Final answer:
The new growth after a volcanic eruption is replaced through a process called Primary succession, wherein pioneer species help establish soil for other species to flourish.
Step-by-step explanation:
The term that describes the new growth that replaces plant life covered by lava after a volcano eruption is Primary succession. This process occurs when new land is formed following a volcanic event, as seen with lava flows in places like Hawaii. Here, weathering and other natural forces break down the hard rock to create a substratum where pioneer species, such as hardy plants and lichens, can establish themselves. These pioneer species break down the mineral-rich lava into soil, allowing for less hardy species to eventually grow and replace them, leading to a diverse ecosystem over time.