Research News

Holden ants help us understand evolutionary responses to warmer urban climates.

When scientists think about how plants and animals will cope with warmer temperatures from global climate change, they typically study species in their native habitats. But with an increasing prevalence of urban environments across the globe, one group of scientists at Case Western Reserve University decided to use the hustle-bustle of Cleveland to their advantage. Cities are typically a few degrees warmer than the surrounding rural environments, making them great proxies for studying how quickly organisms could adapt to higher temperatures brought on by global climate change.

Dr. Sarah Diamond and colleagues used the acorn ant—a species whose colony can consist of over 200 individuals within a single acorn—to examine evolution on a compressed timescale. The researchers collected colonies within the city from the CWRU campus and the Cleveland Botanical Garden, and from rural areas outside the city including the Holden Arboretum and Squire Valleevue Farm. To distinguish short-term acclimation from evolutionary change, ant colonies from both habitats were held for 10 weeks at warmer or colder rearing environments and were then examined for changes in thermal physiology. The researchers found that ants held at warmer laboratory temperatures were able to tolerate higher temperatures than those held at colder laboratory temperatures, but also that ants from urban environments were able to tolerate warmer temperatures than their rural counterparts, regardless of what temperature regime they were held at in the laboratory. So in the short timeframe of 10 weeks, this species of ant showed an acclimation response, but more importantly, with just 100 years of urban warming, ants showed evidence of rapid evolutionary change. While a certain degree of flexibility may aid in dealing with short-term temperature changes, many studies suggest that acclimation responses won’t be sufficient for dealing with climate change in the long run. Luckily, some species—like the acorn ant—may be able to evolve quickly enough to deal with such changes.

For more information take a look at this NY Times article or the scientific article in the Biological Journal of the Linnean Society.

What are dominance hierarchies and how are they used in ant community ecology?

Ant communities have long been thought to be structured by competition. That is to say that what ants are present, and how common they are in our forests, is determined at least in part by competition for food and nest sites. For decades scientists have studied these dynamics by creating dominance hierarchies; basically ranking ant species based on their ability to win fights or defend food resources. A new paper by staff scientist, Katie Stuble, examines how dominance hierarchies have been used over the past six decades and how these rankings relate to various aspects of ant biology including the ability of ants to gather food and their relative abundance in an ecosystem. Findings suggest that these dominance hierarchies tend to be wildly inconsistent across space and time. Collapsing complicated networks of interactions into neat linear relationships seems to be inadequate in representing real world interactions. Further, the past obsession with aggression among ant species seems to miss other more nuanced traits that can help ant species succeed, including persistence, or even the ability to be sneaky and avoid conflict. For more information, see the paper in Myrmecological News:
Stuble KL, I Jurić, X Cerdá, NJ Sanders (2017) Dominance hierarchies are a dominant paradigm in ant ecology, but should they be? And what is a dominance hierarchy, anyway? Myrmecological News 24: 71-81.

Arboretum Celebrates 25 Years of Research, Renames Science Facility

The Holden Arboretum celebrated the 25th anniversary of its research building with a ceremony rename the facility that houses the research program the Ellen Corning Long and T. Dixon Long Center for Plant and Environmental Science. Both T. Dixon Long and his late wife, Ellen Corning Long, were long-time supporters of the Arboretum and its research program. T. Dixon Long was a member of the Arboretum’s board of directors from 1971 until 2003, serving as board president from 1982 until 1991. He is credited with leading the board through its most turbulent years from 1982 until the maturation of the Holden Trust in 1988 an played a large role in the creation of the science facility at Holden.

His wife’s connection with the Arboretum began when her family built Lantern Court in the 1930s, and her parents, Warren H. and Maud Corning, took an interest in the arboretum. Corning served as the Arboretum’s director on a volunteer basis, helping the Arboretum acquire new property and grow in its early years. Corning Long’s work as an educator, biologist and botanist is honored by the research departments dedication to environmental sciences, as well as the scientists commitment to wringing with interns.

Learn more about the research projects taking place at the Arboretum.

Pictured are Ali Long, T. Dixon Long, Sam Long, Clem Hamilton and David Burke.

Plant and Microbial Ecology Summer 2016 Internship at The Holden Arboretum

This 12-week summer internship will provide you with an opportunity to work with scientists from The Holden Arboretum studying the effects of environmental change on plants and forests of Northeast Ohio. Internships typically run from late May through early August, but timing is flexible.

Duties may include: assisting in soil and plant sampling, plant data collection, as well as extracting, amplifying, and analyzing DNA from soils and roots. Interns will be compensated with a stipend of $400/week and on-site housing is available if needed for a nominal fee ($30 per week). Due to our rural location, interns are responsible for their own transportation.

Persons with knowledge of or interest in ecology, microbiology, and plant biology are encouraged to apply. Applicants should send a letter of interest, a resume that discusses your prior experience, and two references. Applicants should also indicate their primary research interest. Holden research staff and a description of their respective programs can be found at online by clicking here. Questions concerning the internships can be addressed to Dr. David Burke (

Review of applications begins immediately and continues until the positions are filled. Qualified applicants should submit a resume online. Apply here.

Posting Date: January 2016
Closing Date: Until filled

The Holden Arboretum/Cleveland Botanical Garden is an Equal Opportunity Employer committed to hiring a diverse and talented workforce. We seek skilled, knowledgeable and experienced individuals to join our staff and enhance our reputation as one of the country’s foremost arboreta.

Holden Scientists award funds to organize international conference on plant water transport.

A proposal for a new conference on multiscale plant vascular biology submitted by Arboretum scientist Juliana Medeiros (conference co-chairperson) and collaborators William Pickman (conference chairman, University of New Mexico) and Barbara Lachenbruch (conference vice-chairperson, Oregon State University) has been accepted as a Gordon Research Conference-sponsored meeting. Gordan Research Conferences (GRC) is a non-profit organization dedicated to providing support for international conferences that cover topics on the frontiers of research in the biological, chemical and physical sciences. GRC meetings are small, fewer than 200 people, but they cover very specific subfields of research and are considered premier conferences for networking and collaboration. Proposals for new conferences are highly competitive, and the GRC Board of Trustees approves only a few new conferences each year. The conference will bring together scientists working at all scales of plant water transport research. The meeting will take place in the summer of 2016 and pending positive outcomes of the conference, it may be promoted to an official biannual Gordan Research Conference. Advances in plant water transport are of critical importance for understanding how plants may respond to global climate change.