What best describes particulate organic matter (POM)?

Particulate organic matter (POM) is an essential component of nutrient cycling within ecosystems and is primarily made up of organic materials derived from dead plant and animal matter. As POM is ingested by various organisms, like detritivores, it undergoes processes of digestion and mineralization. During these processes, the organic matter is broken down into simpler compounds, releasing nutrients that are vital for plant growth and microbial activity. This transformation allows POM to contribute significantly to soil fertility and nutrient availability.

The nature of POM is dynamic; it does not remain static or merely accumulate without undergoing any changes. Instead, it actively participates in nutrient cycling, being transformed by biotic interactions and ultimately influencing the nutrient composition of the soil. Hence, the characteristic that POM is ingested, digested, and mineralized as it moves downward best encapsulates its role in ecosystem functioning.