a cooling effect. GWP values are usually expressed in comparison to the warming potential of CO₂ over 100 years.

The effects of conservation land management on GHG flux

In the full CLM article, the authors describe the GHG flux of the main types of habitats in Britain, and how this is affected by conservation management. The habitats included are listed below, starting with those that produce the greatest overall warming effect on the climate, and finishing with those that have a cooling effect.

Intensive arable on organic soil
Intensive grassland on organic soil
Eutrophic/mesotrophic open water
Lowland wet grassland on organic soil
Intensive arable on mineral soil (incl. emissions from farming operations)
Bare peat
Oligotrophic open water
Heather-dominated drained bog
Intensive arable on mineral soil (excl. emissions from farming operations)
Lowland and upland heathland
Unimproved low-input grassland (incl. LWG on mineral soil)
Near-natural bog
Improved grassland (excl. emissions from farming/livestock operations)
Near-natural fen
Mudflat
Conifer plantation on mineral soil (managed on a 55-year-rotation)
Saltmarsh
Dry broadleaved woodland (mean over first 100 years)
Wet woodland
Dry broadleaved woodland (mean over first 30 years)

Conifer plantations can have a cooling effect on the climate if grown on mineral soil and managed on a 55-year-rotation. Image by Andrew Arch via Flickr.

Intensive arable on organic soil (soils derived from peat) produces the biggest warming effect per unit area, as large quantities of CO₂ are released via oxidation of dried-out peat that is repeatedly exposed during the cultivation process. The manufacture and use of nitrate fertilisers and the use of machinery also contributes to significant emissions of GHGs. At the other end of the spectrum is dry broadleaved woodland, particularly during the first 30 years after its establishment. The GHG flux of woodland fluctuates depending on its age, species composition, the density and growth rate of trees, and management. For unmanaged woodland, the net uptake of CO₂ is low while trees are small, and planting of trees can even lead to a net release of CO₂ as a result of soil disturbance. The rate of CO₂ uptake increases during the main growth stage of the trees, slowing as they mature, although carbon does continue to accumulate in the soil.

Ways to benefit both the climate and wildlife

Conservation management can provide climate benefits either by reducing the amount of GHGs released into the atmosphere, or by actively removing them (i.e. carbon sequestration). For example, rewetting drained peatland reduces, and should eventually stop, the release of CO₂ that occurs through the drying out and oxidation of peat. Although there is an initial release of methane after rewetting, accumulation of carbon in the peat will resume. The climate benefits per unit area of wet peatland are surprisingly low compared to some other types of habitat, but due to the large quantities of carbon stored within the vast expanse of peat in upland Britain, rewetting drained areas is an incredibly important measure to prevent the ongoing release of CO₂, and will also provide a number of benefits for wildlife.

On organic soils used for arable, the greatest climate benefits per unit area come by creating wet woodland, as this prevents the oxidation of the peat and allows carbon to accumulate during tree growth. There are, however, limited opportunities to create new wet woodland on ex-arable organic soils and to keep them adequately saturated. The next best option is the creation of swamp/fen, which offers far greater climate benefits than agriculturally drained peat soils, even though the habitat itself has an overall GWP₁₀₀ near to zero.

Swamp/fens offer far greater climate benefits than agriculturally drained peat soils. Image by Liz West via Flickr

The authors look at multiple management approaches and describe the climate benefits of different types of habitat restoration and creation. All the methods listed below are beneficial for the climate, and are ordered here by the magnitude of their cooling effect, from the least to the greatest.

Creating swamp/fen on ex-arable on mineral soil
Rewetting drained bog
Creating lowland wet grassland on ex-arable on mineral soil
Creating intertidal habitat on ex-arable on mineral soil
Establishing broadleaved woodland on ex-arable on mineral soil
Creating lowland wet grassland on drained grassland on organic soil
Creating swamp/fen on drained grassland on organic soil
Creating lowland wet grassland on ex-arable on organic soil
Creating swamp/fen on ex-arable on organic soil
Creating wet woodland on ex-arable on organic soil

A large aspect of the management of semi-natural habitats involves cutting and clearing vegetation in order to maintain a particular vegetation structure and to slow or reverse succession. But this means that the amount of carbon accumulated in the soil and vegetation is reduced. In addition, the removal of vegetation is often carried out by using domestic livestock, which release large quantities of methane, by machinery, which is often powered by fossil fuel or biofuel and releases CO₂, or by burning, which also releases CO₂.

Domestic livestock release large quantities of methane. Image by USDA NRCS Montana via Flickr

But there are changes that can be made to management that can help contribute to a habitat’s cooling effect. For example, the amount of vegetation that is removed from a site can be reduced to allow more carbon to be stored in the vegetation or soil. In some instances this can mean allowing a site, such as a swamp/fen, to develop into woodland or scrub. This can contradict conservation goals where maintaining an early successional habitat is the priority, but can be an option for sites that are currently poor for wildlife.

Another option is to change the method used to clear the vegetation. One way that this can be achieved is by swapping livestock for grazers that release less methane per quantity of vegetation removed. Ponies, for example, produce much lower levels of methane compared to cattle and sheep, although before changing the type of livestock it is important to understand that different livestock have different effects on vegetation structure and composition. In the full article, the authors explore this and other changes that site owners can make to increase the cooling effect of different habitats and their management.

It can be difficult for conservationists and land managers to know how to best manage a site in the interest of both nature conservation and the climate, and in many cases there are trade-offs between maximising the benefits for the two. But as the article demonstrates, there are restoration approaches that can be used that provide significant climate and conservation benefits, and it is helpful to consider and quantify the net flux of GHGs before implementing any changes to conservation management plans.

Other articles featured in the Summer 2022 issue include:

Saltmarsh restoration through flash re-creation
Measuring conservation success on farmland
Viewpoint: Dams without beavers: could beaver dam analogues yield benefits in the UK?

In this and every issue you can expect to see Briefing, keeping you up to date with the latest training courses, events and publications, and On the ground which provides helpful tips or updates on products relevant to land management. Other features that regularly appear in CLM include Viewpoint, a similar length to our main articles, but here authors can voice their own views on various conservation issues, and Review, which can include letters from readers or updates from our authors.

CLM is published four times a year in March, June, September and December, and is available by subscription only, delivered straight to your door. Subscriptions start from £22 per year. Previous back issues are also available to purchase individually (subject to availability).

If you are involved in a conservation project and think your experiences could be useful to other practitioners, we would love to hear from you. If you are interested in writing for CLM feel free to contact us – we will be happy to discuss your ideas with you.

Environmental DNA for Ecologists

In the Spring 2022 issue of Conservation Land Management (CLM) Dr Helen Rees, Director of the Biotechnology group at ADAS, provides an introduction to environmental DNA (eDNA) analysis and its potential uses in conservation. Here you can read a summary of the article.

Animals naturally shed DNA into the environment via, for example, faeces, saliva, urine and skin cells, and this DNA (collectively known as eDNA), can be extracted from environmental samples, such as water, sediment and soil, for genetic analysis. It is possible to screen for species-specific DNA in these samples, and its successful detection determines the recent presence of the target species at the site from which the sample was collected. eDNA analysis therefore offers a non-invasive method for ecological surveys, and as DNA can persist in the environment from a few days to a couple of weeks, it can be used to indicate that a species has visited a site even after it has moved on.

Pros and cons of the technique

30ml ladle used to collect water samples. Image credit: Claire Baker

One of the main advantages of eDNA analysis is that the target species does not have to be caught, disturbed or even seen to get a positive identification. Not only is this method less invasive for the animal, but it also saves the surveyor a great deal of time in the field when monitoring species that are elusive, rare or require a licence to survey. It can also be a cost-effective method in comparison to traditional techniques, mainly due to the simplicity of collecting samples and the low-cost sampling equipment used.

eDNA analysis has proven to be a robust technique, but errors can occur. If there is any cross contamination between samples either in the field or the laboratory, for instance, this can lead to false-positive results, and so a carefully controlled laboratory set up is imperative to prevent contamination during the different stages of eDNA analysis.

How eDNA analysis is used – great crested newts

Water samples added to tubes of preserving fluid. Image credit: Claire Baker

One of the most well-known examples of how eDNA is being used in the UK is for the detection of the great crested newt. A study commissioned by Natural England and led by the Freshwater Habitats Trust demonstrated a detection rate of 99% for eDNA testing, but only 76%, 75% and 44% for bottle trapping, torching and egg searching respectively. eDNA techniques are particularly useful when used on ‘borderline’ ponds where the presence of great crested newts is unlikely based on the habitat. In this instance, a negative eDNA result quickly confirms this assumption, but traditional bottle-trapping/torching surveys would need to be repeated multiple times to confirm that newts are absent.

In the full article Helen describes how eDNA analysis works behind the scenes in the laboratory, including an explanation of how the polymerase chain reaction – a key part of eDNA analysis – works and how its results are interpreted. The advantages and drawbacks of using eDNA are discussed in greater detail, and further examples of how this technique is applied to the survey of other species are also given.

ADAS eDNA kits

NHBS has partnered with ADAS to provide you with the kits and analysis you need for the 2022 season. ADAS is the only laboratory to correctly identify all samples in every great crested newt eDNA proficiency test to date, and can also provide analysis to identify bat species from collected droppings. A range of services are available under a tiered pricing system to ensure that you get your results when you need them. Take a look at the kit options below to find out more.

Great Crested Newt eDNA Kit
Each kit includes:

Protocol sheet
Sterile 30ml ladle
Sterile bag
Sterile plastic pippette
2 x Sterile gloves
6 x Conical tubes, 2/3 full of preserving fluid

Bat Genotyping (eDNA) Kit
Each kit includes:

8 x Screw top Eppendorf tubes
4 x Sterile forceps
4 x Sterile gloves
Sample record sheet
Return postage label

Cardboard tree guards: a suitable and sustainable alternative to plastic?

In the forthcoming Winter 2021 issue of Conservation Land Management (CLM) magazine Jenny Price and Lyndsay Wayman-Rook describe how the Old Chalk New Downs project in Kent has been trialling biodegradable cardboard tree guards as an alternative to plastic. Here you can read a summary of the article.

The main purpose of a tree guard is to protect newly planted trees from browsing, but they also provide other benefits; they create a more favourable microclimate that helps to promote the growth of young trees and protect the plants from wind, competing vegetation, herbicides and water loss. Wooden and wire tree guards have been in use since the 1820s, but it wasn’t until the 1980s that plastic versions were first used. As a cheaper material compared to alternatives, plastic is now widely used for guards in planting schemes.

It has been predicted that between 1980 and 2020 over 200 million plastic tree guards were used, and with the UK government’s ambitious target to increase woodland cover by 19% by 2050, the rate of tree planting is sure to increase, as will the number of tree guards used. It is recommended that plastic tree guards are removed 2–3 years after their installation, but they are often left behind to degrade in the landscape, which can be both damaging to the wider environment (although the impacts of this are not yet fully understood) and to the tree itself. It is possible to recycle plastic polymer guards, but not if they have already started to break down or are contaminated.

Cardboard tree guards offer a viable alternative to plastic. Lyndsay Wayman-Rook and Hannah Simmons

The Old Chalk New Downs project, hosted by Kent County Council and funded by the National Lottery Heritage Fund, has been exploring alternative options to plastic tree guards. It first compared the costs of different materials, including plastic, cardboard and biodegradable plastic, and looked at the pros and cons for each guard type. For instance, one of the advantages of a cardboard guard is that it does not need to be removed after installation, but it may deteriorate a lot faster than other guard types, especially in particularly wet areas.

Biodegradable tree guard options Lyndsay Wayman-Rook

It was decided that cardboard guards would be used for this particular project, owing to their no-plastic design and availability. Between autumn 2019 and spring 2021, more than 9,000 trees with cardboard guards were planted across seven hedgerows at three different sites. How these fared was closely monitored, and the success rate of planting was high. One key aspect of this project was to gather feedback from landowners and contractors involved in sourcing and using the cardboard guards, and overall the comments were positive.

In the full article Jenny Price and Lyndsay Wayman-Rook discuss how the cost of tree guards made from plastic, biodegradable plastic and cardboard compare, and provide an in-depth overview of how cardboard guards performed when used for hedge planting, both in this project and in examples from elsewhere. They also include a summary of the feedback received from landowners and contractors, and clearly describe the advantages and disadvantages of different tree guard options.

Plastic tree guards are commonly used in planting schemes. Lyndsay Wayman-Rook

Other articles featured in the Winter 2021 issue include:

RSPB Nigg Bay: Scotland’s first coastal realignment
Helping to make and document conservation decisions: the Evidence-to-Decision tool
The Stage Zero approach – lessons from North America on restoring river, wetland and floodplain habitats
Viewpoint: Plant fewer, better: good tree and shrub establishment

In this and every issue you can expect to see Briefing, keeping you up to date with the latest training courses, events and publications, and On the ground which provides helpful tips or updates on products relevant to land management. Other features that regularly appear in CLM include Viewpoint, a similar length to our main articles, but here authors can voice their own views on various conservation issues, and Review, which can include letters from readers or updates from our authors.

Conservation Land Management: Autumn 2021

The Autumn issue of Conservation Land Management (CLM) covers a variety of themes relevant to those involved in managing land for conservation, from the creation of bare ground habitats to incorporating climate objectives into the management of wildlife sites. Here, Assistant Editor Catherine Mitson provides a summary of the articles featured in this latest issue.

Ingleborough National Nature Reserve (NNR) covers a huge expanse of limestone grassland and pavement, acidic grassland, blanket bog and heath in the south-western Yorkshire Dales. Previously, the land had been grazed by sheep, numbers of which had doubled from the late 1960s to the 1980s while the number of cattle halved. The negative impact of sheep grazing was evident, especially in heavily-grazed areas where grasses dominated, and the only plants remaining in significant numbers were hardy species such as thyme, clovers and daisies. But an opportunity arose to reduce sheep numbers and to promote cattle grazing, and in this article Andrew Hinde, Peter Welsh and Bill Grayson describe the success of the reintroduction of cattle grazing to Ingleborough and outline the NNR’s conservation objectives going forward.

The next article brings us to Havergate Island in the Alde–Ore Estuary SSSI in Suffolk. Since 1997, spoonbills have been trying to colonise the estuary but breeding attempts failed, mainly due to the presence of and predation by foxes. But over on Havergate Island, a more secluded site with little human disturbance, spoonbill numbers were increasing. To encourage breeding on Havergate, RSPB set up elevated nesting platforms and, owing to the presence of foxes and other predators on the island, installed predator-exclusion fences. Vivienne Booth, Aaron Howe and Adam Rowland describe how the predator-exclusion fences were designed and installed, leading to the return of breeding spoonbills to Suffolk.

Christopher du Feu and Michael Gillman take us to Treswell Wood in north-east Nottinghamshire. In 2014 Nottinghamshire Wildlife Trust purchased an area of the wood that had previously been cleared for agriculture, known as the assart. Instead of planting trees, it was decided to let nature take its course and leave the assart to return to woodland naturally. Monitoring of woodland regeneration began in 2016, but in 2017 ash dieback struck the assart. In this article the authors report the results of this ongoing monitoring, and demonstrate the remarkable effect that ash dieback has had on natural regeneration.

With COP 26 fast approaching, many of us have noticed increasing news coverage of the climate and biodiversity emergencies. But on nature conservation sites, can climate objectives and biodiversity-related priorities co-exist? Heathlands, for example, are managed by techniques such as burning, a contradictory approach from a climate perspective. John Bacon addresses this dilemma, and takes a look at some initiatives in Shropshire to demonstrate how climate objectives are being incorporated into habitat management, with biodiversity still being the top priority.

The final article encourages us to appreciate the importance of bare ground habitats. Many species of spiders, ground beetles, wasps, bees and reptiles (to name a few) depend on the warm microclimate that bare ground provides for hunting, basking and nesting. Using examples from south Staffordshire, Katie Lloyd describes the process of bare ground creation, including the design, type and size of scrapes; how to maintain and manage newly-created bare patches; mitigation and other considerations to be aware of before undertaking such a project; and the benefits that this overlooked habitat provides.

Other features that regularly appear in CLM include Viewpoint, a similar length to our main articles, but here authors can voice their own views on various conservation issues, and Review, which can include letters from readers or updates from our authors.

Tag: CLM