What is the difference the healthy ecosystem and unhealthy ecosystem

Each step in the FOOD CHAIN contains appropriate numbers of organisms

If one group becomes too numerous, the chain becomes UNBALANCED

Each step in the FOOD CHAIN contains appropriate numbers of organisms

For example, agricultural runoff creates a SURPLUS of nutrients which can cause sudden INCREASES in algae growth

Each step in the FOOD CHAIN contains appropriate numbers of organisms

Too much algae blocks sunlight from reaching vascular plants

Each step in the FOOD CHAIN contains appropriate numbers of organisms

Too few plants means LESS FOOD for herbivores

Ecosystem health is a metaphor used to describe the condition of an ecosystem. Ecosystem condition can vary as a result of fire, flooding, drought, extinctions, invasive species, climate change, mining, over exploitation in fishing, farming or logging, chemical spills, and a host of others

Explain:

heat from the core of the earth causes convection currents to occur in the mantle. these currents slowly move the crust around.