Center for Tree Science Current Projects

These are the first Collaborative Research Projects (CRPs) being undertaken by the Center for Tree Science.  They illustrate the types of research that are aligned with the Center’s goals. A brief description of each project is provided, along with lead investigators and their institutional affiliations.  For more on the Center for Tree Science, click here.


Historic composition and distribution of the Chicago region oak ecosystem. Before European settlement, oak-dominated savanna, woodland, and forest characterized the woody vegetation ecosystem of the Chicago region. Gaining knowledge of the original characteristics and extent of this system is critical for understanding the magnitude of native vegetation loss, assessing management and restoration needs, and projecting effects of future ecological change on this system. The principal method for understanding these presettlement vegetation patterns is through analysis of data and maps compiled in the early 1800s by the US Public Land Survey. By combining GIS technology and ecological landscape analysis, the Arboretum has produced maps and technical reports describing the historical pattern and structure of woody vegetation of northeastern Illinois, and made this information available through an internet-based interactive map ( This project increases the scale and value of this work by partnering with the US Geological Survey and Paleo- Ecological Observatory (PalEON). It extends the vegetation map into the Lake Michigan watershed and adjacent morainal region of northwest Indiana, which will contribute to mapping the entire southern Lake Michigan ecoregion of Wisconsin, Illinois, and Indiana. This work provides a database of more than 10,000 bearing trees that provide historical context for documenting vegetation changes in natural and urban areas in relation to changing fire processes and climate change. It also contributes to larger-scale efforts by PalEON to quantify presettlement vegetation as a baseline for understanding how climate shaped the vegetation patterns of the Midwest prairie peninsula region, and how it may be altered by ongoing climate change.

M. Bowles, R. Fahey (The Morton Arboretum); J. McBride (Alaska Department of Fish and Game); N. Pavlovic (US Geological Survey); Paleo-Ecological Observatory (PalEON;; Chicago Wilderness


Developing management strategies to maintain oak dominance in Chicago-region woodlands. Oak woodlands have historically been the predominant forest type in northeastern Illinois, including the Chicago metropolitan region. Oaks are part of a unique ecological system that supports a wide variety of wildlife and plant species. Changes to landscape disturbance regimes in the Midwestern US have promoted the development of dense-canopied forests, which inhibit the regeneration of light-demanding oak species and promote dominance of shade-tolerant tree species and invasive shrubs. As a result, oak populations are not reproducing at a rate to keep pace with the decline of the older, mature oaks, which will likely result in widespread loss of oak-dominated woodland ecosystems in the region. Through the collaborative efforts of scientists at The Morton Arboretum, several Chicago-region universities, Chicago Wilderness, and the Lake County Forest Preserve District and its Sothern Des Plaines River Habitat Restoration Project, this project uses a large-scale replicated experimental design to examine the effects of forest restoration treatments on oak recruitment and growth. Results from this experiment will lead to the development of management strategies and tools that can be applied at a regional scale to enhance oak woodlands in the Chicago region. This project will act as a demonstration site to illustrate these practices to the regional management community, as well as provide opportunities to train undergraduates and graduate students.

R. Fahey (The Morton Arboretum); D. Goldblum, N. Barber (Northern Illinois University); D. Larkin (Chicago Botanic Garden/Northwestern University); D. Wise (University of Illinois at Chicago); L. Heneghan (DePaul University/Chicago Wilderness Science Team); S. Menke (Lake Forest College)


Will interspecific gene flow help oaks adapt to climate change? Oaks play a critical role in global carbon sequestration, community dynamics, and the life cycles of fungi, insects, birds, and mammals. Yet we know little about how oaks will respond to climate change. This study will utilize next-generation DNA sequencing and genome mapping methods to investigate how oak genomes have responded to past climate changes as a way of forecasting the future. It integrates (1) a phylogenomic dataset of >100 New World oak species with (2) an oak genetic linkage map and (3) climatic niche data to investigate whether gene flow has facilitated adaptation to climate change.

A. Hipp (The Morton Arboretum); A. Kremer (French National Institute for Agricultural Research—INRA Bordeaux-Aquitaine); J. Cavender-Bares (University of Minnesota); A. González-Rodríguez (National Autonomous University of Mexico); P. Manos (Duke University); J. Romero-Severson (Notre Dame University)


Getting the right tree in the right place: developing an urban site index. Many urban tree problems are derived in the soil. Unfortunately, urban landscape managers do not have the knowledge or resources to adequately identify urban soil problems inhibiting tree growth and health. Soil quality indices have long been used in agriculture and forestry to get an idea of the soil conditions without extensive laboratory testing. Given the strong linkage between urban soil quality and plant health, an urban site index would also have substantial application in arboriculture, horticulture, urban agriculture, and other fields. The Morton Arboretum Soil Science lab is developing a system to evaluate site and soil conditions and predict tree condition and growth in 400 plots across 10 cities. This Urban Site Index will merge two independently derived urban site assessments, one from The Morton Arboretum and one from urban foresters with the Ohio Department of Natural Resources, into a standardized, accurate, practical, and field-based framework for assessing urban site quality for trees. Data on soil, tree attributes, and growth rates will be collected and indicators will be interpreted to score values which will be integrated to an index value. A website will be created to host all products from this research including the urban site index protocols and publications derived from the research. This urban site index will save communities money by helping them plant the right tree in the right place for a healthier, more sustainable urban forest. This work is also part of the Chicago Urban Forest Study (p. 33).

B. Scharenbroch, R. Fahey (The Morton Arboretum); A. Siewert, S. Miller (Ohio DNR); N. Bassuk (Cornell University); S. Raciti, L. Hutyra (Boston University); R. Harper (University Massachusetts-Amherst); R. Pouyat, I. Yesilonis (USDA Forest Service Northern Region); S. Day (Virginia Tech); K. Fite (Bartlett Tree); L. Purcel (Purdue University); L. Werner, R. Hauer (University of Wisconsin– Stevens Point); G. Johnson (University of Minnesota)


The biomechanics of tree risk assessment. Trees can pose real threats when trunks, root systems, or branches fail. Researchers studying tree biomechanics are constantly striving to understand why and how trees fail, and if it is possible to predict when a tree will fail. Zones of mechanical weakness (e. g. , decay, splits, hollows, and poor anchorage) may be identified through analysis of surface strain distributions and soil surface movements. Locally high strains along the stem and roots are indicative of areas of mechanical weakness, but available technology limits advancements in this research. No effective system is available to track ground movement. A new technology, stereo photogrammetry, may be able to overcome these limitations. Through an international partnership, scientists are using digital imaging technology developed to measure stress in the skin of the space shuttle to study tree deformation and strain under static and dynamic loading. By understanding more about what goes on in a tree as it is stressed, this research has the potential to improve tree risk assessment methods.

G. Watson, J. Miesbauer (The Morton Arboretum); A. Stokes (French National Institute for Agricultural Research—INRA), T. Fourcaud (Agricultural Research for Development—CIRAD, France), M. Hoenigman (TREE Fund); M. Melis, J. Littell (NASA); E. Gilman (University of Florida); A. Detter (Brudi & Partner TreeConsult, Germany); P. van Wassenaer (Urban Forest Innovations, Canada); T. Mucciardi (Tree Radar, Inc. ); P. Markworth (Wachtel Tree Service)


Phylogeny as a framework for conservation of East Asian oaks. The ring-cupped oaks of Quercus subgenus Cyclobalanopsis comprise a key component of the woody plant diversity in East and Southeast Asia, with somewhere between 90 and 150 species, some critically endangered. However, their taxonomy and genetic relationships are not well known. Efforts to identify even major evolutionary lineages in the group have been problematic. A phylogenetic framework is crucial baseline data for understanding how many species there are in Cyclobalanopsis and for prioritizing conservation efforts in the group. This study utilizes a next-generation DNA sequencing approach to identify evolutionary lineages within this subgenus.

A. Hipp (The Morton Arboretum); M. Deng (Shanghai Chenshan Plant Sciences Research Center, Chinese Academy of Sciences, Chenshan Botanical Garden)


Improving the conservation value of ex situ tree collections. In collaboration with Botanic Gardens Conservation International, the Global Trees Campaign, and collaborators at other leading botanical institutions, The Morton Arboretum will initiate a new research program to understand and improve the science and practice of maintaining ex situ tree collections of high conservation value. Using threatened oaks as a model group, experiments will be conducted that examine issues such as hybridization, pollen flow, propagation techniques, and the feasibility of assisted migration, all of which will improve our understanding of how to protect and care for threatened trees outside their natural environments.

M. Westwood, N. Cavender, A. Hipp, J. Rothleutner (The Morton Arboretum); S. Oldfield (Botanic Gardens Conservation International); P. Griffith (Montgomery Botanical Center); A. Kramer (Chicago Botanic Garden); A. Hird (Botanic Gardens Conservation International-USA).