Emergy and a Policy for the Commons.

An emergy-based evaluation of the Astroni wildlife reserve (Southern Italy) was performed in order to investigate its energy metabolism and potential benefits in return on resource investments from society. The economic and environmental sustainability of the wildlife reserve were also explored, placing a special focus on the evaluation of natural capital and ecosystem services. Matter, energy and economic flows supporting the wildlife reserve in the year 2006 were quantified and compared in terms of their total emergy content. Finally, the sustainability of the wildlife reserve and its carrying capacity for environmental education and sustainable tourism were evaluated. The main products and services generated by the Astroni wildlife reserve were identified, then the environmental performance of the system was evaluated in terms of selected emergy-based indicators, among which the following values of emergy cost per unit of output: a) net primary production, 1.30·104 seJ/J; b) service of shelter for birds, 1.72·1015 seJ/bird; c) educated and recreated visitors, 2.85·1014 seJ/visitor; d) research products, 1.16·1017 seJ/publication. The Environmental Loading Ratio calculated for educated and recreated visitors (1.24) showed a well balanced human pressure in terms of visitors per year, while the same indicator for other services pointed out the opportunity to further develop the services of birds protection (0.28) and research products (0.35). The return on economic investment (0.12) and the emergy self-sufficiency ratio (0.14) were also calculated in order to assess the economic and emergy trade-off between the wildlife reserve and its surrounding environment. These figures showed a return on the economic investment performed by the Government to operate the wildlife reserve of about 1:10. The same applies to the emergy investment. The study points out the unsustainable management of the wildlife reserve in the long run, highlighting the need for more sustainable management schemes oriented to improving both biological conservation and economic self-sufficiency. The study also exemplifies the concrete contribution of science to improve the effectiveness of the management of protected areas that are recognized under relevant national and international networks and programmes.