Extraction and purification of DNA from wood at various stages of decay for metabarcoding of wood-associated fungi

Assessment of endophytic and saprotrophic microbial communities from wood-extracted DNA presents challenges due to the presence of surface microbes that contaminate samples and plant compounds that act as inhibiting agents. Here, we describe a method for decontaminating, sampling, and processing wood at various stages of decay for high-throughput extraction and purification of DNA

Soil microbial communities influence seedling growth of a rare conifer independent of plant-soil feedback

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

Variation in soil microbial communities associated with critically endangered Wollemi pine affects fungal, but not bacterial, assembly within seedling roots

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

Conservation by translocation : establishment of Wollemi pine and associated microbial communities in novel environments

Background and aims 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. Methods 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. Results 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. Conclusion 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