NRCM Nutrient Cycling Practice Exam 2025 - Free Nutrient Cycling Practice Questions and Study Guide

Primary production refers to the process by which autotrophs, mainly plants and phytoplankton, convert sunlight and inorganic substances into organic matter through photosynthesis. The rate of primary production is influenced by various factors, and one major limitation is the availability of nutrients.

A deficiency of nutrients, such as nitrogen, phosphorus, or potassium, can significantly hamper the growth of primary producers. These nutrients are essential for the synthesis of vital compounds like proteins and nucleic acids. When the supply of these nutrients is low, even if sunlight and water are abundant, the overall rate of primary production will be limited because the producers cannot adequately grow and reproduce. This nutrient limitation can lead to decreased biomass and lower productivity in both terrestrial and aquatic ecosystems.

In contrast, an abundance of sunlight and excess water typically support higher rates of primary production, as these factors are conducive to photosynthesis and plant growth, respectively. High temperatures can also promote growth to a certain extent, but excessive heat can lead to stress or damage to plant tissues. Therefore, the availability of nutrients stands out as a crucial limiting factor for primary production in many ecosystems.