The study by Hautier, Niklaus, and Hector (2009) investigates the impact of eutrophication on plant biodiversity in grasslands and identifies competition for light as a key mechanism driving this loss. They conducted an experiment using 32 grassland plant communities, manipulating both nutrient addition and supplementary light in the understory. The results showed that while nutrient addition increased aboveground biomass production and reduced light availability in the understory, it also led to a significant decrease in species diversity, particularly of low-growing perennial grasses and forbs. However, when additional light was provided to the understory, it compensated for the reduced light levels, maintaining plant diversity and preventing species loss. The study concludes that competition for light is a major factor in the decline of plant diversity following eutrophication, emphasizing the need to control nutrient enrichment to preserve biodiversity.The study by Hautier, Niklaus, and Hector (2009) investigates the impact of eutrophication on plant biodiversity in grasslands and identifies competition for light as a key mechanism driving this loss. They conducted an experiment using 32 grassland plant communities, manipulating both nutrient addition and supplementary light in the understory. The results showed that while nutrient addition increased aboveground biomass production and reduced light availability in the understory, it also led to a significant decrease in species diversity, particularly of low-growing perennial grasses and forbs. However, when additional light was provided to the understory, it compensated for the reduced light levels, maintaining plant diversity and preventing species loss. The study concludes that competition for light is a major factor in the decline of plant diversity following eutrophication, emphasizing the need to control nutrient enrichment to preserve biodiversity.