PhD candidate, Department of Botany
Lineage diversification in relation to biomes: within or across biome boundaries?
Diversification of lineages from one into multiple species is a key evolutionary process for generating biological diversity, but the role of biomes in facilitating speciation is controversial. Both niche conservatism and biome shifts have been promoted as critical mechanisms for lineage diversification. My research focuses on where and how diversification of lineages occurs, and evaluates the importance of trait, biome and niche shifts in speciation. I assess whether diversification primarily occurs within or across biome boundaries, the frequency and timing of biome shifts in relation to initiation of novel biomes, and how traits evolve in relation to biomes occupied.
I will explore this question using the hyper-diverse Australian Acacia, NZ Poaceae and three woody NZ lineages: Melicytus, Myrsine and Pseudopanax. My approach combines evolutionary modelling, Species Distribution Modelling, phylogenetic analyses, and trait data. Diversification was accompanied by frequent biome shifts in all my focal lineages. There was clear partitioning of traits within biomes and biome shift frequencies were more closely related to clade size than any other clade or biome characteristic. Biome shifts are integral to adaptation of lineages to a range of habitats and appear to be more influential than biome niche conservatism during lineage diversification at a range of scales.
Wednesday, May 30th, 12.00pm Betts Workroom, Union Street West
Taylor Davies-Colley, Grace Lim and Cara-Lisa Schloots
Taylor Davies-Colley, MSc Candidate, Botany, ‘Investigating the decline, and uncertain future of the unique threatened plant, Utricularia australis’
Grace Lim, MSc Candidate, Plant Biotechnology, ‘Genome Instability in Cyanobacteria’
Cara-Lisa Schloots, MSc Candidate, Botany, ‘Wetlands of Mahu Whenua’
Wednesday, May 16th, 12.00pm, Betts Workroom, Union Street Lecture Theatre, Union Street West
Tennant Lecture - Dr Peter de Lange
24th May Botany Tennant Lecture Dr Peter de Lange, Conservation & Biodiversity, Unitec Auckland
Archway 2, 6.00-7.00pm
PhD candidate, Departments of Geology & Botany, University of Otago.
Fossil plant and fungal floras of Auckland’s Pliocene
A remarkable suite of plant and fungal fossils of late Pliocene age (Waipipian, 3.7 to 3.0 Ma) have been collected from sites near Auckland. Fluvial, estuarine and near-shore sediments of the Tauranga Group have yielded a remarkable diversity of fossils, including fruits, seeds, vascular and non-vascular leaves, wood, amber, pollen, spores, fungi, mites and other arthropod fragments. The specimens are mostly organically-preserved and retain fine details such as leaf cuticle, fungal-spore ornamentation and endocarp/cone cellular patterns that complement their macro-morphology.
Globally uncommon fossils are preserved in these sediments, such as bracket fungus basidiocarps and highly distinctive moss gametophytes. Fossil fruits, seeds and cones form an informative component of the vascular flora. Interestingly, most of these fossil ‘fruits’ share affinities with locally extinct groups, such as Vitaceae, Menispermaceae, Casuarinaceae, Brassospora-type Nothofagus or represent locally extinct genera/taxa of Cupressaceae and Elaeocarpus, although several morphotypes do share possible affinities with extant species of Prumnopitys, Passiflora and Elaeocarpus.
The fossil plants in these sediments provide an unparalleled glimpse into the species living in northern New Zealand near the end of the Pliocene, a time when temperatures were warmer than today, prior to the climatic fluctuations of the Pleistocene.
Wednesday, May 2nd, 12.00pm, Betts Workroom, Union Street Lecture Theatre, Union Street West
PhD Candidate, Department of Botany, University of Otago.
Does non-human charisma affect conservation decisions in New Zealand?
The term “charismatic megafauna” has been used in the conservation literature since the mid 1980’s to signify a creature that has a quality, or qualities, that makes it attractive to humans. That an organism is valued for its charisma does not, however, mean that it has any extraordinary ecological value. A charismatic animal will be a popular choice for conservation, but conserving it, especially when resources are limited, may not be the best choice to ensure positive outcomes for whole ecosystems.
This project is investigating the role of non-human charisma in conservation decisions in New Zealand, focusing especially on the role of the public. Although charisma in humans has been widely studied, charisma in the non-human, a term that includes animals, plants and ecosystems, has been examined more sporadically. The literature on non-human charisma is scattered across disciplines and there has yet to be work that measures non-human charisma and then investigates links to national conservation decisions.
Wednesday, April 11, 12.00pm, Betts Workroom, Union Street Lecture Theatre, Union Street West
Professor, Department of Biological Sciences, University of Denver.
Causes and consequences of exotic tree removal in riparian zones of the Southwestern US
Ecological restoration of river systems in arid regions of the United States often include large-scale efforts to remove invasive exotic Tamarix spp. trees. Several species of Tamarix were introduced to western U.S. states during the 1800’s from the Middle East and Asia as a wind-break, stream-bank stabilizer, and ornamental; Tamarix is now the third most common species along rivers in these regions. Invasion by Tamarix is associated with elevated salinity, increased wildfire risk, lowered water tables, and altered plant and animal communities, however there is debate regarding whether removal of the trees has any hope of returning these ecosystems to their former state. Of particular concern and interest is the impact of a biological control insect, Diorhabda spp, that has been successfully defoliating Tamarix trees at a much higher rate than had been predicted when it was first released in 2003. By analyzing plant community data from more than 200 sites across the southwestern U.S., we have been able to identify several environmental and management factors that explain when and where removal by both the bio-control and traditional methods results in “successful” restoration. Our current NSF-sponsored research involves deeper exploration of the human component by using multivariate analysis of data from surveys of the land managers to better understand whether the attitudes and backgrounds of the people doing the restoration matters for outcomes. Our ultimate goals are to improve ecological restoration in arid lands while illuminating more general principles about the impact of anthropogenic activity on ecosystems.
Wednesday, March 28th, 12.00pm, Betts Workroom, Union Street Lecture Theatre, Union Street West
Janneke Hille Ris Lambers
Walker Endowed Professor of Natural History, University of Washington, Seattle.
Forest Community Assembly in Response to Climate Change
Predicting how climate change will influence the plants and animals with which we share our planet is one of the most challenging problems ecologists face. Climate is often assumed to be the dominant force governing species distributions, which leads to the prediction that all species will simply shift their ranges poleward and upward as the planet warms. Locally, plant communities should therefore lose cold-adapted species, while warm-adapted species increase in abundance. However, species differences in climate sensitivity, geographically variable rates in warming, slow generation times and dispersal limitation will all add significant complexity to these simple predictions, as will many other factors. A major research goal of the HilleRisLambers lab is to explore these complexities with observations, experiments and modeling. In this talk, I will present some of our most recent work disentangling the many processes that will influence how coniferous forests Mt. Rainier National Park (Washington State, USA) and beyond will respond to climate change.
Wednesday, March 14th, 12.00pm, Betts Workroom, Union Street Lecture Theatre, Union Street West
Professor, Department of Biology, Brigham Young University, Utah, USA.
On the Ecology and Evolution of Dehiscence in NZ Tussock Grasses
New Zealand tussock grasses are unique in their overexpression of the trait leaf abscision. This has generated lively debate over why this trait is common in the New Zealand environment but effectively absent from the rest of the world. Using tools of niche modeling, plant physiological ecology, phylogeography, and experimental studies, we explore potential hypothesese about the conditions that lead to the expansion of dehiscent grasses in two genera--Chionochloa and Rytidosperma.
Wednesday, February 28th, 12.00pm Betts Workroom, Union Street Lecture Theatre, Union Street West
No talks scheduled for January