Biodiversity

From SEA.unu.edu/wiki

This text is derived from the report on Strategic Environmental Assessment and Biodiversity: Guidance for Practicioners, June 2004. The report was published by the Countryside Council for Wales, English Nature, Environment Agency and the Royal Society for the Protection of Bird. The report can be accessed via the Royal Society for the Protection of Birds.

What is Biodiversity?

According to the Convention on Biological Diversity, biodiversity can be defined as:

The variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems. (Convention on Biological Diversity (1992), Art. 2)

In other words, it is the variety of life on earth at all levels, from genes to worldwide populations of the same species; from communities of species sharing the same small area of habitat to worldwide ecosystems. At each of these levels, it is necessary to evaluate biodiversity components in terms of:

   * composition: what there is and how abundant it is
   * structure: how biological units are organised in time and space
   * function: the role different biological units play in maintaining natural processes and dynamics.

Biodiversity is a key component of the environment, and maintenance of biodiversity is a key test of sustainability because biodiversity:

   * Is a vital, integral part of the planet's life support system;
   * Is the basis for evolution and adaptation to a rapidly changing environment;
   * Is a key component of a functioning environment for future generations;
   * Is essential to maintain clean water, fertile soil and clean air, thereby providing the basis for existence and indirect economic benefits;
   * Can be managed and used for economic benefit, for instance to produce crops, medicines, building materials, fuel and tools;
   * Has economic and social values e.g. in leisure and recreation or tourism;
   * Has educational, aesthetic and spiritual value, and so enriches our quality of life;
   * It determines the distinctive character or ‘feel’ to an area, be it a chalk downland, estuary, woodland or moor;
   * People value the existence of biodiversity and want it conserved.

The report continus by arguing that biodiversity decline is affecting the supply of environmental goods

   * water, clean air, food and productive and fertile soil 
   * that support people's livelihoods and quality of life.

The main threats to global biodiversity are associated with human activities causing habitat loss or damage. Worldwide, people are taking 40-50% of all primary production away from natural systems, and an unprecedented number of species (more than 12,000) are now threatened with extinction as a direct result of human activity. Rates of extinction are more than ten times ‘normal’ or recorded historical rates. Fires, fossil fuel use and soil cultivation have changed global carbon, nitrogen, phosphorus and sulphur cycles. Natural resources are being extracted faster than they are replenished, and ecosystems are being degraded. Many species-populations are being reduced and fragmented below viable sizes.

What SEA can do for Biodiversity?

SEA is intended to help achieve a high level of environmental protection and is identified in key international agreements (notably the Convention on Biodiversity and the Ramsar Convention) as an important tool for promoting the conservation and sustainable use of biodiversity. This is consistent with two key principles for the conservation and sustainable use of biodiversity:

   * The precautionary principle implies a presumption in favour of biodiversity protection where the knowledge required to ensure effective mitigation or compensation for a significant adverse impact is lacking. It should also apply in situations where there is sufficient evidence to suggest that adverse impacts are possible, but not enough to confirm ‘no significant impact’.
   * The ‘no net loss’ principle requires the status quo to be maintained in terms of quantitative and qualitative aspects of biodiversity (how much is there, what there it, how it is structured and distributed). 

SEA is particularly suited to protecting and enhancing biodiversity because it can

   * build biodiversity objectives into plan development; 
   * provide an opportunity for those with an interest in, and responsibility for, biodiversity to influence plan-development;
   * identify biodiversity-friendly alternatives;
   * focus on the longer term and larger scales;
   * consider all the threats affecting biodiversity in an area, enabling identification and assessment of cumulative threats and impacts;
   * suggest effective mitigation strategies to ensure no net loss of biodiversity throughout the development and implementation of plans, allowing sufficient ‘lead-time’ to ensure that effective mitigation can be put in place;
   * establish monitoring to provide necessary biodiversity data and to enable remedial measures to be taken.

In particular, SEA should follow the "positive planning" sequential approach:

   * avoiding biodiversity loss or damage
   * enhancing biodiversity where possible or securing opportunities for recovery
   * compensating for unavoidable loss of biodiversity
   * consolidating information on biodiversity.

Damage should always be avoided in the first instance if possible, mitigating only where impacts cannot be avoided and there are no alternative solutions. In particular, damage and loss should be avoided where biodiversity is particularly high, rare, threatened and difficult to replace or substitute. Opportunities to enhance biodiversity should be sought wherever possible.