Final answer:
Leaf litter and soil invertebrates, soil micro-organisms, nitrogen-fixing plants, ants, birds, and mammals.
Step-by-step explanation:
Some examples of organisms (other than plants) that would have lived in the hay field before it was abandoned include:
- Leaf litter and soil invertebrates
- Soil micro-organisms
- Nitrogen-fixing plants
- Ants, birds, and mammals
These organisms play important roles in the ecosystem, such as decomposing organic matter, providing nutrients, and contributing to pollination and seed dispersal.