Background : According to the Swedish curriculum teachers in all subjects have a responsibility to integrate a holistic perspective of sustainable development (SD) and teach according to an education for sustainable development (ESD) approach. However previous research has shown that teachers from different subjects perceive SD differently. Purpose : The study aimed at investigating if and how teachers’ subject area influences their ability to implement a holistic perspective of ESD; we investigated both the impact of teaching traditions and the barriers that teachers experienced. Sample : A stratified sample of 224 Swedish upper secondary schools participated. An online questionnaire was sent and answered by a total of 3229 teachers at these schools. In total, there were 669 science teachers, 373 social science teachers, 483 language teachers, 713 vocational and esthetical–practical teachers, and 739 teachers from other disciplines who participated in the survey. Design and methods : The questionnaire consisted of questions requiring Likert-scale responses and multiple-choice questions. The data from the questionnaire were analyzed using Pearson’s Chi-square test and one-way ANOVA. The significance level accepted was p < 0.05. Results : Teachers were influenced by their own subject traditions. Science teachers in our study were grounded in the fact-based tradition and lectures were the most common teaching method used. The teaching tradition of the social science teachers seemed to be most in line to an ESD approach. Many language teachers (41%) stated they did not include SD issues in their teaching at all. Among the barriers identified, the most common obstacles were that the teachers lacked inspiring examples of how to include SD in their teaching and that they lacked the necessary expertise about SD. Conclusion : This study highlights the need for the management within schools to create opportunities for teachers to work collaboratively when teaching ESD. It is also important to provide further training that is adjusted to the needs of different disciplines.

This article describes the results of a nationwide questionnaire study of 3229 Swedish upper secondary school teachers’ conceptual understanding of sustainable development in relation to their subject discipline and teaching experience. Previous research has shown that teachers have difficulties understanding the complex concept of sustainable development. According to the Swedish curriculum, all teachers in all subjects should integrate a holistic perspective of sustainable development including economic, ecological, and social dimensions. This study shows that teachers differ in their understanding of the concept mostly according to their subject traditions. Social science teachers emphasize social dimensions and science teachers’ ecological dimensions, respectively. Teachers are aware of the relevance of the three dimensions to various degrees, but do not generally have a holistic understanding. The greatest uncertainty in teachers’ understanding is related to the economic dimension. Science and social science teachers are critical of incorporating economic growth into the concept of sustainable development while language, vocational, and esthetical–practical teachers are not. No experience-bound differences of the teachers’ understanding could be found, but recently qualified teachers consider their understanding of sustainable development to be poorer in comparison with more experienced teachers’ self-evaluation. The study highlights the need for further training in sustainable development since more than 70% of the questioned teachers stated that they need such training.

Along a gradient of increasing productivity in lakes, the abundance of perch (Perca fluviatilis) first increases and then decreases, whereas the abundance of ruffe (Gymnocephalus cernuus) and that of roach (Rutilus rutilus) continue to increase. Perch, unlike roach and ruffe, undergoes dramatic ontogenetic diet shifts. The decrease in the abundance of perch along the productivity gradient may be due to competition from roach at its plankton—feeding stage and from ruffe at its benthic—macroinvertebrate—feeding stage. Previous studies of these three species have focused on the effects of roach on the other species. To further examine the competitive relationship among these species, we studied the effect of increasing the density of ruffe, while maintaining a relatively high, constant density of roach, on the diet and growth of perch. Food resources were also monitored during this 2—mo experiment, which was conducted in 10 enclosures in a pond in southern Sweden. Based on prior experiments we expected roach, an efficient planktivore, to reduce the biomass of zooplankton in all enclosures. Moreover, we expected that the increased density of benthic—feeding ruffe would force perch to increase its consumption of zooplankton, resulting in reduced growth. We found, as predicted, that the biomass of cladocerans of copepods decreased over time but was not affected by ruffe density. The biomass of the commonly consumed macroinvertebrates Sialis (a megalopteran), trichopterans, and ephemeropterans was lower in enclosures with ruffe than in enclosures without ruffe. Moreover, the biomass of Sialis decreased and that of chironomids and the clam Pisidium increased over time. High ruffe densities were related to an increased proportion of zooplankton in the diet of perch in August, but not in September. The diet of ruffe changed little along the ruffe gradient. Only the proportion of trichopterans (in August) and Pisidium (in September) in the diet of ruffe increased along the ruffe gradient. The growth of both perch and ruffe decreased with increasing ruffe density, whereas the growth of roach was constant. These data suggest that one reason perch decrease in abundance along a productivity gradient may be because they are competitively sandwiched between plantivore and benthivore specialists.