Do the lichens Xanthoparmelia conspersa (Ach.) Hale and Rhizocarpon Ram. Em. Th. Fr. subgenus Rhizocarpon utilise exogenous carbohydrates for radial growth?

To field test the hypothesis that lichen thalli can use environmental sources of carbon, solutions of ribitol, arabitol and mannitol were added to intact thalli of Xanthoparmelia conspersa (Ach.) Hale and a yellow species of Rhizocarpon (Rhizocarpon Ram. Em. Th. Fr. subgenus Rhizocarpon). In addition, ribitol and an arabitol/mannitol mixture were added to the marginal hypothalli of Rhizocarpon thalli after removal of the areolae. Carbohydrates were added at the beginning of 2- or 3-month growth periods for up to 15 months at concentrations approximately three times the levels estimated to be in the thalli. Addition of carbohydrates to intact thalli of both species had no effect on total radial growth but addition of mannitol significantly increased growth of X. conspersa thalli in the September/October growth period in one experiment. However, this effect was not repeated in a subsequent experiment in which different concentrations of mannitol were added to intact thalli. Addition of ribitol to hypothalli of Rhizocarpon resulted in significantly increased growth in the first few months of the experiment, growth then declining to levels below that of untreated thalli. The data suggest that although hypothalli of Rhizocarpon may have the ability to utilise exogenous carbohydrates for growth, there was little evidence that intact thalli of either species utilise environmental sources of carbon in the field.

Unity in Christ or Pan-Europeanism?:Nathan Söderblom and the ecumenical peace movement in the interwar period

In the summer of 2014 the Swedish Church is celebrating the 100th anniversary of the appointment of Nathan Söderblom as archbishop of Uppsala, and thus head of the Swedish church organisation. As a Lutheran with an enormously broad-minded and broad-reaching approach to ecumenical understanding and community-building, Söderblom shot to prominence in the interwar period not only because of his ecumenical engagement, calling for an evangelical catholicity so stand side by side with the Roman catholic and Orthodox catholic traditions, but also because of his comprehensive secular engagement for peace and understanding between peoples. In the latter context he also acquired a solid reputation as a perhaps less prominent but still noteworthy figure in the history of European integration. This article investigates how, why and to what extent Söderblom’s ecumenical and secular engagements were intertwined. The first part discusses how his biographical and academic background led to such staunch ecumenical positions, while the second part focuses on the secular engagement, which was perceived by Söderblom as necessary to make progress on the ecumenical front in the practical political realities of the 1920s. The final part, comparing and contrasting Söderblom’s views with those of Count Richard von Coudenhove-Calergi and the Pan-European Union, demonstrates why Söderblom’s engagement for Europe had to be limited: unity in Christ is by definition global in nature and therefore cannot be continent-specific.