Climate change puts the humble seed at risk

Climate is already having impacts on where and when seeds germinate, and has the potential to become a major driver of change in Australia's natural ecosystems.
 
In a new review released today by the Ecological Society of Australia (http://www.ecolsoc.org.au/hot-topics), Dr. Anne Cochrane from the Western Australian Department of Parks and Wildlife reports how changing environmental conditions impact on seeds.

Dr Cochrane said, “Some of the recent observations include a reduction in germination with warmer soils, shifts in timing of germination and reduced seedling survival”. 

"Temperature and moisture have a strong influence on seed germination.  Even small increases in temperature or slight changes in rainfall can disrupt germination, threatening populations of some plant species."

The impacts of these changes are likely to be felt throughout Australia's ecosystems;

In south-west Western Australia, the forecast warmer, drier conditions associated with climate change may reduce the numbers of seeds that germinate.

In south-eastern Australia's alpine regions, warmer temperatures can alter when seeds germinate, causing some species to emerge in autumn instead of in spring, whilst changes to snow melt mean that some species will be exposed to freezing conditions where once they were insulated by snow.
In desert ecosystems, rising temperatures can reduce the length of time that seed remains viable in the soil.

"The soil-stored seed bank is vital for plant species to survive after disturbances like fire. But global climate change will alter fire regimes, leading to declines in seed production, seedling survival and seed-bank viability for some plant species."

"Some species will face a high risk of local population extinction, potentially leading to biodiversity decline over time."

"Planning for unexpected seed responses to global warming may require seed conservation in seed banks, and assisted plant migration to help plants persist in areas with a more suitable climate."

Dr. Cochrane's report was prepared in conjunction with Professor Adrienne Nicotra from the Australian National University and Dr Mark Ooi from the University of Wollongong.

Contacts:

Anne Cochrane
anne.cochrane@dpaw.wa.gov.au

ESA Director-Hot Topics - Don Driscoll
don.driscoll@anu.edu.au