Archives For Boyce Tankersley

This past summer, the Chicago Botanic Garden joined an intrepid team of plant collectors from four other American institutions on an expedition to the Republic of Georgia.

Our focus: to collect seeds to diversify the genetic diversity of ex-situ plant collections; to bring back and evaluate species for their ornamental potential; and to provide a hedge against natural and man-made disasters—all while building upon institutional collaborations developed during previous expeditions.

The PCC16-Georgia group poses at the Old Omalo Guest House in the Tusheti Region, Georgia.

The PCC16-Georgia group poses at the Old Omalo Guest House in the Tusheti Region, Georgia. From left to right: Joe Meny (US National Arboretum), Peter Zale (Longwood Gardens), Boyce Tankersley (Chicago Botanic Garden), Vince Marrocco (Morris Arboretum), Koba (owner of Old Omalo Guest House/Hotel Tusheti), Matt Lobdell (The Morton Arboretum), Temuri Siukaev (driver), Koba’s daughter, Constantine Zagareishvili (driver), Manana Khutsishvili (botanist), David Chelidze (botanist)

Map showing the location of the Republic of Georgia.

Just east of the Black Sea is the Republic of Georgia. Map courtesy worldatlas.

The Republic of Georgia was chosen because it is the only biodiversity hotspot that is situated within the temperate climatic zones.

Over millennia, the high peaks of the Greater Caucasus Mountains to the north, Lesser Caucasus Mountains to the south, and their inter-connecting mountain ranges situated between the Black Sea to the west and Caspian Sea to the east have provided a refuge for species that have gone extinct elsewhere due to glaciation and other climate extremes.

Tucked into hundreds of microclimates created by this varied topography, many of these endemic species (found nowhere else on earth) are perfectly hardy in American, Russian, and European gardens much farther north. 

Coordinating the trip on the Georgian side were our colleagues from the Institute of Botany, Tbilisi and Bakuriani Alpine Botanical Garden. They provided invaluable logistical support through the use of two of the foremost botanists in the region, drivers, vehicles, and places to stay.

The varied topography of the Tusheti Region.

The varied topography of the Tusheti Region.

Bakuriani Alpine Botanical Garden, Institute of Botany, and American collectors at Bakuriani Field Station.

Bakuriani Alpine Botanical Garden, Institute of Botany, and American collectors at Bakuriani Field Station

In a little more than two weeks in the field, the group traveled more than 1,100 miles from the high—and barely accessible—Greater Caucasus Mountains of the Tusheti region in northeastern Georgia, through the central valleys, to Lake Tabatskuri in the Lesser Caucasus Mountains in the south, between the Tetrobi Reserve and Bakuriani Alpine Botanical Garden.

The central valley separating the Greater and Lesser Caucasus mountain ranges.

The central valley separating the Greater and Lesser Caucasus mountain ranges

Lake Tabatskuri is situated between the Tetrobi Reserve and Bakuriani Alpine Botanical Garden; the Lesser Caucasus mountain peaks are in the distance.

Lake Tabatskuri is situated between the Tetrobi Reserve and Bakuriani Alpine Botanical Garden; the Lesser Caucasus mountain peaks are in the distance.

The geographic location of Georgia (Russia to the north, Central Asia to the east, Persia to the south and Asia Minor, the Middle East, and Europe to the west) has made this region a favorite transit point for merchants. Tucked into remote mountain valleys are small communities created from the descendants of Greeks, Germans, Hebrews, Persians, Armenians, Turks, Russians, Circassians, Huns, Mongols, and more, with remnants of each people’s own unique culinary, religious and linguistic traditions.

It was also, unfortunately, a thoroughfare for invading armies. Ancient fortifications, places of worship, homes—all show evidence of destruction and rebuilding.  

Samshvilde Fortress ruins.

Samshvilde Fortress ruins

Fortified towers are a typical feature of many homes in the Greater Caucasus mountains.

Fortified towers are a typical feature of many homes in the Greater Caucasus mountains.

Church of St. George.

Church of St. George

The collections wrapped up with a foray into western Georgia (ancient Colchis in Greek mythology) in and around Kutaisi, the legislative capital and its third largest city. A brief visit to the Kutaisi Botanical Garden was in order here, before we left the region. A highlight: a small shrine built inside a living 450-year-old oak. 

In all, 205 different seed lots and herbarium vouchers—representing 169 different species of trees, shrubs, perennials, and bulbs—were collected, including six of seven species of Quercus (oaks) in support of the IUCN Redlist of all of the Quercus in the world.

Religious shrine built inside a 450-year-old Quercus hartwissiana at Kutaisi Botanical Garden.

A religious shrine is built inside this 450-year-old Quercus hartwissiana at Kutaisi Botanical Garden.

What a haul! Seed collectors admire hundreds of seed collections to be cleaned.

What a haul! Admiring hundreds of seed collections to be cleaned are (left to right): Dr. Fritz, Dr. Tatyana Shulina (Garden consultant), Dr. Manana Khutsishvili (lead Georgian botanist) and Dr. Marina Eristavi (botanist on a former trip).

While we each came away with a fantastic collection of seed to propagate, this trip was about much more than collecting plants. Our journey’s end featured a meeting with representatives of institutions from America, Armenia, Azerbaijan, and Georgia all focused on expanding collaboration to match areas of expertise with areas of need—not only in the area of collections, but also horticulture, conservation science, education, and fundraising/collaborative grants.

The Caucasus Regional Meeting Participants pose on balcony at the of Institute of Botany. The ancient Narikala Fortress of Tbilisi is in the background.

The Caucasus Regional Meeting participants pose on balcony at the of Institute of Botany. The ancient Narikala Fortress of Tbilisi is in the background.

Left to right: Dr. Marine Eristavi, conservation scientist, National Botanical Garden of Georgia, Dr. Tinatin Barblishvili, deputy director, National Botanical Garden of Georgia, Dr. Lamara Aieshvili, curator of rare and endemic plants of Georgia ex situ collection, National Botanical Garden of Georgia, Vince Marrocco, horticulture director, Morris Arboretum, Dr. Manana Khutsishvili, botanist, Institute of Botany, Tbilisi, Dr. Peter Zale, curator and plant breeder at Longwood Gardens, Matt Lobdell curator of The Morton Arboretum, Dr. Fritz, Dr. Tatyana Shulkina, former curator of the living collections of the Soviet Union, Komarov Botanical Garden and currently Chicago Botanic Garden consultant, Dr. Rashad Selimov, head of education, Institute of Botany Azerbaijan Academy of Sciences, Baku, Joe Meny from the US National Arboretum, Dr. Vahid Farzaliyev, National Botanical Garden Azerbaijan Academy of Sciences, Baku, Boyce Tankersley director of living plant documentation at the Chicago Botanic Garden, Dr. Shalva Sikharulidze, director of Institute of Botany, Georgia and Bakuriani Alpine Botanical Garden, Dr. George Fayvush, Department of Geo-botany Armenian Academy of Sciences, Yerevan, Dr. Zhirayr Vardanyan director of the Institute of Botany and National Botanical Garden Armenian Academy of Sciences Yerevan

What can we expect from our efforts? New blooms in the Garden! We have added quite a few plants to those brought back from Georgia on three previous trips:

Lilium monadelphum

Lilium monadelphum

Muscari armeniacum

Muscari armeniacum

Tulipa undulatifolia

Tulipa undulatifolia

Bellevalia makuensis

Bellevalia makuensis

Campanula lactiflora

Campanula lactiflora

Gentiana schistocalyx

Gentiana schistocalyx

Stachys macrantha

Stachys macrantha

Stokesia major

Stokesia major

Dianthus cretaceous

Dianthus cretaceous

Iris iberica ssp. Elegantissima

Iris iberica ssp. elegantissima

Verbascum pyramidatum

Verbascum pyramidatum

Colchicum trigyna

Colchicum trigyna

Stay tuned! Invitations have been received from institutions in Armenia, Azerbaijan, and Georgia for future plant collecting trips to the region. Likewise, scientists from these countries were invited to collect American native plants to increase the biodiversity of their ex-situ collections.


©2016 Chicago Botanic Garden and my.chicagobotanic.org

Embracing Trees for Our Future

Undercover Science

Julianne Beck —  July 13, 2015 — 1 Comment

If you spot a Chicago Botanic Garden volunteer wrapping their arms around a tree trunk this summer, don’t be surprised—what looks like a loving hug is actually a scientific measurement in process.

Using a specially designed tape measure, volunteers are recording the diameter of each tree before calculating the amount of carbon dioxide it stores. The study, launched by the Living Plant Documentation department five years ago, records the amount of the pervasive greenhouse gas stored by the Garden’s trees. The research team is interested in determining which trees are able to hold the most carbon for the longest amount of time.

PHOTO: Boyce Tankersley is researching the trees' response to increased carbon in the atmosphere, using data such as the growth rate of the particular tree species.

Boyce Tankersley and volunteers measure the diameter of each tree on the Garden campus.

The Tall and Short of It

It is one of the first such studies underway in a botanic garden setting. “We know carbon is increasing but we don’t have the numbers on how much carbon is being locked up by the urban forest,” said Boyce Tankersley, director of the Living Plant Documentation department. “This is where the Garden can play a role.”

Although similar studies have been completed by the lumber industry and others, it is important to understand how increased levels of carbon dioxide in the atmosphere are mitigated by cultivated trees, explained Tankersley. It’s also essential to document how those trees fare long term in evolving conditions.

The Garden has an especially diverse number of taxa, Tankersley said, positioning it perfectly to document how numerous species behave in locations from the McDonald Woods to the English Walled Garden to the parking lot. “The Garden is among the first to look at the trees in a Garden setting and at the diversity of taxa,” said Tankersley. “That’s a piece we’d like to shed more light on.”

This summer marks the second time the trees have been measured since the original data was gathered in the first year. Measurements will continue to be taken for another 15 to 20 years.

“We hope, when the data is analyzed, to be able to identify not only the trees that are best but the Garden settings that support their efforts in this regard,” anticipated Tankersley.

PHOTO: Tree canopy.

The Living Plant Documentation department is calculating the amount of carbon dioxide stored in each of the Garden’s trees.

Deep in the Woods

Trees are lauded for coming to our rescue in the face of climate change, but scientists have learned that these strapping heroes may not be infallible. “One thing we are looking for is the influence of carbon on the growth rate,” said Tankersley. His research team is paying close attention to the trees’ response to increased carbon levels in our atmosphere.

According to Tankersley, it has been documented that trees are growing more quickly than they have in the past, which comes with positive and negative repercussions. “Trees are providing an environmental service in a major way by absorbing carbon, but there’s a point of diminishing returns,” he explained. The wood of a fast-growing tree is softer, for example, which has a negative impact on the lumber industry, he explained. In addition, “with an increased growth rate, you also get increased susceptibility to insects and diseases.”

The concern underscores the need to observe the Garden’s trees for many years to take all such factors into consideration.

In addition, the team is watching the impact of weather on the trees, and taking dry spells or rainy periods, for example, into account when documenting tree growth over a given time frame. The Garden hosts a National Weather Service monitor on-site, which allows for weather-related calculations to be even more precise.

The Zipline

When the measurement phase of the study is complete, Tankersley plans to provide the data to a doctoral student in the Garden’s joint degree program with Northwestern University for formal analysis. “My take-home would be a list of the six best trees, perennials, and shrubs for sequestering carbon in the landscape in Chicago,” he said.

“We expect to find that trees like oaks, elms, and hickories—trees that are long-lived—provide a greater environmental service in this regard,” he added.

For homeowners who would like to assist with the issue now rather than wait for the final analysis, he suggests that they begin planting longer-lived trees. It may help mitigate, or reduce, the amount of carbon in the air and resulting climate change impacts such as extreme weather.

Our 2013 adaptive planting study carefully selected 60 suitable trees to plant for future generations. View the full list of suggested trees here.
PHOTO: Fastigiate English Oak acorns (Quercus robur).

It takes more than one year for the Garden volunteers to check the diameter of the 13,493 trees on-site, and enter the estimated carbon storage into a specialized database. The calculations are made using a formula developed by the U.S. Forest Service, said Tankersley.

The technique of measuring existing trees and planning for new plantings is something Tankersley hopes will have broad impact. He has already shared his process with countries in Africa through The Eden Projects and in China in an effort to help governments replace denuded forests there.

Tankersley is hopeful about the long-term implications of the study. After all, he said, when pioneers first came to the United States, they found oak trees that were about 300 years old, and had been providing benefits such as carbon sequestration for all of that time. Many of those hard-working, long-lived species have been a key part of our natural heritage since the beginning. By embracing the issue now, Tankersley and team have cleared the way for trees and their vital functions to endure.


©2015 Chicago Botanic Garden and my.chicagobotanic.org

Boyce Tankersley, Director of Living Plant Documentation, takes us on a tour of what’s blooming in the display gardens on the first day of fall.

Sweeps of perennials on Evening Island, the cascading mums on the Visitor Center bridge, and masses of mums in the Crescent Garden, are found in the boundaries of our formal garden areas. Our show doesn’t end there, however — find gorgeous asters and sunflowers in the English Walled Garden, Japanese anemones and Endless Summer hydrangeas in the Waterfall Garden, mums mixed with later blooming annuals like zinnias and rudbeckia in the Sensory Garden, and an amazing array of colorful annuals in the Circle Garden.

We only visited six of the 25 display gardens, so come out to see them all this fall! Visit chicagobotanic.org/inbloom/ for more information on what’s in bloom.