What is ecosourcing?
Ecosourcing refers to the propagation of native plants from local areas and the planting of them back within the same geographic area.
Why ecosource?
Ecosourcing is often used in restoration projects because locally sourced plants are thought to be more likely to survive than those from further away. This is because species are often better adapted to local conditions. For example, if planting northern rātā in Wellington City then using local seed sources is likely to be more efficient and effective than sourcing rātā plants from a different region.
Advances in plant science sometimes leads to a common species being split into several new species. If ecosourcing principles are not followed then natural plant distributions and gene pools are mixed together. Kānuka, for example, has often been planted from any source and yet kānuka was recently split into at least 8 species of Kunzea. The different species of kānuka, whose distribution was such that they never grew together, may now have been mixed up. This ‘genetic pollution’ can lead to hybridism and ultimately the loss of species.
The Network recommends following ecosourcing principles especially for plant species that show marked genetic variation between populations (such as mānuka, kānuka and kōwhai).
In some rare instances the local seed source for a particular species is of planted origin or has been reduced to only a few plants or even a single individual. This can often mean the population has an extremely limited gene pool. In these situations it may be better to supplement the seed collected from your local populations with seeds from further afield. This may be advantageous to future proof your planting against environmental changes or diseases that would otherwise impact detrimentally on populations sourced from plants with a narrow gene pool.
Ecosourcing and Nurseries
The Network recommends that you buy local native plants from local plant nurseries that follow ecosourcing principles. This also reduces handling and transport costs and helps support local businesses. Many plant nurseries sell plants originating from outside of their own regions where the major seed suppliers are based.
For more information about ecosourcing see:
- Ecosourcing in the Waikato
- Ecosourcing brochure - Waitakere City Council
- Eco-sourcing guidelines for Nelson City