Sir

As observed in your News Feature “Dollars and sense” (Nature 437, 614–616; 2005), there is increasing evidence that many conservation organizations remain focused on single species instead of addressing the urgent problems caused by loss of ecosystem functionality.

The anthropogenic climate change that is expected during the next century looms as an overarching and unprecedented threat. P. Ibisch, M. Jennings, S. Kreft

More and more conservation scientists are calling for a holistic approach that considers ecological processes and the functional properties of ecosystems, rather than just parts and patterns of species, as crucial conservation targets (see, for example, P. Kareiva and M. Marvier Am. Sci. 91, 344–351; 2003).

However, ecosystem functions — which become services when used by people — are not yet considered in most mainstream conservation approaches. Another shortcoming is the rather static view of biodiversity held by many conservation organizations today. Thus, there are even more reasons for a paradigm shift in conservation than those addressed in your News Feature.

Ecosystem functionality means that an ecosystem itself can sustain processes required to maintain its parts by being, for example, resilient enough to return to its previous state after environmental disturbance. Functionality depends in various specific ways on the quantity and quality of a system's biodiversity. An important characteristic of ecosystem functionality is that it develops and responds dynamically to constantly occurring environmental changes.

The anthropogenic climate change that is expected during the next century looms as an overarching and unprecedented threat to biodiversity. The predicted rate of warming alone may move many species well beyond their current climate-niche ranges.

Some species will find themselves in habitats that are unsuitable in many secondary ways, for example, as specific breeding microhabitats or for symbiotic interaction with other species.

Further, individual species within an ecosystem will be threatened by unpredictable factors, such as changes in seasonal resources and in the biogeography of pathogens, predators and competitors, which could trigger extinction events.

Although ecosystems never have been in a steady state and species distributions have always been on the move at one timescale or another, it is now more clear than ever that it is impossible to statically conserve current biodiversity patterns, in hotspots or anywhere else.

Unfortunately, many conservationists have not yet grasped the need to be ‘global change managers’ rather than museum-keepers, a shift of perception that is urgently required to mitigate the impacts of global change and help ecosystems adapt to them.