Discuss the various types of positive interactions between species.

(N/A) Positive interactions are those in which at least one species benefits and none are harmed. These are primarily categorized into two types:
$1$. Mutualism: In this interaction,both participating species benefit from each other.
Examples include:
- Lichens: $A$ symbiotic association between algae and fungi.
- Mycorrhizae: $A$ symbiotic association between fungi and the roots of higher plants (e.g.,$Pinus$ roots).
$2$. Commensalism: This is an interaction where one species benefits,while the other is neither benefited nor harmed.
Examples include:
- An orchid growing as an epiphyte on the branch of a tree.
- Barnacles growing on the back of a whale.
Summary of Positive Population Interactions:

Species $A$	Species $B$	Nature of Interaction
$+$	$+$	Mutualism
$+$	$0$	Commensalism