A pinboard by
Nick Gellie

PhD candidate, University of Adelaide


I test the efficacy of the plants and the practices we use to restore landscapes.

During my PhD (submitted 2017) I explored practical ways to improve restoration outcomes. The published research from my thesis included; (1) the investigation of local adaptation in plants and how this knowledge can best be applied to seed collection for better restoration outcomes; (2) the development of cost effective metrics to monitor and compare restoration success; (3) the use of embedded experiments in broad-scale restoration to assist land management. Along with my colleagues and close industry partners we are now successfully applying innovative restoration strategies that were developed during my PhD into globally significant and multi-scaler restoration interventions and monitoring.

An overarching theme of my research is about using the empirical evidence that is gained from robust embedded experiments to help solve contemporary environmental dilemmas (e.g. using restoration to reconcile or mitigate the effects of climate change, population growth, intensive agriculture, biodiversity loss and land degradation). By undertaking a programmed experimental approach to tackle the existing barriers in restoration, I aspire to align the goals of restoration practitioners, planners, researchers and policy makers, whilst simultaneously helping to create sustainable restoration outcomes (e.g. the creation of informed adaptive management options for land managers).

My work-space spans degraded woodlands through to agro-ecological and urban systems. I use tools from genomics, plant evolutionary ecology, restoration science, forestry, landscape architecture and conservation biology to conduct my research. The cross disciplinary synergies and conceptual advances borne from this research have had diverse applications in ecological restoration, green-space management, agriculture and human health. Therefore, by applying the most innovative and relevant science available to the emerging conservation and restoration challenges of our time, I hope to continue to deliver pragmatic solutions to the restoration industry and to improve restoration practices more broadly.


Genetic diversity and structure of the Australian flora

Abstract: To investigate the relationships between species attributes and genetic parameters in Australian plant species and to determine the associations in relation to predictions from population theory and previous global analyses.Continent of Australia.We assembled a dataset of all known population genetic analyses of Australian plants based on neutral markers and catalogued them according to key species attributes, including range, abundance, range disjunction, biome and growth form; and genetic parameters, mean number of alleles per locus, observed and expected heterozygosity and population differentiation. We determined relationships between species attributes and genetic parameters using a maximum-likelihood, multimodel inference approach.We found many associations that were consistent with predictions. Species attributes with greatest effect on genetic diversity were range size, growth form, abundance and biome. The most important attributes influencing genetic differentiation were range disjunction and abundance. We found unexpected results in the effects of biome and growth form on genetic diversity, with greater diversity in the eastern biome of Australia, and lower diversity in shrubs compared to trees.Our analysis of genetic diversity of Australian plants showed associations consistent with predictions based on population genetics theory, with strong effects of range size, abundance and growth form. We identified a striking effect of range disjunction on population genetic differentiation, an effect that has received little attention in the literature. We also found some notable differences to global predictions, which were most likely explained by confounding effects across variables. This highlights that caution is needed when extrapolating trends from global analyses to regional floras. Identifying associations between species attributes and patterns of genetic diversity enables broadscale predictions to facilitate the inclusion of genetic considerations into conservation decision-making.

Pub.: 13 Nov '16, Pinned: 31 Jul '17

Local maladaptation in a foundation tree species: Implications for restoration

Abstract: Publication date: November 2016 Source:Biological Conservation, Volume 203 Author(s): Nicholas J.C. Gellie, Martin F. Breed, Nicole Thurgate, Shaun A. Kennedy, Andrew J. Lowe Replanting native vegetation is a broadly accepted method for restoring degraded landscapes. Traditionally, seed used for restoration has been locally sourced to avoid introducing maladapted plants and to minimize the risk of outbreeding depression. However local adaptation is not universal and is disrupted by, for example, climate change and habitat fragmentation. We established a common garden experiment of ca. 1500 seedlings sourced from one local and two non-local provenances of Eucalyptus leucoxylon to test whether local provenancing was appropriate. The three provenances spanned an aridity gradient, with the local provenance sourced from the most mesic area. We explored the effect of provenance on four fitness proxies after 15months, including survival, above-ground height, susceptibility to insect herbivory, and pathogen related stress. The local provenance had the highest mortality and grew least. The local provenance also suffered most from invertebrate herbivory and pathogen related stress. These results provide evidence that no advantage would be gained during the establishment of Eucalyptus leucoxylon at this site by using only the local provenance from within the range we sampled. Our results suggest that incorporating more diverse seed mixes from across the aridity gradient during the restoration of Eucalyptus leucoxylon open woodlands would provide quantifiable benefits to restoration (e.g. 6–10% greater survival, 20–25% greater plant height, 16–45% more pathogen resistance during establishment). We demonstrated these restoration gains by embedding a common garden experiments into a restoration project, and we recommend this approach be more widely adopted because it provides an effective way to facilitate adaptive management options for restoration stakeholders based on empirical evidence. Graphical abstract

Pub.: 10 Oct '16, Pinned: 31 Jul '17

Revegetation rewilds the soil bacterial microbiome of an old field.

Abstract: Ecological restoration is a globally important and well-financed management intervention used to combat biodiversity declines and land degradation. Most restoration aims to increase biodiversity towards a reference state, but there are concerns that intended outcomes are not reached due to unsuccessful interventions and land use legacy issues. Monitoring biodiversity recovery is essential to measure success, however most projects remain insufficiently monitored. Current field-based methods are hard to standardise and are limited in their ability to assess important components of ecosystems, such as bacteria. High-throughput amplicon sequencing of environmental DNA (metabarcoding of eDNA) has been proposed as a cost-effective, scalable and uniform ecological monitoring solution, but its application in restoration remains largely untested. Here we show that metabarcoding of soil eDNA is effective at demonstrating the return of the native bacterial community in an old field following native plant revegetation. Bacterial composition shifted significantly after 8 years of revegetation, where younger sites were more similar to cleared sites and older sites were more similar to remnant stands. Revegetation of the native plant community strongly impacted on the belowground bacterial community, despite the revegetated sites having a long and dramatically altered land use history (i.e. >100 years grazing). We demonstrate that metabarcoding of eDNA provides an effective way of monitoring changes in bacterial communities that would otherwise go unchecked with conventional monitoring of restoration projects. With further development, awareness of microbial diversity in restoration has significant scope for improving the efficacy of restoration interventions more broadly. This article is protected by copyright. All rights reserved.

Pub.: 07 Mar '17, Pinned: 31 Jul '17