Deutsche Bundesstiftung Umwelt

After a long period of prevarication, Russia ratified the Paris Agreement. The population now accepts that climate change is real and that it has negative consequences. Yet Russia is only willing to make a small-scale contribution to limiting climate change. Ambitious strategies for reducing greenhouse gases are being thwarted by powerful political and business opponents, and Russian citizens are almost entirely unwilling change their behaviour. Energy efficiency is an important issue, but renewable energies remain a low priority. One reason for initiating rapid change could come from outside Russia, however. The European Union is planning to take greenhouse gas emissions into account when setting import duty levels, and this is now a cause for concern.

Animationen, Trickfilme, Hörstationen – in der Ausstellung „Menschen Welt“ verdeutlichen interaktive Stationen wie Konsum und Aktivitäten in Deutschland mit Ökosystemen, Klima und Lebensqualität auf der ganzen Welt zusammenhängen. Die Ausstellung der Deutschen Bundesstiftung Umwelt macht Komplexes einfach, Globales überschaubar und zeigt Lösungswege auf, um scheinbar unlösbare Probleme konsequent anzugehen.

The task of points-of-interest (POI) recommendations has become an essential feature in location-based social networks (LBSNs) with the significant growth of shared data on LBSNs. However it remains a challenging problem, because the decision process of a user choosing to visit a POI depends on numerous factors. The high level of sparsity of the data in LBSNs makes the POI recommendation problem even more challenging, especially for large geographical areas and worldwide datasets. Moreover, in this context the mobility behavior of the users is very heterogeneous, ranging from urban to worldwide mobility. In this paper, we explore the impact of spatial clustering on the recommendation quality. The proposed approach combines spatial clustering with users' influences. It is based on a Poisson factorization model built on an implicit social network, inferred from the geographical mobility patterns. We conduct a comprehensive performance evaluation of our approach on the YFCC dataset (a very large-scale real-world dataset). The experiments show that our approach achieves a significantly superior recommendation quality compared to other state-of-the-art recommendation techniques.

Explaining the diversity and distribution of tree taxa in the isolated tropical mountain forests (TMF) of the Malesian archipelago remains one of the great challenges of tropical biogeographical research. We investigated tree diversity, endemism and community composition in 13 plots of 0.24ha between 700 and 2400m in the TMF of Central Sulawesi’s (Indonesia) highlands and related the patterns to gradients in elevation, climate and soil properties. Special attention was paid to understorey trees with stem diameters as low as 2cm, not exceeding 2/3 of stand canopy height. Based on extensive taxonomic work on the plots, we found that Sulawesi’s TMF flora is with 27–78 species per 0.24ha not species-poorer than that of other Malesian islands, and vascular plant endemism is higher (22% of the species endemic to Sulawesi) than previously thought. Alpha diversity was mainly dependent on elevation and not soil factors (7 parameters tested). The alpha diversity of tree species, genera and families declined linearly with elevation, as did the number of species and genera per family, revealing higher phylogenetic clustering at lower elevations. Indicator Species Analysis and cluster analysis identified three main forest belts (sub-montane at c. 700–1400m, lower montane at c. 1400–2000m, upper montane at >c. 2000m), deviating from earlier zonation concepts by separating sub-montane (rich in taxa related to the lowlands) and lower montane communities (rich in Fagaceae and Myrtaceae). With 27–51% of all tree species in a plot never found in the upper canopy, our data suggest that the guild of true understorey tree species is species-rich (estimated at c. 130 species in our region), contradicting the hypothesis that Southeast Asian tropical forests with mass-flowering trees (here: Fagaceae) are particularly poor in understorey tree species. We conclude that the mountains of Sulawesi harbour remarkably species-rich, but still understudied, TMF with a unique tree flora rich in understorey trees, which are of high conservation priority.