Question

What is relationship between two species?

Answer 1

It depends on their physical characters , their habitats , food requirments, nutrient specific etc....

Answer 2

Mutualism descries the ecological interaction between two or more species where fitness is increased through direct interaction. Mutualism is thought to be the most common type of ecological interaction, and it is often dominant in most communities worldwide. Prominent examples include most vascular plants engaged in mutualistic interactions with mycorrhizae, flowering plants being pollinated by animals, vascular plants being dispersed by animals, and corals with zooxanthellae, among many others. Mutualism can be contrasted with interspecific competition, in which each species experiences reduced fitness, and exploitation, or parasitism, in which one species benefits at the "expense" of the other.

Mutualism is often conflated with two other types of ecological phenomena: cooperationand symbiosis. Cooperation refers to increases in fitness through within-species (intraspecific) interactions. Symbiosisinvolves two species living in close proximity and may be mutualistic, parasitic, or commensal, so symbiotic relationships are not always mutualistic.

Mutualism plays a key part in ecology. For example, mutualistic interactions are vital for terrestrial ecosystem function as more than 48% of land plants rely on mycorrhizalrelationships with fungi to provide them with inorganic compounds and trace elements. As another example, the estimate of tropical forest trees with seed dispersal mutualisms with animals ranges from 70–90%. In addition, mutualism is thought to have driven the evolution of much of the biological diversity we see, such as flower forms (important for pollination mutualisms) and co-evolution between groups of species.[1]However mutualism has historically received less attention than other interactions such as predation and parasitism.[2][3]