Forward-looking approach needed to conserve biodiversity corridors

The importance of predicting future threats to the areas connecting biodiversity hotspots when planning conversation projects is highlighted in a new study. Using Costa Rican forest as a case study, researchers compared forward-looking planning methods to those that focus exclusively on current threats and found the forward-looking approaches to be more effective and reliable.

As so many different factors lead to environmental changes, such as development or impacts caused by climate change, predicting future threats to an environmental project can be very complicated. Thus, those striving to achieve conservation goals can sometimes be faced with 'surprises' which can prevent goals being reached.

The study focuses on habitat connectivity, an important concept in biodiversity. Corridors between different habitats prevent declining species from becoming isolated. One of the major threats to biodiversity conservation projects is corridors being blocked or fragmented before the project is completed. The key to effective conservation planning is predicting accurately whether there is sufficient time to save certain valuable habitat linkages, or whether it is better to focus on less valuable linkages that are more likely to survive for the duration of the project.

Making such predictions requires complex modelling and the researchers employed and compared several different methods for selecting conservation projects in their forest case study. They developed one particular method that considered the ecological costs of delaying conservation action. More specifically, they identified corridors where delaying action would be most costly, usually because the corridors contained thin strips of forest that could cut off corridors if trees were removed. Using predictive modelling, they demonstrated that projects with the highest ecological costs of delayed action were more effective at conserving diverse habitats than projects with lower delay costs.

The problem of maintaining habitat connectivity, the researchers suggest, requires urgent attention if the adverse effects of climate change and habitat loss on biodiversity are to be limited. Their study shows that considering habitat changes that might occur in the distant future is preferable to a reactive approach that only considers immediate threats. Conservation planning must therefore employ strategies that consider variations in future funding availability and deforestation rates. Ideally, funding should be sustained for conservation projects but given that funding and deforestation are always uncertain, it is important to identify strategies that are robust to such uncertainty.

Source: Spring, D. Baum, J., Mac Nally, R., et al. (2010). Building a Regionally Connected Reserve Network in a Changing and Uncertain World. Conservation Biology. 24(3): 691-700.

Contact: daniel.spring@sci.monash.edu.au