BISC201 - Exam 2 Decomposition

What is decomposition in ecology?

The breakdown of organic matter into simpler, non-organic forms and energy.

What formula represents the decomposition rate?

dM/dt = -kM, where M is the current mass and k is the decomposition constant.

How do temperature and precipitation affect decomposition rates?

Overall rates of decomposition increase with temperature and precipitation, with variation between habitats and species.

How does fast-moving water affect decomposition?

It speeds up decomposition through the physical breakdown of litter.

What is aerobic decomposition?

A process where organic compounds are converted to energy and CO2 in the presence of oxygen through oxidation.

What are the three steps of anaerobic decomposition?

1. Hydrolysis, 2) Fermentation, 3) Methanogenesis.

What happens during hydrolysis in anaerobic decomposition?

Water breaks down larger molecules (carbohydrates, proteins) into simpler molecules (simple sugars, amino acids).

What is the role of nitrogen in leaf litter decomposition?

Nitrogen is a limiting nutrient; too little nitrogen slows decomposition.

What influences the palatability of leaf litter?

Lower C:N ratio increases palatability; high amounts of lignin and cellulose decrease palatability.

What are the stages of succession in leaf litter decomposition?

1. Large arthropods, 2) Small arthropods, 3) Fungi and bacteria.

What are the classifications of decomposers based on size?

Epiedaphic (soil surface), Eudaphic (deep soil), Hemiedaphic (both).

What is the first group of insects to colonize decomposing animals?

Blow flies, flesh flies, and house flies.

Which insects are scavengers in the decomposition process?

Scavenger flies and rove beetles.

What role do fungi and dermestid beetles play in decomposition?

They are involved later in the process, often feeding on decomposing material.