What is the greatest limiting factor for plants that grow on the floor of a rain forest?

The greatest limiting factor for plants that grow on the floor of a rain forest is sunlight. In these ecosystems, the dense canopy formed by tall trees significantly reduces the amount of sunlight that reaches the forest floor. As a result, plants that thrive in this environment have adapted to low-light conditions, which can restrict their growth and photosynthesis.

While rain forests typically have abundant water availability and relatively rich soil nutrients, the competition for sunlight becomes the primary challenge for the understory plants. They have evolved various strategies, such as broad leaves and slow growth, to maximize the limited light they receive. Temperature tends to be less of a limiting factor in the stable climate of a rainforest, as it does not vary drastically throughout the year. Therefore, while other factors are important, it is the scarcity of sunlight that most greatly limits plant growth on the forest floor.