Aquatic plants in lakes respond differently to nitrogen levels. In a study, two types of plants, Ceratophyllum demersum and Phragmites australis, were grown together in tanks with varying nitrogen levels. They found that high nitrogen levels led to more competition between the plants. Ceratophyllum demersum grew better with less nitrogen, while Phragmites australis did better with more nitrogen. As nitrogen levels increased, Phragmites australis became the dominant plant. Moderate nitrogen levels can support a diverse plant community in shallow lakes. This information can help protect biodiversity and guide lake restoration efforts.