How do global systems interact to affect ecosystems?

is a functional unit that results from interactions of abiotic, biotic, and anthropogenic components and are a combination of interacting, interrelating parts that form a unitary whole.  Ecosystems vary in size.  They can be as small as a puddle, or as large as the earth itself.  Basically, any living and non-living things interacting together can be considered an ecosystem.  Within each ecosystem, there are habitats that vary in size.  A habitat is a place where a population lives.  A population is a group of living organisms of the same kind living in the same place at the same time.  Natural ecosystems are made up of abiotic factors such as air, water, rocks, and energy and biotic factors such as plants, animals, and microorganisms.

I know just that

typically, most spiders possess eight eyes. however, others have as many as 12, and some don't have any. these eyes are for detecting light from dark, deciphering shapes and for gathering their prey.