The topic of biodiversity is of high value for education for sustainable development as it reflects the interaction of ecological, economic and social issues particularly well. Especially in so-called biodiversity hotspots, among them Chile, natural resources are often depleted for economic interest which, in many cases, is required income. Therefore, economic and social aspects must be considered in order to fully understand biodiversity loss. Being such an important issue, it is surprising that little is known thus far about learning prerequisites concerning biodiversity. This paper presents a qualitative interview study that investigated 16 to 18-year-old Chilean and German learners' perception of biodiversity and its loss (n = 24). Firstly, the pupils' cognitive frameworks were analysed. Secondly, subjective theories about biodiversity loss due to resource dilemmas were explored. Three subjective theories that emerged from the data reflected the notion that most pupils focused on either ecological or economic aspects of biodiversity loss. Pupils who concentrated on ecological aspects often referred to incorrect ecological facts. Moreover, these pupils showed difficulties in developing empathy and solidarity with impoverished people, who depend economically on plants in a resource dilemma. A smaller group of pupils succeeded in integrating the ecological, economic, and social aspects. Regarding the two samples, Chilean pupils seemed to have greater difficulties in recognising the social aspects of biodiversity loss, while German pupils were largely unaware of biodiversity loss on a local level. Implications for biodiversity education and future research will be outlined and discussed.