In an ecosystem, organisms of same and different species are usually found. However, some organisms appear too commonly than others in that particular ecosystem. These commonly observed organisms (plants and animals) due to their large numbers are called DOMINANT species. An ecological dominant species is that which numerically outshines its competitors in an ecosystem.
A species may be dominant because it is better adapted to certain processes than Its competitors e.g. getting resources, disease resistance etc. or even deters its competitors. Hence, they appear large in number. This is the case of the abundance of pinyon pine and juniper trees along the desert slope of the sierra nevada mountains in california. In that ecosystem, these two plants dominate, hence, will be referred to as ecological dominants.
