There is increasing attention being given to the importance of colonization traits like seed number and seed size for species coexistence and distribution in plant communities. In this study a null-model analyses of species co-occurrence and trait dispersion was performed to evaluate the importance of seed size and seed number for coexistence in a Swedish semi-natural grassland. Species abundance was inventoried in two grids based on quadrats differing in size (1 dm 2 and 25 dm 2 ). For both grids Monte Carlo simulations showed that species (in general) co-occurred more often than expected from a null model. Both seed size and seed number were underdispersed, species possessing similar seed traits tended to co-occur more often than expected from a random model. Species packing in a niche space based on seed number and seed size was found to be positively correlated to species richness. In species-rich sites species were more densely packed. The results contradict predictions from classical competition theories concerning species coexistence, and suggest that seed traits are important for species coexistence.

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Today, concerns prevail about the unsustainable use of phosphorus and worldwide eutrophication, thus requiring efficient management of phosphorus flows. With increasing population and associated urban growth, urban management of phosphorus flows in the perspectives of recycling, eutrophication and total budget becomes increasingly important. This study mapped phosphorus flows for a reference year (2013) and a future year (2030) using different scenarios for the city of Stockholm, Sweden. The results indicated that the Swedish goal of recycling phosphorus from wastewater would cover the majority of the total phosphorus budget for Stockholm. However, in 2013, only 10% of phosphorus was recycled for agricultural use, around half of which was from sewage sludge and the other half from food waste. Almost 50% of total phosphorus was sent to landfill/mining waste capping with sewage sludge, for economic reasons and lack of market. Among the scenarios of upstream and downstream urban management options studied in combination with population growth, recovery of phosphorus from sewage sludge had the greatest potential to increase the fraction recycled to agriculture. However, only upstream measures, e.g. changed diet, were able to reduce the total phosphorus budget. Urban management of phosphorus flows based on the different perspectives of recycling, eutrophication or total budget was shown to potentially result in different preferred management actions and both upstream and downstream measures need to be considered. Moreover, management needs to pay attention to small but environmentally sensitive flows, particularly when setting city goals on phosphorus recycling by percentage in a large budget.

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