Pioneer plants, also known as pioneer species, are the first plants to colonize an area that has been disturbed or has undergone a significant change, such as a volcanic eruption, landslide, or clear-cutting of a forest. These plants are able to thrive in harsh, inhospitable environments and help to establish a new ecosystem.

Pioneer plants are typically fast-growing, have a high reproductive rate, and are able to tolerate extreme conditions such as poor soil quality, high winds, and drought. Examples of pioneer plants include weeds such as dandelions and thistles, as well as shrubs like willows and alders.

As pioneer plants establish themselves and create a new ecosystem, they also create conditions that allow other, less hardy plants to thrive. Over time, the pioneer plants may be outcompeted by these more established species, and the ecosystem will continue to evolve and mature.