ABSTRACT
During the 1970s a debate involving natural science, economic and social science perspectives emerged around the issue of the 'value' of ecosystems and biodiversity. The Ecological Economics camp is composed of a wide range of analysts from a number of disciplinary backgrounds, including natural science. The distinctive features of Ecological Economics are the acceptance of a pluralistic interdisciplinary methodology. Sustainable economic development has been characterized as a process of change in an economy that ensures that welfare is non-declining over the long run. Ecosystem services benefits are the 'exports' from the ecosystem sector to the human economic sector. In the wider context, an Ecosystem Services Framework began to evolve from an earlier natural science-based and more holistic analytical approach known as the 'Ecosystem Approach' as detailed by the 1992 Convention on Biological Diversity. Ecological economists warn that some services will not be amenable to monetary valuation because they are linked to socio-cultural entities, with specific historical conditions and symbolic significance.
