A Cost-effective Site Selection Model for Biodiversity Conservation

These strategies are often based on a single objective (e.g. species richness conservation or species abundance conservation), a constant site protection cost (regardless of the location and productivity of the site) and a spatial scale that are not always relevant for decision-making.

In this regard, Finnish researchers have developed a new model to select several alternative sites so they can be compared for efficient biodiversity maintenance. From this, they determined the site that would be selected to meet both budget constraints and one or more conservation objectives (species richness, red-listed species or species abundance preservation).

The outcome is therefore a cost-effective solution, which takes into account the monetary losses resulting from protecting the selected areas (e.g. the revenue losses due to harvest restrictions). The authors calibrated their model on 32 semi-natural old-growth forest stands in Finland, which contain 632 species, 18 of them red-listed in Finland according to the IUCN1 criteria.

Their modelling reveals that:

The benefits from conservation increase with the conservation budget, but at a diminishing rate.

The site selection varies depending upon the single conservation objective.

When selection is based on multiple objectives, conflicts appear between protecting red-listed species and maintaining species richness. Results show that selecting sites to protect 6% more red-listed species diminishes the overall species richness by 3%.

As the marginal costs of conservation increase as the number of selected sites increases, the authors conclude that it is not economically efficient to protect all the species in every region or planning area. In addition, they highlight that protecting red-listed species is often in conflict with other conservation objectives (such as species richness preservation). As a consequence, trade-offs appear between conservation objectives.

Practically, they indicate that if the budget for conservation is low, it might be reasonable to make a pre-selection of sites based on the ecological information available and to then choose the sites that are the cheapest to protect. On the contrary, if the conservation budget is high, the sites should be selected in a complementary way. The authors also note that generally focussing on red-listed species might be reasonable, as they are a conservation priority.

Overall, this model provides new insight and new support for decision-making, which could be useful to achieve the EU target of halting biodiversity losses by 2010.