Image of researcher studying oak gall wasps in the UC Davis Arboretum and Public Garden.


As a living museum, we maintain careful records on each plant in the Arboretum's collection. These records include:

  • the correct scientific and common names of the plant
  • the plant family to which it belongs
  • source information for all wild and cultivated plants received at the institution
  • other plants with which the plant was associated in its native site
  • when and how the plant material was propagated
  • propagation method success rates
  • when and where it was planted in the garden
  • horticultural, culinary, medicinal, or economic uses of the plant
  • geographic range of the species

The Arboretum maintains a Geographic Information System (GIS) and digital maps that are linked to the plant records.

The Arboretum's documented plant collections are used by researchers in a variety of fields. Recent studies have focused on natural pest control methods, DNA analysis of  evolutionary relationships among plant groups, plant susceptibility to disease, genome classification, and plant-insect interactions. Other researchers study the wildlife in the Arboretum, the water quality in the creek, the history of the site, or the ways people use the gardens.

For more information about conducting research at the Arboretum, contact our Director of Collections, Mary Burke at (530) 752-3150 or

Recent Research in the UC Davis Arboretum

2015, Griffin Hall, Megan Morris & Dr. Rachel Vannette (UC Davis) are studying the nectar-associated microbial communities within Epilobium canum (California fuchsia) and other California native species.

Molecular Phylogenetic Study of Arboretum Oaks
2015, Terence M. Murphy and Daniel Potter (UC Davis) performed a molecular phylogenetic study of Arboretum oaks. DNA samples of oaks from the Arboretum collection have been isolated, and partial gene sequences have been determined for two genes, rbcL and ITS. A comparison of these sequences contributes to an determination of the relationships among species of this important plant genus. The agreement between the patterns of rbcL and ITS sequences strengthens considerably the conclusion that molecular data can reveal the actual pattern of evolutionary relationships among Quercus species. READ THE STUDY

2015, Laurie Casebier (UC Davis) with the help of the Bohart Museum of Entomology is doing a study on the biology of Neuroterous saltatorious, known as the “jumping gall wasp”. This native wasp makes galls on the leaves of white oaks from which the adults emerge. This study is designed to observe how these wasps interact with other organisms, and their importance to the environment.

2015, Shawn Overstreet (UC Davis) is researching the horticultural potential of oak acrons to be a commercial animal feed crop. His project involves analyzing the nutritional composition (including tannin content) of the acorns of approximately 100 oak taxa; specifically he is trying to determine which acorns would be most suitable for animal feed. Because of the excellent living oak collection in the Arboretum, Shawn will be able to collect acorns from the wild-collected trees of 19 oak taxa.

2014, Joanna Solins and Dr. Mary Cadenasso (UC Davis) are researching the effects of urbanization on the water status of native oaks growing along headwater streams in the Sacramento area. Preliminary research on Q. lobata (valley oak) and Q. wislizeni (interior live oak) in the Arboretum is helping to establish procedures for fieldwork.

2014, Paul Nabity (University of Arizona) is studying how oak host phenotypes change upon interaction with native phylloxeran insects. Both insects and plant specimens were collected for phylogenetic analyses and to assess insect-induced changes in chemistries and microorganisms.

2013, Researchers at the John Muir Institute of the Environment (Mary Brooke McEachern, PI) are conducting a long-term study of the dispersal and feeding ecology of dusky-footed woodrats at the UC Davis Quail Ridge Reserve. The team is using arboretum plant samples in food preference trials, to better understand how woodrats respond to novel, chemically-defended food sources they encounter when dispersing to new habitats.

2012, Kamyar Aram, Heather Mehl, Dr. David Rizzo (UC Davis) conducted an experiment comparing sporulation rates of exotic Phytophthora species, including P. ramorum (the causal agent of Sudden Oak Death), P. nemorosa, and P. pseudosyringea (the later two have host ranges similar to P. ramorum, but do not cause significant levels of disease in California forests).

2012, Andrew L. Hipp (The Morton Arboretum, Lisle, IL) collaborated with the University of Notre Dame (IN), Duke University (NC), University of Minnesota, and Universidad Nacional Autónoma de México to conduct a comprehensive systematic study of the oaks of the New World. The project integrated next-generation genomic (DNA) sequencing, plant physiology, and direct study of plants in the field and museum collections to gain insights into the oak tree of life and the basic question of how oak traits, distributions, and diversity evolve in response to changes in habitat and climate. 

2011, Emily Bzdyk (UC Davis) examined populations of leafcutter and resin bees (genus Megachile, subgenus Litomegachile) in the Arboretum to revise the taxonomy of the subgenus and create a phylogeny for Litomegachile. She investigated distribution, morphology, and ecological relationships such as pollination.

2011, John Chau (University of Washington) examined the systematics of the genus Buddleja for phylogenetic analysis using samples from the Arboretum.

2011, Yigen Chen (UC Davis) was part of a joint UC Davis and USDA Forest Service research team working on the biology and host selection behavior of the invasive insect species Agrilus auroguttatus (gold spotted oak borer). The team is using samples from Quercus agrifolia(coast live oak), Quercus kelloggii (California black oak), and Quercus engelmannii (Engelmann oak) in the Arboretum to characterize volatile odors that attract the insect, in order to develop a more effective bait to improve detection.

2011, Ashley Clingen (Natural Resources Canada) is investigating behavioral patterns of Megastigmus, a genus of wasp, that is actively parasitizing Cupressaceae species in North America and other parts of the world. Cypress cone samples from the Arboretum were sent to her for analysis. 

2011, Andrew Engilis, Jr. (UC Davis, Curator, Museum of Wildlife and Fish Biology) created a checklist of all the bird species found in the Arboretum based on species observations starting in the 1960s. 

2011, Richard Jeannotte (UC Davis) is investigating the composition of waxes in Salvia plants to explore their role in reducing water loss through transpiration.

2011, Takao Kasuga and David Rizzo (UC Davis and USDA) inoculated twigs of Umbellularia california, Quercus agrifolia and Lithocarpus densiflorus from the Arboretum with Phytophthora ramorum (the etiological agent of Sudden Oak Death) in growth chambers to monitor gene activity in the pathogen.

2011, Max Lambert (UC Davis) studied the eating habits of turtles in the Arboretum.

2011, Julien Massoni (Université Paris-Sud) used samples of plant tissue from the Arboretum for DNA extraction to investigate the phylogenetics and floral evolution of magnoliids. 

2011, Daniel Park (UC Davis) is studying the phylogenetic distance between native taxa and introduced taxa of the family Asteraceae as a measure of predicting invasive and/or weedy behavior.

2011, David Rizzo (UC Davis) used Quercus agrifolia and Quercus chrysolepis cuttings from the Arboretum for inoculation studies in the Department of Plant Pathology. 

2011, Connie Sibernagel (UC Davis) sampled Western pond turtles and red-eared sliders in the Arboretum to determine differences in disease prevalence between these populations, as part of a statewide study with California Fish and Game.

2011, Margaret Swisher (UC Davis) is trapping and tagging California ground squirrels in the Arboretum as part of an investigation of coat color variation. 

2010, Jacob Landis (University of Kansas) focused his research on gene expression during flower development of members of Plantaginaceae, tribe Antirrhineae. He studied cell morphology in the petals to look for the presence of conical cells and the cell shape.

2010, George Newcombe (University of Idaho) used fresh seeds of Populus fremontii from the Arboretum for research on genes for resistance to exotic pathogens of plants.

2009, Ann Chang (UC Davis) installed minnow traps in the Arboretum to catch crayfish to induce predator cues for hatching frog eggs. The experiment looked at the ability of frogs to adaptively change their morphology (phenotypic plasticity) in the presence of predators.

2009, John Eadie (UC Davis) and undergraduate students in Wildlife, Fish and Conservation Biology 136: Ecology of Waterfowl and Game Birds, worked with researchers from the Wildlife Health Center in the School of Veterinary Medicine to examine the health of the mallard ducks in the Arboretum. 

2009, Maxwell Joseph (UC Davis) studied the oak moth’s response to leaf toughness in Quercus agrifolia in the Arboretum.

2009, Melody Keena (USDA Forest Service) took samples of adelgids (small, soft bodied aphids that feed exclusively on coniferous plants) from conifers in the Arboretum to assess genetic variation.

2009, Eric Wohlgemut (contract archeobotanist) collected Brodiaeacormlets from the Arboretum to compare with charred plant remains from Native Californian archaeological sites to understand the native use of root crops in this region.

2009, Kamyar Aram (UC Davis) collected twig samples from canyon oak and coast live oak for the Sudden Oak Death Program, Department of Plant Pathology.

2009, Michelle Stevens (UC Davis) harvested Carex barbarae roots for research on the ethnobotany of Putah Creek.

2008, Christina Rosa (UC Davis) extracted DNA samples from Populustrees to amplify a xylem specific promoter that should be common to multiple species.

2008, Craig Keller (UC Davis) investigated the physiological effects of serene and non-serene (arousing) environments using six specific sites within the Arboretum. Blood pressure and heart rates were measured on participants taking a one-hour tour. 

2008, Bryan Hom (UC Davis) photographed endangered pines in the Arboretum for the Department of Plant Sciences plants database.

2008, Kevin M. Potter (North Carolina State University) requested herbarium specimens as well as DNA samples (leaves) of Abies vejariand Abies durangensis for the Department of Forestry and Environmental Resources.

2008, Shannon Tushingham (UC Davis) characterized samples of tobacco species, angelica root, bearberry and jimson weed using mass spectrometry to determine which plants were smoked in pipes excavated at archaeological sites on the Smith River in northwestern California.

2008, Annabelle Kleist (UC Davis) collected leaves from species closely related to French broom (Genista monspessulana) to study the mechanisms of the spread of this invasive plant in California.

2007, Esperanza Martinez Romero (Centro de Ciencias Genómicas, Universidad Nacional Autonóma de México) collected new leaves of Cercis occientalis to work on the genome of this species.

2007, Kjell Bolmgren (UC Berkeley) collected cuttings of Rhamnusrelations for a comparative study of American buckthorns.

2007, Justin Draheim (UC Davis) used the Mary Wattis Brown Garden as a case study for the design of a native plant garden at the Rush Ranch Courtyard in Fairfield near the Suisun Marsh.

2007, Darren Minier (UC Davis) studied the interaction during basking of an invasive turtle species, Trachemys scripta, and a native species, Emys marmorata, with the Arboretum serving as a model urban waterway. 

2007, Katherine Holmes (UC Davis) collected cuttings from the Arboretum to investigate the effects of herbicide residues in soil on subsequent restoration plantings of Ribes aureum and several other common Central Valley natives. 

2007, Clare Aslan (UC Davis) studied bird relationships with fruiting trees in the Central Valley, concentrating on Chinese tallow (Sapium sebiferum) and glossy privet (Ligustrum lucidum) found in the Arboretum.

2007, Ian Wright (UC Davis) installed turtle basking platforms as part of a marking and recapture study to determine the population of turtles in the Arboretum.

Image of the cover of the Proceedings of the National Academy of Sciences of the United States of America featuring the UC Davis Arboretum and Public Garden's mosaic work entitled Evolution of Oaks.2007, Ian Pearse (UC Davis) compared insect populations on native versus non-native oak trees in the Arboretum’s Shields Oak Grove. His research, featured on the cover of the Proceedings of the National Academy of Sciences (PNAS), determined that insects do more damage to non-native oaks that are closely related to their native oak hosts than they do to more distant relatives.

2007, Kylie Ireland (Centre for Phytophthora Science & Management, CRC National Plant Biosecurity, Perth, Australia) studied the susceptibility of Australian plant species to Phytophthora ramorum (the etiological agent of Sudden Oak Death), using plant samples collected from the Arboretum to identify trends and susceptibility across families, genera and species.

2007, Jennifer Siembieda (UC Davis) studied infectious diseases in egrets and herons at rookery sites within the Arboretum. 

2007, Erica (Smith) Brown (UC Davis) studied the germination of Umbellularia californica seeds collected from different areas of California to determine if different stratification times required for germination are related to local genetic diversity.

2007, Melanie Gentles (UC Davis) studied oak galls on trees in the Arboretum.

2006, Robert Thomson (UC Davis) trapped turtles in order to census the native western pond turtle population in the Arboretum waterway.

2006, Meghin Williams (UC Davis) examined the prevalence, seasonal fluctuations, and natural parasitoids of iris whitefly in the Arboretum.