The Morton Arboretum

Morton Grove, IL, United States

The Morton Arboretum

Morton Grove, IL, United States

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News Article | May 9, 2017
Site: www.eurekalert.org

In a first-ever assessment of urban forest vulnerability to climate change in the Chicago region, a team led by the USDA Forest Service concluded that native tree species in a 7-million-acre area may decline while invasive species may thrive with shifts in habitat suitability. Seventeen percent of the tree species currently present in the region have either moderate-high or high vulnerability to climate change, and 77 percent of individual trees with low vulnerability are invasive species. "The value of assessing the region's vulnerability to climate change is that it gives decision-makers, land managers and homeowners an opportunity to plan ahead," said Leslie Brandt, a climate change specialist with the Forest Service and lead author of the Chicago region assessment. "Communities have invested in their urban forests, and the information that we provide can be used to maintain healthy forests that continue to provide services like removing pollutants from the air, reducing energy costs, and managing stormwater." Published this week by the USDA Forest Service's Northern Research Station, the assessment evaluates urban forests within a region served by Chicago Wilderness, an alliance of more than 200 organizations working to improve quality of life for people and improve natural resources in portions of Illinois, Indiana, Michigan, and Wisconsin. The vulnerability assessment documents past and current conditions, and synthesizes the potential impacts of climate change on urban forests in the Chicago Wilderness region. The assessment also presents case studies of assessing vulnerability at the scale of municipal forestry and parks departments and describes future management considerations. The assessment also provides a process for municipalities, park districts, and forest preserve districts to assess their vulnerability to climate change based on impacts and adaptive capacity. "Chicago Wilderness Region Urban Forest Vulnerability Assessment and Synthesis: A Report from the Urban Forestry Climate Change Response Framework Chicago Wilderness Pilot Project" is available online at. https:/ In the past century, the Chicago region has warmed by about 1 degree Fahrenheit and has experienced a significant increase in precipitation, as much as 3 inches during the summer. Climate modeling for the region projects that: "We see this information as an important resource as communities struggle to manage the urban forest with fewer resources," said Lydia Scott, director of the Chicago Region Trees Initiative and a co-author of the report. "They need to have the best science available to assist them to make informed decisions. The urban forest in the Chicago region provides $51.2 billion in compensatory services to the residents who live here, so careful management of this critical resource is imperative." Led by the Forest Service's Northern Institute of Applied Climate Science, the assessment is part of the Urban Forestry Climate Change Response Framework project, a collaborative approach among researchers, managers, and landowners to incorporate climate change considerations into urban forest management. More information can be found at https:/ A partnership among the Forest Service, universities, non-government organizations and industry, the Northern Institute of Applied Climate Science develops synthesis products, fosters communication, and pursues science in the focus areas of carbon science and management, climate change, and bioenergy. In addition to Forest Service researchers, the report's authors include staff with Chicago Wilderness, the Chicago Region Trees Initiative, the Field Museum, The Morton Arboretum, DuPage County, Chicago Botanic Garden, Davey Institute, and the University of California, Davis Arboretum and Public Garden. The mission of the Forest Service, part of the U.S. Department of Agriculture, is to sustain the health, diversity, and productivity of the Nation's forests and grasslands to meet the needs of present and future generations. The agency manages 193 million acres of public land, provides assistance to state and private landowners, and maintains the largest forestry research organization in the world. Public lands the Forest Service manages contribute more than $13 billion to the economy each year through visitor spending alone. Those same lands provide 20 percent of the Nation's clean water supply, a value estimated at $7.2 billion per year. The agency has either a direct or indirect role in stewardship of about 80 percent of the 850 million forested acres within the U.S., of which 100 million acres are urban forests where most Americans live. USDA is an equal opportunity provider and employer. To file a complaint of discrimination, write to USDA, Assistant Secretary for Civil Rights, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, S.W., Stop 9410, Washington, DC 20250-9410, or call toll-free at (866) 632-9992 (English) or (800) 877-8339 (TDD) or (866) 377-8642 (English Federal-relay) or (800) 845-6136 (Spanish Federal-relay).


News Article | May 17, 2017
Site: phys.org

A white oak (Quercus alba) in the summer. Credit: (c) The Morton Arboretum Research published this week in Proceedings of the Royal Society B: Biological Sciences solves a mystery that has long shrouded our understanding of white oaks: where did they come from? The approximately 125 white oak species in the Americas and 25 in Eurasia—including the massive bur oak of American prairies and savannas, the valley oak of California and the eponymous white oak of eastern North American forests—are important in forests and savannas throughout much of the northern hemisphere. Yet, despite their economic and ecological importance, not much was known about the evolutionary history of the white oak group until now. This paper, co-authored by Andrew Hipp of The Morton Arboretum and Paul Manos and John McVay of Duke University, reveals for the first time that Europe and east Asia have eastern North America to thank for their white oaks. Coupling genomic data with fossil records and novel analytical methods, the research suggests that the Eurasian white oaks arose from a North American ancestor that migrated to Europe, perhaps by way of the North Atlantic land bridge. This is a story that has long been hidden by ancient hybridization among the Eurasian white oaks. The research implements new analytical tools to tease apart hybridization from evolutionary history to tell the full white oak story. The study, funded by a collaborative four-year National Science Foundation grant to five institutions led by The Morton Arboretum, also shows that two oak species found on opposite ends of the globe, the Armenian oak (Quercus pontica) found in the Caucasus mountains and Sadler's oak (Quercus sadleriana) of California and Oregon, are each other's closest relatives. These species, the authors argue, are the last remnants of a widespread white oak lineage that stretched at least from Europe to the Pacific Northwest, of which all are extinct except for these two species. "Understanding even the most basic questions—how many oak species are there? Where do they live?—rests on our understanding of oak evolution," said study co-author Andrew Hipp of The Morton Arboretum. "This is the first paper to conclusively separate the role of gene flow and divergence to recover a holistic portrait of the white oak tree of life. It is a crucial step toward understanding why white oaks became so important to the ecology of temperate forests and savannas in the northern hemisphere." White oaks are just one of many types of more than 450 species of oaks which live around the world. Considered a keystone species, oaks support our planet's ecosystem like very few other tree species do. These stately trees are fundamental to the health of our forests, providing critical food, habitat and shelter for animals, birds and insects, and have the highest amount of biomass compared to any other tree species in the forest, working harder to clean our air than many of their fellow tree species. In the Chicago region alone, oak ecosystems provide more than $2 billion worth of flood control and other water management services. Today, oaks need our help. Around the world, due to pests, disease, forest loss and low rates of reproduction, oak forests are now a fraction of what they once were, upsetting the delicate balance of our forest ecosystems and leaving humans without their benefits. With only 17 percent of ancient oak forest area remaining in the Chicago region and similar oak loss throughout the world, human intervention is critical to ensure we don't lose this important species. Explore further: Research into oaks helps us understand climate change More information: John D. McVay et al, A genetic legacy of introgression confounds phylogeny and biogeography in oaks, Proceedings of the Royal Society B: Biological Sciences (2017). DOI: 10.1098/rspb.2017.0300


News Article | May 18, 2017
Site: www.sciencedaily.com

Research published this week in Proceedings of the Royal Society B: Biological Sciences solves a mystery that has long shrouded our understanding of white oaks: where did they come from? The approximately 125 white oak species in the Americas and 25 in Eurasia -- including the massive bur oak of American prairies and savannas, the valley oak of California and the eponymous white oak of eastern North American forests -- are important in forests and savannas throughout much of the northern hemisphere. Yet, despite their economic and ecological importance, not much was known about the evolutionary history of the white oak group until now. This paper, co-authored by Andrew Hipp of The Morton Arboretum and Paul Manos and John McVay of Duke University, reveals for the first time that Europe and east Asia have eastern North America to thank for their white oaks. Coupling genomic data with fossil records and novel analytical methods, the research suggests that the Eurasian white oaks arose from a North American ancestor that migrated to Europe, perhaps by way of the North Atlantic land bridge. This is a story that has long been hidden by ancient hybridization among the Eurasian white oaks. The research implements new analytical tools to tease apart hybridization from evolutionary history to tell the full white oak story. The study, funded by a collaborative four-year National Science Foundation grant to five institutions led by The Morton Arboretum, also shows that two oak species found on opposite ends of the globe, the Armenian oak (Quercus pontica) found in the Caucasus mountains and Sadler's oak (Quercus sadleriana) of California and Oregon, are each other's closest relatives. These species, the authors argue, are the last remnants of a widespread white oak lineage that stretched at least from Europe to the Pacific Northwest, of which all are extinct except for these two species. "Understanding even the most basic questions -- how many oak species are there? Where do they live? -- rests on our understanding of oak evolution," said study co-author Andrew Hipp of The Morton Arboretum. "This is the first paper to conclusively separate the role of gene flow and divergence to recover a holistic portrait of the white oak tree of life. It is a crucial step toward understanding why white oaks became so important to the ecology of temperate forests and savannas in the northern hemisphere."


News Article | May 17, 2017
Site: www.eurekalert.org

Research published this week in Proceedings of the Royal Society B: Biological Sciences solves a mystery that has long shrouded our understanding of white oaks: where did they come from? The approximately 125 white oak species in the Americas and 25 in Eurasia--including the massive bur oak of American prairies and savannas, the valley oak of California and the eponymous white oak of eastern North American forests--are important in forests and savannas throughout much of the northern hemisphere. Yet, despite their economic and ecological importance, not much was known about the evolutionary history of the white oak group until now. This paper, co-authored by Andrew Hipp of The Morton Arboretum and Paul Manos and John McVay of Duke University, reveals for the first time that Europe and east Asia have eastern North America to thank for their white oaks. Coupling genomic data with fossil records and novel analytical methods, the research suggests that the Eurasian white oaks arose from a North American ancestor that migrated to Europe, perhaps by way of the North Atlantic land bridge. This is a story that has long been hidden by ancient hybridization among the Eurasian white oaks. The research implements new analytical tools to tease apart hybridization from evolutionary history to tell the full white oak story. The study, funded by a collaborative four-year National Science Foundation grant to five institutions led by The Morton Arboretum, also shows that two oak species found on opposite ends of the globe, the Armenian oak (Quercus pontica) found in the Caucasus mountains and Sadler's oak (Quercus sadleriana) of California and Oregon, are each other's closest relatives. These species, the authors argue, are the last remnants of a widespread white oak lineage that stretched at least from Europe to the Pacific Northwest, of which all are extinct except for these two species. "Understanding even the most basic questions--how many oak species are there? Where do they live?--rests on our understanding of oak evolution," said study co-author Andrew Hipp of The Morton Arboretum. "This is the first paper to conclusively separate the role of gene flow and divergence to recover a holistic portrait of the white oak tree of life. It is a crucial step toward understanding why white oaks became so important to the ecology of temperate forests and savannas in the northern hemisphere." The study was funded by National Science Foundation awards to A.L.H. (1146488) and P.S.M. (1146102).


News Article | April 25, 2017
Site: www.prweb.com

Washington & Jefferson College (W&J) will continue its Arbor Day tradition of environmental excellence. For the fourth consecutive year, W&J has been honored with the Tree Campus USA® recognition by the Arbor Day Foundation for its commitment to effective urban forest management. The college was one of only 15 institutions in Pennsylvania, a state with more than 100 two- and four-year higher learning institutions, to receive this honor, part of a national program created in 2008. Currently there are 296 campuses across the United States with this recognition. In addition to the Tree Campus USA honor, the arboretum was awarded Level I Accreditation by The ArbNet Arboretum Accreditation Program and The Morton Arboretum last spring. “I’m excited to have earned this recognition four years in a row and look forward to subsequent years of this recognition. This includes more plantings on campus, more students getting involved, more of the community getting involved and enhancing the campus arboretum and the campus landscape,” said Associate Professor of Biology Jason Kilgore, Ph.D. Kilgore noted that it’s become increasingly more difficult to qualify for the designation over the past few years as the Arbor Day Foundation has raised its standards when examining Tree Campus USA submissions. “It’s become more selective, which is good, because it forces us to work harder to be bigger and better than we were before,” he said. In honor of the recognition, students in Kilgore’s Plant Diversity course will plant Quaking Aspen trees at the developing Rocky Mountain-themed grove near the W&J Admission House at 1 p.m. April 29. Kilgore and Grounds Supervisor Doston Kish chose the trees to fit the soil profile in the area. It will be the first themed grove on campus, according to Kilgore. Washington & Jefferson College achieved the title by meeting Tree Campus USA’s five standards, which include maintaining a tree advisory committee, a campus tree-care plan, dedicated annual expenditures for its campus tree program, an Arbor Day observance, and a student service-learning project. W&J has been recognized every year it has applied for the honor. Kilgore started W&J’s Campus Arboretum nine years ago after previously being involved with Michigan State University’s arboretum. Working with students, he created two databases identifying types of trees on campus and their location, with notes of what trees have been added and removed from the grounds. The Campus Arboretum now encompasses the entire 85 acres of urban campus and athletic facilities. All of the nearly 1,200 trees from 83 species are recorded and evaluated, with over 930 trees bearing metal tags with accession number and family, scientific, and common names. Particularly noteworthy trees include a mature American elm, a mature willow oak, and five mature osage-oranges from an historical property line separating the College from the former Washington Female Seminary. The Arboretum Advisory Committee, consisting of members of the faculty, staff, and the community, meets twice a year to make decisions about the arboretum’s presence on campus and what progress will be made.


Pearse I.S.,University of California at Davis | Hipp A.L.,The Morton Arboretum
Evolution | Year: 2012

Plant defensive traits drive patterns of herbivory and herbivore diversity among plant species. Over the past 30 years, several prominent hypotheses have predicted the association of plant defenses with particular abiotic environments or geographic regions. We used a strongly supported phylogeny of oaks to test whether defensive traits of 56 oak species are associated with particular components of their climatic niche. Climate predicted both the chemical leaf defenses and the physical leaf defenses of oaks, whether analyzed separately or in combination. Oak leaf defenses were higher at lower latitudes, and this latitudinal gradient could be explained entirely by climate. Using phylogenetic regression methods, we found that plant defenses tended to be greater in oak species that occur in regions with low temperature seasonality, mild winters, and low minimum precipitation, and that plant defenses may track the abiotic environment slowly over macroevolutionary time. The pattern of association we observed between oak leaf traits and abiotic environments was consistent with a combination of a seasonality gradient, which may relate to different herbivore pressures, and the resource availability hypothesis, which posits that herbivores exert greater selection on plants in resource-limited abiotic environments. © 2012 The Author(s). Evolution © 2012 The Society for the Study of Evolution.


Morgenroth J.,University of Canterbury | Buchan G.,Lincoln University at Christchurch | Scharenbroch B.C.,The Morton Arboretum
Ecological Engineering | Year: 2013

Impermeable pavements cover a considerable land area in cities. Their effect on the hydrological cycle is clear; as a barrier in the soil-atmosphere continuum they minimise rainfall infiltration and evaporation. Porous pavements are beginning to replace impermeable alternatives because of perceived hydrologic benefits. The impact of porous pavements on soil moisture and chemistry as they relate to urban vegetation was investigated in Christchurch, New Zealand. An experiment was established comprising 25 plots evenly distributed amongst controls (no pavement, exposed soil) and four different pavement treatments: a factorial combination of pavement type (porous, impervious) and pavement profile design (including or excluding a greywacke gravel base). Results indicate that pavements altered soil pH from moderately acidic (pH = 5.75) to more neutral levels (pH = 6.3). The effect on pH was greater beneath porous pavements, and also when a gravel base was included. Concentration of soil Al, Fe, and Mg decreased, while Na increased beneath pavements. Soil moisture was consistently higher beneath pavements than control plots, except following periods of heavy rainfall where high soil moisture muted all treatment effects. Throughout most of the study period, soil moisture content was lower beneath pavement profiles designed with the gravel base, presumably due to the gravel acting as a capillary break to a distillation process, whereby soil moisture migrates upwards to the soil surface. In early autumn, when soil moisture content was lowest for all treatments, precipitation recharged soil moisture in control plots and beneath porous pavements. But impervious pavements prevented infiltration resulting in significantly lower soil moisture content beneath these pavements. Pavements can alter soil moisture and chemical characteristics, but the effects differ depending on pavement porosity and profile design. Implications of the results pertain to stress physiology of urban vegetation, in particular drought stress avoidance. © 2012 Elsevier B.V.


Escudero M.,The Morton Arboretum | Escudero M.,Pablo De Olavide University | Hipp A.L.,The Morton Arboretum | Waterway M.J.,McGill University | Valente L.M.,Imperial College London
Molecular Phylogenetics and Evolution | Year: 2012

The sedge family (Cyperaceae: Poales; ca. 5600 spp.) is a hyperdiverse cosmopolitan group with centres of species diversity in Africa, Australia, eastern Asia, North America, and the Neotropics. Carex, with ca. 40% of the species in the family, is one of the most species-rich angiosperm genera and the most diverse in temperate regions of the Northern Hemisphere, making it atypical among plants in that it inverts the latitudinal gradient of species richness. Moreover, Carex exhibits high rates of chromosome rearrangement via fission, fusion, and translocation, which distinguishes it from the rest of the Cyperaceae. Here, we use a phylogenetic framework to examine how the onset of contemporary temperate climates and the processes of chromosome evolution have influenced the diversification dynamics of Carex. We provide estimates of diversification rates and map chromosome transitions across the evolutionary history of the main four clades of Carex. We demonstrate that Carex underwent a shift in diversification rates sometime between the Late Eocene and the Oligocene, during a global cooling period, which fits with a transition in diploid chromosome number. We suggest that adaptive radiation to novel temperate climates, aided by a shift in the mode of chromosome evolution, may explain the large-scale radiation of Carex and its latitudinal pattern of species richness. © 2012 Elsevier Inc.


Aerated compost teas (ACTs) are applied to soils with the intent of improving microbial properties and nutrient availability and stimulating plant growth. Anecdotal accounts of ACT for these purposes far outnumber controlled, replicated, and peerviewed experiments that have examined the impacts of ACT on soil properties and plant growth responses. This research assessed the impacts of four rates of ACT compared with water on containerized Acer saccharum and Quercus macrocarpa saplings growing in loam, compacted loam, and sandy soils. No significant differences were found comparing water with ACT applied at rates of 2, 4, and 40 kL ACT/ha for any of the six tree responses and 21 soil responses. Microbial biomass nitrogen (N) and potassium (K) increased, and available N decreased, in soils treated with ACT at 400 kL·ha-1 compared with water. Shoot, root, total biomass, and the root/shoot ratio were significantly greater for Quercus macrocarpa trees growing in compact loam with the 400 kL ACT/ha treatment compared with water, but significant differences were not detected for this application rate compared with water in the other soil types and in no instances with Acer saccharum saplings. These results provide some support for claims of ACT being able to increase soil microbial biomass and K, but provide minimal support for ACT being able to increase tree growth across multiple species in a variety of soil types. An application rate of 400 kL ACT/ha may be attainable for trees in containers with limited soil volumes, but this application rate is likely cost-prohibitive, and not practical, in the landscape. At this application rate, ≈1000 L of ACT would be required to treat a typical, and relatively small, critical root zone of 25 m2.


Chung K.-S.,The Morton Arboretum | Weber J.A.,The Morton Arboretum | Hipp A.L.,The Morton Arboretum
American Journal of Botany | Year: 2011

Premise of the study: High intraspecific cytogenetic variation in the sedge genus Carex (Cyperaceae) is hypothesized to be due to the "diffuse" or non-localized centromeres, which facilitate chromosome fission and fusion. If chromosome number changes are dominated by fission and fusion, then chromosome evolution will result primarily in changes in the potential for recombination among populations. Chromosome duplications, on the other hand, entail consequent opportunities for divergent evolution of paralogs. In this study, we evaluate whether genome size and chromosome number covary within species. Methods: We used flow cytometry to estimate genome sizes in Carex scoparia var. scoparia, sampling 99 plants (23 populations) in the Chicago region, and we used meiotic chromosome observations to document chromosome numbers and chromosome pairing relations. Key results: Chromosome numbers range from 2 n = 62 to 2 n = 68, and nuclear DNA 1C content from 0.342 to 0.361 pg DNA. Regressions of DNA content on chromosome number are nonsignificant for data analyzed by individual or population, and a regression model that excludes slope is favored over a model in which chromosome number predicts genome size. Conclusions: Chromosome rearrangements within cytogenetically variable Carex species are more likely a consequence of fission and fusion than of duplication and deletion. Moreover, neither genome size nor chromosome number is spatially autocorrelated, which suggests the potential for rapid chromosome evolution by fission and fusion at a relatively fine geographic scale (< 350 km). These findings have important implications for ecological restoration and speciation within the largest angiosperm genus of the temperate zone. © 2011 Botanical Society of America.

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