My main expertise is in water movement and wastewater treatment in the field; I especially love applied science that works for the professional in the field. I invented the Aardvark Borehole Permeameter and Soilmoisture heard about my invention and contacted me. I was truly impressed with their flexible technical staff who, after much work on their part, turned my design into the world's only automated Borehole Permeameter: tough, portable, reliable, highly accurate, and complete with software. Still known as the Aardvark, it is now sold worldwide through their extensive global network. I am proud to have my name and invention associated with Soilmoisture Equipment!

Thomas Macfie,
Inventor of the Aardvark Permeameter

Home :: More than a Tree

More than a Tree

excerpt from the Soil Report Newsletter of Soilmoisture Equipment Corp.

A stand of trees, a forest, is one of nature's wonders, serene and quiet, yet somehow powerful, even majestic, dwarfing human beings to insignificance. To some a forest offers a religious experience. Yet, a forest is also a fragile ecosphere, often greatly threatened by the vagaries of nature.

Few know this better than Dr. C. S. "Chris" Papadopol of the Ontario Forest Research Institute, financed by the Ministry of Natural Resources of the Province of Ontario, Canada. For five years he has intensely studied the effects of soil moisture, or lack of it, on a forest 60 miles west of Sault Ste. Marie, Ontario, near the shores of Lake Huron.

The Kirkwood forest measures about 50,000 acres, although his studies apply to only a few of them. As Chris, which he prefers to be called, explains, his is an entirely artificial forest, that is, man-made, planted mostly in conifers, red and white pines, invaluable to the pulp paper and lumbering industries.
From a conifer's viewpoint, it is a hellish place to grow. Oh, there is generally adequate rain, but the "soil" is coarse sand, almost gravel. Since the conifer, unlike most other trees, has a shallow root system, extending only three feet below the surface, Chris' trees are in a feast or famine situation.

"When it rains," he explains, "there is an abundance of water. But it quickly disappears into the sand. In two or three days the conifers are in a stressful situation because of the lack of soil moisture. If it goes two or three weeks without rain, the trees become severely stressed and suffer current year growth." Unfortunately for the trees, as part of his study Dr. Papadopol offers no irrigation or spraying. The forest is on its own with nature--well, not quite.

Dr. Papadopol's study is one of the first attempt worldwide to measure the effect of soil moisture on forest growth. How much moisture does a tree need? What are the effects of too much or too little moisture? How much stress can a forest take?

The only way to help the forest withstand dry periods is to thin it. Fewer trees require less soil moisture. Chris' study is learning when to thin and how much to enable the forest to survive and prosper. And what works in the sandy terrain of Sault Ste. Marie is invaluable information for use in different types of soils which hold their moisture. Interest in his reports is worldwide, especially in dry areas.

The significance of Chris' work extends far beyond forestry. His findings concerning soil moisture and productivity can be used extensively in agriculture. For example, corn, which also has a shallow root structure, will thrive and produce in direct response to soil moisture. Knowing how densely to plant and when to irrigate or spray results in more bushels per acre.

To determine the amount of water a forest uses, Dr. Papadopol employs automated equipment to monitor both atmospheric parameters every l0 minutes and soil moisture every half hour. At the same time strain gauges on trees measure the circumference every l0 minutes, monitoring expansion when soil moisture is plentiful and shrinkage during drought. Speaking in his soft voice, tinged with the accent of his native Romania, Dr. Papadopol explains just how fragile a forest is. "The amount of soil moisture consumed varies within a single day. On a warm, sunny day, there is a great demand for moisture by noon. Even within a half hour, the results may change dramatically."

When he began his studies more than 30 years ago in Romania, Chris used manual means to measure soil moisture. "Aside from the physical effort required to collect 20 samples up to a depth of six feet with a manually operated auger," he says, "an added difficulty was the long time required for processing the sample. As much as three days elapsed between taking the sample and determining the result. For irrigation experiments this was clearly inadequate."
When he immigrated to Canada in l981 to continue his work, the difficulty of measuring soil moisture continued to be a problem. "While the automated equipment for monitoring atmospheric parameters worked flawlessly, again the soil moisture determinations were a great pain." He points out that a forest environment is much more variable than one for an agricultural crop. "To obtain reliable information on soil moisture the density of manual sampling had to be at least 20 times greater than we could afford. While we had data on atmospheric parameters every 10 minutes, we could determine soil moisture manually only about once a week." He speaks of the "frustration" the situation caused, not only because of the time involved and delay in obtaining measurements, but also because readings couldn't be made in the same spot.

Then in l993, he installed Trase electronic machines developed and manufactured by the Soilmoisture Equipment Corp.--four of them. These are permanently installed at locations in the forest. Electrical power to operate Trase comes from solar panels. Probes, or sensors, are inserted in the ground at various locations, some as far away as 25 yards from Trase, and to diverse depths, some as deep as three feet. These sensors offer virtually instant measurements of soil moisture--and how much the forest has used. That accurate information allows Dr. Papadopol to determine the health of the forest. Will it survive or must the forest be thinned?

"Our work would not be possible without Trase equipment," Dr. Papadopol says. "It permits accurate and frequent measurements at the same location and offers a permanent record of soil moisture content and consumption."

It was not always so. Trase got off to a rocky start--or better said, sandy start. In June, l993, shortly after Chris' equipment was operational, it was apparent the Trase measurements were too variable and far from accurate. Trase would analyze soil moisture as high, when obviously it wasn't, or show zero moisture after a rainfall. SEC soil scientist Richard White was the first to arrive at the Papadopol plantation. He correctly surmised that Trase had the same problem as the trees--that coarse sandy soil. As White put it, "Trase was designed to analyze all types of soils, but clearly all soils are not created equal."

Determined to meet Dr. Papadopol's needs, SEC assigned engineer Robert van't Riet to solve the problem. He concurred that the soil caused the problem. Solution lay in amending the electronic software in Trase to accommodate the gravelly soil. It was no easy task. Back in Santa Barbara, van't Riet tried to duplicate the soil at Sault Ste. Marie, using various combinations of sand, gravel and loam. It took all summer, but by autumn the glitch in Trase, never foreseen when it was designed, had been corrected. SEC engineers continue to monitor Dr. Papadopol's Trase equipment. It operates fine now.

Dr. Papadopol was born in Constanta, Romania, in 1939. Always interested in forestry, he earned his Master of Science degree in silviculture in l960 and his Ph. D. in forest physiology in l971, both from the University of Brasov in Romania. After graduation, he was hired by the Romanian Forest Research and Design Institute as a researcher on the staff of Forest Experiment Station "Baragan" in Southeast Romania. It was located on a dry plateau with inadequate rainfall, stimulating his interest in the environmental effects of water and light on trees and crops. In time, he became leader of the experiment station.

All the while, Chris was increasingly disenchanted with the oppression of the Romanian Communist regime. Defection became an appealing option, despite the fact all his property would be confiscated by doing so. In 1981, Chris and his wife Helen, herself a horticulturist, were permitted to visit relatives in Greece, leaving behind their daughter Kathleen, then l8, to live with Helen's parents. To have attempted to take her to Greece, would have tipped off authorities they planned to defect. Chris had hoped to be offered asylum in the United States, but Canada was more interested. "Somehow we were believed," he says. After a six months trial period by the Greek government, he and Helen immigrated to Canada. Their daughter was able to join them in l99l, after the fall of Communism in Romania.

In Canada he continued his work in forestry at the same institute north of Toronto, working with hybrid poplars, sugar maples and conifers impacted by acid rain. His studies were designed to inform about maple sap flow under various weather and soil moisture conditions. He also studied problems associated with the use of forests to recycle effluent from sewage treatment plants.

In l990 Dr. Papadopol's institute, of which he is lead scientist in ecophysiology and intensive silviculture, moved to the Sault Ste. Marie area, adapting his research to the characteristics of a northern forest growing in the coarse sandy soil. He anticipates his research will continue to the end of the century. The provincial government of Ontario deems it important work, providing a $300,000 annual budget. Five persons are employed.

One product of the research is already apparent to Dr. Papadopol, the effects of climatic changes. He points out that average global temperatures have increased one degree in the last l20 to l50 years due to the industrial revolution and the global burning of fossil fuels, putting more carbon dioxide in the atmosphere. This has been further exacerbated by deforestation in the Amazon region, along with China, Asia and Africa. He anticipates further global warming of from one to five degrees in the next l20 years.

What does this mean for the planet? He believes the effects on agriculture and forestry will be pronounced. Pines, for example will have to be moved further north, replaced by deeply-rooted oak, walnut and ash trees.

The poet Joyce Kilmer was doubtlessly correct when he wrote that "only God can make a tree." But our trees and majestic forests can surely use a little of the help Chris Papadopol provides.