I am a research plant physiologist with the Agricultural Research Service (ARS) of the U.S. Department of Agriculture (USDA), where I have worked for about 25 years. Working for the ARS was never part of my career plan, in fact, I barely knew that the organization existed before I was called for a job interview.

I currently study physiological responses of crops and weeds to long-term exposure to different concentrations of carbon dioxide. Part of this research is an effort is to quantify the decreases in the aperture of the stomatal pores on plant leaves with rising atmospheric concentrations of carbon dioxide, which would decrease evaporative cooling, and could affect climate as well as exposing plants to more heat stress. My work is also directed toward determining why plants exposed to elevated carbon dioxide concentrations often have only a temporary increase in growth rate, and toward determining what plant characteristics might be most beneficial to the productivity and to the nutritional value of crops if atmospheric carbon dioxide concentrations continue to rise.

Using carbon dioxide concentration as an experimental variable has proven valuable in answering more fundamental questions about plant physiology and the adaptation of plants to the environment. My interest in carbon dioxide concentration as a variable evolved from the recognition that the rapidly changing concentration of carbon dioxide in the atmosphere was likely to disrupt the relationships between plant physiological processes and adaptations to the environment that I had been studying.

I have had a lifelong interest in biology, fostered by growing up in rural upstate New York, surrounded by forests and a few fields, with a pond and a stream across the street. Coming from a high school with a graduating class of about 60 students, I opted for a small undergraduate college rather than a university. I chose Bates College for its academic excellence, its offering of exotic biology courses in optional short semesters, and easy access to the outdoors.

As an undergraduate, I studied what interested me most, with little concern about future employment. I knew that I liked doing research and assumed that someone would employ me to do that. From courses in general botany and cell physiology, taught by the same stimulating teacher, I developed an interest in plants, physiology, and ecology. I thought it would be interesting to understand how the physiology of an organism determined the environments in which it could survive.

While investigating graduate schools, I learned that others had similar interests. They were called physiological ecologists. I entered a Ph.D. program in plant physiological ecology at Cornell University, having never had a course in either plant physiology or general ecology. My graduate advisor believed in immersing students in research from the beginning. I began learning specialized laboratory techniques by the end of the first semester, and by the first summer, I was collecting the experimental material and assembling the analytical apparatus to be used for my thesis project.

Nearly all of the graduate students in ecology assumed that they would have careers in academia. Those most interested in research were trying for jobs at large universities, and those more interested in teaching or in avoiding the "publish or perish" gauntlet were aiming for smaller schools. A very few considered working for private industry, mostly to do environmental impact assessment work. However, the one student I knew who actually followed that path was considered an outcast for working for the "enemy."

Toward the end of my time as a graduate student, in the mid-1970s, academic positions were starting to become more difficult to obtain. Those doing research in physiological aspects of ecology or in plant physiology often needed to take postdoctoral positions before they could find tenure-track faculty positions. One of the perils of academic life struck home when my graduate advisor failed to gain tenure, could not find another faculty position, and changed careers. I was fortunate that his replacement at the university was willing to serve as my advisor, without drastically changing my thesis project.

Partly out of fear of not finding a faculty job, and partly because of the temptation to work with one of the legends in plant environmental physiology, I accepted a postdoctoral position with Paul Kramer at Duke University, just prior to defending my thesis. Although my research in Kramer's lab focused on crop species, it applied similar techniques to those I had acquired as a grad student and addressed similar questions.

Duke is not a land-grant university: There was no agronomy or crop science department that would have had contact with the USDA-ARS. I was in a traditional botany department where most of the graduate students and postdoctoral students were aiming toward academic careers. However, when word spread through the department that the federal register was open, all of us filled out the paperwork to have our names put on the federal civil service register as plant physiologists and plant ecologists, without knowing what that accomplished.

About a year later, while visiting family over Christmas, I received a call from a USDA-ARS laboratory in Beltsville, Maryland, that had a position open for someone with my interests, and wanted me to stop by. Despite a discouraging first meeting on New Year's day, when I competed for the attention of the lab scientists with a football game being shown on an adjacent television set, I returned later for a real interview. I have not regretted my decision to join the ARS.

ARS employs about 2000 scientists, covering a wide range of disciplines, including chemists, hydrologists, microbiologists, and soil, plant, and animal scientists. It also employs a large number of technicians and support scientists with bachelor's and master's degrees in science, as well as undergraduate students. There are about 100 ARS locations throughout the country, many on the campuses of land-grant institutions. Check it out on the Web at