IAN D. ROTHERHAM
Emerging in the 1980s and 1990s, ideas of habitat rescue and transplantation, and of habitat creation have developed on an unprecedented scale and they offer considerable potential benefits (see for example, Gilbert, & Anderson, 1998).1 Serious attempts at habitat creation and restoration emerged on the back of work to restore or rehabilitate degraded and derelict post-industrial landscapes, in many cases to become the new country parks.2 The created sites in post-industrial landscapes like, for instance, South Yorkshire, Nottinghamshire, and North Derbyshire, soon became renowned as prime locations for bird conservation and associated birdwatching. Nevertheless, they were often disparagingly described by local botanists as ‘duck ponds’ and created on lands which decades back had been rich in invertebrates and flora. This is particularly in the context that lakes and ponds are easy to create and bring immediate and visible benefit as a focus for community greenspaces. Many other habitats are difficult to create and often prone to long-term failure in terms of reliably replacing what was originally present, but they can generate interesting, exciting but different ecologies. Indeed, if we accept these changing and evolving landscapes then success of a sort becomes easier, but in terms of replacing or transplanting like-for-like, we must be cautious what we claim.
Shifting habitats
As the techniques emerged and the science of site assessment and evaluation prior to industrial exploitation developed, there began experiments (varying in scale and success) in habitat rescue and translocation. These in effect took materials identified in preliminary surveys and particularly rich in biodiversity and transplanted them pre-development to a nearby compensatory created site. There was a degree of at least short-term success but often problems with both long-term management and especially with effective monitoring. The latter was rarely costed into projects and once site creation was complete, a developer generally expected to simply walk away. Occasionally a commuted sum was set aside to cover ongoing maintenance, and this has become standard and helpful in more recent schemes.
During the 1980s and 1990s, when the science and practice were in their early days and practitioners were experimenting to develop effective techniques, there was much debate. In discussion with a senior officer from the Nature Conservancy Council in the 1990s, he made the valid observations that rescue and transplantation, generally resulted in a created site that was ecologically richer than would otherwise be the case. However, the result rarely matched that of the donor site and tended to diverge over time with rare or target species often being lost. Furthermore, the receiver sites were almost always considerably smaller than the donors, and significantly, they generally lacked the historically and economically driven management regimes of the old sites. The absence of monitoring meant there was no effective mechanism to assess success or failure.
Since then there has been considerable progress in terms of the underlying science of habitat creation and some of the results have been outstanding. However, the interpretation of any success must be carefully embedded in context, and this is particularly the planning background and the history and ecology of a site being destroyed and/or donating materials to the restoration plots. From the outset of habitat creation programmes, there was always a worry that success could be used to undermine the integrity of in situ conservation and thus be to the detriment of wildlife and species richness. In generating newly created habitats it is desirable to achieve the best possible outcomes. Nevertheless, the limitations of both creation and translocation do need to be made apparent with acceptance that these in no way compensate for losses of good sites. In many situations it seems that this is where misinformation and possible conflict come into play.
Photo: Ian Rotherham
Why these interventions in the landscape do not compensate for the losses:
First, most if not all habitat creation focusses on easy to establish and obvious features and species, whereas an established conservation site entails a rich and intricately interlinked diversity of fauna, flora, fungi, and other taxa. Most of these are rarely considered and yet they (for example mycorrhizal fungi) are probably the key to long-term sustainability of the ecosystem.
Second, long-established, ecologically rich sites are not merely determined by physical and chemical conditions and constraints but also by traditional, customary, and continuous or at least predictable, human interventions. Unless these site histories can be replicated or closely mimicked in a receiver site or created area, then the ecology is bound to drift from the desired outcome. It may still be rich in wildlife, but it will be significantly different from the original site being lost. Similar issues may follow when a traditionally managed site such as ancient meadow, heath, or common, comes out of usage, and it drifts to a new condition through successional processes. This new community may still have wildlife benefits and some diversity, but it will be different with both winners and losers in the new ecology.
Third, almost all created sites in compensation for development losses, are significantly smaller than the areas destroyed.
Fourth, and of relevance to ideas of biodiversity offset, many good quality habitats are simply irreplaceable because of their unique, long timelines of management history and site evolution. These generally cannot be replicated. An ancient woodland for example is not replaced by planting a few trees and shrubs in an area of set-aside land but is a semi-natural or eco-cultural system and complex that has taken over 500 years to develop. Whereas a plantation remains what it is, a plantation woodland which can be designed to enhance the (visible) wildlife, but does not include much of the invisible wildlife that powers a truly ancient wood. Neither does it have the uniquely important heritage of the woodmen and their families who worked the woods for millennia. This unique heritage has driven and created the wildlife of these remarkable landscapes and is responsible for their conservation significance and their future sustainability.
Fifth, there is the inconvenience of geographical, spatial location. By this I mean that any new site is in a different location from the one being lost, or if it is in the same place then it is temporarily displaced such as is the case with the idea of ‘borrow pits’ for minerals extraction. In the latter case, a site is re-constructed but long after the destruction and with a totally altered ecology. But in most cases, a new site may be constructed but in a place which is simply convenient for the developer and not necessarily beneficial to wildlife. Additionally, for the greenspace of a local community, then the creation of a site elsewhere does not compensate for the loss on their doorstep. For a developer this fact is a major inconvenience.
These are just a selection of the reasons why habitat creation and translocation do not compensate for or mitigate the destruction of good quality, long-term sustainable, ecologically rich sites.
Habitat creation as part of a strategic approach to post-industrial restoration, to damaged landscapes, or even the repair of degraded intensively farmed agricultural land can bring huge benefits though. Additionally, habitat rescue and translocation can have a part to play in this process. However, a key issue is that this is not compensation for loss and will not replace good habitats that are destroyed. These are important considerations if we are playing the biodiversity and habits trade-off game.
Photo: Ian Rotherham
Habitat creation and translocation as justification for destruction
Following from the above, whilst habitat creation can be a very useful part of a wider conservation strategy, it does not compensate for losses of existing good sites. Indeed, for some of the created sites to eventually develop high quality and sustainable ecologies, they rely on the survival of the good areas in good condition for re-colonisation of essential eco-components to occur. Even for sites such as minerals extraction borrow pits, it is often the survival of characteristic fauna and flora in landscape refugia, which may result in the emergence of a richer ecology more typical of the location.
Therefore, for many reasons, it is vital that the argument of created habitats providing replacements and compensation for sites and ecology being lost is dispelled. The new sites do not replace the original resource or compensate for their loss. In appropriate situations, and when effectively undertaken with funded future management to direct ecological succession towards clearly defined objectives and outcomes, habitat creation can be a useful tool. But this does not justify or mitigate in full, the destruction of existing high-quality sites.
I suggest that the destruction of a site or habitat being justified by the idea that it can be replaced is fundamentally flawed. If an existing site is already of low value, then a replacement might be adequate compensation or even of greater ecological interest. But even then, it is not a replacement like-for-like. However, if the habitat to be destroyed is of higher value, then the new site neither replaces nor compensates for the loss. We may create a new habitat and ultimately this may have conservation worth, but it does not cancel out the losses and suggestions that it does, need to be refuted.
Biodiversity offset as an opportunity in the planning process
Habitat creation and transplantation come to the fore in current planning and development processes and inquiries. The current planning mantra appears to be ‘no net biodiversity loss’ but sadly when established high quality sites are being destroyed, this has zero credibility. Indeed, current guidance excludes irreplaceable habitats from compensation schemes. Yet at planning inquiries, when areas such as ancient, species-rich hedgerows are lost and ancient woods or grasslands too, consultant ecologists claim mitigation through compensation and offset. A major flaw in the presently emerging guidance is that it takes no account of factors such as unique site history, heritage, and archaeology, even when these are the primary drivers of associated ecological interest.
Despite the shortcomings and misinterpretations, biodiversity offset can trigger major benefits. However, for these to be fulfilled requires much greater financial contribution from developers and more effective planning, implementation, and monitoring which I suggest should be independent of any consultants involved in the developer’s planning process. This removes some of the incentive for a consultant ecologist to promote site destruction and compensatory offset through which they personally or corporately benefit.
With better recognition and protection for the irreplaceable ecology and for landscape heritage too, then creation and transplantation can generate valuable areas. Placed within a local and regional strategy with effective long-term management by a funded professional conservation agency or body, then considerable benefit can be generated. Nevertheless, the current guidance is thin on details for how some of these are to be achieved, overlooks landscape history and heritage, and neglects issues of community access to good quality greenspaces and associated issues of health and wellbeing. So, there is a very long way to go if the benefits are to be maximised. Furthermore, many local authorities are no longer staffed or resourced in such a way as to deal effectively with these situations.
There are major opportunities to be had such as the creation of new meadows, heaths, woodlands, and wetlands on presently poor sites, but this begs a very important question. Where are the sites for compensatory habitat creation going to be found in the same locale as the destruction? If they exist, then why is the development not taking place there rather than in the good areas? Furthermore, if they are not close to the sites that are lost, in what way are they compensatory?
Photo: Ian Rotherham
Biodiversity offset as a scam
A major problem with current process is that it operates through conflict and with overwhelming resources on the side of developers with batteries of highly paid consultants and barristers to do their bidding. I have heard senior landscape managers claim that ancient woods are not a problem as they can be moved and re-located. The same goes for veteran trees and ancient hedgerows. Such claims were made by the senior landscape manager for the HS2 project at the national amenity trees conference some years ago, yet nobody at the meeting challenged the statements. Such claims are flawed for all the reasons I have presented, but still they are made and sometimes believed. But by the time the dismal failures become apparent, then planning inspectors, planning officers, consultant ecologists, and the rest will long since have moved on. Only nature and local people will remain to experience and evidence the long-term results.
Offset cannot be applied to irreplaceable habitats and created areas supposedly must be on sites which currently have no, or at least very low, existing wildlife interest or value. This situation raises the matter of defining what is irreplaceable and doing so in the absence of any consideration of eco-cultural heritage. Guidance, planners, and consultants, generally seem to overlook all of this.
If there are sites of wildlife interest that are being destroyed for development, but close by are areas of low value suitable for compensatory habitat creation, then why don’t we safeguard the former and build on the latter?
The landscape heritage conundrum
One of the biggest headaches in terms of the above issues is the total neglect of landscape history and the heritage landscape. Not only are such areas of countryside irreplaceable (they are, by definition, unique outcomes of specific timelines), but it is the associated conditions of ancient woods, ancient hedgerows, heaths, commons, meadows, fens, and moors, for example, which determine their ecological interest. In historic and eco-cultural landscapes, the human footprint over time through traditional management has interacted with nature to generate the interest which we seek to conserve. This is a core problem in nature conservation generally because many landscapes are abandoned but not rewilded and is a particular issue for created compensatory landscapes. The removal of traditional, pre-industrial countryside management from eco-cultural landscapes is known as ‘cultural severance’ and in various forms has been commented on since the 1950s through to the late 1900s as ecological decline across Britain became increasingly apparent.3 The processes had begun in earnest with the industrial and agricultural revolutions and especially with the parliamentary enclosures of commonland in the 1700s and 1800s and continued into the latter stages of the twentieth century.
This issue of the abandonment of cultural landscapes and their long-term ecologies has been recognised in principle for many years. In the 1950s for example, in the Cambridgeshire Fens, James Wentworth-Day wrote about how at Wicken Fen the National Trust would fail to maintain and conserve the rare invertebrate species characteristic of the area.4,5 This was he said, because the fenman had been taken out of the fen. In other words, over countless centuries, the reed cutter, sedge cutter, peat cutter, osier cutter, shepherd and more, had worked with nature to shape the fen and its unique ecology. The progressive ending of these cultural rural activities changed the fen and its ecology forever. The relevance to habitat creation is that unless management, including perhaps large-scale rewilding with large, grazing herbivores, can maintain or re-create the ecological conditions required, then succession will proceed. This may not be inherently problematic unless we desire specific conservation outcomes which may not be forthcoming. With restored or created sites this can be a serious issue. For example, with a degraded raised peat bog it may be easy to re-wet the site, but you may well end up with a lake and a fen or carr. A functioning sphagnum bog is unlikely to fully establish for several centuries and even then, only with a lot of luck. Spontaneous ecological succession from established baseline conditions in created habitats may generate interest but include a significant degree of randomness and potentially invasive species too. This is not necessarily a problem if those outcomes are acceptable.
The same ecological considerations apply with say created woodland which differs from genuinely ancient woods or forests. Ancient woodland can be identified by examination of ‘ancient woodland indicators’ (particularly plant species) and these depend on continuity of woodland cover and land-use, ancientness, or antiquity, and on the resulting soil conditions. These factors cannot be replicated and so a new ‘secondary’ woodland has species reflecting its own origins, timelines, and conditions, and is different and distinctive. Even if those species characteristic of an older, established site are translocated or else introduced, they will not thrive and may not even establish because the conditions of soils, light, and humidity are unsuitable. Suggestions from ecological consultants from a recent inquiry for example, to introduce plant species such as primrose, absent from an ancient woodland adjacent to an area being destroyed, simply amount to inappropriate gardening and not nature conservation. Yet along with cloned plug-plants of wood avens this has been seriously suggested as compensation for destruction. The latter plant is a denizen of woodlands, but its ecological strategy is that of a ‘weed’ and so, carried on animals’ fur, it will arrive by itself in due course and when conditions are right. Suggestions and actions such as these are potentially damaging as they reduce the remaining anciently wooded landscape to the status of a garden and inherently replaceable.
Photo: Ian Rotherham
Trading places and ecologies
Habitat creation and transplantation in its modern form has evolved over perhaps forty or fifty years since the 1970s restoration projects. Nevertheless, this is not an entirely new phenomenon, and was for example a feature of the great eighteenth-century landscape designers such as Capability Brown.6 They created landscapes with parks, lakes, watercourses, woodlands, and grasslands and even transplanted semi-mature trees. However, the underlying science and associated practice has developed in the twenty-first century and has grown in sophistication. Nevertheless, this needs to be recognised as just one part of a conservation toolkit and not a replacement for real-time in situ protection and management of sites and species. Compensatory habitat creation can help develop new futurescapes which are ecologically rich and support ecological recoveries. Very often the successional trajectories will involve novel and unexpected outcomes, and this is not a problem and indeed, is to be expected. As is the case in many ‘rewilding’ projects, the baseline conditions set the starting point, but then successional changes kick in, and nature will follow its own track. We may seek to influence the direction and the outcomes of this by intervention management, and in the past, this would have been through socially or economically driven land-uses. Very often, we simply do not know what the outcomes will be, and in the spirit of rewilding we should let nature find its own way from the initial baseline conditions. Habitat creation is essentially the triggering of a process and not necessarily a product.
In light of the above, habitat creation and transplantation are selective in terms of what is introduced and maybe what is transplanted, and in the setting of baseline conditions like soils, water, and any management. The ecological trajectories then follow. However, habitat creation omits entirely the human cultural footprint in the countryside. Wentworth-Day’s fenman is removed from the fen. For woodland, common, heath, and hedgerow for instance, the unique timeline of the landscape and its people cannot be transplanted, created, or traded. This is the unique pathway of the ancient countryside whereas the created lands are new futurescapes. The archaeological heritage generated by this human footprint in the landscape, including ecological indicator species, is unique to a locale and is a timeline which cannot be re-created or transplanted.
In conclusion:
1. conservation (in situ) is the best way for good quality habitats,
2. if traditionally managed countryside is abandoned, then successional changes over varying timescales will trigger evolution in the ecological systems,
3. created habitats through either imposed new ecosystems or rewilded countryside can usefully re-connect fragmented landscapes, but
4. created or transplanted habitats do not compensate for losses of good sites. Indeed, once the latter are established, they will change, and the desired species or communities may not be stable or sustainable.
Therefore, in terms of offset or compensation for damage done through development processes, site creation, habitat creation and transplantation help generate new landscapes but without the heritage. Places in the countryside may evolve and change but they cannot be traded, and we need to be transparent and honest that this is the case. Society may demand a high-speed railway to get more quickly, between say London and Birmingham, but let’s not pretend you can move ancient woods and hedgerows along the route and compensate for the ecological impact. Yes, we can take opportunities to create new environments, but this is a futurescape and not conservation.
References
1. Gilbert, O.L. & Anderson, P. (1998) Habitat Creation and Repair. Oxford University Press, Oxford.
2. Rotherham, I.D. (2015) The Rise and Fall of Countryside Management. Routledge, London.
3. Rotherham, I.D. (2008) The Importance of Cultural Severance in Landscape Ecology Research. In: Editors: Dupont, A., & Jacobs, H. Landscape Ecology Research Trends, ISBN 978-1-60456-672-7, Nova Science Publishers Inc., USA, Chapter 4, pp 71-87.
4. Wentworth-Day, J. (1954) History of the Fens. George Harrap & Co. Ltd., London.
Rotherham, I.D. (2014) Eco-history: An Introduction to Biodiversity and Conservation. The White Horse Press, Cambridge.
Websites:
https://www.communityplanningalliance.org/
Ian Rotherham is with the Advanced Wellbeing Research Centre, Sheffield Hallam University.