Botanic Gardens Trust, Sydney, Australia

Rohan Mellick

Name
Dr Rohan S. Mellick

Position
Researcher & Technical Officer

Branch
Science & Conservation

Section
Evolutionary Ecology

Email
rohan.mellick@rbgsyd.nsw.gov.au

Phone
+61-2-9231 8069

Fax
+61-2-9251 7231

Keywords
Clarence River Corridor, Climate change, Coalescent-based analyses, Environmental modelling, Genetic diversity/structure, Past-current-future range shift, Population expansion/contraction, Post-glacial warming, Rainforest.

Research interests

I am interested in understanding the evolutionary role climate change and intraspecific divergence have played as mechanisms of adaptation and speciation along wide environmental gradients. Also, in developing methods to reliably predict the future change in distribution of genetic diversity so to better inform management strategies.

Current research

  • Projecting future loss/gain of genetic diversity for multiple lineages over varied habitats. An integrative approach using current methods tailored for multiple marker types and species’ ecological traits.
  • Using ecological models to increase sampling efficiency. Sampling along environmental gradients found to be significant in explaining the distributional character of a species so to maximise the chance of detecting intraspecific divergence (i.e. associated selective filtering)
  • Exploring intraspecific divergence among Australian Wet Tropic endemic Elaeocarpus spp. Four of 11 Australian Wet Tropics Elaeocarpus spp. show genetic structure over the Black Mountain Corridor. We are using molecular models and prior knowledge of divergence to understand the demographic history and splitting time between these population groups.
  • Hybridisation between a rainforest tree & a fire-adapted shrub ought to warrant revision of sub-genus Foliatus (Podocarpaceae). While collecting Podocarpus elatus at a number of sites, putative hybrids (P. elatus with co-occurring P. spinulosus) were found and collected for DNA extraction and genotyping. These individuals have amplified most of the loci characterized in P. elatus (Almany et al. 2009).
  • Reducing genetic load & increasing adaptive potential of species to survive future threats. Ecological models can design habitat corridors and join existing fragmented habitats to accommodate future range shift and navigation around human land-use obstacles. In conjunction, molecular models can anticipate demographic changes and assist in migration of rich genetic individuals into areas of higher climatic suitability to enrich impoverished populations under threat of localised extinction.

Peer-reviewed publications

  • Mellick R, Rossetto M, Allen C, Wilson PD, Hill RS, Lowe A (2013b) Intraspecific divergence associated with a biogeographic barrier and climatic models show future threats and long-term decline of a rainforest conifer. The Open Conservation Biology Journal, 7, 1-10.
  • Mellick R, Wilson PD, Rossetto M (2013a) Post-glacial spatial dynamics in a rainforest biodiversity hot spot. Diversity 5, 124-138.
  • Mellick R, Lowe A, Allen C, Hill RS, Rossetto M (2012) Palaeodistribution modelling and genetic evidence highlight differential post-glacial range shifts of a rain forest conifer distributed across a latitudinal gradient. Journal of Biogeography 39, 2292-2302.
  • Mellick R, Lowe A, Rossetto M (2011) Consequences of long- and short-term fragmentation on the genetic diversity and differentiation of a late successional rainforest conifer. Australian Journal of Botany 59, 351-362.
  • Mellick R, Rossetto M, Porter C (2009) Isolation and characterisation of polymorphic microsatellite loci from Podocarpus elatus (Podocarpaceae). Molecular Ecology Resources 9, 1460-1466.
  • Almany GR, De Arruda MP, Arthofer W, Atallah ZK, Beissinger SR, Berumen ML, Bogdanowicz SM, Brown SD, Bruford MW, Burdine C, et al. (2009) Permanent Genetic Resources added to Molecular Ecology Resources Database 1 May 2009-31 July 2009. Molecular Ecology Resources 9, 1460-1466.
  • Rossetto M, Crayn D, Ford A, Mellick R, Sommerville K (2009) The influence of environment and life-history traits on the distribution of genes and individuals: a comparative study of 11 rainforest trees. Molecular Ecology 18, 1422-1438.
  • Shepherd M, Mellick R, Toon P, Dale G, Dieters M (2005) Genetic control of adventitious rooting on stem cuttings in two Pinus elliottii x Pinus caribaea hybrid families. Annals of Forest Science 62, 403-412.
  • Shepherd M, Eggler P, Mellick R, Cross M, Toon P, Dale G, Dieters M (2003) Stability of gene effects (QTL) in extreme genetic backgrounds: mapping genes controlling adventitious root formation in hybrid pines.
  • Mellick R (1999) Genetic variation in growth, morphology and physiological traits of Eucalyptus pilularis (Smith). Hounours Thesis. Centre for Plant Conservation Genetics, and Resource Science and Management, Southern Cross University.
  • Mellick R (1999) Optimal primer design for PCR amplification of microsatelite loci from the Myrtaceae family. Hounours Minor Thesis. Centre for Plant Conservation Genetics, and Resource Science and Management, Southern Cross University.
  • Mellick R (1999) The efficient of cross-species transfer of microsatelite markers in Myrtaceae. Hounours Minor Thesis II. Centre for Plant Conservation Genetics, and Resource Science and Management, Southern Cross University.
  • Shepherd M, Eggler P, Cross M, Mellick R, Toon P, Dieters M, Henry R (2003) Genetic mapping of adventitious root formation in tropical pine hybrids. CRC for Sustainable Production Forestry, Southern Cross University, Lismore.
  • Shepherd M, Eggler P, Mellick R, Cross M, Dale G, Huang S, Dieters M (2003) Stability of gene effects (QTL) in extreme genetic backgrounds: mapping genes controlling adventitious root formation in hybrid pines. In ‘CRC for Sustainable Production Forestry Annual Meeting’, (Cradle Mountain, Tas.) & Produced by SCU, Marketing & External Relations Directorate. 1318.
  • Shepherd M, Mellick R, Toon P, Dale G, Dieters M (2003) Genetic variation in clonal propagation characters in tropical hybrid pines (Technical Report No.125). CRC for Sustainable Production Forestry, Centre for Plant Conservation Genetics, Southern Cross University, Lismore.
  • Mellick R, Shepherd M, Dieters M (2002) Evidence for simple genetic control of rooting in cuttings of the hybrid between Pinus elliottii var. elliottii and P. caribaea var. hondurensis. CRC for Sustainable Production Forestry, Centre for Plant Conservation Genetics, Southern Cross University, Lismore.
  • Shepherd M, Cross M, Mellick R, Dieters MJ, Henry R. Genetic mapping in tropical hybrid pines. In: International Conference on: Wood, Breeding, Biotechnology and industry expectations, Bordeaux, France, June 11-14 2001.
      rohan mellick