This study explores the impact of phosphorus on the functional diversity (FD) of freshwater fish globally. The FD metrics functional richness (FRic), functional evenness (FEve) and functional divergence (FDiv) are calculated using a compiled dataset of 36,868 total phosphorus (TP) stations and 4,478,635 fish occurrences, leading to a FD analysis for 2498 buffers.
Using linear mixed models and various potential covariates, the effects of TP and freshwater realm on FD was assessed. The best-performing model for FRic, selected based on ANOVA, marginal R2 and conditional R2, included ecoregions as a random factor and temperature as a covariate. This model explained 57.5% of the variance in FRic, but TP's effect was not significant. The models for FEve and FDiv are singular, therefore no response to TP has been found. Contrary to prior research suggesting a significant effect of phosphorus on aquatic ecosystems, these findings reveal no significant relationship between TP and the FD metrics. This result challenges the expectation of decreasing FRic based on findings of decrease in species richness, highlighting that species richness does not necessarily correlate with functional diversity.
These findings suggest that phosphorus alone may not be a reliable indicator of eutrophication's impact on functional diversity. The results underscore the importance of considering additional factors, such as the nitrogen-to-phosphorus (N/P) ratio, in assessing the ecological effects of eutrophication. Consequently, phosphorus should be reconsidered as the sole metric for evaluating freshwater eutrophication in life cycle assessments, especially when using FD as impact category.

Food forests have recently received an increasing amount of attention since they are seen as a possible addition to the Dutch nitrogen-sensitive agricultural sector. Food forests are claimed to positively affect local ecosystem services while producing food for human consumption. Most of the effects and the edible production, however, lack scientific and quantified substantiation. This study aims at quantifying the edible production of food forests in the temperate climate zone, compares it to conventional agricultural systems, and analyses factors that may influence the edible productivity. By monitoring 22 100 m2 plots in eight food forests in the Netherlands and Belgium, it was found that the average food forest of this set of food forests produces 1038 kg edible biomass, 948,344 kcal, 12.39 kg proteins, 104.59 kg carbohydrates, and 22.13 kg fats per hectare. except for carbohydrates in conventional hazelnut production and fats in conventional red and black currant production, the food forests’ edible production, consisting of a diverse set of fruits, turned out to contain significantly lower amounts of energy, proteins, carbohydrates, and fats than conventional apple, pear, red currant, black currant, hazelnut, and dairy production in the Netherlands. Furthermore, no significant relationships were found between age, species richness, or canopy cover and the edible production of the food forests. Management and design, however, are considered factors that likely affect the edible production and need to be analysed in future work. Although food forests have not turned out to be competitive with conventional production systems in terms of edible production, they have many more beneficial characteristics than food production alone. More than conventional agricultural systems, food forests are expected to contribute to biodiversity, carbon capture, natural habitat creation, and soil formation and offer possibilities for social aspects like local community building and education. They are therefore still considered a valuable addition to the Dutch agricultural sector, although less productive and with fewer financial incentives, but more in line with nature-inclusive and circular forms of agriculture and with more focus on social opportunities.