Pioneer Species

( Article Type: Explanation )

Pioneer species are the first species to colonise a new area (for example, a new island that has emerged from the sea or an area that has been disturbed by large-scale activity such as a volcanic eruption or man's clearance of a piece of land for development purposes). These include wind-dispersed microbes, mosses and lichens, which grow close to the ground and establish quickly over large areas. Their basic characteristics include rapid growth, the production of copious, small, easily dispersed seed and the ability to germinate and establish themselves quickly and easily on open sites. These species then trigger the process of soil formation on bare rock by trapping wind-blown soil particles and by secreting acids, which eventually break down rock. This chemical breakdown is supplemented by physical weathering. When the plants die, they decay and their remains then help to form new soil. Plants that are commonly recognised as weeds are often a form of pioneer species establishing on disturbed soils or newly cleared areas.