· Guest post by Christine Dalliston·
Local Provenance is the term used to describe native plant populations that naturally occur in a given area.
Many native plant species can be found to occur naturally across a broad geographic area or range. For example, Hairpin banksia (Banksia spinulosa) naturally occurs across 3 states, from coastal Victoria to Cairns.
However, the plants growing in a specific area will have adapted to the local conditions over a long period of time. Although of the same species, a Hairpin banksia from southern Victoria will have a different genetic makeup to its cousin in Cairns, just as the same species of plant found on the coast will be different from that growing in the mountains. Different populations containing local genetic variations are called provenances.
For true local provenance, the individual plant is grown from seed stock from parent plants within the same population (or as close by as possible).
Bringing in plants sourced from a different region can compromise the genetic integrity of the species i.e. weaken the ability of the plant population to thrive in the specific local conditions through diluting the genes that have been selected over a long period of adaptation to local conditions. Eventually, given time and the right conditions of isolation, this variation between populations can lead to new species evolving.
Preserving local provenance populations, on the other hand, is an important way of protecting biodiversity and combating the threat to biodiversity posed by climate change.