On 22 August 2012 the WCMN hosted a guest speaker evening at the Empire State Hotel in Inglewood. Dr Linda Broadhurst, a research scientist from CSIRO in Canberra spoke to the group about seed genetics and seed provenance in revegetation jobs.
The event was a great success, with 25 people attending. Participants spoke highly of the presentation, with several commenting that the content was “complex but clear”. As well as discussing how genetic diversity comes about, Linda provided several case studies of Victorian species, and provided useful and practical advice to participants about local issues. Some of the key messages of the evening were:
It is hard to do irreparable damage when carrying out revegetation works.
Large trees are important reservoirs of genetic diversity in the landscape.
When collecting seed, harvest over several successive years, and from all sides of the canopy. Blend seed from successive years together to improve genetic diversity in revegetation jobs.
Strong evolutionary forces such as saline soils, or particularly wet or dry climates cause local adaptation – if these strong selective pressures are not present in your area, bringing in new species to boost the gene pool can be a good thing in revegetation.
Create a buffer zone around revegetation sites if pollution of the gene pool is a concern – ask yourself “is it better to get these plants back in the landscape?” Assess the risk, and be aware that cross-pollination may occur.
When working in very high conservation significance sites, be more cautious about mixing provenance than you would be when working with a degrading remnant of lesser conservation significance.
There was strong feedback from participants that they would like a follow up workshop on seed collection and treatment. This will be arranged for Autumn 2013.