Question

List & Explain the key steps of your phosphorus cycle:

a) Long-term Phosphorus Cycle
b) Short-term Phosphorus Cycle
c) Phosphate Ion
d) Plants
e) Animals
f) Birds
g) Decay/Decomposition
h) Limestone
i) Erosion
j) Eutrophication

Answer 1

The phosphorus cycle involves both long-term processes, such as the formation of limestone and erosion, and short-term processes, including plant absorption and animal consumption of phosphorus. The phosphate ion is central to the cycle, and human activities such as the use of fertilizers can result in eutrophication. The cycle is notably slow, with phosphate ions cycling through marine environments for thousands of years before returning to land.

Step-by-step explanation:

The Phosphorus Cycle

Phosphorus is an essential nutrient required for various biological processes such as forming nucleic acids and phospholipids, and acting as a structural component in bones as calcium phosphate. The phosphorus cycle describes how phosphorus moves through the biotic (living) and abiotic (non-living) components of ecosystems.

The cycle can be divided into two parts:

Long-term Phosphorus Cycle: This involves the geological processes that move phosphorus. Phosphorus contained in rocks is released into the soil and water systems through weathering, volcanic activity, and erosion. Over time, phosphorus gets trapped in layers of sediment at the bottom of bodies of water and can eventually form new rocks like limestone.

Short-term Phosphorus Cycle: This cycle deals with the movement of phosphorus in the ecosystem. Plants absorb the phosphate ion (PO4³-) from the soil, which is then used to produce organic compounds. Animals and birds obtain phosphorus by consuming plants or other animals. Upon death, decomposition by microorganisms returns phosphorus back to the soil and water.

Human activities, such as the use of fertilizers and detergents, can lead to the runoff of phosphates into local water bodies, resulting in eutrophication, which is an excessive growth of algae and a decline in aquatic health.

The slowness of the phosphorus cycle is significant, with the average phosphate ion having an oceanic residence time between 20,000 and 100,000 years. This means that the exchange of phosphorus from the ocean to the land is an extremely slow process, impacting its availability as a nutrient in various ecosystems.