Botanist roots around for flood answers
Out of the chaos of Minot’s 2011 flood there has been much to learn, ranging from lessons in water systems management and civic planning to drywalling and home repair.
For Alexey Shipunov, a botanical expert and assistant professor of biology at Minot State University, the flood has taught him something about the area’s trees.
Born and schooled in Moscow, Shipunov has worked and taught in Russia, Great Britain and most recently in North Dakota, joining the MSU faculty in 2010.
“I guess the story starts when the flood starts,” Shipunov began, when the MSU campus was under threat.
While ferrying equipment from the lower floors of the Cyril Moore Science Center to higher ground, Shipunov wondered how extensive the floodwaters had become. An emergency levee saved the science department and library, but much else of Minot was not so lucky.
While Shipunov regularly uses the first couple of weeks in the fall semester to take his introductory botany students out for field research around campus, those August and September weeks of 2011 were spent examining trees along the nearby neighborhood and along the river for damage.
“It was their first year studying off campus,” he said.
To study the extent of damage done to the trees, Shipunov developed a grading scale from 1 to 5, with 1 denoting no or invisible damage and 5 indicating a dead tree. Breaking off into small groups, students identified trees for size, species and distance from the river and classified their level of damage. The data was then tabled and put to a map, with about 80 different kinds of tree listed.
“We found some trees have higher levels of flood damage” than others, Shipunov had been surprised to learn.
With a few of his top students, he next surveyed Oak and Roosevelt parks. They also sampled cherry trees along a transect running perpendicular to the river that led up to University Avenue. They chose the cherries both because they are numerous and as a non-native plant fared poorly during the flood. The road they had chosen for the study was ideal, only varying by about 3 or 4 degrees from the river to campus.
“The level of flood has direct influence on the level of damage,” he concluded, based on the data.
“Trees are slow diers,” he explained. “Most trees died from the roots,” with damage spreading upwards. Smaller trees generally died outright, with larger ones experiencing varying degrees of sickness in the roots, trunk and lower-level limbs.
His students would survey the same trees successively in the spring and fall semesters of 2012, though a number of dead trees were quickly removed by the city forestry department during the recovery. From what they were able to observe, the “levels of damage did not increase much” after November 2011.
“Everything that is native will survive, and it is mostly true that everything brought would die,” Shipunov said of their findings.
Oaks were the exception, being a hardier tree with a deeper root system. “Oaks survived very well. Some died, but only a few,” he said. Based on his scaling, Shipunov rated them at a 3 or 2 damage level overall; after only a year or so, affected oaks generally recovered.
“Smaller oaks died after the flood completely,” but their root systems remained alive, sprouting new shoots. “Our oaks are very much adapted,” was his conclusion, citing the slow but steady expansion of oaken savannah systems in the eastern portions of the state. Apple and cherry trees did very poorly, as did pines and other coniferous plants. Maples too, were affected adversely. Most area maples are not even native to America, being brought from Europe.
Of Minot’s tree population, only a handful are native to the region. Trees native to the area include cottonwood, two kinds of poplar (including aspen), ash and box elder. There are only two conifers native to North Dakota, the creeping juniper and the ponderosa pine, which is native to the western portions of the state. Because of its vast plains, North Dakota has very few natural forests, with trees mostly growing around lakes and culverts. Humidity in the state is also much lower than larger forests require, and hills are too dry.
“We don’t have many trees,” is how Shipunov summed up the situation.
Box elders and ash fared relatively OK, despite their smaller root system. Shipunov referred to the former of these as a “plant cockroach,” which across Eurasia is considered an invasive species. Ash are susceptible to disease, such as bore. “They were suffering without the flood,” he said. Because of their small size and shallow root systems, junipers were heavily affected. Virtually all that experienced flooding died as a result.
Most of the damage to trees were a result of the warm water. The flood came in July, “which is totally not normal,” said Shipunov.
With warmer temperatures the floodwaters were significantly lower in oxygen content than if they had been near freezing, effectively smothering the root systems of many trees. Trees also experienced “mechanic damage,” injuries caused by swiftly moving waters and free-floating debris. Additionally, the warmer water made conditions ideal for fungal and microbial life, which further affected trees damaged by the flood.
“We didn’t find any visible signs of fungal damage,” he said, but abnormally high mold growth accompanied the flood. Microbial spores “wait for better conditions” in a dormant state, sometimes clinging to the riversides for years. Those conditions came in 2011.
“Nobody can guarantee the next flood will be the same,” said Shipunov.
Because Europeans have only been living in the area for about 150 years and the indigenous plains dwellers did not keep records of such things, it is difficult to say what exactly can be considered the worst possible flood. “We might still experience much worse conditions. We don’t know,” he said.
“Paleobotanical data will not help us,” he went on to explain, citing that glacial flattening during previous ice ages and the location of much of the state beneath the giant, ancient Lake Agassiz have made building a useful fossil record for the area difficult to come by. In stark contrast is the western parts of North Dakota, where the Badlands is known for its many specimens of petrified wood and well-preserved dinosaur fossils. The area was never buried under a massive sheet of ice for millenia.
“Our part is different, so he have a different landscape,” he said.
What Shipunov and his assistants have learned has a practical application. “If the flood repeats itself we have recommendations,” he said. For instance, up to even a few days underwater, apple trees will survive. However, for landscaping he recommends planting indigenous plants such as Juneberries and hawthorns. In addition to being useful fruit-bearers for jamming and cooking, the plants do well in the soil common to the area and are more resistant to disease.
The botanist has been involved in a number of other projects since coming to the state. These range from cataloguing flora native to North Dakota to surveying large portions of the state that have until now gone unnoticed.
Thousands of specimens are taken from sample areas of about 30 square miles and logged into an online database at (http://ashipunov.info
/shipunov/fnddb/index.htm). Through his researches he has already found 16 new plants not known to be native to the state, including two generum of cacti.
Shipunov is also working on a project which takes a molecular approach to sampling, using “barcoding” to help determine species. He explained there is some degree of overlap between plants in North Dakota and those native to his home country of Russia, sharing names and many of the same characteristics. By examining their genetic structures he hopes to better understand what relation they might have. Collected samples are sent to a laboratory at the University of Guelph in Ontario, Canada. The database they have been building so far encompasses more than 6 million samples. Both projects are yet works in progress, and Shipunov hopes to resume his work this summer.