Generating more integrated biodiversity objectives - rationale, principles and practice.
Abstract
Effective biodiversity conservation can be hampered by the compartmentalisation of technical advice, guidance, objectives and strategy according to habitat types, species groups and individual species. Whilst specialists on individual components of biodiversity, as well as local biodiversity decision-makers, often possess a holistic mindset to wildlife conservation, it is not necessarily easy to apply that mindset within such a compartmentalised framework. A more technically integrated approach to biodiversity decision-making would help to deliver greater benefits for our habitats and species in the round, whilst creating sustainable management opportunities that enhance natural capital and generate greater resilience in our ecosystems. This report covers all terrestrial and freshwater-related habitats and their species complements but does not extend to the marine environment. Many of the issues encountered in marine habitats mirror those found in terrestrial and freshwater-related habitats, and as a result much of the rationale and many of the outlined in this report are also applicable (and already applied) in a marine context. The intention of the report is that it will provide a more harmonised technical basis for specialist advice within Natural England, and help partners and stakeholders to understand our rationale for more integrated biodiversity decision-making. It should be seen as critical ecosystem detail for applying the 'ecosystem approach' (adopted under the International Convention on Biological Diversity), which provides a wider framework for environmental decision-making. The project has focused on understanding how different habitat types function and relate to each other naturally in the landscape to provide the combination of structure and niches required to support and safeguard our native wildlife. This has involved consideration of: habitat mosaics at a range of spatial scales, the extent to which current approaches to the conservation of habitat types satisfies the needs of individual species and vice versa, and the role of different elements of natural function (hydrological, nutrient status, soil and sediment processes, natural influences on vegetation succession, and the naturalness of biological assemblages). As part of these considerations the scope and desirability of restoring different elements of natural function in different habitat types was evaluated. Discussions within this project highlighted the key influence of cultural management regimes and associated management boundaries on the existing pattern of biodiversity in England, and the effects of this on the way we perceive habitats and species assemblages in biodiversity conservation. The application of habitat and assemblage classifications in management decision-making can reinforce this cultural perspective and constrain perceptions of how habitats function naturally - their dynamic nature in space and time, natural transitions, and the multiple spatial scales at which habitats exist in mosaics and provide for species. A dichotomy is evident between management philosophies based on: (1) accepting cultural landscapes as the reference point for biodiversity conservation, enhancing them to help certain species and species assemblages; and (2) using natural processes as a reference point, seeking restoration of naturally functioning habitat mosaics within which all characteristic wildlife can thrive. Extreme portrayals of these philosophies (species gardening on the one hand, and rewilding on the other) obscure the importance of both in biodiversity conservation and the need for an appropriate balance between the two in local decision-making and spatial planning. An integrated approach to biodiversity conservation requires a combination of sound ecological rationale and pragmatism - the latter relates to being realistic about what is possible where and taking the best opportunities that present themselves. This is partly about striking the right balance between the concepts of 'land-sparing' for biodiversity and 'land-sharing' (in which some biodiversity objectives are delivered along with other socioeconomic objectives), and being clear about what these terms mean in practice. Encouraging a suitable approach to the local technical evaluation of management and restoration options is the most important step, rather than trying to prescribe specific local outcomes. What is possible at any one location depends on local constraints and opportunities - an informed approach to evaluation and decision-making helps to identify and then seize the opportunities for more integrated biodiversity outcomes that are available. A set of principles has been developed to help with evaluation and decision-making, with the overall aim 'to promote the protection and restoration of natural ecosystem function where this is possible and desirable'. This general aim was felt to strike an appropriate balance between the need for a sound ecological foundation for integration on the one hand and maintaining realism about what can be achieved in our cultural landscapes on the other. It allows encouragement of a greater focus on the naturally functioning habitat mosaics within which our native species evolved, without trying to force impractical outcomes in any particular situation. It also provides critical alignment with efforts to enhance natural capital, for instance through restoring the ability of landscapes to moderate flooding and store water and carbon, Some of these principles are ecological in nature, emphasising the importance of considering how different habitats and their species naturally sit in landscapes and using this as a template for biodiversity planning. Others relate to handling local operational realities, recognising permanent constraints to restoring more naturally functioning habitat mosaics (but encouraging a long-term perspective so that short-term constraints do not unduly influence decision-making), and identifying and promoting synergies with other environmental objectives. These principles can be applied at a range of spatial scales, but there are trade-offs: increasing scale provides greater flexibility for satisfying biodiversity needs in a holistic way and greater likelihood of practical opportunities, but can increase the complexity of evaluation and planning and introduce greater numbers of practical constraints. The application of these principles to different landscapes and in real situations is illustrated using a range of case studies. A great deal can be done at relatively small spatial scales as long as practical opportunities exist - finding such locations is an important task and often requires evaluation of larger areas, of both semi-natural and developed land. A key pitfall to avoid is that, in taking opportunities to enhance particular species within developed land (such as intensively managed agricultural fields), we do not constrain (or deflect attention from) opportunities for restoring naturally functioning habitat mosaics which would provide for characteristic assemblages more widely and still deliver for target species. In many ways these principles simply help codify the type of decision-making already applied by experienced local Natural England staff and stakeholders. Consistent application of the principles within the advice given by habitat and species specialists should support and promote their wider adoption at a local level. Improving transparency in evaluation and decision-making, backed up by evidence about ecological relationships between species and habitat features and the benefits of using natural function as a means of achieving objectives, will help foster support for such decision-making.