An orchid growing as an epiphyte on a mango tree branch is a classic ecological example. Identify the type of population interaction and the respective signs representing the outcomes for the orchid and the mango tree.

Step-by-step solution

An orchid growing as an epiphyte on a mango branch represents commensalism. In this interaction, the orchid benefits (+) by getting physical support and better access to sunlight, while the mango tree is neither benefited nor harmed (0). Therefore, the interaction is commensalism, represented by the signs (+, 0). Mutualism (+, +) would imply both benefit, parasitism (+, -) implies the mango tree is harmed, and amensalism (-, 0) implies one species is harmed while the other is unaffected, none of which apply to this