London’s Ecology - Disappearing London

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Dr Justin Dillon, Chair of Council, London Wildlife Trust/King's College London

Next lecture in the series is Managing for biodiversity in London's Royal Parks

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Disappearing London

Dr Justin Dillon, Chair of Council, London Wildlife Trust




If an area of green space in London the size of twenty-two Hyde Parks were to be concreted over there would, quite rightly, be a huge public outcry. But when the lost green space in question is made up of front gardens rather than parkland, we have let this happen with barely a murmur.
Darren Johnson, chair of the London Assembly Environment Committee

The 'Cockney sparrer' has vanished dramatically from many of our parks and gardens. Brown hares are confined to a few sites within the capital, as are small blue butterfly, black redstart, green-winged orchid and greater yellow-rattle. These are just six of the dozens of wild animals and plants under threat within London; the places they live in are disappearing or changing for the worst, at a far greater rate than was previously thought.

In this talk, I will outline some of the key issues affecting London's ecology as I see them from my position as Chair of Trustees of the London Wildlife Trust.

London Wildlife Trust was founded in 1981. In its short life it has grown steadily, managing more than 40 reserves across London. We have educated thousands of children through our Watch groups and other educational activities and thousands of volunteers have made a huge difference to London's environment, through conservation and campaigning.

London's environment has changed massively in the last two hundred years. With a population conservatively estimated at seven million people and covering an area of 1500 square kilometres it is Europe's biggest city. Put another way, one person in eight lives in the capital, one of the most densely-populated areas in Europe. Despite its overcrowding, a third of London is open space and it is one of the greenest of the world's major cities. Gardens make up 19% of London's area, a figure to which I will return later.


Railway Fields, in Harringay, is close to Finsbury Park. The Gospel Oak to Barking railway line forms its southern boundary and the New river (London's cleanest waterway) runs along its western edge. These both act as valuable ecological corridors, allowing a wide range of plants and animals to access the site – and that's why it's so ecologically diverse.


Over the course of decades we have witnessed an increasing pressure on wildlife habitats in London so that many wild animals and plants are now just about holding on. Some species, such as the fox, tufted duck, and silver birch are so common that the perception is that wildlife is increasing, a perception reinforced by the apparent abundance of greenspace and gardens; the reality is more worrying. We are losing the elements that make wild London special and that make it a bearable place in which to live.

Survey statistics also uphold this perception that wildlife is increasing. According to the Mayor of London's Annual State of the Environment Report, the numbers of Sites of Importance for Nature Conservation in the capital have increased since 2001, and the trends in the populations of common birds are, broadly, okay. These are the two measures by which the quantity and quality of London's biodiversity is measured, as set out in the Mayor's Biodiversity Strategy (2002).

Yet both of these measures give a distorted picture of the true health of London's wildlife. It is not that these measures are false (they are based on probably the best available datasets). It is simply that they provide a very limited account of London's rich diversity of nature and how it is faring.

A closer inspection by London Wildlife Trust reveals a more worrying state of affairs. Over 474 hectares of important wildlife habitat has disappeared since 2001 – equal to the size of 474 football pitches. In short there has been a collective failure to secure the protection and conservation of London's biodiversity and wildlife habitats over recent decades. The positive gains are undermined by a more widespread and profound loss and decline, not shown by the official figures, of quality of habitat and quality of resource.


Despite our best efforts and some superb show-case projects like Camley Street Nature Park, the London Wetland Centre, Rainham Marshes and South Norwood Country Park, our Capital's wildlife is disappearing.

A simple case of cause and effect - as habitats cease to exist, it is inevitable that the wild plants and animals that are dependent upon them will vanish. You will not find tree-creepers spiralling up lamp-posts where trees once stood, nor meadow brown butterflies skipping over the ornamental grasses of a 'ground-forced' garden, nor wild meadow flowers swaying in the breeze in a bright green business park lawn.


Simple analysis of the data supplied by Greenspace Information for Greater London (GIGL) of the area of SINCs in London suggests that there has been a net increase over the past 5 years (see Fig 1).

Figure 1. Greater London SINCs -

Sum of area - Data from Greenspace Information for Greater London.

SINC level







Borough Grade 1






Borough Grade 2


















Grand Total






Yet it is clear that there have been significant losses of SINCs during this 5-year period with the loss of 135 hectares [ha] at Barking Levels; 18 ha at Erith Marshes and 151 ha at Woolwich Arsenal and Tripcock Park for example. In fact a total loss of 474 ha from Sites of Metropolitan Importance over the past 5 years. That's the same as 474 Wembley size football pitches lost from London in half a decade or the equivalent of losing Regent's Park.

So what's going on? Sleight of hand? Smoke and mirrors? Well not exactly. The truth is that when the figures where first compiled not all boroughs had had a recent assessment of their SINC resource. The identification of the full complement of SINCs for the London Borough of Havering, for example, was done for the first time in 2002, at which time an extensive area of new SINCs including new Sites of Metropolitan Importance were added to the London total. Effectively, the area of SINC ebbs and flows as sites are resurveyed and sites are reclassified; they do not reflect that actual area of land of nature conservation value across London, merely that which is 'identified' as such (and there are many areas which have yet to be surveyed because of access constraints).

Statistically speaking, at present, the target of no net loss of SINCs is being met, but this is explained by the fact that prior to 2004 the SINC system was incomplete and the real losses in the area of land which is of importance for wildlife has been disguised by the paper exercise of completing formal classification of SINCs across all London boroughs. In other words we've lost sites that were classified as SINCs but have identified new ones and these new discoveries have camouflaged the losses. This is not to suggest that the identification of SINCs is merely a paper exercise of little real benefit. Indeed, it is fundamental to establishing a baseline of the quality, quantity and distribution of wildlife habitats across London. However, this baseline has taken 20 years to complete (as best possible); monitoring of the quantity and quality of SINCs over the next 5 years might reveal a similarly worrying picture, but with the now more comprehensive baseline in place any changes should become more obvious in the statistics.


The data for the trends in the populations of common birds provides an equally ambiguous picture. Conclusions have been drawn from the British Trust for Ornithology's Breeding Bird Survey (BBS) data. Unfortunately, despite the efforts of a dedicated band of volunteer recorders there are useful datasets from less than 50 locations across London providing meaningful data on just 21 species of birds, the majority of which (such as wood pigeon, collared dove, blackbird, blue tit, magpie, carrion crow, greenfinch and chaffinch) are typical, almost ubiquitous, species found in suburban parks and gardens. Monitoring the populations of these species is useful and important. Changes in the populations of these species can indicate the loss or decline in the quality of widespread habitats (e.g. gardens) but it tells us little about the ecological health of our woodlands, grasslands and wetlands. In addition, the ubiquity of many of the above species means that extrapolating the data from national datasets and identifying what is 'going on' in London is not an easy exercise. For many species, London's habitats are often sub-optimal, and modest declines at a national level may hide a greater degree of decline within London.

A less robust dataset (because the records are not collated systematically) provided by the annual London Bird Report, produced by the London Natural History Society, suggests a real decline in the diversity and numbers of key breeding species. Birds such as skylark and meadow pipit, which are dependent on good quality, relatively undisturbed grassland habitats; and species such as oystercatcher and ringed plover which are dependent upon habitats associated with the lower reaches of the Thames, have declined in recent years or have become confined to isolated nature reserves.

In line with national trends there have also been declines in the populations of species such as turtle dove, sand martin, nightingale, tree sparrow and marsh tit. More worrying still is the fact that the BBS data indicates there are declines in the populations of some of London's commonest and most widespread birds: blackbird, starling and of course house sparrow.

In addition to the common bird species the numbers of species that are the focus of particular conservation action within London, for example grey heron, peregrine falcon and black redstart, also need to be treated with some caution. The increases in breeding grey heron and peregrine are undoubtedly a cause of celebration, but do they reflect positive change on the ground within London? The cleaning up of our rivers over the past 50 years has led to the return of fish populations up and down the Thames and its tributaries, which has, in turn, brought us 26 heronries within London (a species that in 1949 was considered never to return to London), so yes, they do most probably reflect positive change within London. But it's as a result of actions not specifically targeted at the bird. As for the peregrine's nascent presence in London, this is largely due to upturns in its national population after the ravages of persecution and DDT during much of the 20th century; the peregrine's presence reflects plentiful nesting sites (tall buildings) and food (pigeons), rather than terrestrial habitat quality.

For black redstart, the London populations of which may reflect the turnover of available derelict land, possible declines in specific localities need to be set against a general northern expansion of the bird from central Europe since the mid-19th century, and a difficulty in accessing likely sites to monitor its real status in the capital. And yet we know that both the Government's and Mayor's development targets specify building on land where London's black redstarts are likely to breed.

This is not to suggest that current Biodiversity Action Plans to actively conserve these species are superfluous, but that their objectives, which all contain a significant degree of awareness raising and making cross-sectoral linkages, should continue to be pursued. Without the focus on black redstart and peregrine falcon, the work on Design for Biodiversitywould not be so advanced. The public's fascination in seeing grey heron close at hand gives us a lever to generate a wider understanding into the pressures of riparian habitats across the capital.


Whilst significant measures have been put in place to conserve our natural heritage over the past 25 years, through legislation, planning policy guidance, dissemination of best practice and the support and expertise of London's ecologists and conservationists, it is clear that these are being ignored or over-ridden.
These are the key mechanisms resulting in a disappearing London:

local planning authorities are failing to accord sufficient protection to important wildlife habitats in their Unitary Development Plans; local planning authorities are still failing to comply with planning policy and legislation as set out in PPS9, PPG17, the Wildlife & Countryside Act (1981, as amended), Countryside & Rights of Way Act (2000), and European law; developers regularly ignore guidance and legislation, or apply minimal compliance; local planning authorities are failing to require and/or enforce measures to protect and conserve biodiversity as conditions of new developments; the police are failing to enforce breaches of biodiversity conservation law (usually because they are not aware of legislation or they're inadequately resourced);

Whilst statutory agencies, non-government wildlife organisations (such as the Trust) and community groups are often acutely aware of these issues, they are not satisfactorily resourced to monitor all development threats to London's wildlife, or to perform the protective measures that should be the duties of others.
London is a green city, blessed with a great many gardens, parks and many natural green spaces. Londoners cherish these and in many cases guard them jealously. Whilst high profile campaigns have helped to save a few sites, very many more have simply vanished under bricks and tarmac, mainly because there have been too few people living near them or, crucially, they have been the 'wrong type of site in the wrong place' such as rough grasslands, scrub, marshes, and wastelands.

ERITH MARSHES – Case study of a planning system failure

Erith Marshes is an example of the fundamental failure of local planning authorities, developers, and in some cases Government departments, to meet the obligations the UK has established to protect and conserve its natural heritage.
Owners, Tilfen Land, submitted a planning application to build the East Thamesmead Business Park on 68 acres of this irreplaceable grazing marsh. In November 2003 Bexley Council granted planning permission for the business park to go ahead. After Euro MP Jean Lambert made a formal complaint to the European commission, the planning permission was stalled.
London Wildlife Trust proposed a compromise which would allow phase one of the development, the erection of three large industrial buildings, to proceed as long as Tilfen undertook to carry out mitigation proposals; including habitat improvements and enhancements to some of the dykes. London Wildlife Trust opposed planning permission for phases two and three of the development and asked that the remaining land be rehabilitated in order to increase its biodiversity, expand the area of the marshes and increase public access. Our compromise was rejected and Erith's future hangs in the balance.
© London Wildlife Trust

WATER VOLE – Case study of a species threatened by development

London is a water vole stronghold but this native species requires clean water and gentle banks with plenty of vegetation in which to thrive. London Wildlife Trust is working with others to encourage the return of this gentle mammal through habitat creation schemes.
This threatened species is sensitive to change so it is crucial that developments around waterways are closely monitored and that clusters are not cut-off from blue corridors; this would prevent expanding populations from colonising new areas in which to grow and flourish.
© London Wildlife Trust


Many greenspaces, whilst still technically 'with us', have lost their quality; green-ness is not always what it seems, as changes in management can be devastating to wildlife. New greenspaces, for example around business parks and housing developments, rarely replace what was originally there. The fine detail in terms of wild plants and animals present within these habitats is often overlooked or ignored, and no amount of fine design and good intentions can replicate the ecological complexity of a lost habitat. Simplicity replaces complexity; off-the-peg replaces locally distinctive.

BROWNFIELD BIODIVERSITY – Case study of conflict

The Millennium Mills site, next to Royal Victoria Docks, L.B.Newham was surveyed in 2001. An 11 hectare site, it was described at the time by the surveyor as a site of high conservation value with 122 species of plant recorded. An extensive brownfield site with a diversity of hardstanding, rubble and stone, ruderal plants, tall herbs, scrub, grassland and a few scattered trees, with black redstart recorded on site. Other birds included linnet, redwing and grey wagtail.

The site is now targeted for a major mixed use waterfront scheme, that includes the aquatic visitor attraction Biota! a world-class aquarium designed by renowned architect Terry Farrell & Partners. Biota! will present the global diversity of aquatic life with an underlying message being the protection of aquatic species and their habitats. The centre will also carry out scientific research and education overseen by Zoological Society for London

Perhaps the aquarium will achieve more one day for biodiversity conservation than a brownfield site in the Thames Gateway ever could? But regardless of the global objectives, the complexity of plant and animal communities on a site worthy of Site of Metropolitan Importance for nature conservation will be lost for ever.

Black redstart © London Wildlife Trust


In addition, the ecological services that natural spaces provide [for example, climate amelioration and flood-water control] and the contribution they make to our well-being are over-looked in planning decisions, to the detriment of London's economy. Recent research suggests, for example, the provision of a 20 hectare park for Portsmouth can save £4.4m per annum in preventative health costs to the local economy (Bird, 2004). The loss of almost 500 ha of high-quality wildlife habitat in London since 2001 suggests that the socio-economic costs of this were - at best – not recognised.


Studies from as far afield as America, Holland and Tokyo show the beneficial effects of exposure to nature. As long ago as 1984 it was demonstrated that patients with a green view through their hospital window recovered more quickly and required less pain relief than those without. In 1995 a study of office workers showed that a natural view contributed to higher productivity and reduced stress. Elderly residents in Tokyo with more space for taking a local stroll in parks and tree-lined streets showed an increase in longevity In Holland, it was found that people living near green space suffered from less health complaints and had better physical and mental health than those living in an urban environment.

In this country studies have shown that walking is far more cost-effective in promoting longevity than cholesterol lowering drugs and that exercise undertaken in 'Green Gym' type activities produces a higher heart rate response than an equivalent session of step aerobics. What is more these are social activities promoting community cohesion and a shared understanding and valuing of the local environment and neighbourhood.

So it is imperative that the policy makers and planners at this beginning of the 21st Century take their responsibilities seriously. We all know intuitively that being at one with our natural environment, experiencing the complex and beautiful tapestry of the trees and wildlife that should be our natural heritage, is good for us. We can now point to the growing 'evidence base' that supports this self-evident premise.

It is crucially important that the many million houses that we are told need to be constructed, and the neighbourhoods undergoing renewal and regeneration, should have a natural living environment at their very core. Human beings were built to be active, to explore their surroundings and to live in harmony with a diverse and rich natural environment that supports them mentally, physically and spiritually. This is no easy task but its successful completion will be key to public health in the 21st Century.

Angela Mawle
Chief Executive of the UK Public Health Association


Our analysis of data on Sites of Importance for Nature Conservation [SINC] from the last five years shows London has lost valuable habitat equal to the size of Regent's Park.

This is land that is considered so important for biodiversity that it is given the highest possible designation, which should protect it from development. But, what of land with little or no protection? A report released earlier this year by the Greater London Authority, entitled Crazy Paving, found the Capital has lost around two-thirds of its front gardens to hard surfacing in the past decade; that's an additional 5,200 hectares or an area equal to 22 Hyde Parks.

It's not just front gardens that are an issue. Backlands, the patches of wild land behind gardens and in between houses, often perceived as 'wasted,' can also be of significant wildlife value; particularly if they link up, forming wildlife corridors around the Capital. Surburban intensification, where existing buildings are demolished and the whole plot is redeveloped, can often gobble up this so called wasted land and reduce overall wildlife value.

Garden habitat is defined as 'previously developed land,' and is not subject to the usual planning constraints, however, there is no statutory protection afforded to London's gardens. If garden and backland development was subject to stricter planning constraint and every planning application had to be considered in terms of local biodiversity impact, that would go some way to protecting these precious places. In order for policy to change, awareness of this serious issue must be raised across the capital.

"If you care for your community, you should care for nature. It's time we all woke up to the importance of conserving the wild. Londoners want better health, housing, education, prosperity and that sense of a community at ease - nature conservation strengthens them all. Community life, quality life and wildlife - they're inextricably linked."
Charles Secrett, London Development Agency


Whilst existing nature conservation legislative and planning policy frameworks contain their weaknesses (and there are many), London Wildlife Trust believes that this is no reason for local planning authorities, in particular, to shirk their duties or undermine the principles laid out in these. We recognise that resource implications impair local planning authorities from exercising their responsibilities, but the Trust is also equally aware of a worrying absence of recognition, care or concern of these issues amongst a number of planning departments in London. Too often we have witnessed the use of 'political' concerns to sway decisions, this usually is a euphemism for furthering economic development, no matter the impact of such decisions on the local natural heritage and the benefits this provides people; as is happening at Erith Marshes, one of London's ancient grazing marshes. This is a fundamental failure of local planning authorities, developers, and in some cases Government departments, to meet the obligations the UK has established to protect and conserve its natural heritage.

Whilst the measures within the Mayor's Biodiversity Strategy are a good starting point, we urge people to read them with care. As we set out here, they are not enough to measure what is really happening to London's natural heritage, and without qualification they are misleading. The Trust aims to work with others to establish other measures, to help ensure that not only do we monitor changes to London's biodiversity more accurately, but that these changes become positive, to the benefit of the Capital's biodiversity and the people who live, work and visit here.

London is unlikely to ever be devoid of wildlife, but the danger is that the diversity of thousands of species of wild animals, plants and fungi currently found here will be eroded by the accumulative loss of the places in which the vast majority depend upon for survival. With that accumulative loss will go the ecological services that their inter-twined ecological relationships provide, and the benefits they bestow in giving us a subtle, dynamic, sense of place, from birdsong and a butterfly's fly-past, to seasonal colour and the sound of a breeze across a meadow. Without reversing this decline we will be left with a duller, less comforting, 'every-place-else' London.

Matt Davies, Greenspace Information for Greater London
Mathew Frith, London Wildlife Trust
Penny Frith
Iain Green
Catherine Harris, London Wildlife Trust
Mandy Rudd, Greenspace Information for Greater London
Mark Simpson, London Wildlife Trust
Charlotte Williams
Chris Woods


Bird, W. (2004), Natural Fit, RSPB, Sandy.
British Trust for Ornithology, Breeding Bird Survey -
London Natural History Society Bird Report
Crazy Paving – the environmental importance of London's front

Department of Culture, Media and Sport and Office of the Deputy Prime Minister (2002), Planning Policy Guidance note 17: Open Space, Sport and Recreation, ODPM, London.

Department for the Environment, Food, and Rural Affairs (2002), Working with the grain of nature; a biodiversity strategy for England, DEFRA, London.

Design for Biodiversity – A guidance document for development in London – produced by the London Development Agency

Greater London Authority (2002), Connecting with London's nature, The Mayor's Biodiversity Strategy, GLA, London.

Greenspace Information for Greater London [GIGL]
House of Commons Environmental Audit Committee (2004),Environmental Crime: Wildlife Crime, 12th Report of Session 2003-04, House of Commons, London.

London's Life Force and London's Natural Values – both produced by English Nature and London Wildlife Trust 2004/2005.

Machin, N. (2000) Planning for the wild; how to use the planning system to protect London's biodiversity, London Wildlife Trust, London.

Mayor's Biodiversity Strategy
Office of the Deputy Prime Minister (2004) Planning Policy Statement 12 (Local Development Frameworks), ODPM, London.

Office of the Deputy Prime Minister (2005) Planning Policy Statement 9 (Biodiversity and geological conservation), ODPM London.



© Dr Justin Dillon, Gresham College, 2 October 2006

This event was on Mon, 02 Oct 2006


Professor Justin Dillon

Justin is Professor of Science and Environmental Education & Head of School at the University of Bristol.

He is also associated with the Centre for...

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