Answer:
No organism in nature can exist in isolation. Therefore, all organisms must interact among themselves and their environment. The interaction can be intraspecific (within the same species) or interspecific (between different species) and exist for a short period of time or can be permanent. There are various types of ecological interactions that can occur in an ecological community, which are mentioned as follows:
Mutualism: The positive interaction between two or more species in which both species get mutually benefited is called mutualism. It can be facultative (not essential for survival or reproduction) or obligate (essential for the associates). An example of mutualism is the association between algae and fungus which is referred to as lichen. In this type of interaction, the algal partner produces food by the process of photosynthesis that can be utilized by the fungal partner and the fungal partner provides shelter to the algal partner and protects it from the environmental stresses. The relationship can be represented as +/+.
Commensalism: An interaction in which one species gets benefited and the other one is neither benefited nor harmed is called commensalism. Escherichia coli is a commensal bacteria that reside in the human gut and absorbs nutrients from there. In most cases, the bacteria do not harm...
Species interactions within ecological webs include four main types of two-way interactions: mutualism, commensalism, competition, and predation (which includes herbivory and parasitism). Because of the many linkages among species within a food web, changes to one species can have far-reaching effects.