On the value of land

Abstract: The issue of sustainable development is once again moving the production factor land into the focus of economic theory and practise. There are three production factors, capital, labour and land. Land is a synonym to ecosystems. During the major part of the 20th century land in economic theory has been handled as a peripheral issue. The sustainability context implies a challenge to take land in proper consideration. That means to in an adequate way consider system characteristics that result in complex systems, such as thresholds, resilience, irreversibilities, and interdependencies between systems and system levels. The thesis examineshow land can be understood and handled in the context of a sustainable development,the relations between land and society on a conceptual level and in operative terms,the relations between system levels and between the three sustainability dimensions ecological, economic and social,the importance of agriculture and animal production in a sustainable development. The major findings are that in contexts such as economically profitable and natural resource-efficient milk production; methods to measure sustainability performance of production systems generally; and societal strategies for management of natural resources that support economic and social development within ecological sustainability limits, three “laws” need to be handled appropriate: Liebig’s “Law” of the minimum, Shelford´s “Law” of tolerance, and the “Law” of diminishing return in biological-ecological productions systems.The thesis identifies examples within dairy sciences, systems ecology, and engineering sciences that affect or may affect policies in real world systems from local to global level that can be substantially improved. In order to suggest relevant measures a tool-kit supporting a sustainable development have been generated, integrating contributions from agricultural sciences, systems ecology, economic theory, economic geography, applied environmental sciences and theories of complex systems. The thesis summarises around 30 years of professional experiences mainly within advanced consultancy, during which this tool-kit has been developed and applied. Evaluation of some applications afterwards shows relevance. For some of the examples analysed in the thesis, found weaknesses are such that global food security literally is threatened within one to twenty years.