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Karen Sommerville, Bronwyn Clarke, Gunnar Keppel, Craig McGill, Zoe-Joy Newby, Sarah Wyse, Shelley James, and Catherine A. Offord (2017) Australian Journal of Botany 65: 609-624

Rainforests in the South Pacific hold a considerable amount of plant diversity, with rates of species endemism >80% in some countries. This diversity is rapidly disappearing under pressure from logging, clearing for agriculture or mining, introduced pests and diseases and other anthropogenic sources. Ex situ conservation techniques offer a means to limit the loss of plant diversity. Seed banking is considered the most efficient and cost effective of these techniques but is applicable only to seed capable of tolerating desiccation and cold storage.

Data on the degree of tolerance of these conditions was lacking for more than half of the 1503 South Pacific rainforest genera examined for this review.

Of the 710 genera for which data were available, the storage behaviour of 324 was based on an assessment of only one or two species, although 76% of those genera contained at least 10 species. Many of the unstudied or poorly studied genera are shared across several South Pacific nations, providing an excellent opportunity for collaboration on future ex situ research and conservation. Of the 386 genera for which three or more species have been studied, 343 have a very high proportion of species (>95% of those tested) that are suitable for seed banking.

Seed banking could therefore provide a suitable means for preserving a large proportion of the rainforest flora before it becomes extinct in the wild. Alternatives for preserving species that are not suitable for seed banking are also discussed.

Luisa Cogno - Macarthur Chronical - 14th July 2017

Dr Karen Sommerville talks about the Rainforest Seed Conservation Project.

Please contact Dr Sommerville if you would like to view this article.


The Gardens Magazine - Spring 2016

Rainforests cover less than half of one per cent of Australia’s land mass, yet contain around 50 per cent of Australia’s plant and animal diversity. While over 1,000 rainforest plant species are found in New South Wales, more than 100 of these are listed as threatened. Until recently, seed banking has not been considered to be an effective insurance to preserve the genetic diversity of rainforest plants, as large or oily seeds of many species are destroyed by traditional storage methods of drying and freezing.

Marcus Strom, Sydney Morning Hearald, June 3, 2016

Meet Karen Sommerville, the women saving NSW rainforests one precious seed at a time 

Marcus Strom - The Sydney Morning Herald, August 26th 2016

Dr Heidi Zimmer and Dr Cathy Offord explain how a trial planting of Wollemi pines in the Blue Mountains is giving plants the opportunity to grow away from an introduced plant pathogen infecting trees in thier natural habitat.

Georgina Reid - The Planthunter, April 28th 2016

The Australian PlantBank, opened in 2013, was purpose-built to facilitate native plant conservation and education in Australia.

Campbell Philips - Wild Magazine, September 2nd, 2016

Recent research into one of Australia’s most famous living fossils, the rare Wollemi Pine, has given further hope that the species can be brought back from the edge of extinction.

Karen D. Sommerville, Graeme Errington, Zoe-Joy Newby and Catherine A. Offord (2016) Journal of the Australian Network for Plant Conservation 25: 10-12.

It is hard to imagine that, 55 million years ago, rainforest vegetation covered much of the Australian continent. As the land mass drifted north and became more arid, the rainforests contracted to a discontinuous band following the north and east coast of the mainland and the western half of Tasmania. When Europeans arrived on the continent, these remaining rainforest stands were seen as a great resource for timber and agricultural land and were reduced further in size by large scale clearing, particularly in NSW and Queensland.

Today, rainforests occupy less than 0.4% of the Australian land mass. Despite occupying such a small area, rainforests still retain a high proportion of Australia's plant diversity. Of the 277 seed-producing families currently listed on the Australian Plant Census, for example, over 60% are represented in rainforest habitats.

J.L. Rigg, C.A. Offord, B.K. Singh, I.C. Anderson, S. Clarke, J.R. Powell (2016) Pedobiologia 59: 61-71

The critically endangered Wollemi pine (Wollemia nobilis W. Jones, K. Hill & J. Allen) has very low levels of recruitment in the wild. Wollemi pine grows on shallow soils of poor nutrient status and high acidity and is likely to be highly dependent on microorganisms such as mycorrhizal fungi and other microorganisms that contribute to nutrient cycling in soils. The microbial communities present in soil around wild Wollemi pine and the specificity of subsequent assembly in seedling roots has never been assessed.

We analysed soil fungal and bacterial communities associated with wild Wollemi pine and neighbouring co-dominant, coachwood. Root-associated assemblages in seedlings were evaluated in the presence of inoculum collected from under Wollemi pine or coachwood (Ceratopetalum apetalum) in the field. Variation partitioning revealed that fungal and bacterial community assembly in soil were associated with different processes, with fungi more strongly influenced by spatial factors and bacteria influence equally by spatial and edaphic factors. Variation in soil microbial communities in the wild affected fungal, but not bacterial assembly in roots of Wollemi pine seedlings. Wollemi pine recruited a distinct bacterial community in its roots regardless of soil origin.

J. L. Rigg, C. A. Offord, H. Zimmer, I. C. Anderson, B. K. Singh, J. R. Powell (2016) Plant and Soil 114: 209-225

Wollemi Pine (Wollemia nobilis Jones, Hill & Allen) is a critically endangered conifer and living fossil. Translocation has been proposed as a conservation strategy to establish ‘back-ups’ to the wild population; however, knowledge regarding the environmental and biotic requirements of individuals planted in new environments is limited. An experimental translocation was established in a new location in the wild with Wollemi Pines planted along a light and elevation gradient.

Specific abiotic soil properties and associated microbial communities were linked to Wollemi Pine performance in these new locations to inform best practice for future translocations. Our results indicate that soil properties can be used to select appropriate translocation sites that ensure initial establishment and growth. One year after translocation Wollemi Pine had recruited a species-specific fungal community that persisted. Species-specific bacterial communities in their soil and roots formed in the second year after planting. Translocated Wollemi Pines that were unhealthy and were not growing did not have the species-specific fungal community.

The long-term functional consequence of this species-specific microbial community warrants ongoing investigation. This is one of the first studies to explicitly consider the role of microbial communities during the translocation of a rare plant and such approaches will be valuable for informing best translocation practice for other rare plant species.

Jessica L. Rigg, Cathy A. Offord, Brajesh K. Singh, Ian Anderson, Steve Clarke, Jeff R. Powell (2016) Ecology 97: 3346-3358

Plant–soil feedback, the reciprocal relationship between a plant and its associated microbial communities, has been proposed to be an important driver of plant populations and community dynamics. While rarely considered, understanding how plant–soil feedback contributes to plant rarity may have implications for conservation and management of rare species. Wollemi pine (Wollemia nobilis) is a critically endangered species, of which fewer than 100 trees are known to exist in the wild. Seedling survival within the first year after germination and subsequent recruitment of Wollemi pine is limited in the wild.

We used a plant–soil feedback approach to investigate the functional effect of species-specific differences previously observed in the microbial communities underneath adult Wollemi pine and a neighboring species, coachwood (Ceratopetalum apetalum), and also whether additional variation in microbial communities in the wild could impact seedling growth.

There was no evidence for seedling growth being affected by tree species associated with soil inocula, suggesting that plant–soil feedbacks are not limiting recruitment in the natural population. However, there was evidence of fungal, but not bacterial, community variation impacting seedling growth independently of plant–soil feedbacks. Chemical (pH) and physical (porosity) soil characteristics were identified as potential drivers of the functional outcomes of these fungal communities.

The empirical approach described here may provide opportunities to identify the importance of soil microbes to conservation efforts targeting other rare plant species and is also relevant to understanding the importance of soil microbes and plant–soil feedbacks for plant community dynamics more broadly.