Ecosystem functions are the processes that control the flow of energy, nutrients, and organic matter in the environment. The interactions between biotic and abiotic elements create a unique physical structure for each ecosystem. Key aspects to consider when examining ecosystem functions include:

Productivity:

• Ecosystems require a constant input of solar energy to function and sustain.
• Primary production refers to the amount of biomass or organic matter produced per unit area over time through photosynthesis by plants.
• Productivity can be divided into two categories:

• Gross primary productivity (GPP) is the rate of organic matter production during photosynthesis.
• Net primary productivity (NPP) is the GPP minus respiration losses (R), which is the available biomass for consumption by heterotrophs (herbivores and decomposers).

• Primary productivity varies based on plant species, environmental factors, nutrient availability, and photosynthetic capacity of plants.
• The estimated annual NPP of the entire biosphere is approximately 170 billion tons (dry weight) of organic matter.

Decomposition:

• Dead plant and animal material, including feces, are referred to as detritus, which is the raw material for decomposition.
• Key steps in the decomposition process include:
  • Fragmentation by detritivores (e.g. earthworms)
  • Leaching of water-soluble inorganic nutrients
  • Catabolism by bacterial and fungal enzymes
  • Humification and mineralization in soil
    • Humification leads to the accumulation of humus, a dark, resistant substance that decomposes slowly
    • Humus is further degraded by microbes and inorganic nutrients are released through mineralization.
• Decomposition is primarily an oxygen-dependent process and is influenced by temperature and soil moisture. Warm and moist conditions favor decomposition, while low temperature and anaerobiosis inhibit it, resulting in the buildup of organic material.