
Frequently Asked Questions
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 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 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 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.
Who uses the Phytotron?
Scientists, postdoctoral researchers and graduate students from
all over the U.S. can utilize the controlled environment facilities
at the Phytotron (consult our web site for an explanation of the fee
structure for space use). Off-campus users are encouraged; in fact,
historically, over 70% of Phytotron users have been from outside of
Duke. Research and experimentation conducted in the Phytotron
has yielded an impressive record of scholarly publication over the past
33 years.
What facilities are available?
The Phytotron contains 48 plant growth chambers, six controlled
greenhouses - a total of over 450 square meters of growth space - and
associated instrumentation and laboratories. Descriptions of the sizes,
control capabilities, and numbers of these growth facilities can be
found by following the Facilities link. A series of extensive renovations,
begun in 1996, has been undertaken to ensure that the facility's equipment
remains state-of-the-art.
What services are offered?
The Phytotron provides all supplies and services necessary
to conduct many types of controlled environment experiments, from the
simplest to the most complex. The Phytotron staff performs all preparation,
configuration, and maintenance of the growth chambers or greenhouse
units, and any routine plant care requested, including watering, fertilization,
and pest control. The Phytotron is staffed seven days a week, allowing
off-site researchers to run experiments without having to make extended
visits. Chambers and greenhouses are continuously monitored and maintained.
Staff members are on call 24 hours a day to respond to environmental
control problems before they adversely affect experiments in progress.
Expertise in electronics and instrumentation is available for routine
instrument maintenance or developing equipment for specialized uses.
The Phytotron staff has extensive experience growing many species of
native and agricultural plants from different habitats. Assistance with
experimental design and data analysis is also available.
How is research space allocated?
Requests for the use of growth chamber or greenhouse space can be made
at any time. No priority is given to researchers in a particular field
or geographic location. Scheduling is at the user's convenience and
is coordinated to make best use of the available space and funding cycles.
What supplies and equipment are available to Phytotron users?
The following supplies are provided free to Phytotron users:
- growth media
- pots
- fertilizer
- plant stakes
- paper bags and coin envelopes for drying plant samples
The Phytotron owns the following equipment which is available for use in Phytotron experiments:
- drying ovens
- balances - analytical and toploading
- leaf area meters
- thermocouples
- quantum sensors
- dataloggers
- water potential measurement system (pressure bomb)
- LI-COR 6200 photosynthesis system
- Optronics spectroradiometer
The following types of equipment can generally be borrowed from labs at Duke - by arrangement with professors - for use by Phytotron researchers:
- dataloggers
- soil moisture (TDR) probes
- sap flow measurement systems
- LI-COR 6400 photosynthesis system