The importance of revegetating with local natives

By: Ken Baker, Regional Landcare Facilitator
December 11, 2011

If you have been involved with revegetating with native plants you may have heard people talk about ‘local provenance’. A ‘provenance’ is a plant population containing local genetic variability. Local provenance is considered important to ensure the success of revegetation projects.

To channel the legendary science communicator of my youth, Julius Summer Miller, I think it is fairly reasonable to ask ‘Why is this so?’ Why should it matter if the plants we use in revegetation projects are local provenance or not?

Well, the plants growing locally have adapted, over a long period of time, to things like the local soil, temperature, rainfall and wind conditions.

As an example, the River Red Gum, which occurs naturally along waterways on the Liverpool Plains, is also widespread along rivers throughout Australia. However, River Red Gums exhibit significant differences in growth form and chemical and genetic makeup throughout its range. These differences are an adaptive response by the plant to variations in its local environment.

This being the case, it is very unlikely that River Red Gums imported from other regions will do as well in your revegetation projects as those that come from the local area.

So, plants grown from seed collected from healthy plants growing near to and in similar environmental conditions as the site you are revegetating, will give these plants the best chance of flourishing.

But how do you work out the extent of a species local provenance? How far can seed be collected from the parent plant of a particular species (the provenance range)? To determine this you need to consider a plant’s pollination and seed dispersal methods. For example, where the parent plant drops seed close by, seed should be collected as close to the planting site as possible. If seed is dispersed by wind or water, seed can be collected from remnant vegetation with matching environmental conditions, which were once connected to the planting site.

If plants have fleshy fruits that are spread by birds, seed could be collected further afield. Pollination distance for many Eucalypts can be a few kilometres, whereas for Acacias the distance will generally be much smaller.

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