A never ending and universal challenge in the management of biodiversity collections is to find a balance between on the one hand creating optimal conditions for conservation and maximizing accessibility and on the other, achieving this with limited resources, i.e. funding, time and space. If for instance available resources do not allow storage under the conditions required for optimal preservation and accessibility, what compromises and solutions can be made or found? Finding solutions and making compromises is far from easy, differs in each situation and per collection and is by and large carried out independently and single-handedly by each facility.<br> In this presentation elements that are decisive in collection development are reviewed, starting from strategic choices regarding acquisition up to deaccession. Some examples of compromises and solutions are provided regarding collection acquisition, deselection and efficient storage. A typical phenomenon in natural history collections is asymmetrical space requirements per species: common species take up (a lot) more space in collections than rare species. As a potential solution, this presentation explores the idea of establishing a national or transnational centralized storage facility for 'common species' in combination with digitization and discusses its advantages and disadvantages.
