Area-selection methods are about the 'where first' of in situ conservation action rather than the 'how', particularly in deciding which combinations of available areas could represent the most biodiversity value for the future (ref 8). The problem is how to deal with a problem involving so many species and areas to find efficient solutions, while retaining flexibility, and yet still make the process transparent and accountable to the people for whom conservationists are acting.
Conservation is about ensuring persistence of value. Area selection for conservation includes emotive issues of values, goals and priorities. The first problem to be faced is that values and goals are not universal, but differ among people and among situations. Therefore values and goals have to be made explicit and have to be agreed as broadly as possible at the beginning of any particular area-selection exercise if conflicts are to be minimised. Area selection methods can then be used to apply rigorous and explicit rules to determine priorities consistent with these values and goals. This procedure should not be viewed dogmatically but rather as a flexible means of exploring the consequences of different values, rules and data to inform the decision-making process. The result will be a process that is explicit, accountable and repeatable.
The value chosen for conservation should be broadly shared by the people giving conservationists their mandate and preferably ought to be quantifiable (at least in relative terms) for arguments presented to economists, politicians and their constituency. Biodiversity value is one popular choice since the Rio Convention.
A goal of ensuring the best representation of biodiversity value within a set of areas has often been used in an attempt to approach conservation as a 'proactive' process, as opposed to 'firefighting' reactively as particular species become endangered. Resources for priority action may still be deployed in relation to perceptions of imminent threat. Representativeness simply implies monitoring all valued biota, not just those parts that are currently threatened.
Distinguishing higher from lower priority of areas for urgent conservation management in the context of a particular representation goal is the purpose of area-selection methods. The need for priorities is usually unavoidable because competition with incompatible land uses limits the extent of the area that is available for conservation. Intensity of management within priority areas may vary depending upon circumstances, from seeking to exclude some of these land uses, such as certain kinds of agriculture, to being very limited and integrated with other current land uses.
Areas selected as priorities are chosen on the grounds that they are necessary to meet a particular goal, without illusions that they are sufficient for all broader goals. Analysts are often obliged to begin selection by trying to meet minimum requirements to satisfy a particular goal. It is clearly important that minimum priority areas are then added to systematically so as to improve prognoses for the biota (e.g. these areas might conceivably be considered as seed areas for future habitat restoration). However, an acceptance of priorities must recognise that this idea also implies that some areas and biota will be given lower priority. This is not to say that they have no conservation value, rather that in relation to agreed goals the actions are not as urgent.
Quantitative methods provide substantial advantages: