Plant Biodiversity and Phylogenetics

I combine molecular, morphological and ecological data with bioinformatic tools to investigate the evolution and systematics of plants.  My main interest is the plant genus Acacia but I work on many plants including orchids, Eucalyptus and the whole flora of Australia.  My overall goal is to use my research and management skills to inform and guide public policy for better environmental  outcomes.

Acacia evolution

I have developed a 700 species phylogeny of the Australian plant genus Acacia.  With fossil Acacia data we have dated the major lineage diversification and now will trace the evolution of plant morphology and environmental niche. ongoing projects include:



  • Evolution of phyllodes

  • Insect codiversification

  • Biogeography of Acacia

  • ​Phylogenetic classification

Other legume groups I am working on:
 

  • Senegalia, Vachellia, (Mimosoids, all Legumes with collaborators)

  •  

Spatial Phylogenetics

Over the past few years our group has developed novel metrics to identify and quantify areas for evidenced-based conservation planning.  Categorical Analysis of Neo- and Paleo-Endemism (CANAPE)  quantitatively differentiates areas of paleo- and neo-endemism. This work is a collaboration with Brent Mishler at UC Berkeley and Shawn Laffan at UNSW.

 

These methods are valuable in the conservation decision-making process; reserve design can be guided by assessment of phylogeny rather than species counts alone and can identify complementary areas of biodiversity that have unique evolutionary histories and traits in need of conservation.

Plants and Soil Geochemistry

Evolution of the Australian Flora

As part of our phylogenetic diversity and endemism work my former postdoc Andrew Thornhill has generated a phylogeny of 90% of the Australian genera.  This tree has over 2,500 terminals and with the allied spatial data from the AVH we are exploring the big picture of Australian flora.

 

We have generated large, near species-level phylogeny of  the Eucalypts including Eucalyptus, Angophora and Corymbia.  The first papers will be coming out soon.

 

With Elisabth Bui at CSIRO I have been investigating the role of soil geochemistry in plant distributions. This work has determined that species with small ranges tend to be highly correlated with the distribution of geochemical variables in the soil, especially pH and salt (González-Orozco et al. 2012; Bui et al. 2104a,b).  This supports the hypothesis of the importance of geochemistry in determining plant responses to climate change. The data suggests that species distribution models that are predicting the effects of climate change need to include not only climatic but geochemical soil variables in the calculations.  I have initiated a collaborative project with the Unites States Geological Survey to generate soil layers to test these conservation relevant questions in the United States.

© 2018 by Joe Miller.