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Frequently Asked Questions about
Controlled Environments and the Phytotron

 

What is a controlled environment facility?
What are the advantages of using the National Phytotron?
What is the role of the National Phytotron in global change research?


 

What is a controlled environment facility?
Controlled environment facilities permit investigators to create experimental systems in which biotic and/or abiotic variables and factors are controlled by the investigator.


What are the advantages of using the National Phytotron?
We can reproduce different types of environments, ranging from the arctic to the desert to the tropics. Researchers can maintain precise control over environmental conditions (e.g., soil type, air temperature, light levels, carbon dioxide (CO2) concentration, relative humidity, nutrients) and the organisms under study (e.g., mixtures of plant and animal species and their spatial arrangement). Such a degree of rigor and control is virtually impossible to achieve under natural field conditions. Other advantages include the ability to study without disturbing the organism, the ease of replication and manipulation, and relatively low research costs. With the large number of chambers available, experiments can be designed to explore key interactions among multiple stressors, e.g., temperature, CO2, and air pollutants. This provides the opportunity to gain increased understanding of the complex interactions between plants and their environment in studies of global change.


What is the role of the National Phytotron in global change research?
While direct observation of ecosystem responses in manipulative field experiments is an important approach to the study of global environmental change, the sheer number of environmental variables that simultaneously affect ecosystems poses serious constraints. To adequately test null hypotheses - and to successfully tease out a signal (effect) against a background of noise (random variation) - it is necessary to have adequate replication and control, something that is often impossible to do in nature. The National Phytotron plays a key role in experimental research on global change by providing researchers with tools to aid in disentangling the complexities of natural ecosystems.




Last modified Feb. 21, 2002