Finland

Ilkka Hanski

2000 Balzan Prize for Ecological Sciences

For his outstanding contributions to population and community ecology. His work has profoundly influenced our understanding of how populations in nature persist and how conservation policy of endangered species should be implemented.

Born in 1953 (1953 – 2016), Professor of Zoology at Helsinki University, Hanski has made a decisive contribution to the development of one of the most productive concepts in population ecology in the past ten years. It makes for easier understanding of the delicate mechanisms governing the extinction and survival of several small communities of the same species scattered over non-contiguous areas: such a condition is now widespread among many animal populations. In the light of the objective difficulties faced by this kind of research, his study of a butterfly community on the Aland islands is unique and unsurpassed.

Ilkka Hanski is one of the foremost ecologists of his generation. His highly original contributions to both theoretical and observational experimental work in ecological science have had a deep and wide-ranging impact.
More than any other ecologist, Hanski has been responsible for the development of the concept of “metapopulations”, one of the most influential ideas in late 20th century population ecology.
Many species in nature exist as “metapopulations”. A metapopulation is a series of semi-isolated populations linked by occasional migration between them. What Hanski has done, building on an idea put forward by Richard Levins, is to show how the persistence of populations often depends critically on the way in which they are divided into sub-groups. Even though any single sub-group may be vulnerable to extinction, the population as a whole persists as a result of movement between sub-groups.
This work is of great importance in conservation. Many endangered species survive in small isolated pockets of suitable habitat.

Hanski’s other contributions to ecology are wide-ranging. For example, he has done exquisite work on the structuring of ecological communities and made important contributions to our understanding of the well-known population cycles of voles and lemmings. Hanski’s world-wide influence has come from the many papers he has published, his books, and from the students he has supervised.