Biosphere Contents

4. Interdependence

Some species interactions are beneficial; others are neutral; others are harmful

There are situations where one species provides a service for another, at no cost to itself, as with birds nesting in trees (+0 interaction), or where a species harms another without noticing as with a cow trampling on an insect (0- interaction). Most interactions, however, involve feeding relationships. At their simplest these involve antagonistic situations where one organism eats another (clearly a +- interaction).

Caterpillars feedingA Komodo dragon feeding

Can you think of examples of beneficial and of harmful species interactions?